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Sample records for coronary flow reserve

  1. Correlation between coronary computed tomographic angiography and fractional flow reserve

    DEFF Research Database (Denmark)

    Kristensen, Thomas Skaarup; Engstrøm, Thomas; Kelbæk, Henning

    2010-01-01

    Coronary CT angiography (CCTA) has become an important modality to evaluate the presence of coronary artery disease. Coronary artery stenosis of intermediate severity remains a therapeutic dilemma. Measurement of fractional flow reserve (FFR) during coronary angiography is the most established...... technique to determine the hemodynamic severity of a coronary artery lesion. The aim of this study was to compare CCTA with FFR....

  2. [Role of measurement of fractional flow reserve in coronary artery atherosclerosis].

    Science.gov (United States)

    Kopylovi, F Yu; Bykova, A A; Vasilevsky, Yu V; Simakov, S S

    2015-01-01

    The paper considers coronary flow in health and coronary flow autoregulation in health and disease. It gives basic methods used to estimate coronary flow reserve in patients with coronary atherosclerosis. The physiological bases for determining fractional flow reserve are presented. Clinical trials investigating the use of fractional flow reserve in patients with coronary heart disease are analyzed.

  3. Fractional flow reserve derived from coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Eftekhari, Ashkan; Min, James; Achenbach, Stephan

    2016-01-01

    AIMS: Fractional flow reserve (FFR) derived from coronary computed tomography (FFRCT) has high diagnostic performance in stable coronary artery disease (CAD). The diagnostic performance of FFRCT in patients with hypertension (HTN) and diabetes (DM), who are at risk of microvascular impairment, is...

  4. Coronary flow velocity reserve by echocardiography

    DEFF Research Database (Denmark)

    Olsen, Rasmus Huan; Pedersen, Lene Rørholm; Snoer, Martin

    2016-01-01

    reserve (MFR) measured by PET in overweight and obese patients. METHODS: Participants with revascularized coronary artery disease were examined by CFVR. Subgroups were examined by repeated CFVR (reproducibility) or Rubidium-82-PET (agreement). To account for time variation, results were computed for scans...... %, and reliability 0.97. Agreement with MFR of the LAD territory (n = 35) was without significant bias and overall LOA were (-1.40;1.46). Agreement was best for examinations performed within 1-week of participants without MI of the LAD-territory (n = 12); LOA = (-0.68;0.88). CONCLUSIONS: CFVR was highly feasible...... with a good reproducibility on par with other contemporary measures applied in cardiology. Agreement with MFR was acceptable, though discrepancy related to prior MI has to be considered. CFVR of LAD is a valid tool in overweight and obese patients....

  5. Does intracoronary papaverine dilate epicardial coronary arteries? Implications for the assessment of coronary flow reserve

    NARCIS (Netherlands)

    F. Zijlstra (Felix); J.H.C. Reiber (Johan); P.W.J.C. Serruys (Patrick)

    1988-01-01

    textabstractIntracoronary papaverine is used as a means to induce a strong and short-lasting hyperemia in several recently developed methods to measure coronary flow reserve. Changes in stenosis geometry from papaverine would influence the measured coronary flow reserve. Therefore, we investigated

  6. Fractional flow reserve versus angiography for guiding percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Tonino, Pim A L; De Bruyne, Bernard; Pijls, Nico H J

    2009-01-01

    BACKGROUND: In patients with multivessel coronary artery disease who are undergoing percutaneous coronary intervention (PCI), coronary angiography is the standard method for guiding the placement of the stent. It is unclear whether routine measurement of fractional flow reserve (FFR; the ratio......-eluting stents guided by angiography alone or guided by FFR measurements in addition to angiography. Before randomization, lesions requiring PCI were identified on the basis of their angiographic appearance. Patients assigned to angiography-guided PCI underwent stenting of all indicated lesions, whereas those...

  7. Coronary Flow Velocity Reserve Assessed by Transthoracic Doppler

    DEFF Research Database (Denmark)

    Michelsen, Marie M; Peña, Adam; Mygind, Naja D

    2016-01-01

    the feasibility and factors associated with the quality of CFVR obtained in a large prospective study of women suspected of having microvascular disease. METHODS: Women with angina-like chest pain and no obstructive coronary artery disease on coronary angiography (stenosis) were consecutively examined......BACKGROUND: Coronary flow velocity reserve (CFVR) measured by transthoracic Doppler echocardiography is a noninvasive measure of microvascular function, but it has not achieved widespread use, mainly because of concerns of validity and feasibility. The aim of this study was to describe...... by transthoracic Doppler echocardiography of the left anterior descending coronary artery to measure CFVR (n = 947). Quality was evaluated on the basis of (1) identification of the left anterior descending coronary artery, (2) maintained probe position throughout the examination, (3) visibility and configuration...

  8. Coronary Computed Tomography Angiography Derived Fractional Flow Reserve and Plaque Stress

    DEFF Research Database (Denmark)

    Nørgaard, Bjarne Linde; Leipsic, Jonathon; Koo, Bon-Kwon;

    2016-01-01

    Fractional flow reserve (FFR) measured during invasive coronary angiography is an independent prognosticator in patients with coronary artery disease and the gold standard for decision making in coronary revascularization. The integration of computational fluid dynamics and quantitative anatomic...

  9. Coronary flow reserve measurement in the coronary sinus in pre and post CABG status

    Directory of Open Access Journals (Sweden)

    M Hajaghaei

    2007-11-01

    Full Text Available Background: Coronary flow reserve (CFR is defined as a maximal(hyperemic to resting ratio of coronary blood flow. It is a physiologicparameter of coronary circulation and depends on the patency of the epicardialcoronary arteries and integrity of the microvascular circulation.CFR measurement has many clinical applications including functional assessmentof intermediate stenosis, detection of critical stenosis monitoring of coronaryflow in the post angioplasty period, assessment of post infarct blood flow andassessment of coronary graft patency. The aim of this study was to measure CFRin the coronary sinus through the transthoracic echocardiographic approach, inpatients who were candidate for coronary artery bypass graft surgery (CABGbefore and one month after operation.Patients and Methods: The present study included 19 patients (meanage=56±9.1 including 15 males and 4 females, admitted for CABG. All patientshad a sinus rhythm, normal wall thickness, normal RV systolic pressure, andtricuspid valvular regurgitation equal or less than grade 2. The antegrade phaseof coronary flow in the coronary sinus moving into the right atrium was analyzedin two phases (systolic and diastolic. Each wave was determined considering thepeak velocity and velocity time integral (VTI. The volumetric blood flow in thecoronary sinus calculated at the baseline and then in hyperemic phase was usedfor determination of CFR both before and after CABG.Results: There was a significant increase in the diameter of the coronarysinus after CABG (9.4±1.2mm compared with that of before CABG values (8.6±1.05mm. Also there was a trend of increasing the diameter in the hyperemicphase before and after CABG. The absolute increase in mean coronary sinusdiameter was 0.5 mm before and 1.5 mm after CABG. Coronary flow reserve (CFRwas significantly higher after surgery, despite a significant increase insystolic velocity ratio (hyperemic/baseline after CABG. This is also true forsystolic

  10. Turbulent flow as a cause for underestimating coronary flow reserve measured by Doppler guide wire

    Directory of Open Access Journals (Sweden)

    Richartz Barbara M

    2006-03-01

    Full Text Available Abstract Background Doppler-tipped coronary guide-wires (FW are well-established tools in interventional cardiology to quantitatively analyze coronary blood flow. Doppler wires are used to measure the coronary flow velocity reserve (CFVR. The CFVR remains reduced in some patients despite anatomically successful coronary angioplasty. It was the aim of our study to test the influence of changes in flow profile on the validity of intra-coronary Doppler flow velocity measurements in vitro. It is still unclear whether turbulent flow in coronary arteries is of importance for physiologic studies in vivo. Methods We perfused glass pipes of defined inner diameters (1.5 – 5.5 mm with heparinized blood in a pulsatile flow model. Laminar and turbulent flow profiles were achieved by varying the flow velocity. The average peak velocity (APV was recorded using 0.014 inch FW. Flow velocity measurements were also performed in 75 patients during coronary angiography. Coronary hyperemia was induced by intra-coronary injection of adenosine. The APV maximum was taken for further analysis. The mean luminal diameter of the coronary artery at the region of flow velocity measurement was calculated by quantitative angiography in two orthogonal planes. Results In vitro, the measured APV multiplied with the luminal area revealed a significant correlation to the given perfusion volumes in all diameters under laminar flow conditions (r2 > 0.85. Above a critical Reynolds number of 500 – indicating turbulent flow – the volume calculation derived by FW velocity measurement underestimated the actual rate of perfusion by up to 22.5 % (13 ± 4.6 %. In vivo, the hyperemic APV was measured irrespectively of the inherent deviation towards lower velocities. In 15 of 75 patients (20% the maximum APV exceeded the velocity of the critical Reynolds number determined by the in vitro experiments. Conclusion Doppler guide wires are a valid tool for exact measurement of coronary flow

  11. Coronary Flow Reserve Predicts Cardiopulmonary Fitness in Patients with Coronary Artery Disease Independently of Systolic and Diastolic Function

    DEFF Research Database (Denmark)

    Snoer, Martin; Olsen, Rasmus Huan; Monk-Hansen, Tea

    2014-01-01

    Aims Despite revascularization and optimal medical treatment, patients with coronary artery disease (CAD) have reduced exercise capacity. In the absence of coronary artery stenosis, coronary flow reserve (CFR) is a measure of coronary microvascular function, and a marker of future poor outcome...... early (E) and late (A) inflow velocities, and tissue Doppler diastolic (e′) and systolic (s′) velocities. Peak coronary flow velocity (CFV) was measured in the LAD using pulse-wave Doppler. CFR was calculated as the ratio between peak CFV at rest and during vasodilator stress. Median CFR was 2.22 (1....... Conclusions Coronary flow reserve measured noninvasively predicts cardiopulmonary fitness independently of resting systolic and diastolic function in CAD patients, indicating that cardiac output during maximal exercise is dependent on the ability of the coronary circulation to adapt to the higher metabolic...

  12. Association of arterial stiffness with coronary flow reserve in revascularized coronary artery disease patients

    Institute of Scientific and Technical Information of China (English)

    Vlassis Tritakis; Stavros Tzortzis; Ignatios Ikonomidis; Kleanthi Dima; Georgios Pavlidis; Paraskevi Trivilou; Ioannis Paraskevaidis; Giorgos Katsimaglis; John Parissis; John Lekakis

    2016-01-01

    AIM: To investigate the association of arterial wave reflection with coronary flow reserve(CFR) in coronary artery disease(CAD) patients after successful revascularization.METHODS: We assessed 70 patients with angiographically documented CAD who had undergone recent successful revascularization. We measured(1) reactive hyperemia index(RHI) using fingertip peripheral arterial tonometry(RH-PAT Endo-PAT);(2) carotid to femoral pulse wave velocity(PWVc-Complior);(3) augmentation index(AIx), the diastolic area(DAI%) and diastolic reflection area(DRA) of the central aortic pulse wave(Arteriograph);(4) CFR using Doppler echocardiography; and(5) blood levels of lipoprotein-phospholipase A2(LpPLA2).RESULTS: After adjustment for age, sex, blood pressure parameter, lipidemic, diabetic and smoking status, we found that coronary flow reserve was independently related to AIx(b =-0.38, r = 0.009), DAI(b = 0.36, P = 0.014), DRA(b = 0.39, P = 0.005) and RT(b =-0.29,P = 0.026). Additionally, patients with CFR < 2.5 had higher PWVc(11.6 ± 2.3 vs 10.2 ± 1.4 m/s, P = 0.019), SBPc(139.1 ± 17.8 vs 125.2 ± 19.1 mm Hg, P = 0.026), AIx(38.2% ± 14.8% vs 29.4% ± 15.1%, P = 0.011) and lower RHI(1.26 ± 0.28 vs 1.50 ± 0.46, P = 0.012), DAI(44.3% ± 7.9% vs 53.9% ± 6.7%, P = 0.008), DRA(42.2 ± 9.6 vs 51.6 ± 11.4, P = 0.012) and Lp PLA2(268.1 ± 91.9 vs 199.5 ± 78.4 ng/m L, P = 0.002) compared with those with CFR ≥ 2.5. Elevated Lp PLA2 was related with reduced CFR(r =-0.33, P = 0.001), RHI(r =-0.37, P < 0.001) and DRA(r =-0.35, P = 0.001) as well as increased PWVc(r = 0.34, P = 0.012) and AIx(r = 0.34, P = 0.001). CONCLUSION: Abnormal arterial wave reflections are related with impaired coronary flow reserve despite successful revascularization in CAD patients. There is a common inflammatory link between impaired aortic wall properties, endothelial dysfunction and coronary flow impairment in CAD.

  13. Profound spatial heterogeneity of coronary reserve. Discordance between patterns of resting and maximal myocardial blood flow.

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    Austin, R E; Aldea, G S; Coggins, D L; Flynn, A E; Hoffman, J I

    1990-08-01

    We examined the ability of individual regions of the canine left ventricle to increase blood flow relative to baseline rates of perfusion. Regional coronary flow was measured by injecting radioactive microspheres over 90 seconds in seven anesthetized mongrel dogs. Preliminary experiments demonstrated a correlation between the regional distributions of blood flow during asphyxia and pharmacological vasodilatation with adenosine (mean r = 0.75; 192 regions in each of two dogs), both of which resulted in increased coronary flow. Subsequent experiments, during which coronary perfusion pressure was held constant at 80 mm Hg, examined the pattern of blood flow in 384 regions (mean weight, 106 mg) of the left ventricular free wall during resting flow and during maximal coronary flow effected by intracoronary adenosine infusion. We found that resting and maximal flow patterns were completely uncorrelated to each other in a given dog (mean r = 0.06, p = NS; n = 3 dogs). Furthermore, regional coronary reserve, defined as the ratio of maximal to resting flow, ranged from 1.75 (i.e., resting flow was 57% of maximum) to 21.9 (resting flow was 4.5% of maximum). Thus, coronary reserve is spatially heterogeneous and determined by two distinct perfusion patterns: the resting (control) pattern and the maximal perfusion pattern. Normal hearts, therefore, contain small regions that may be relatively more vulnerable to ischemia. This may explain the patchy nature of infarction with hypoxia and at reduced perfusion pressures as well as the difficulty of using global parameters to predict regional ischemia. Despite the wide dispersion of coronary reserve, we found, by autocorrelation analysis, that reserve in neighboring regions (even when separated by a distance of several tissue samples) was significantly correlated. This also applied to patterns of resting myocardial flow. Thus, both resting coronary blood flow and reserve appear to be locally continuous and may define functional

  14. Fractional flow reserve-guided PCI for stable coronary artery disease

    DEFF Research Database (Denmark)

    De Bruyne, Bernard; Fearon, William F; Pijls, Nico H J

    2014-01-01

    BACKGROUND: We hypothesized that in patients with stable coronary artery disease and stenosis, percutaneous coronary intervention (PCI) performed on the basis of the fractional flow reserve (FFR) would be superior to medical therapy. METHODS: In 1220 patients with stable coronary artery disease, we......-therapy group (8.1% vs. 19.5%; hazard ratio, 0.39; 95% confidence interval [CI], 0.26 to 0.57; Pratio, 0.23; 95% CI, 0.14 to 0.38; P

  15. Coronary flow reserve : a functional measure of stenosis severity

    NARCIS (Netherlands)

    F. Zijlstra (Felix)

    1988-01-01

    textabstractIn 1959 Sones developed selective coronary cineangiography. To date, this technique has remained the only means available for the visualization of the coronary arterial system with such image contrast and resolution, that the presence and severity of coronary stenosis can be

  16. Inability of coronary blood flow reserve measurements to assess the efficacy of coronary angioplasty in the first 24 hours in unselected patients

    NARCIS (Netherlands)

    G-J. Laarman (GertJan); P.W.J.C. Serruys (Patrick); H. Suryapranata (Harry); M.J.B.M. van den Brand (Marcel); P.R. Jonkers; P.J. de Feyter (Pim)

    1991-01-01

    textabstractTo determine functional and anatomic changes in the first 24 hours after coronary angioplasty, we studied at random 15 patients (9 men, mean age 60 years) who underwent coronary angioplasty of 16 coronary arteries. Quantitative coronary angiography and coronary flow reserve measurements

  17. Inability of coronary blood flow reserve measurements to assess the efficacy of coronary angioplasty in the first 24 hours in unselected patients

    NARCIS (Netherlands)

    G-J. Laarman (GertJan); P.W.J.C. Serruys (Patrick); H. Suryapranata (Harry); M.J.B.M. van den Brand (Marcel); P.R. Jonkers; P.J. de Feyter (Pim)

    1991-01-01

    textabstractTo determine functional and anatomic changes in the first 24 hours after coronary angioplasty, we studied at random 15 patients (9 men, mean age 60 years) who underwent coronary angioplasty of 16 coronary arteries. Quantitative coronary angiography and coronary flow reserve measurements

  18. Physiological basis and long-term clinical outcome of discordance between fractional flow reserve and coronary flow velocity reserve in coronary stenoses of intermediate severity.

    Science.gov (United States)

    van de Hoef, Tim P; van Lavieren, Martijn A; Damman, Peter; Delewi, Ronak; Piek, Martijn A; Chamuleau, Steven A J; Voskuil, Michiel; Henriques, José P S; Koch, Karel T; de Winter, Robbert J; Spaan, Jos A E; Siebes, Maria; Tijssen, Jan G P; Meuwissen, Martijn; Piek, Jan J

    2014-06-01

    Discordance between fractional flow reserve (FFR) and coronary flow velocity reserve (CFVR) may reflect important coronary pathophysiology but usually remains unnoticed in clinical practice. We evaluated the physiological basis and clinical outcome associated with FFR/CFVR discordance. We studied 157 intermediate coronary stenoses in 157 patients, evaluated by FFR and CFVR between April 1997 and September 2006 in which revascularization was deferred. Long-term follow-up was performed to document the occurrence of major adverse cardiac events: cardiac death, myocardial infarction, or target vessel revascularization. Discordance between FFR and CFVR occurred in 31% and 37% of stenoses at the 0.75, and 0.80 FFR cut-off value, respectively, and was characterized by microvascular resistances during basal and hyperemic conditions. Follow-up duration amounted to 11.7 years (Q1-Q3, 9.9-13.3 years). Compared with concordant normal results of FFR and CFVR, a normal FFR with an abnormal CFVR was associated with significantly increased major adverse cardiac events rate throughout 10 years of follow-up, regardless of the FFR cut-off applied. In contrast, an abnormal FFR with a normal CFVR was associated with equivalent clinical outcome compared with concordant normal results: ≤ 3 years when FFR requirement of intracoronary flow assessment in addition to coronary pressure for optimal risk stratification in stable coronary artery disease. © 2014 American Heart Association, Inc.

  19. Fractional flow reserve and resting indices for coronary physiologic assessment: Practical guide, tips, and tricks.

    Science.gov (United States)

    Picard, Fabien; Pighi, Michele; Ly, Hung Q

    2017-02-04

    Physiologic assessment using fractional flow reserve (FFR) to guide percutaneous coronary interventions (PCI) has been demonstrated to improve clinical outcomes, compared to angiography-guided PCI. Recently, resting indices such as resting Pd/Pa, "instantaneous wave-free ratio", and contrast medium induced FFR have been evaluated for the assessment of the functional consequences of coronary lesions. Herein, we review and discuss the use of FFR and other indices for the functional assessment of coronary lesions. This review will cover theoretical aspects, as well as practical points and common pitfalls related to coronary physiological assessment. © 2017 Wiley Periodicals, Inc.

  20. Endothelial and non-endothelial coronary blood flow reserve and left ventricular dysfunction in systemic hypertension

    Directory of Open Access Journals (Sweden)

    Aloísio Marchi Rocha

    2009-04-01

    Full Text Available OBJECTIVES: We evaluated the impairment of endothelium-dependent and endothelium-independent coronary blood flow reserve after administration of intracoronary acetylcholine and adenosine, and its association with hypertensive cardiac disease. INTRODUCTION: Coronary blood flow reserve reduction has been proposed as a mechanism for the progression of compensated left ventricular hypertrophy to ventricular dysfunction. METHODS: Eighteen hypertensive patients with normal epicardial coronary arteries on angiography were divided into two groups according to left ventricular fractional shortening (FS. Group 1 (FS >0.25: n=8, FS=0.29 ± 0.03; Group 2 (FS <0.25: n=10, FS= 0.17 ± 0.03. RESULTS: Baseline coronary blood flow was similar in both groups (Group 1: 80.15 ± 26.41 mL/min, Group 2: 100.09 ± 21.51 mL/min, p=NS. In response to adenosine, coronary blood flow increased to 265.1 ± 100.2 mL/min in Group 1 and to 300.8 ± 113.6 mL/min (p <0.05 in Group 2. Endothelium-independent coronary blood flow reserve was similar in both groups (Group 1: 3.31 ± 0.68 and Group 2: 2.97 ± 0.80, p=NS. In response to acetylcholine, coronary blood flow increased to 156.08 ± 36.79 mL/min in Group 1 and to 177.8 ± 83.6 mL/min in Group 2 (p <0.05. Endothelium-dependent coronary blood flow reserve was similar in the two groups (Group 1: 2.08 ± 0.74 and group Group 2: 1.76 ± 0.61, p=NS. Peak acetylcholine/peak adenosine coronary blood flow response (Group 1: 0.65 ± 0.27 and Group 2: 0.60 ± 0.17 and minimal coronary vascular resistance (Group 1: 0.48 ± 0.21 mmHg/mL/min and Group 2: 0.34 ± 0.12 mmHg/mL/min were similar in both groups (p= NS. Casual diastolic blood pressure and end-systolic left ventricular stress were independently associated with FS. CONCLUSIONS: In our hypertensive patients, endothelium-dependent and endothelium-independent coronary blood flow reserve vasodilator administrations had similar effects in patients with either normal or decreased left

  1. Diagnostic Accuracy of Stress Myocardial Perfusion Imaging Compared to Invasive Coronary Angiography With Fractional Flow Reserve Meta-Analysis

    NARCIS (Netherlands)

    Takx, Richard A. P.; Blomberg, Bjorn A.; El Aidi, Hamza; Habets, Jesse; de Jong, Pim A.; Nagel, Eike; Hoffmann, Udo; Leiner, Tim

    2015-01-01

    Background-Hemodynamically significant coronary artery disease is an important indication for revascularization. Stress myocardial perfusion imaging is a noninvasive alternative to invasive fractional flow reserve for evaluating hemodynamically significant coronary artery disease. The aim was to det

  2. Fractional flow reserve derived from coronary CT angiography in stable coronary disease: a new standard in non-invasive testing?

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard, B.L.; Jensen, J.M. [Aarhus University Hospital Skejby, Department of Cardiology B, Aarhus N (Denmark); Leipsic, J. [St. Paul' s Hospital, Department Radiology, Vancouver, British Columbia (Canada)

    2015-08-15

    Fractional flow reserve (FFR) measured during invasive coronary angiography is the gold standard for lesion-specific decisions on coronary revascularization in patients with stable coronary artery disease (CAD). Current guidelines recommend non-invasive functional or anatomic testing as a gatekeeper to the catheterization laboratory. However, the ''holy grail'' in non-invasive testing of CAD is to establish a single test that quantifies both coronary lesion severity and the associated ischemia. Most evidence to date of such a test is based on the addition of computational analysis of FFR to the anatomic information obtained from standard-acquired coronary CTA data sets at rest (FFR{sub CT}). This review summarizes the clinical evidence for the use of FFR{sub CT} in stable CAD in context to the diagnostic performance of other non-invasive testing modalities. (orig.)

  3. Comparative Study between Perfusion Changes and Positive Findings on Coronary Flow Reserve

    Directory of Open Access Journals (Sweden)

    Costantino Roberto Frack Costantini

    Full Text Available Abstract Background: Functional assessment of coronary artery obstruction is used in cardiology practice to correlate anatomic obstructions with flow decrease. Among such assessments, the study of the coronary fractional flow reserve (FFR has become the most widely used. Objective: To evaluate the correlation between FFR and findings of ischemia obtained by noninvasive methods including stress echocardiography and nuclear medicine and the presence of critical coronary artery obstruction. Methods: Retrospective study of cases treated with systematized and standardized procedures for coronary disease between March 2011 and August 2014. We included 96 patients with 107 critical coronary obstructions (> 50% in the coronary trunk and/or ≥ 70% in other segments estimated by quantitative coronary angiography (QCA and intracoronary ultrasound (ICUS. All cases presented ischemia in one of the noninvasive studies. Results: All 96 patients presented ischemia (100% in one of the functional tests. On FFR study with adenosine 140 g/kg/min, 52% of the cases had values ≤ 0.80. On correlation analysis for FFR ≤ 0.80, the evaluation of sensitivity, specificity, positive and negative predictive values, accuracy, and ROC curve in relation to the stenosis degree and length, and presence of ischemia, no significant values or strong correlation were observed. Conclusion: Coronary FFR using a cut-off value of 0.80 showed no correlation with noninvasive ischemia tests in patients with severe coronary artery obstructions on QCA and ICUS.

  4. Comparative Study between Perfusion Changes and Positive Findings on Coronary Flow Reserve

    Science.gov (United States)

    Costantini, Costantino Roberto Frack; Ramires, Jose Antonio; Costantini, Costantino Ortiz; Denk, Marcos Antonio; Tarbine, Sergio Gustavo; Santos, Marcelo de Freitas; Zanuttini, Daniel Aníbal; Silveira, Carmen Weigert; de Souza, Admar Moraes; de Macedo, Rafael Michel

    2017-01-01

    Background Functional assessment of coronary artery obstruction is used in cardiology practice to correlate anatomic obstructions with flow decrease. Among such assessments, the study of the coronary fractional flow reserve (FFR) has become the most widely used. Objective To evaluate the correlation between FFR and findings of ischemia obtained by noninvasive methods including stress echocardiography and nuclear medicine and the presence of critical coronary artery obstruction. Methods Retrospective study of cases treated with systematized and standardized procedures for coronary disease between March 2011 and August 2014. We included 96 patients with 107 critical coronary obstructions (> 50% in the coronary trunk and/or ≥ 70% in other segments) estimated by quantitative coronary angiography (QCA) and intracoronary ultrasound (ICUS). All cases presented ischemia in one of the noninvasive studies. Results All 96 patients presented ischemia (100%) in one of the functional tests. On FFR study with adenosine 140 g/kg/min, 52% of the cases had values ≤ 0.80. On correlation analysis for FFR ≤ 0.80, the evaluation of sensitivity, specificity, positive and negative predictive values, accuracy, and ROC curve in relation to the stenosis degree and length, and presence of ischemia, no significant values or strong correlation were observed. Conclusion Coronary FFR using a cut-off value of 0.80 showed no correlation with noninvasive ischemia tests in patients with severe coronary artery obstructions on QCA and ICUS. PMID:27982159

  5. Quantitative relationship between coronary calcium content and coronary flow reserve as assessed by integrated PET/CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Curillova, Zelmira [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); VA Boston Healthcare System, Division of Cardiology, Department of Medicine, West Roxbury, MA (United States); Yaman, Bettina F.; Sitek, Arkadius; El Fakhri, Georges [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Dorbala, Sharmila [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Noninvasive Cardiovascular Imaging Program, Departments of Medicine (Cardiology) and Radiology, Boston, MA (United States); Kwong, Raymond Y. [Harvard Medical School, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women' s Hospital, Boston, MA (United States); Brigham and Women' s Hospital, Noninvasive Cardiovascular Imaging Program, Departments of Medicine (Cardiology) and Radiology, Boston, MA (United States); Anagnostopoulos, Constantinos [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Royal Brompton Hospital, Department of Nuclear Medicine, London (United Kingdom); Di Carli, Marcelo F. [Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Harvard Medical School, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women' s Hospital, Boston, MA (United States); Brigham and Women' s Hospital, Noninvasive Cardiovascular Imaging Program, Departments of Medicine (Cardiology) and Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Division of Nuclear Medicine and Molecular Imaging, Boston, MA (United States)

    2009-10-15

    To evaluate the relationship between coronary artery calcium (CAC) and coronary vasodilator function. We evaluated 136 patients without known coronary artery disease (CAD) undergoing vasodilator stress {sup 82}Rb PET/CT and CAC scoring who showed normal myocardial perfusion. The CAC score, resting and hyperemic myocardial blood flow (MBF), coronary flow reserve (CFR) and coronary vascular resistance were analyzed. Global and regional CAC scores showed significant but weak inverse correlations with hyperemic MBF (r=-0.31 and r=-0.26, p{<=}0.0002 respectively) and CFR (r=-0.28 and r=-0.2, p{<=}0.001 respectively). With increasing CAC score, there was a modest stepwise decline in CFR on a per-patient basis (1.8{+-}0.5 vs 1.7{+-}0.5 vs 1.5{+-}0.4, p=0.048, with total CAC=0, 1-400 and >400, respectively) and on a per-vessel basis. In multivariable modeling only body mass index and CAC score were predictive of CFR. In patients with an intermediate likelihood of, but without overt, CAD, there is a statistically significant but weak inverse correlation between CAC content and coronary vasodilator function. The strength of this association weakens after adjusting CAC scores for age, gender and coronary risk factors. This suggests that CAC and coronary vasodilator function provide biologically different information regarding atherosclerosis. (orig.)

  6. Adenosine-induced coronary flow reserve in Watanabe heritable hyperlipidemic rabbits

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    Shimada, Kazuhiro; Yoshida, Katsuya [Chiba Univ. (Japan). School of Medicine; Tadokoro, Hiroyuki [and others

    2000-12-01

    The Watanabe heritable hyperlipidemic (WHHL) rabbit develops coronary atherosclerosis and hypercholesterolemia because of a genetic deficiency of low-density lipoprotein receptors and is therefore a good animal model for studying the relationships of coronary atherosclerosis, hypercholesterolemia and coronary flow reserve. The aim of the present study was to assess myocardial perfusion at baseline and during adenosine infusion (0.2 mg{center_dot}kg{sup -1}{center_dot}min{sup -1}) in 8 WHHL rabbits (13.8{+-}0.5 months) with {sup 13}N-ammonia, small-animal positron emission tomography (PET) and colored microspheres. Results were compared with those from 6 age-matched Japanese white rabbits. Plaque distribution was also examined in the extramural coronary arteries. All 8 WHHL rabbits had coronary plaques, with 6 showing multiple plaques. Mean global myocardial blood flow (ml{center_dot}min{sup -1}{center_dot}g{sup -1}) did not differ significantly between control and WHHL groups both at baseline (3.67{+-}0.72 vs 4.26{+-}1.12 ml{center_dot}min{sup -1}{center_dot}g{sup -1}, p=NS) and with adenosine (7.92{+-}2.00 vs 9.27{+-}2.91 ml{center_dot}min{sup -1}{center_dot}g{sup -1}, p=NS), nor did coronary flow reserve (2.16{+-}0.37 vs 2.18{+-}0.41, p=NS). None showed evidence of regional perfusion abnormalities by visual and semiquantitative analyses of PET images. It was concluded that WHHL rabbits preserve adenosine-induced coronary flow reserve despite coronary atherosclerosis and hypercholesterolemia, suggesting that a compensatory mechanism develops in this animal model. (author)

  7. Coronary plaque quantification and fractional flow reserve by coronary computed tomography angiography identify ischaemia-causing lesions

    DEFF Research Database (Denmark)

    Gaur, Sara; Øvrehus, Kristian Altern; Dey, Damini

    2016-01-01

    tomography angiography (CTA)-derived fractional flow reserve (FFRCT), and lesion-specific ischaemia identified by FFR in a substudy of the NXT trial (Analysis of Coronary Blood Flow Using CT Angiography: Next Steps). METHODS AND RESULTS: Coronary CTA stenosis, plaque volumes, FFRCT, and FFR were assessed...... the receiver-operating characteristics curve (AUC) analysis. Ischaemia was defined by FFR or FFRCT ≤0.80. Plaque volumes were inversely related to FFR irrespective of stenosis severity. Relative risk (95% confidence interval) for prediction of ischaemia for stenosis >50%, NCP ≥185 mm(3), LD-NCP ≥30 mm(3), CP...

  8. Significant regional heterogeneity of coronary flow reserve in paediatric hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Tadamura, E.; Kudoh, T.; Kubo, S.; Konishi, J. [Kyoto Univ. (Japan). School of Medicine; Yoshibayashi, M.; Yonemura, T. [Dept. of Pediatrics, Kyoto Univ. Graduate School of Medicine, Kyoto (Japan); Motooka, M.; Nohara, R.; Matsumori, A.; Sasayama, S. [Third Div., Dept. of Internal Medicine, Kyoto Univ. Graduate School of Medicine, Kyoto (Japan); Matsuda, T. [Dept. of Medical Informatics, Kyoto Univ. Graduate School of Medicine, Kyoto (Japan); Tamaki, N. [Dept. of Nuclear Medicine, Hokkaido Univ. School of Medicine, Sapporo (Japan)

    2000-09-01

    Previous studies have indicated that cardiac events in young patients with hypertrophic cardiomyopathy (HCM) are related to ischaemia rather than to arrhythmia. We measured coronary flow reserve in paediatric HCM and compared the values with those in adult HCM. We studied 12 patients with HCM including six paediatric (<20 years old; mean 13 years) and six adult patients (>20 years old: mean 62 years), and six healthy young adults (mean 29 years) as controls. Every patient underwent magnetic resonance imaging (MRI) for anatomical assessment. Myocardial blood flow at rest and after dipyridamole infusion was measured with dynamic nitrogen-13 ammonia positron emission tomography (PET). Partial volume effect was corrected for using the anatomical data obtained with MRI. In adult patients with HCM, coronary flow reserve in the hypertrophied septal region was not significantly different from that in the non-hypertrophied lateral wall (1.38{+-}0.29 vs 1.77{+-}0.39, respectively). In the paediatric patients, coronary flow reserve in the hypertrophied septal region was significantly lower than in the non-hypertrophied lateral wall (0.84{+-}0.33 vs 2.74{+-}0.90, respectively, P<0.01). In addition, coronary flow reserve in adult patients was lower than in control subjects both in the septal wall (1.38{+-}0.29 vs 2.94{+-}0.35, respectively, P<0.0001) and in the lateral wall (1.77{+-}0.39 vs 2.85{+-}0.69, respectively, P<0.05). In contrast, coronary flow reserve in paediatric patients was not significantly different from that in control subjects in the lateral wall (2.74{+-}0.90 vs 2.85{+-}0.69, respectively), while absolute reduction of myocardial blood flow was noted after pharmacological vasodilatation in the hypertrophied septal region. In conclusion, significant regional differences of coronary flow reserve were present in the paediatric patients with HCM. These results suggest that paediatric patients with HCM intrinsically have the potential to experience significant

  9. Transthoracic coronary flow reserve and dobutamine derived myocardial function: a 6-month evaluation after successful coronary angioplasty

    Directory of Open Access Journals (Sweden)

    Pardo Moira

    2004-12-01

    Full Text Available Abstract After percutaneous transluminal coronary angioplasty (PTCA, stress-echocardiography and gated single photon emission computerized tomography (g-SPECT are usually performed but both tools have technical limitations. The present study evaluated results of PTCA of left anterior descending artery (LAD six months after PTCA, by combining transthoracic Doppler coronary flow reserve (CFR and color Tissue Doppler (C-TD dobutamine stress. Six months after PTCA of LAD, 24 men, free of angiographic evidence of restenosis, underwent standard Doppler-echocardiography, transthoracic CFR of distal LAD (hyperemic to basal diastolic coronary flow ratio and C-TD at rest and during dobutamine stress to quantify myocardial systolic (Sm and diastolic (Em and Am, Em/Am ratio peak velocities in middle posterior septum. Patients with myocardial infarction, coronary stenosis of non-LAD territory and heart failure were excluded. According to dipyridamole g-SPECT, 13 patients had normal perfusion and 11 with perfusion defects. The 2 groups were comparable for age, wall motion score index (WMSI and C-TD at rest. However, patients with perfusion defects had lower CFR (2.11 ± 0.4 versus 2.87 ± 0.6, p m at high-dose dobutamine (p m of middle septum (r = 0.55, p In conclusion, even in absence of epicardial coronary restenosis, stress perfusion imaging reflects a physiologic impairment in coronary microcirculation function whose magnitude is associated with the degree of regional functional impairment detectable by C-TD.

  10. Association of Coronary Stenosis and Plaque Morphology With Fractional Flow Reserve and Outcomes

    DEFF Research Database (Denmark)

    Ahmadi, Amir; Stone, Gregg W; Leipsic, Jonathon

    2016-01-01

    IMPORTANCE: Obstructive coronary lesions with reduced luminal dimensions may result in abnormal regional myocardial blood flow as assessed by stress-induced myocardial perfusion imaging or a significant fall in distal perfusion pressure with hyperemia-induced vasodilatation (fractional flow reserve......: Having a normal FFR requires unimpaired vasoregulatory ability and significant luminal stenosis. Therefore, FFR should identify lesions that are unlikely to possess large necrotic core, rendering them safe for treatment with medical therapy alone. Further studies are warranted to determine whether...

  11. Transthoracic Doppler echocardiography – noninvasive diagnostic window for coronary flow reserve assessment

    Directory of Open Access Journals (Sweden)

    Dimitrow Paweł

    2003-04-01

    Full Text Available Abstract This review focuses on transthoracic Doppler echocardiography as noninvasive method used to assess coronary flow reserve (CFR in a wide spectrum of clinical settings. Transthoracic Doppler echocardiography is rapidly gaining appreciation as popular tool to measure CFR both in stenosed and normal epicardial coronary arteries (predominantly in left anterior descending coronary artery. Post-stenotic CFR measurement is helpful in: functional assessment of moderate stenosis, detection of significant or critical stenosis, monitoring of restenosis after revascularization. In the absence of stenosis in the epicardial coronary artery, decreased CFR enable to detect impaired microvascular vasodilatation in: reperfused myocardial infarct, arterial hypertension with or without left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, syndrome X, hypertrophic cardiomyopathy. In these diseases, noninvasive transthoracic Doppler echocardiography allows for serial CFR evaluations to explore the effect of various pharmacological therapies.

  12. Subendocardial viability ratio as an index of impaired coronary flow reserve in hypertensives without significant coronary artery stenoses.

    Science.gov (United States)

    Tsiachris, D; Tsioufis, C; Syrseloudis, D; Roussos, D; Tatsis, I; Dimitriadis, K; Toutouzas, K; Tsiamis, E; Stefanadis, C

    2012-01-01

    Subendocardial viability ratio (SEVR), calculated through pulse wave analysis, is an index of myocardial oxygen supply and demand. Our aim was to evaluate the relationship between coronary flow reserve (CFR) and SEVR in 36 consecutive untreated hypertensives (aged 57.9 years, 12 males, all Caucasian) with indications of myocardial ischaemia and normal coronary arteries in coronary angiography. CFR was calculated by a 0.014-inch Doppler guidewire (Flowire, Volcano, San Diego, CA, USA) in response to bolus intracoronary administration of adenosine (30-60 μg). SEVR was calculated by radial applanation tonometry, while diastolic function was evaluated by means of transmitral flow and tissue Doppler imaging. Hypertensive patients with low CFR (n=24) compared with those with normal CFR (n=12) exhibited significantly decreased SEVR by 24.5% (P=0.002). In hypertensives with low CFR, CFR was correlated with SEVR (r=0.651, P=0.001). After applying multivariate linear regression analysis, age, left ventricular mass index, Em/Am, 24-h diastolic blood pressure (BP) and SEVR turned out to be the only independent predictors of CFR (adjusted R(2)=0.718). Estimation of SEVR by using applanation tonometry may provide a reliable tool for the assessment of coronary microcirculation in essential hypertensives with indications of myocardial ischaemia and normal coronary arteries.

  13. Physiologic Assessment of Coronary Artery Disease: Focus on Fractional Flow Reserve

    OpenAIRE

    Hwang, Doyeon; Lee, Joo Myung; Koo, Bon-Kwon

    2016-01-01

    The presence of myocardial ischemia is the most important prognostic factor in patients with ischemic heart disease. Fractional flow reserve (FFR) is a gold standard invasive method used to detect the stenosis-specific myocardial ischemia. FFR-guided revascularization strategy is superior to angiography-guided strategy. The recently developed hyperemia-free index, instantaneous wave free ratio is being actively investigated. A non-invasive FFR derived from coronary CT angiography is now used ...

  14. Coronary Flow Velocity Reserve in Burn Injury: A Prospective Clinical Cohort Study.

    Science.gov (United States)

    Caliskan, Mustafa; Turk, Emin; Karagulle, Erdal; Ciftci, Ozgur; Oguz, Hakan; Kostek, Osman; Moray, Gokhan; Haberal, Mehmet

    2016-01-01

    The authors sought to evaluate coronary microvascular function and left ventricular diastolic dysfunction using transthoracic Doppler echocardiography in burn patients. In this study, 32 adult burn patients with partial or full-thickness scald burns that were hospitalized and treated were included. The control group was matched for age and sex and was composed of otherwise healthy volunteers. Transthoracic Doppler echocardiography examinations and simultaneous laboratory tests for cardiac evaluation were performed on the sixth month after burn injury as well as with the control group. High-sensitivity C-reactive protein levels were significantly higher in the burn patients than in controls (5.17 ± 3.86 vs 2.42 ± 1.78; P = .001). Lateral isovolumic relaxation time was significantly higher in the burn injury group than in the control group (92.7 ± 15.7 vs 85.5 ± 8.3; P = .03). Baseline coronary diastolic peak flow velocity of the left anterior descending artery was similar in both groups. However, hyperemic diastolic peak flow velocity and coronary flow velocity reserve (2.26 ± 0.48 vs 2.94 ± 0.47; P < .001) were significantly lower in the burn injury group than in the control group. Coronary flow velocity reserve was significantly and inversely correlated with high-sensitivity C-reactive protein, burn ratio, creatinine, and mitral A-wave max velocity. At the sixth month of treatment, burn patients had high-sensitivity C-reactive protein levels during this period, suggesting that inflammation still exists. In addition, subclinical coronary microvascular and left ventricular diastolic dysfunction can occur in burn patients without traditional cardiovascular risk factors. However, these results must be supported by additional studies.

  15. Higher CHADS2 score is associated with impaired coronary flow reserve: A study using phase contrast cine magnetic resonance imaging.

    Science.gov (United States)

    Kirigaya, Hidekuni; Kato, Shingo; Gyotoku, Daiki; Yamada, Nao; Iinuma, Naoki; Kusakawa, Yuka; Iguchi, Kohei; Miki, Yuko; Nakachi, Tatsuya; Fukui, Kazuki; Iwasawa, Tae; Kimura, Kazuo

    2016-10-15

    The presence of coronary microvascular dysfunction (CMD) is an important prognostic marker for coronary artery disease (CAD) patients. The purpose of this study was to investigate whether the CHADS2 score is associated with CMD evaluated by magnetic resonance imaging (MRI). One hundred forty three patients with known or suspected CAD (mean age 70.3±9.5years) were enrolled. All patients did not have any significant coronary stenosis on X-ray coronary angiography (CAG) at the time of MRI acquisition. By using a 1.5T MRI scanner, breath-hold phase contrast cine MRI images of coronary sinus (CS) were obtained to assess the blood flow of CS both at rest and during adenosine triphosphate (ATP) infusion. Coronary flow reserve (CFR) was calculated as CS blood flow during ATP infusion divided by CS blood flow at rest. CMD was defined as CFRcine MRI. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Outcomes of coronary stenoses deferred revascularization for borderline versus nonborderline fractional flow reserve values.

    Science.gov (United States)

    Depta, Jeremiah P; Patel, Jayendrakumar S; Novak, Eric; Masrani, Shriti K; Raymer, David; Facey, Gabrielle; Patel, Yogesh; Zajarias, Alan; Lasala, John M; Singh, Jasvindar; Bach, Richard G; Kurz, Howard I

    2014-06-01

    Current evidence supports deferral of revascularization for lesions with fractional flow reserve (FFR) values >0.80. The natural history after deferral of revascularization of lesions with borderline FFR values is unknown. This study evaluated the outcomes of patients after deferred revascularization of coronary stenoses based on a borderline FFR value. We retrospectively studied 720 patients with 881 intermediate-severity coronary stenoses who underwent FFR assessment from October 2002 to July 2010 and were deferred revascularization. Patients were divided into gray zone (0.75 to 0.80), borderline (0.81 to 0.85), and nonborderline (>0.85) FFR groups. Any subsequent percutaneous coronary intervention or coronary artery bypass grafting of a deferred stenosis during follow-up was classified as a deferred lesion intervention (DLI). Patient and/or lesion characteristics and clinical outcomes were compared between the FFR groups using univariate and propensity score-adjusted inverse probability of weighting Cox proportional hazards analyses. During a mean follow-up of 4.5 ± 2.1 years, 157 deferred lesions (18%) underwent DLI by percutaneous coronary intervention (n = 117) or coronary artery bypass grafting (n = 40). No statistically significant differences were observed in clinical outcomes between the gray zone and borderline FFR groups. Lesions with a borderline FFR were associated with a significantly higher risk of DLI compared with lesions with nonborderline FFR values (hazard ratio 1.63, 95% confidence interval 1.14 to 2.33, p = 0.007). Lesions deferred revascularization because of a borderline FFR (0.81 to 0.85) were associated with a higher risk of DLI compared with lesions with a nonborderline FFR (>0.85). Further study is needed to determine the optimal management of coronary stenoses with a borderline FFR value. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Impact of individual and cumulative coronary risk factors on coronary flow reserve assessed by dobutamine stress echocardiography.

    Science.gov (United States)

    Ahmari, Saeed A L; Bunch, T Jared; Modesto, Karen; Stussy, Vicky; Dichak, Amy; Seward, James B; Pellikka, Patricia A; Chandrasekaran, Krishnaswamy

    2008-06-15

    Traditional cardiovascular risk factors have been shown to cause microvascular dysfunction. Most studies that have evaluated microcirculation rely on invasive measurement tools. We used dobutamine stress echocardiography, a validated method to measure coronary flow velocity (CFV) and coronary flow reserve (CFR), in a previously unstudied population without known significant coronary artery disease to determine the impact of traditional risk factors on CFR. Consecutive patients who had no evidence of regional wall motion abnormalities at rest or during dobutamine stress echocardiography were studied. Left anterior descending artery CFV was measured at baseline and at peak dobutamine stress and CFR was calculated as the ratio of peak stress CFV to baseline CFV. Fifty-nine consecutive patients (28 men) with mean age of 66.8+/-14.5 years were studied. CFR was lower in patients with diabetes mellitus (DM) compared with those without (1.7+/-0.74 vs 2.48+/-0.98, p50 mm Hg), and obesity with a wide pulse pressure. In a multivariate model, DM, obesity, and wide pulse pressure were significantly associated with variation in CFR (p<0.0008). In conclusion, CFR was abnormal in patients with DM, hypertension, and obesity. CFR impairment is exaggerated as the number of risk factors increases. Despite a negative dobutamine stress echocardiographic result, aggressive risk factor assessment and control should be implemented in patients with coronary risk factors due to an underlying abnormal CFR.

  18. Feasibility and diagnostic power of transthoracic coronary Doppler for coronary flow velocity reserve in patients referred for myocardial perfusion imaging

    Directory of Open Access Journals (Sweden)

    Nylander Eva

    2008-03-01

    Full Text Available Abstract Background Myocardial perfusion imaging (MPI, using single photon emission computed tomography (SPECT is a validated method for detecting coronary artery disease. Transthoracic Doppler echocardiography (TTDE of flow at rest and during adenosine provocation has previously been evaluated in selected patient groups. We therefore wanted to compare the diagnostic ability of TTDE in the left anterior descending coronary artery (LAD to that of MPI in an unselected population of patients with chest pain referred for MPI. Our hypothesis was that TTDE with high accuracy would identify healthy individuals and exclude them from the need for further studies, enabling invasive investigations to be reserved for patients with a high probability of disease. Methods Sixty-nine patients, 44 men and 25 women, age 61 ± 10 years (range 35–82, with a clinical suspicion of stress induced myocardial ischemia, were investigated. TTDE was performed at rest and during adenosine stress for myocardial scintigraphy. Results We found that coronary flow velocity reserve (CFVR determined from diastolic measurements separated normal from abnormal MPI findings with statistical significance. TTDE identified coronary artery disease, defined from MPI, as reversible ischemia and/or permanent defect, with a sensitivity of 60% and a specificity of 79%. The positive predictive value was 43% and the negative predictive value was 88%. There was an overlap between groups which could be due to abnormal endothelial function in patients with normal myocardial perfusion having either hypertension or diabetes. Conclusion TTDE is an attractive non-invasive method to evaluate chest pain without the use of isotopes, but the diagnostic power is strongly dependent on the population investigated. Even in our heterogeneous clinical cardiac population, we found that CFVR>2 in the LAD excluded significant coronary artery disease detected by MPI.

  19. Metoprolol does not effect myocardial fractional flow reserve in patients with intermediate coronary stenoses.

    Science.gov (United States)

    Ozdemir, Murat; Yazici, Guliz Erdem; Turkoglu, Sedat; Timurkaynak, Timur; Cengel, Atiye

    2007-07-01

    Myocardial fractional flow reserve (FFR) is utilized to determine the hemodynamic significance of coronary stenoses. We sought to determine the effect, if any, of metoprolol on FFR in patients with coronary stenoses of intermediate severity. Eighteen patients (10 males, mean age, 59.4 +/- 7.7 years) with isolated, intermediate (30% to 70% narrowing on coronary angiogram) lesions on the proximal LAD and a preserved ejection fraction, underwent FFR measurement using a 0.014 inch pressurewire and intracoronary adenosine injection before and after intravenous metoprolol at a dose that achieved at least a 10% decrease in the heart rate. Heart rate dropped significantly with metoprolol. At the premetoprolol measurement, aortic pressure (Pa) remained essentially the same (105.7 +/- 11.5 versus 105.6 +/- 11.6 mmHg, P > 0.05) and distal coronary pressure (Pd) dropped significantly by 9% from 96.3 +/- 12.7 to 87.4 +/- 13.4 mmHg (P 0.05). In this study, FFR was found not to be influenced by metoprolol treatment in patients with intermediate coronary stenoses and a preserved ejection fraction.

  20. Clinical Relevance of Coronary Fractional Flow Reserve: Art-of-state

    Institute of Scientific and Technical Information of China (English)

    Yohanes Adiputra; Shao-Liang Chen

    2015-01-01

    Objective:The objective was to delineate the current knowledge of fractional flow reserve (FFR) in terms of definition,features,clinical applications,and pitfalls of measurement of FFR.Data Sources:We searched database for primary studies published in English.The database of National Library of Medicine (NLM),MEDLINE,and PubMed up to July 2014 was used to conduct a search using the keyword term "FFR".Study Selection:The articles about the definition,features,clinical application,and pitfalls of measurement of FFR were identified,retrieved,and reviewed.Results:Coronary pressure-derived FFR rapidly assesses the hemodynamic significance of individual coronary artery lesions and can readily be performed in the catheterization laboratory.The use of FFR has been shown to effectively guide coronary revascularization procedures leading to improved patient outcomes.Conclusions:FFR is a valuable tool to determine the functional significance of coronary stenosis.It combines physiological and anatomical information,and can be followed immediately by percutaneous coronary intervention (PCI) if necessary.The technique of FFR measurement can be performed easily,rapidly,and safely in the catheterization laboratory.By systematic use of FFR in dubious stenosis and multi-vessel disease,PCI can be made an even more effective and better treatment than it is currently.The current clinical evidence for FFR should encourage cardiologists to use this tool in the catheterization laboratory.

  1. Clinical Relevance of Coronary Fractional Flow Reserve: Art-of-state.

    Science.gov (United States)

    Adiputra, Yohanes; Chen, Shao-Liang

    2015-05-20

    The objective was to delineate the current knowledge of fractional flow reserve (FFR) in terms of definition, features, clinical applications, and pitfalls of measurement of FFR. We searched database for primary studies published in English. The database of National Library of Medicine (NLM), MEDLINE, and PubMed up to July 2014 was used to conduct a search using the keyword term "FFR". The articles about the definition, features, clinical application, and pitfalls of measurement of FFR were identified, retrieved, and reviewed. Coronary pressure-derived FFR rapidly assesses the hemodynamic significance of individual coronary artery lesions and can readily be performed in the catheterization laboratory. The use of FFR has been shown to effectively guide coronary revascularization procedures leading to improved patient outcomes. FFR is a valuable tool to determine the functional significance of coronary stenosis. It combines physiological and anatomical information, and can be followed immediately by percutaneous coronary intervention (PCI) if necessary. The technique of FFR measurement can be performed easily, rapidly, and safely in the catheterization laboratory. By systematic use of FFR in dubious stenosis and multi-vessel disease, PCI can be made an even more effective and better treatment than it is currently. The current clinical evidence for FFR should encourage cardiologists to use this tool in the catheterization laboratory.

  2. Physiological assessment of coronary lesion severity: fractional flow reserve versus nonhyperaemic indices.

    Science.gov (United States)

    Robertson, Keith E; Hennigan, Barry; Berry, Colin; Oldroyd, Keith G

    2015-08-01

    Coronary angiography alone cannot accurately identify the haemodynamic impact of a coronary artery stenosis. Current international guidelines for myocardial revascularization recommend that inducible ischaemia should be demonstrated before the consideration of percutaneous coronary intervention. Invasive physiological assessment of coronary stenosis severity has increasingly been utilized for this purpose and use of the best validated technique, fractional flow reserve (FFR), has been shown to improve clinical outcomes in patients with stable and unstable coronary artery disease. This has led to the use of FFR being recommended in international revascularization guidelines, despite which, clinical uptake has been limited. One potential reason for slow adoption has been the requirement for maximal hyperaemia at the time of FFR measurement, usually achieved by the administration of pharmacological vasodilators such as adenosine. In some healthcare systems, adenosine is expensive and, in addition, its use can be associated with significant, albeit transient, adverse effects that patients (and some operators) find uncomfortable. Consequently, several methods of nonhyperaemic lesion assessment and their potential role in decision making have been reported. In this review we will review and discuss the current evidence for hyperaemic and nonhyperaemic methods of lesion assessment. We will also look at hybrid strategies that utilize both hyperaemic and nonhyperaemic methods as a means of potentially maintaining diagnostic accuracy while minimizing the requirement for adenosine administration and discuss whether or not they represent viable clinical alternatives.

  3. Target heart rate to determine the normal value of coronary flow reserve during dobutamine stress echocardiography

    Directory of Open Access Journals (Sweden)

    Rousse Maria G

    2011-04-01

    Full Text Available Abstract Background The determination of coronary flow reserve (CFR is an essential concept at the moment of decision-making in ischemic heart disease. There are several direct and indirect tests to evaluate this parameter. In this sense, dobutamine stress echocardiography is one of the pharmacological method most commonly used worldwide. It has been previously demonstrated that CFR can be determined by this technique. Despite our wide experience with dobutamine stress echocardiography, we ignored the necessary heart rate to consider sufficient the test for the analysis of CFR. For this reason, our main goal was to determine the velocity of coronary flow in each stage of dobutamine stress echocardiography and the heart rate value necessary to double the baseline values of coronary flow velocity in the territory of the left anterior descending (LAD coronary artery. Methods A total of 33 consecutive patients were analyzed. The patients included had low risk for coronary artery disease. All the participants underwent dobutamine stress echocardiography and coronary artery flow velocity was evaluated in the distal segment of LAD coronary artery using transthoracic color-Doppler echocardiography. Results The feasibility of determining CFR in the territory of the LAD during dobutamine stress echocardiography was high: 31/33 patients (94%. Mean CFR was 2.67 at de end of dobutamine test. There was an excellent concordance between delta HR (difference between baseline HR and maximum HR and the increase in the CFR (correlation coefficient 0.84. In this sense, we found that when HR increased by 50 beats, CFR was ≥ 2 (CI 93-99.2%. In addition, 96.4% of patients reached a CFR ≥ 2 (IC 91.1 - 99% at 75% of their predicted maximum heart rate. Conclusions We found that the feasibility of dobutamine stress echocardiography to determine CFR in the territory of the LAD coronary artery was high. In this study, it was necessary to achieve a difference of 50 bpm

  4. Applicability of 3-Dimensional Quantitative Coronary Angiography-Derived Computed Fractional Flow Reserve for Intermediate Coronary Stenosis.

    Science.gov (United States)

    Yazaki, Kyoichiro; Otsuka, Masato; Kataoka, Shohei; Kahata, Mitsuru; Kumagai, Asako; Inoue, Koji; Koganei, Hiroshi; Enta, Kenji; Ishii, Yasuhiro

    2017-06-23

    Quantitative flow ratio (QFR) is a newly developed image-based index for estimating fractional flow reserve (FFR).Methods and Results:We analyzed 151 coronary arteries with intermediate stenosis in 142 patients undergoing wire-based FFR measurement using dedicated software. Predefined contrast flow QFR, which was derived from 3-dimensional quantitative coronary angiography (3-D QCA) withThrombolysis in Myocardial Infarction (TIMI) frame counts, was compared with FFR as a reference. QFR had good correlation (r=0.80, P<0.0001) and agreement (mean difference: 0.01±0.05) with FFR. After applying the FFR cut-off ≤0.8, the overall accuracy rate of QFR ≤0.8 was 88.0%. On receiver operating characteristics analysis, the area under the curve was 0.93 for QFR. In contrast, 3-D QCA-derived anatomical indices had insufficient correlation with FFR and diagnostic performance compared with QFR. QFR had good correlation and agreement with FFR and high diagnostic performance in the evaluation of intermediate coronary stenosis, suggesting that QFR may be an alternative tool for estimating myocardial ischemia.

  5. Coronary flow reserve evaluated by {sup 201}Tl myocardial perfusion SPECT after coronary artery bypass grafting (CABG) for angina pectoris

    Energy Technology Data Exchange (ETDEWEB)

    Ishino, Yoichi; Nakata, Hajime [Univ. of Occupational and Environmental Health, Kitakyusyu, Fukuoka (Japan)

    2000-11-01

    We compared the flow reserves of the coronary bypass vessels between arterial and venous grafts by {sup 201}Tl myocardial perfusion SPECT on the patients with angina pectoris who had no past history of myocardial infarction or intervention therapy such as PTCA. Thirty two patients had undergone a total of 70 bypass grafts and 66 of them were proved to be patent at postoperative CAG. Reversible defects were observed in 6 of 40 segments (15.0%) covered by patent venous grafts, and in 11 of 26 segments (42.3%) by patent arterial grafts. The rate of postoperative reversible defects was higher in the areas grafted by artery but this had no relation with the severity of coronary artery stenosis before CABG. This reversible defect is most likely to be caused by the character of artery graft itself and this should not be considered to highly suggest the restenosis or occlusion of the graft vessel. (author)

  6. Assessment of Coronary Flow Velocity Reserve by Noninvasive Transthoracic Doppler Echocardiography in Patients with Angiographically Normal Coronary Arteries

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The measurement of coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography (TTDE) with invasive intracoronary Doppler flow wire technique (ICD) was validated and the pathologicalfactors which influence CFVR in patients with angiographically normal coronary arteries were analyzed. CFVR was determined successfully in left anterior descending artery (LAD) in 37 of 40 patients with angiographically normal coronary arteries (men 22, women 15, age 20-75 years, mean age 54 ± 12 years). Coronary flow velocity was measured in the distal LAD by TTDE with contrast enhancement at baseline and during intravenous adenosine infusion of 140 μg/kg per min within 48 h after ICD technique. Average peak velocity at baseline (APVb), average peak velocity during hyperemia (APVh) and CFVR determined from TTDE were correlated closely with those from ICD measurements (APVb: y=0. 64x+5. 04, r=0. 86, P<0. 001;APVh: y=0.63x+14.36, r=0.82, P<0.001; CFVR: y=0.65x+0.92, r=0.88, P<0. 001).For CFVR measurements, the mean differences between TTDE and ICD methods were 0. 12 ±0.39. CFVR in patients with history of hypertension was significantly lower than that in patients without history of hypertension (P<0.05). Intravascular ultrasound (IVUS) was performed in 34patients. Plaque formation was found in LAD by IVUS in 17 (50 %) patients. No significant difference in CFVR was found between the patients without plaque formation (3. 11±0. 49) and those with plaque formation (2. 76±0.53, P=0. 056). It is suggested that TTDE with contrast enhancement provides reliable measurement of APV and CFVR in the distal LAD. The early stage of atherosclerosis could be detected by IVUS, which may be normal in angiography. CFVR is impaired in patients with history of hypertension compared with that in patients without history of hypertension.

  7. Impact of uncontrolled blood pressure on diagnostic accuracy of coronary flow reserve for detecting significant coronary stenosis in hypertensive patients

    Institute of Scientific and Technical Information of China (English)

    LI Wei-hong; XU Wei-xian; LI Zhao-ping; LI Cui-ping; WANG Xin-yu; HE Li-yun; ZHAO Wei

    2013-01-01

    Baciground Impaired coronary flow reserve (CFR) in patients with hypertension may be caused by epicardial coronary stenosis or microvascular dysfunction.Antihypertensive treatment has been shown to improve coronary microvascular dysfunction.The aim of this study was to evaluate the impact of uncontrolled blood pressure (BP) on diagnostic accuracy of CFR for detecting significant coronary stenosis.Methods A total of 98 hypertensive patients scheduled for coronary angiography (CAG) due to chest pain were studied.Of them,45 patients had uncontrolled BP (defined as the office BP >140/90 mmHg (1 mmHg=0.133 kPa) in general hypertensive patients,or >130/80 mmHg in hypertensive individuals with diabetes mellitus),and the remaining 53 patients had well-controlled BP.CFR was measured in the left anterior descending coronary artery (LAD) during adenosine triphosphate-induced hyperemia by non-invasive transthoracic Doppler echocardiography (TTDE) within 48 hours prior to CAG.Significant LAD stenosis was defined as >70% luminal narrowing.Diagnostic accuracy of CFR for detecting significant coronary stenosis was analyzed with a receiver operating characteristic analysis.Results CFR was significantly lower in patients with uncontrolled BP than in those with well-controlled BP (2.1±0.6 vs.2.6±0.9,P <0.01).Multivariate linear regression analysis of the study showed that the value of CFR was independently associated with the angiographically determined degree of LAD stenosis (β=-0.445,P <0.0001) and the presence of uncontrolled BP (β=-0.272,P=0.014).With a receiver operating characteristic analysis,CFR <2.2 was the optimal cut-off value for detecting LAD stenosis in all hypertensive patients (AUC 0.83,95%C/0.75-0.91) with a sensitivity of 75%,a specificity of 78%,and an accuracy of 77%.A significant reduction of diagnostic specificity was observed in patients with uncontrolled BP compared with those with well-controlled BP (67% vs.93%,P=0

  8. A machine-learning approach for computation of fractional flow reserve from coronary computed tomography.

    Science.gov (United States)

    Itu, Lucian; Rapaka, Saikiran; Passerini, Tiziano; Georgescu, Bogdan; Schwemmer, Chris; Schoebinger, Max; Flohr, Thomas; Sharma, Puneet; Comaniciu, Dorin

    2016-07-01

    Fractional flow reserve (FFR) is a functional index quantifying the severity of coronary artery lesions and is clinically obtained using an invasive, catheter-based measurement. Recently, physics-based models have shown great promise in being able to noninvasively estimate FFR from patient-specific anatomical information, e.g., obtained from computed tomography scans of the heart and the coronary arteries. However, these models have high computational demand, limiting their clinical adoption. In this paper, we present a machine-learning-based model for predicting FFR as an alternative to physics-based approaches. The model is trained on a large database of synthetically generated coronary anatomies, where the target values are computed using the physics-based model. The trained model predicts FFR at each point along the centerline of the coronary tree, and its performance was assessed by comparing the predictions against physics-based computations and against invasively measured FFR for 87 patients and 125 lesions in total. Correlation between machine-learning and physics-based predictions was excellent (0.9994, P machine-learning algorithm with a sensitivity of 81.6%, a specificity of 83.9%, and an accuracy of 83.2%. The correlation was 0.729 (P machine-learning model on a workstation with 3.4-GHz Intel i7 8-core processor. Copyright © 2016 the American Physiological Society.

  9. Coronary flow reserve in the remote myocardium predicts left ventricular remodeling following acute myocardial infarction.

    Science.gov (United States)

    Cheng, Rongchao; Wei, Guoqian; Yu, Longhao; Su, Zhendong; Wei, Li; Bai, Xiuping; Tian, Jiawei; Li, Xueqi

    2014-07-01

    Coronary flow reserve (CFR) in the non-infarcted myocardium is often impaired following acute myocardial infarction (AMI). However, the clinical significance of CFR in the non-infarcted myocardium is not fully understood. The objective of the present study was to assess whether a relationship exists between CFR and left ventricular remodeling following AMI. We enrolled 18 consecutive patients undergoing coronary intervention. Heart function was analyzed using real-time myocardial contrast echocardiography at one week and six months after coronary angioplasty. Ten subjects were enrolled as the control group and were examined using the same method at the same time to assess CFR. Cardiac troponin I (cTnI) levels were routinely analyzed to estimate peak concentration. CFR was 1.55±0.11 in the infarcted zone and 2.05±0.31 in the remote zone (p2.05). The levels of cTnI were higher in Group I compared to Group II on admission (36.40 vs. 21.38, p<0.05). Furthermore, left ventricular end diastolic volume was higher in Group I compared to Group II at six months following coronary angioplasty. Microvascular dysfunction is commonly observed in the remote myocardium. The CFR value accurately predicts adverse ventricular remodeling following AMI.

  10. Pooled comparison of regadenoson versus adenosine for measuring fractional flow reserve and coronary flow in the catheterization laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Stolker, Joshua M., E-mail: jstolker@yahoo.com [Mercy Heart and Vascular, 901 Patients First Drive, Washington, MO 63090 (United States); Saint Louis University, 3635 Vista Ave, St. Louis, MO 63110 (United States); Lim, Michael J., E-mail: limmj@slu.edu [Saint Louis University, 3635 Vista Ave, St. Louis, MO 63110 (United States); Shavelle, David M., E-mail: david.shavelle@med.usc.edu [University of Southern California, 1510 San Pablo St, Suite 322, Los Angeles, CA 90033 (United States); Morris, D. Lynn, E-mail: morrisdl@einstein.edu [Albert Einstein Medical Center, 5501 Old York Rd, Philadelphia, PA 19141 (United States); Angiolillo, Dominick J., E-mail: dominick.angiolillo@jax.ufl.edu [University of Florida Health-Jacksonville, 655 West 8th St, Jacksonville, FL 32209 (United States); Guzman, Luis A., E-mail: luis.guzman@jax.ufl.edu [University of Florida Health-Jacksonville, 655 West 8th St, Jacksonville, FL 32209 (United States); Kennedy, Kevin F., E-mail: kfkennedy@saint-lukes.org [Saint Luke' s Mid America Heart Institute, 4401 Wornall Road, Kansas City, MO 64111 (United States); Weber, Elizabeth, E-mail: eweber1@slu.edu [Saint Louis University, 3635 Vista Ave, St. Louis, MO 63110 (United States); Zareh, Meena, E-mail: meena.zareh@med.usc.edu [University of Southern California, 1510 San Pablo St, Suite 322, Los Angeles, CA 90033 (United States); Neumayr, Robert H., E-mail: robneumayr@gmail.com [Mercy Heart and Vascular, 901 Patients First Drive, Washington, MO 63090 (United States); Saint Louis University, 3635 Vista Ave, St. Louis, MO 63110 (United States); Zenni, Martin M., E-mail: martin.zenni@jax.ufl.edu [University of Florida Health-Jacksonville, 655 West 8th St, Jacksonville, FL 32209 (United States)

    2015-07-15

    Background: Adenosine is the gold standard for augmenting coronary flow during fractional flow reserve (FFR) testing of intermediate coronary stenoses. However, intravenous infusion is time-consuming and intracoronary injection is subject to variability. Regadenoson is a newer adenosine alternative administered as a single intravenous bolus during nuclear stress testing, but its efficacy and safety during FFR testing have been evaluated only in small, single-center studies. Methods: We pooled data from 5 academic hospitals, in which patients undergoing clinically-indicated FFR prospectively underwent comparison of intravenous adenosine infusion (140–175 mcg/kg/min) versus regadenoson bolus (400 mcg). Hemodynamics and symptoms with adenosine were recorded until maximal hyperemia occurred, and after returning to baseline hemodynamics, regadenoson was administered and monitoring was repeated. In a subset of patients with coronary flow data, average peak velocity (APV) at the distal flow sensor was recorded. Results: Of 149 patients enrolled, mean age was 59 ± 9 years, 76% were male, and 54% underwent testing of the left anterior descending artery. Mean adenosine-FFR and regadenoson-FFR were identical (0.82 ± 0.10) with excellent correlation of individual values (r = 0.96, p < 0.001) and no difference in patient-reported symptoms. Four patients (2.6%) had discrepancies between the 2 drugs for the clinical decision-making cutoff of FFR ≤ 0.80. Coronary flow responses to adenosine and regadenoson were similar (APV at maximal hyperemia 36 cm/s for both, p = 0.81). Conclusions: Regadenoson single-bolus administration has comparable FFR, symptoms, and coronary flow augmentation when compared with standard intravenous adenosine infusion. With its greater ease of administration, regadenoson may be a more “user-friendly” option for invasive ischemic testing.

  11. Virtual Resting Pd/Pa From Coronary Angiography and Blood Flow Modelling: Diagnostic Performance Against Fractional Flow Reserve.

    Science.gov (United States)

    Papafaklis, Michail I; Muramatsu, Takashi; Ishibashi, Yuki; Bourantas, Christos V; Fotiadis, Dimitrios I; Brilakis, Emmanouil S; Garcia-Garcia, Héctor M; Escaned, Javier; Serruys, Patrick W; Michalis, Lampros K

    2017-05-03

    Fractional flow reserve (FFR) has been established as a useful diagnostic tool. The distal coronary pressure to aortic pressure (Pd/Pa) ratio at rest is a simpler physiologic index but also requires the use of the pressure wire, whereas recently proposed virtual functional indices derived from coronary imaging require complex blood flow modelling and/or are time-consuming. Our aim was to test the diagnostic performance of virtual resting Pd/Pa using routine angiographic images and a simple flow model. Three-dimensional quantitative coronary angiography (3D-QCA) was performed in 139 vessels (120 patients) with intermediate lesions assessed by FFR. The resting Pd/Pa for each lesion was assessed by computational fluid dynamics. The discriminatory power of virtual resting Pd/Pa against FFR (reference: ≤0.80) was high (area under the receiver operator characteristic curve [AUC]: 90.5% [95% CI: 85.4-95.6%]). Diagnostic accuracy, sensitivity and specificity for the optimal virtual resting Pd/Pa cut-off (≤0.94) were 84.9%, 90.4% and 81.6%, respectively. Virtual resting Pd/Pa demonstrated superior performance (pvirtual resting Pd/Pa and FFR (r=0.69, pVirtual resting Pd/Pa using routine angiographic data and a simple flow model provides fast functional assessment of coronary lesions without requiring the pressure-wire and hyperaemia induction. The high diagnostic performance of virtual resting Pd/Pa for predicting FFR shows promise for using this simple/fast virtual index in clinical practice. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  12. Physiologic Assessment of Coronary Artery Disease: Focus on Fractional Flow Reserve.

    Science.gov (United States)

    Hwang, Doyeon; Lee, Joo Myung; Koo, Bon-Kwon

    2016-01-01

    The presence of myocardial ischemia is the most important prognostic factor in patients with ischemic heart disease. Fractional flow reserve (FFR) is a gold standard invasive method used to detect the stenosis-specific myocardial ischemia. FFR-guided revascularization strategy is superior to angiography-guided strategy. The recently developed hyperemia-free index, instantaneous wave free ratio is being actively investigated. A non-invasive FFR derived from coronary CT angiography is now used in clinical practice. Due to rapid expansion of invasive and non-invasive physiologic assessment, comprehensive understanding of the role and potential pitfalls of each modality are required for its application. In this review, we focus on the basic and clinical aspects of physiologic assessment in ischemic heart disease.

  13. Physiologic assessment of coronary artery disease: Focus on fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Do Yeon; Koo, Bon Kwon [Dept. of Radiology, Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul (Korea, Republic of); Lee, Joo Myung [Dept. of Internal Medicine and Cardiovascular Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-06-15

    The presence of myocardial ischemia is the most important prognostic factor in patients with ischemic heart disease. Fractional flow reserve (FFR) is a gold standard invasive method used to detect the stenosis-specific myocardial ischemia. FFR-guided revascularization strategy is superior to angiography-guided strategy. The recently developed hyperemia-free index, instantaneous wave free ratio is being actively investigated. A non-invasive FFR derived from coronary CT angiography is now used in clinical practice. Due to rapid expansion of invasive and non-invasive physiologic assessment, comprehensive understanding of the role and potential pitfalls of each modality are required for its application. In this review, we focus on the basic and clinical aspects of physiologic assessment in ischemic heart disease.

  14. Coronary flow reserve in hypertrophic cardiomyopathy: relation with microvascular dysfunction and pathophysiological characteristics.

    Science.gov (United States)

    Kofflard, M J; Michels, M; Krams, R; Kliffen, M; Geleijnse, M L; Ten Cate, F J; Serruys, P W

    2007-01-01

    BACKGROUND.: The decrease in coronary flow reserve (CFR) in hypertrophic cardiomyopathy (HCM) predisposes to myocardial ischaemia, systolic dysfunction and cardiac death. In this study we investigate to which extent haemodynamic, echocardiographic, and histological parameters contribute to the reduction of CFR. METHODS.: In ten HCM patients (mean age 44+/-14 years) and eight heart transplant (HTX) patients (mean age 51+/-6 years) CFR was calculated in the left anterior descending coronary artery. In all subjects haemodynamic, echocardiographic and histological parameters were assessed. The relationship between these variables and CFR was determined using linear regression analysis. RESULTS.: CFR was reduced in HCM compared with HTX patients (1.6+/-0.7 vs. 2.7+/-0.8, p<0.01). An increase in septal thickness (p<0.005), indexed left ventricular (LV) mass (p<0.005), LV end-diastolic pressure (p<0.001), LV outflow tract gradient (p<0.05) and a decrease in arteriolar lumen size (p<0.05) were all related to a reduction in CFR. CONCLUSION.: In HCM patients haemodynamic (LV end-diastolic pressure, LV outflow tract gradient), echocardiographic (indexed LV mass) and histological (% luminal area of the arterioles) changes are responsible for a decrease in CFR. (Neth Heart J 2007;15:209-15.).

  15. Relationship between glycosylated hemoglobin A1c and coronary flow reserve in patients with Type 2 diabetes mellitus.

    Science.gov (United States)

    Huang, Runqing; Abdelmoneim, Sahar S; Nhola, Lara F; Basu, Rita; Basu, Ananda; Mulvagh, Sharon L

    2015-04-01

    Type 2 diabetes mellitus patients are at increased risk for macrovascular and microvascular complications. Both in vivo and in vitro studies of small arteries and arterioles of diabetic subjects demonstrate impaired endothelial function without anatomic lesions. Coronary flow reserve (CFR) is a surrogate marker of coronary microcirculatory endothelial function in diabetic patients without significant stenosis of the associated epicardial coronary artery. Glycosylated hemoglobin A1c is related to likelihood of occurrence of microvascular events. The objective of this article is to report on recent developments in multiple noninvasive techniques to assess CFR and their use in aiding the understanding of the relationship of CFR, glycemic control and cardiovascular outcomes.

  16. Effects of hypoxia on coronary flow reserve as determined by myocardial contrast echocardiography in swine

    Institute of Scientific and Technical Information of China (English)

    YANG Yuan 杨源; LI Shu-qing 李树清; Barry Peters; Anthony N DeMaria

    2004-01-01

    Background Time-intensity curves derived from microbubble destruction/refilling sequences and recorded using myocardial contrast echocardiography (MCE) can provide parameters that correlate with coronary blood flow. The response of these parameters to adenosine vasodilatation correlates with coronary flow reserve (CFR) measured by fluorescent microsphere techniques (FMT). Currently, no data exist regarding the effect of physiological variables, such as hypoxia, on the determination of CFR by MCE. The purpose of this study was to define the effects of decreases in blood partial pressure of oxygen (PO2) on CFR as measured by MCE. Methods Studies were performed in 9 closed chest swine. Low-energy, real-time MCE was performed with commercial instruments in short axis view at papillary muscle level while infusing BR1 at 30 ml/h. High-energy ultrasound bursts (referred to as FLASH frames) destroyed the bubbles every 15 cardiac cycles, and resultant time-intensity curves derived from these sequences were fitted to the exponential function y = A (1-e-bt) +c, from which the rate of signal rise (b) was obtained. CFR was calculated as the ratio of b values after adenosine infusion to baseline and was obtained during the control period and after decreasing blood PO2 by giving nitrogen via a respirator to create artificial hypoxic conditions. CFR was independently determined by FMT. Results Nitrogen led to significant decreases in mean PO2, from (120.6±18.9) mmHg to (51.8±15.9) mmHg (P0.05 compared with the baseline). Conclusions CFR values diminish under hypoxic conditions according to both MCE and FMT. The reductions in CFR involve both an increase in resting values and a decrease in post adenosine measurements, as determined by both techniques. The reduction in CFR under hypoxia is slightly greater using MCE than using FMT. Physiological variables, such as hypoxia, must be taken into consideration when assessing CFR by MCE.

  17. Echocardiographic and hemodynamic determinants of right coronary artery flow reserve and phasic flow pattern in advanced non-ischemic cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Mady Charles

    2007-09-01

    Full Text Available Abstract Background In patients with advanced non-ischemic cardiomyopathy (NIC, right-sided cardiac disturbances has prognostic implications. Right coronary artery (RCA flow pattern and flow reserve (CFR are not well known in this setting. The purpose of this study was to assess, in human advanced NIC, the RCA phasic flow pattern and CFR, also under right-sided cardiac disturbances, and compare with left coronary circulation. As well as to investigate any correlation between the cardiac structural, mechanical and hemodynamic parameters with RCA phasic flow pattern or CFR. Methods Twenty four patients with dilated severe NIC were evaluated non-invasively, even by echocardiography, and also by cardiac catheterization, inclusive with Swan-Ganz catheter. Intracoronary Doppler (Flowire data was obtained in RCA and left anterior descendent coronary artery (LAD before and after adenosine. Resting RCA phasic pattern (diastolic/systolic was compared between subgroups with and without pulmonary hypertension, and with and without right ventricular (RV dysfunction; and also with LAD. RCA-CFR was compared with LAD, as well as in those subgroups. Pearson's correlation analysis was accomplished among echocardiographic (including LV fractional shortening, mass index, end systolic wall stress more hemodynamic parameters with RCA phasic flow pattern or RCA-CFR. Results LV fractional shortening and end diastolic diameter were 15.3 ± 3.5 % and 69.4 ± 12.2 mm. Resting RCA phasic pattern had no difference comparing subgroups with vs. without pulmonary hypertension (1.45 vs. 1.29, p = NS either with vs. without RV dysfunction (1.47 vs. 1.23, p = NS; RCA vs. LAD was 1.35 vs. 2.85 (p Conclusion In patients with chronic advanced NIC, RCA phasic flow pattern has a mild diastolic predominance, less marked than in LAD, with no effects from pulmonary artery hypertension or RV dysfunction. There is no significant correlation between any cardiac mechanical-structural or

  18. Coronary artery and thoracic aorta calcification is inversely related to coronary flow reserve as measured by 82Rb PET/CT in intermediate risk patients

    OpenAIRE

    Kim, Jongho; Bravo, Paco E.; Gholamrezanezhad, Ali; Sohn, Seil; Rafique, Ash; Travis, Arlene; Machac, Josef

    2013-01-01

    Background The strength and nature of the relationship between myocardial perfusion imaging (MPI), coronary flow reserve (CFR), and coronary artery calcium (CAC) and thoracic aorta calcium (TAC) remain to be clarified. Methods Dynamic rest-pharmacological stress 82Rb positron emission tomography/computed tomography MPI with CFR, CAC, and TAC was performed in 75 patients (59 ± 13 years; F/M = 38/37) with intermediate risk of coronary artery disease. Results A total of 29 (39%) patients had isc...

  19. Myocardial FFR (Fractional Flow Reserve in patients with angiographically intermediate coronary artery stenosis - an initial institutional experience

    Directory of Open Access Journals (Sweden)

    Jagadish H. Ramaiah

    2013-02-01

    Full Text Available Background: The clinical significance of coronary artery stenosis of intermediate severity can be difficult to determine. The management of intermediate coronary lesions, defined by a diameter stenosis of ¡I40% to ¡U70%, continues to be a therapeutic dilemma for cardiologists. The 2-dimensional representation of the arterial lesion provided by angiography is limited in distinguishing intermediate lesions that require stenting from those that simply need appropriate medical therapy. In the era of drug-eluting stents, some might propose that stenting all intermediate coronary lesions is an appropriate solution. However, the possibility of procedural complications such as coronary dissection, no reflow phenomenon, in-stent restenosis, and stent thrombosis requires accurate stratification of patients with intermediate coronary lesions to appropriate therapy. Myocardial fractional flow reserve (FFR is an index of the functional severity of coronary stenosis that is calculated from pressure measurements made during coronary angiography. The objective of the study is to evaluate the usefulness of FFR in patients with angiographically intermediate coronary artery stenosis. Methods: 20 patients with intermediate coronary stenosis and chest pain of uncertain origin. The Exercise Electrocardiography (TMT, Myocardial Perfusion Imaging study (MPI, Quantitative Coronary Angiography (QCA were compared with the results of FFR measurements. Results: 20 patients were undergone FFR measurement during the study period. With the mean age of 57.25¡À11.2 and male patients were 16 (80%, female patients 4 (20%, in all 13 patients with an FFR of 0.75 tested negative for reversible myocardial ischemia on TMT and MPI study. No revascularization procedures were performed in 7 (35% patients, and no adverse cardiovascular events were noted in all these patients during 6 months of follow-up. Conclusions: In patients with coronary stenosis of intermediate severity, FFR

  20. Influence of routine assessment of fractional flow reserve on decision making during coronary interventions.

    Science.gov (United States)

    Sant'Anna, Fernando M; Silva, Expedito E R; Batista, Leonardo Alves; Ventura, Fábio Machado; Barrozo, Carlos Alberto Mussel; Pijls, Nico H J

    2007-02-15

    In complex coronary artery disease, it is sometimes difficult to determine which lesions are associated with reversible ischemia and should be stented. Fractional flow reserve (FFR) is an established objective methodology to indicate which lesions produce ischemia. Despite this, the selection of lesions to be stented is often based on the subjectively interpreted angiogram alone. The aim of this study in patients admitted for elective percutaneous intervention (PCI) was to evaluate the change in strategy if the decision to intervene was based on FFR measurement rather than on angiographic assessment. Two hundred fifty consecutive patients (471 arteries) scheduled for PCI were included in this study. All stenoses >or=50% by visual estimation and initially selected to be stented by 3 independent reviewers were assessed by FFR measurements. If FFR was or=0.75, no interventional treatment was given. Optimal pressure measurements were obtained in 452 lesions (96%). Diameter stenosis was 62 +/- 12%, and FFR was 0.67 +/- 0.17 for the entire group. In 68% of the stenoses, initial strategy as assessed from the angiogram was followed, and in 32%, there was a change in the planned approach based on FFR. In 48% of the patients, there was >or=1 lesion in which the treatment decision was changed after physiologic measurements. In conclusion, in this prospective, nonselective, but complete study representing the real world of PCI, 32% of the coronary stenoses and 48% of patients would have received a different treatment if the decision had been based on angiography only, stressing the utility of physiologic assessment in refining decision making during PCI.

  1. Relationship between coronary flow reserve evaluated by phase-contrast cine cardiovascular magnetic resonance and serum eicosapentaenoic acid

    Science.gov (United States)

    2013-01-01

    Background Long-term intake of long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs), especially eicosapentaenoic acid (EPA) is associated with a low risk for cardiovascular disease. Phase-contrast cine cardiovascular magnetic resonance (PC cine CMR) can assess coronary flow reserve (CFR). The present study investigates the relationship between CFR evaluated by PC cine CMR and the serum EPA. Methods We studied 127 patients (male, 116 (91%); mean age, 72.2 ± 7.4 years) with known or suspected coronary artery disease (CAD). X-ray coronary angiography revealed no significant coronary arterial stenoses (defined as luminal diameter reduction ≥50% on quantitative coronary angiogram (QCA) analysis) in all study participants. Breath-hold PC cine CMR images of the coronary sinus (CS) were acquired to assess blood flow of the CS both at rest and during adenosine triphosphate (ATP) infusion. We calculated CFR as CS blood flow during ATP infusion divided by that at rest. Patients were allocated to groups according to whether they had high (n = 64, EPA ≥ 75.8 μg/mL) or low (n = 63, EPA  2.5, which is the previously reported lower limit of normal flow reserve without obstructive CAD. Multivariate analysis revealed that EPA is an independent predictor of CFR > 2.5 (odds ratio, 1.01; 95% confidence interval, 1.00 – 1.02, p = 0.008). Conclusions The serum EPA is significantly correlated with CFR in CAD patients without significant coronary artery stenosis. PMID:24359564

  2. Quantitative assessment of harmonic power doppler myocardial perfusion imaging with intravenous levovist™ in patients with myocardial infarction: comparison with myocardial viability evaluated by coronary flow reserve and coronary flow pattern of infarct-related artery

    Directory of Open Access Journals (Sweden)

    Nagai Kunihiko

    2005-08-01

    Full Text Available Abstract Background Myocardial contrast echocardiography and coronary flow velocity pattern with a rapid diastolic deceleration time after percutaneous coronary intervention has been reported to be useful in assessing microvascular damage in patients with acute myocardial infarction. Aim To evaluate myocardial contrast echocardiography with harmonic power Doppler imaging, coronary flow velocity reserve and coronary artery flow pattern in predicting functional recovery by using transthoracic echocardiography. Methods Thirty patients with anterior acute myocardial infarction underwent myocardial contrast echocardiography at rest and during hyperemia and were quantitatively analyzed by the peak color pixel intensity ratio of the risk area to the control area (PIR. Coronary flow pattern was measured using transthoracic echocardiography in the distal portion of left anterior descending artery within 24 hours after recanalization and we assessed deceleration time of diastolic flow velocity. Coronary flow velocity reserve was calculated two weeks after acute myocardial infarction. Left ventricular end-diastolic volumes and ejection fraction by angiography were computed. Results Pts were divided into 2 groups according to the deceleration time of coronary artery flow pattern (Group A; 20 pts with deceleration time ≧ 600 msec, Group B; 10 pts with deceleration time Conclusion The preserved microvasculature detecting by myocardial contrast echocardiography and coronary flow velocity reserve is related to functional recovery after acute myocardial infarction.

  3. Myocardial Perfusion Imaging Versus Computed Tomography Angiography-Derived Fractional Flow Reserve Testing in Stable Patients With Intermediate-Range Coronary Lesions

    DEFF Research Database (Denmark)

    Nørgaard, Bjarne L; Gormsen, Lars C; Bøtker, Hans Erik

    2017-01-01

    BACKGROUND: Data on the clinical utility of coronary computed tomography angiography-derived fractional flow reserve (FFRCT) are sparse. In patients with intermediate (40-70%) coronary stenosis determined by coronary computed tomography angiography, we investigated the association of replacing st...

  4. Coronary CT angiography-derived fractional flow reserve correlated with invasive fractional flow reserve measurements - initial experience with a novel physician-driven algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Stefan [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); University Medical Centre Mannheim (UMM), University of Heidelberg, First Department of Medicine, Faculty of Medicine Mannheim, Mannheim (Germany); Wang, Rui [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); Beijing Anzhen Hospital, Capital Medical University, Department of Radiology, Beijing (China); Schoepf, U.J.; Steinberg, Daniel H.; Spearman, James V.; Bayer, Richard R. [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); Hamm, Christian W. [Giessen University, Department of Internal Medicine I, Cardiology/Angiology, Giessen (Germany); Renker, Matthias [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); Giessen University, Department of Internal Medicine I, Cardiology/Angiology, Giessen (Germany)

    2015-04-01

    The present study aimed to determine the feasibility of a novel fractional flow reserve (FFR) algorithm based on coronary CT angiography (cCTA) that permits point-of-care assessment, without data transfer to core laboratories, for the evaluation of potentially ischemia-causing stenoses. To obtain CT-based FFR, anatomical coronary information and ventricular mass extracted from cCTA datasets were integrated with haemodynamic parameters. CT-based FFR was assessed for 36 coronary artery stenoses in 28 patients in a blinded fashion and compared to catheter-based FFR. Haemodynamically relevant stenoses were defined by an invasive FFR ≤0.80. Time was measured for the processing of each cCTA dataset and CT-based FFR computation. Assessment of cCTA image quality was performed using a 5-point scale. Mean total time for CT-based FFR determination was 51.9 ± 9.0 min. Per-vessel analysis for the identification of lesion-specific myocardial ischemia demonstrated good correlation (Pearson's product-moment r = 0.74, p < 0.0001) between the prototype CT-based FFR algorithm and invasive FFR. Subjective image quality analysis resulted in a median score of 4 (interquartile ranges, 3-4). Our initial data suggest that the CT-based FFR method for the detection of haemodynamically significant stenoses evaluated in the selected population correlates well with invasive FFR and renders time-efficient point-of-care assessment possible. (orig.)

  5. Fractional flow reserve versus angiography for guidance of PCI in patients with multivessel coronary artery disease (FAME)

    DEFF Research Database (Denmark)

    van Nunen, Lokien X; Zimmermann, Frederik M; Tonino, Pim A L

    2015-01-01

    BACKGROUND: In the Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) study, fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) improved outcome compared with angiography-guided PCI for up to 2 years of follow-up. The aim in this study...... artery disease were randomly assigned to undergo angiography-guided PCI or FFR-guided PCI. Before randomisation, stenoses requiring PCI were identified on the angiogram. Patients allocated to angiography-guided PCI had revascularisation of all identified stenoses. Patients allocated to FFR-guided PCI had...

  6. Assessment of left anterior descending artery stenosis of intermediate severity by fractional flow reserve, instantaneous wave-free ratio, and non-invasive coronary flow reserve.

    Science.gov (United States)

    Meimoun, P; Clerc, J; Ardourel, D; Djou, U; Martis, S; Botoro, T; Elmkies, F; Zemir, H; Luycx-Bore, A; Boulanger, J

    2016-10-17

    To test the usefulness of non-invasive coronary flow reserve (CFR) by transthoracic Doppler echocardiography by comparison to invasive fractional flow reserve (FFR) and instantaneous wave-free ratio (IFR), a new vasodilator-free index of coronary stenosis severity, in patients with left anterior descending artery (LAD) stenosis of intermediate severity (IS) and stable coronary artery disease. 94 consecutive patients (mean age 68 ± 10 years) with angiographic LAD stenosis of IS (50-70 % diameter stenosis), were prospectively studied. IFR was calculated as a trans-lesion pressure ratio during the wave-free period in diastole; FFR as distal pressure divided by mean aortic pressure during maximal hyperemia (using 180 μg intracoronary adenosine); and CFR as hyperemic peak LAD flow velocity divided by baseline flow velocity using intravenous adenosine (140 μg/kg/min over 2 min). The mean values of IFR, FFR, and CFR were 0.88 ± 0.07, 0.81 ± 0.09, and 2.4 ± 0.6 respectively. A significant correlation was found between CFR and FFR (r = 0. 68), FFR and IFR (r = 0.6), and between CFR and IFR (r = 0.5) (all, p < 0.01). Using a ROC curve analysis, the best cut-off to detect a significant lesion based on FFR assessment (FFR ≤ 0.8, n = 31) was IFR ≤ 0.88 with a sensitivity (Se) of 74 %, specificity (Sp) of 73 %, AUC 0.81 ± 0.04, accuracy 72 %; and CFR ≤ 2 with a Se = 77 %, Sp = 89 %, AUC 0.88 ± 0.04, accuracy 85 % (all, p < 0.001). In stable patients with LAD stenosis of IS, non-invasive CFR is a useful tool to detect a significant lesion based on FFR. Furthermore, there was a better correlation between CFR and FFR than between CFR and IFR, and a trend to a better diagnostic performance for CFR versus IFR.

  7. Safety and Efficacy of a Novel Technique in the Use of Fractional Flow Reserve in Complex Coronary Artery Lesions

    Directory of Open Access Journals (Sweden)

    Wen-Ming He

    2015-01-01

    Full Text Available Background: Fractional flow reserve (FFR has become an increasingly important index when making decisions with respect to revascularization of coronary artery stenosis. However, the pressure guidewire used in obtaining FFR measurements is difficult to control and manipulate in certain complex coronary artery lesions, resulting in increased fluoroscopy time and contrast dye usage. This study examined a novel (NOV technique for obtaining FFR measurements in hope of easing the difficulties associated with evaluating and treating complex coronary artery lesions. Methods: Fifty-six patients with complex coronary artery lesions were assigned to a conventional (CON FFR technique group or a NOV FFR technique group. The NOV technique involved the use of a balloon and wire exchange within the coronary artery. The fluoroscopy time, contrast dye usage, and FFR-related complications were assessed after completing the FFR measurement procedure for each patient. Results: The median time required for fluoroscopy in the NOV technique group was significantly less than that in the CON technique group; additionally, lesser amounts of contrast dye were used in the NOV technique group (both P 0.05. Conclusions: Compared to the CON technique used for measuring FFR, the new technique reduced the fluoroscopy time and amount of contrast dye used when evaluating complex coronary artery lesions. The new technique did not increase the risk of operation or decrease the success rate.

  8. Coronary flow reserve as a link between diastolic and systolic function and exercise capacity in heart failure

    DEFF Research Database (Denmark)

    Snoer, Martin; Monk-Hansen, Tea; Olsen, Rasmus Huan

    2012-01-01

    AIMS: In heart failure, a reduced exercise capacity is the prevailing symptom and an important prognostic marker of future outcome. The purpose of the study was to assess the relation of coronary flow reserve (CFR) to diastolic and systolic function in heart failure and to determine which...... are the limiting factors for exercise capacity. METHODS AND RESULTS: Forty-seven patients with left ventricular ejection fraction (LVEF)...

  9. Quantification of coronary flow reserve in patients with ischaemic and non-ischaemic cardiomyopathy and its association with clinical outcomes

    Science.gov (United States)

    Majmudar, Maulik D.; Murthy, Venkatesh L.; Shah, Ravi V.; Kolli, Swathy; Mousavi, Negareh; Foster, Courtney R.; Hainer, Jon; Blankstein, Ron; Dorbala, Sharmila; Sitek, Arkadiusz; Stevenson, Lynne W.; Mehra, Mandeep R.; Di Carli, Marcelo F.

    2015-01-01

    Aims Patients with left ventricular systolic dysfunction frequently show abnormal coronary vascular function, even in the absence of overt coronary artery disease. Moreover, the severity of vascular dysfunction might be related to the aetiology of cardiomyopathy. We sought to determine the incremental value of assessing coronary vascular dysfunction among patients with ischaemic (ICM) and non-ischaemic (NICM) cardiomyopathy at risk for adverse cardiovascular outcomes. Methods and results Coronary flow reserve (CFR, stress/rest myocardial blood flow) was quantified in 510 consecutive patients with rest left ventricular ejection fraction (LVEF) ≤45% referred for rest/stress myocardial perfusion PET imaging. The primary end point was a composite of major adverse cardiovascular events (MACE) including cardiac death, heart failure hospitalization, late revascularization, and aborted sudden cardiac death. Median follow-up was 8.2 months. Cox proportional hazards model was used to adjust for clinical variables. The annualized MACE rate was 26.3%. Patients in the lowest two tertiles of CFR (CFR ≤ 1.65) experienced higher MACE rates than those in the highest tertile (32.6 vs. 15.5% per year, respectively, P = 0.004), irrespective of aetiology of cardiomyopathy. Conclusion Impaired coronary vascular function, as assessed by reduced CFR by PET imaging, is common in patients with both ischaemic and non-ischaemic cardiomyopathy and is associated with MACE. PMID:25719181

  10. Advanced computed tomographic anatomical and morphometric plaque analysis for prediction of fractional flow reserve in intermediate coronary lesions

    Energy Technology Data Exchange (ETDEWEB)

    Opolski, Maksymilian P., E-mail: opolski.mp@gmail.com [Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland); Kepka, Cezary, E-mail: c.kepka@ikard.pl [Department of Coronary and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Achenbach, Stephan, E-mail: stephan.achenbach@uk-erlangen.de [Department of Internal Medicine 2 (Cardiology), University of Erlangen, Erlangen (Germany); Pregowski, Jerzy, E-mail: jerzypregowski74@gmail.com [Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland); Kruk, Mariusz, E-mail: mariuszkruk2000@yahoo.com [Department of Coronary and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Staruch, Adam D., E-mail: adstarman@gmail.com [Medical University of Warsaw, Warsaw (Poland); Kadziela, Jacek, E-mail: j.kadziela@ikard.pl [Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland); Ruzyllo, Witold, E-mail: w.ruzyllo@ikard.pl [Department of Coronary and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Witkowski, Adam, E-mail: witkowski@hbz.pl [Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland)

    2014-01-15

    Objective: To determine the application of advanced coronary computed tomography angiography (CCTA) plaque analysis for predicting invasive fractional flow reserve (FFR) in intermediate coronary lesions. Methods: Sixty-one patients with 71 single intermediate coronary lesions (≥50–80% stenosis) on CCTA prospectively underwent coronary angiography and FFR. Advanced anatomical and morphometric plaque analysis was performed based on CCTA data set to determine optimal criteria for significant flow impairment. A significant stenosis was defined as FFR ≤ 0.80. Results: FFR averaged 0.85 ± 0.09, and 19 lesions (27%) were functionally significant. FFR correlated with minimum lumen area (MLA) (r = 0.456, p < 0.001), minimum lumen diameter (MLD) (r = 0.326, p = 0.006), reference lumen diameter (RLD) (r = 0.245, p = 0.039), plaque burden (r = −0.313, p = 0.008), lumen area stenosis (r = −0.305, p = 0.01), lesion length (r = −0.692, p < 0.001), and plaque volume (r = −0.668, p < 0.001). There was no relationship between FFR and CCTA morphometric plaque parameters. By multivariate analysis the independent predictors of FFR were lesion length (beta = −0.581, p < 0.001), MLA (beta = 0.360, p = 0.041), and RLD (beta = −0.255, p = 0.036). The optimal cutoffs for lesion length, MLA, MLD, RLD, and lumen area stenosis were >18.5 mm, ≤3.0 mm{sup 2}, ≤2.1 mm, ≤3.2 mm, and >69%, respectively (max. sensitivity: 100% for MLA, max. specificity: 79% for lumen area stenosis). Conclusions: CCTA predictors for FFR support the mathematical relationship between stenosis pressure drop and coronary flow. CCTA could prove to be a useful rule-out test for significant hemodynamic effects of intermediate coronary stenoses.

  11. The relationship between fractional flow reserve, platelet reactivity and platelet leukocyte complexes in stable coronary artery disease.

    Directory of Open Access Journals (Sweden)

    Jan-Willem E M Sels

    Full Text Available BACKGROUND: The presence of stenoses that significantly impair blood flow and cause myocardial ischemia negatively affects prognosis of patients with stable coronary artery disease. Altered platelet reactivity has been associated with impaired prognosis of stable coronary artery disease. Platelets are activated and form complexes with leukocytes in response to microshear gradients caused by friction forces on the arterial wall or flow separation. We hypothesized that the presence of significantly flow-limiting stenoses is associated with altered platelet reactivity and formation of platelet-leukocyte complexes. METHODS: One hundred patients with stable angina were studied. Hemodynamic significance of all coronary stenoses was assessed with Fractional Flow Reserve (FFR. Patients were classified FFR-positive (at least one lesion with FFR≤0.75 or FFR-negative (all lesions FFR>0.80. Whole blood samples were stimulated with increasing concentrations of ADP, TRAP, CRP and Iloprost with substimulatory ADP. Expression of P-selectin as platelet activation marker and platelet-leukocyte complexes were measured by flowcytometry. Patients were stratified on clopidogrel use. FFR positive and negative patient groups were compared on platelet reactivity and platelet-leukocyte complexes. RESULTS: Platelet reactivity between FFR-positive patients and FFR-negative patients did not differ. A significantly lower percentage of circulating platelet-neutrophil complexes in FFR-positive patients and a similar non-significant decrease in percentage of circulating platelet-monocyte complexes in FFR-positive patients was observed. CONCLUSION: The presence of hemodynamically significant coronary stenoses does not alter platelet reactivity but is associated with reduced platelet-neutrophil complexes in peripheral blood of patients with stable coronary artery disease.

  12. Safety and Efficacy of a Novel Technique in the Use of Fractional Flow Reserve in Complex Coronary Artery Lesions

    Institute of Scientific and Technical Information of China (English)

    Wen-Ming He; Chang-Ling Li; Yong Sun; Zhong Zhou; Yi-Feng Mai

    2015-01-01

    Background:Fractional flow reserve (FFR) has become an increasingly important index when making decisions with respect to revascularization of coronary artery stenosis.However,the pressure guidewire used in obtaining FFR measurements is difficult to control and manipulate in certain complex coronary artery lesions,resulting in increased fluoroscopy time and contrast dye usage.This study examined a novel (NOV) technique for obtaining FFR measurements in hope of easing the difficulties associated with evaluating and treating complex coronary artery lesions.Methods:Fifty-six patients with complex coronary artery lesions were assigned to a conventional (CON) FFR technique group or a NOV FFR technique group.The NOV technique involved the use of a balloon and wire exchange within the coronary artery.The fluoroscopy time,contrast dye usage,and FFR-related complications were assessed after completing the FFR measurement procedure for each patient.Results:The median time required for fluoroscopy in the NOV technique group was significantly less than that in the CON technique group; additionally,lesser amounts of contrast dye were used in the NOV technique group (both P < 0.05).The NOV technique was successfully performed in thirty patients,without any FFR-related complications.However,the CON technique failed in three patients,including two who experienced coronary artery spasms (P > 0.05).Conclusions:Compared to the CON technique used for measuring FFR,the new technique reduced the fluoroscopy time and amount of contrast dye used when evaluating complex coronary artery lesions.The new technique did not increase the risk of operation or decrease the success rate.

  13. Resolution of Angina Pectoris and Improvement of the Coronary Flow Reserve after Ranolazine Treatment in a Woman with Isolated Impaired Coronary Microcirculation

    Directory of Open Access Journals (Sweden)

    Alessandro Santoro

    2013-01-01

    Full Text Available In a 61-year-old woman with well controlled arterial hypertension, hypercholesterolemia, and smoke and suffering from recurrent angina pectoris despite angiographically normal epicardial coronary vessels and maximal therapy, the replacement of nitrates with novel antiangina drug ranolazine, after 6-month therapy, induced a complete relief of angina and a relevant rising of the transthoracic Doppler-derived coronary flow reserve (CFR. The present clinical case underlines therefore how in patients with chronic ischemic heart disease without epicardial coronary stenosis ranolazine can induce an improvement till the complete solution of the angina symptoms and a substantial increase of CFR as expression of the enhancement of the microvascular coronary function. The improvement of both symptoms and coronary microvascular function is strictly linked to the mechanism of action of the drug. Ranolazine induces in fact a reduction of the intracellular late sodium current that leads to a reduction of the intracellular calcium concentration thus producing a better myocardial diastolic relaxation process which in its turns enhances the myocardial perfusion. The ranolazine acts therefore as a lusitropic drug that improves the diastolic dysfunction and the segmental ischemia thus affecting one of the first steps of the ischemic cascade.

  14. Functional Relevance of Coronary Artery Disease by Cardiac Magnetic Resonance and Cardiac Computed Tomography: Myocardial Perfusion and Fractional Flow Reserve

    Directory of Open Access Journals (Sweden)

    Gianluca Pontone

    2015-01-01

    Full Text Available Coronary artery disease (CAD is one of the leading causes of morbidity and mortality and it is responsible for an increasing resource burden. The identification of patients at high risk for adverse events is crucial to select those who will receive the greatest benefit from revascularization. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography, but the diagnostic yield of elective invasive coronary angiography remains unfortunately low. Stress myocardial perfusion imaging by cardiac magnetic resonance (stress-CMR has emerged as an accurate technique for diagnosis and prognostic stratification of the patients with known or suspected CAD thanks to high spatial and temporal resolution, absence of ionizing radiation, and the multiparametric value including the assessment of cardiac anatomy, function, and viability. On the other side, cardiac computed tomography (CCT has emerged as unique technique providing coronary arteries anatomy and more recently, due to the introduction of stress-CCT and noninvasive fractional flow reserve (FFR-CT, functional relevance of CAD in a single shot scan. The current review evaluates the technical aspects and clinical experience of stress-CMR and CCT in the evaluation of functional relevance of CAD discussing the strength and weakness of each approach.

  15. Functional Relevance of Coronary Artery Disease by Cardiac Magnetic Resonance and Cardiac Computed Tomography: Myocardial Perfusion and Fractional Flow Reserve

    Science.gov (United States)

    Andreini, Daniele; Bertella, Erika; Mushtaq, Saima; Guaricci, Andrea Igoren; Pepi, Mauro

    2015-01-01

    Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality and it is responsible for an increasing resource burden. The identification of patients at high risk for adverse events is crucial to select those who will receive the greatest benefit from revascularization. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography, but the diagnostic yield of elective invasive coronary angiography remains unfortunately low. Stress myocardial perfusion imaging by cardiac magnetic resonance (stress-CMR) has emerged as an accurate technique for diagnosis and prognostic stratification of the patients with known or suspected CAD thanks to high spatial and temporal resolution, absence of ionizing radiation, and the multiparametric value including the assessment of cardiac anatomy, function, and viability. On the other side, cardiac computed tomography (CCT) has emerged as unique technique providing coronary arteries anatomy and more recently, due to the introduction of stress-CCT and noninvasive fractional flow reserve (FFR-CT), functional relevance of CAD in a single shot scan. The current review evaluates the technical aspects and clinical experience of stress-CMR and CCT in the evaluation of functional relevance of CAD discussing the strength and weakness of each approach. PMID:25692133

  16. Use of fractional flow reserve in patients with coronary artery disease: The right choice for the right outcome.

    Science.gov (United States)

    Park, Jae Yoon; Lerman, Amir; Herrmann, Joerg

    2017-02-01

    Despite advances in therapy, coronary artery disease (CAD) remains the leading cause of morbidity and mortality worldwide. Over the past years, the utilization of revascularization procedures has been refined, and in the best interest of the patient and to reduce the healthcare burden of CAD, it is paramount that patients are appropriately selected for therapies aiming at improving their symptoms and prognosis. Fractional flow reserve (FFR) is the current invasive standard test to identify hemodynamically significant coronary artery stenoses with resultant implications for revascularization and clinical outcomes. In this review, we discuss the current evidence behind the use of FFR as well as new trends in the application of this technique to help guide clinicians in making the best management decisions for patients with CAD.

  17. Instantaneous wave-free ratio to guide coronary revascularization: physiological framework, validation and differences with fractional flow reserve.

    Science.gov (United States)

    de Waard, Guus A; Di Mario, Carlo; Lerman, Amir; Serruys, Patrick W; van Royen, Niels

    2017-02-14

    Determining the optimal treatment strategy for revascularization of coronary artery stenosis involves the use of fractional flow reserve (FFR). To improve the low clinical uptake of physiological lesion assessment to guide revascularization, the instantaneous wave-free period (iFR) was proposed as a simpler alternative to FFR that does not require adenosine administration. iFR is calculated as the ratio of blood pressure distal and proximal to a coronary artery stenosis during the diastolic wave- free period. The wave-free period is a part of the cardiac cycle where generation of new pressure wavefronts does not occur and resting microvascular resistance is relatively minimized. iFR indicates the hemodynamic severity of a stenosis, by assessing the extent to which the epicardial stenosis depletes the microcirculatory, autoregulatory reserve. The introduction of iFR and the potential to assess hemodynamic stenosis severity without the need for administration of potent vasodilators such as adenosine, sparked an interesting debate about the fundamentals of human coronary physiology. Outcomes of two randomized clinical trials investigating iFR are pending. These studies are designed to evaluate whether iFR guided revascularisation is non-inferior to an FFR guided approach. The purpose of this review article is to discuss the physiological concepts underlying iFR, examine the existing validation studies and discuss the advantages and disadvantages of iFR as compared to FFR.

  18. Usefulness of coronary flow reserve over regional wall motion when added to dual-imaging dipyridamole echocardiography.

    Science.gov (United States)

    Rigo, Fausto; Richieri, Margherita; Pasanisi, Emilio; Cutaia, Valeria; Zanella, Carlo; Della Valentina, Patrizia; Di Pede, Francesco; Raviele, Antonio; Picano, Eugenio

    2003-02-01

    Vasodilator stress echocardiography allows semi-simultaneous imaging of left anterior descending (LAD) coronary flow and regional wall function. To assess the relative (and additive?) value of regional flow and function for noninvasive identification of angiographically assessed LAD disease in patients with chest pain syndrome, we studied 230 consecutive in-hospital patients (134 men, aged 63.5 +/- 11 years) with chest pain syndrome and normal regional and global left ventricular function. All patients underwent stress echocardiography with dipyridamole (up to 0.84 mg/kg over 10 minutes), including wall motion analysis by 2-dimensional echocardiography and coronary flow reserve (CFR) evaluation of the LAD artery by Doppler, with or without contrast injection. A new regional wall motion abnormality in >or=2 contiguous segments was required for 2-dimensional echocardiographic positivity. CFR was evaluated as the ratio of dipyridamole to peak diastolic coronary blood flow velocity at rest. All patients underwent coronary angiography within 60 days; a quantitatively assessed diameter reduction >50% of the LAD artery was considered significant. Of the 230 patients, 70 had LAD disease. A regional wall motion abnormality in LAD territory was present in 52 patients, and reduced CFR (<1.9) in 62 patients. Sensitivity for detecting LAD disease was 74% for 2-dimensional echocardiography (95% confidence interval [CI] 64% to 84%) and 81% for CFR <1.9 (95% CI 72% to 90%); specificity was 91% (95% CI 87% to 96%) for 2-dimensional echocardiography and 84% for CFR (95% CI 79% to 90%). Accuracy was 86% for 2-dimensional echocardiography (95% CI 82% to 91%) and 83.5% for CFR (95% CI 79% to 88%). When 2-dimensional echocardiography and CFR criteria were considered, sensitivity increased to 93% (95% CI 87% to 99%), with 80.6% specificity (95% CI 74.5% to 86.7%). CFR was assessed during vasodilator stress echocardiography. Its diagnostic accuracy for detecting LAD disease was comparable

  19. Reduced coronary flow reserve in patients with primary hyperparathyroidism: a study by G-SPECT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Marini, Cecilia [CNR Institute of Bioimages and Molecular Physiology Milan, Genoa (Italy); Giusti, Massimo; Vera, Lara; Minuto, Francesco [University of Genoa, Department of Endocrinological and Metabolic Sciences, Genoa (Italy); Armonino, Riccardo; Ghigliotti, Giorgio; Bezante, Gian Paolo; Morbelli, Silvia; Pomposelli, Elena; Massollo, Michela; Gandolfo, Patrizia; Sambuceti, Gianmario [University of Genoa, Department of Internal Medicine, Genoa (Italy)

    2010-12-15

    The mechanisms underlying increased cardiovascular risk in primary hyperparathyroidism (pHPT) have not been fully defined. Recently, this issue has become the subject of renewed interest due to the increasing evidence that the endothelium and vascular wall are targets for parathyroid hormone (PTH). The aim of this study was to measure regional coronary flow reserve (CFR) to determine whether the vascular damage induced by pHPT extends to affect the coronary microvascular function. A total of 22 pHPT patients without a history of coronary artery disease and 7 age-matched control subjects were recruited. Dipyridamole myocardial blood flow (MBF) was assessed using {sup 99m}Tc-sestamibi by measuring first-transit counts in the pulmonary artery and myocardial count rate from G-SPECT images. Baseline MBF was estimated 2 h later according to the same procedure. Regional CFR was defined as the ratio between dipyridamole and baseline MBF using a 17-segment left ventricular model. Three pHPT patients showed reversible perfusion defects and were excluded from the analysis. In the remaining 19, CFR was significantly lower with respect to the control subjects (1.88 {+-} 0.64 vs. 3.36 {+-} 0.66, respectively; p < 0.01). Moreover, patients studied for more than 28 months from pHPT diagnosis showed lower CFR values than the others (1.42 {+-} 0.18 vs. 2.25 {+-} 0.64, respectively; p < 0.01). Consequently, the time from diagnosis to the nuclear study showed a reasonable correlation with the degree of CFR impairment (Spearman's rho -0.667, p < 0.02). pHPT is associated with a significant dysfunction of the coronary microcirculation. This disorder might contribute to the high cardiovascular risk of conditions characterized by chronic elevations in serum PTH levels. (orig.)

  20. Stress Perfusion Coronary Flow Reserve Versus Cardiac Magnetic Resonance for Known or Suspected CAD.

    Science.gov (United States)

    Kato, Shingo; Saito, Naka; Nakachi, Tatsuya; Fukui, Kazuki; Iwasawa, Tae; Taguri, Masataka; Kosuge, Masami; Kimura, Kazuo

    2017-08-15

    Phase-contrast (PC) cine magnetic resonance imaging (MRI) of the coronary sinus is a noninvasive method to quantify coronary flow reserve (CFR). This study sought to compare the prognostic value of CFR by cardiac magnetic resonance (CMR) and stress perfusion CMR to predict major adverse cardiac events (MACE). Participants included 276 patients with known coronary artery disease (CAD) and 400 with suspected CAD. CFR was calculated as myocardial blood flow during adenosine triphosphate infusion divided by myocardial blood flow at rest using PC cine MRI of the coronary sinus. During a median follow-up of 2.3 years, 47 patients (7%) experienced MACE. Impaired CFR (10% ischemia on stress perfusion CMR were significantly associated with MACE in patients with known CAD (hazard ratio [HR]: 5.17 and HR: 5.10, respectively) and suspected CAD (HR: 14.16 and HR: 6.50, respectively). The area under the curve for predicting MACE was 0.773 for CFR and 0.731 for stress perfusion CMR (p = 0.58) for patients with known CAD, and 0.885 for CFR and 0.776 for stress perfusion CMR (p = 0.059) in the group with suspected CAD. In patients with known CAD, sensitivity, specificity, and positive and negative predictive values to predict MACE were 64%, 91%, 38%, and 97%, respectively, for CFR, and 82%, 59%, 15%, and 97%, respectively, for stress perfusion CMR. In the suspected CAD group, these values were 65%, 99%, 80%, and 97%, respectively, for CFR, and 72%, 83%, 22%, and 98%, respectively, for stress perfusion CMR. The predictive values of CFR and stress perfusion CMR for MACE were comparable in patients with known CAD. In patients with suspected CAD, CFR showed higher HRs and areas under the curve than stress perfusion CMR, suggesting that CFR assessment by PC cine MRI might provide better risk stratification for patients with suspected CAD. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  1. Clinical Outcomes in Patients with Deferred Coronary Lesions according to Disease Severity Assessed by Fractional Flow Reserve.

    Science.gov (United States)

    Won, Ki Bum; Nam, Chang Wook; Cho, Yun Kyeong; Yoon, Hyuck Jun; Park, Hyoung Seob; Kim, Hyungseop; Han, Seongwook; Hur, Seung Ho; Kim, Yoon Nyun; Park, Sang Hyun; Han, Jung Kyu; Koo, Bon Kwon; Kim, Hyo Soo; Doh, Joon Hyung; Lee, Sung Yun; Yang, Hyoung Mo; Lim, Hong Seok; Yoon, Myeong Ho; Tahk, Seung Jea; Kim, Kwon Bae

    2016-12-01

    Data on the clinical outcomes in deferred coronary lesions according to functional severity have been limited. This study evaluated the clinical outcomes of deferred lesions according to fractional flow reserve (FFR) grade using Korean FFR registry data. Among 1,294 patients and 1,628 lesions in Korean FFR registry, 665 patients with 781 deferred lesions were included in this study. All participants were consecutively categorized into 4 groups according to FFR; group 1: ≥ 0.96 (n = 56), group 2: 0.86-0.95 (n = 330), group 3: 0.81-0.85 (n = 170), and group 4: ≤ 0.80 (n = 99). Primary endpoint was major adverse cardiac events (MACE), a composite of all-cause death, myocardial infarction, and target vessel revascularization. The median follow-up period was 2.1 years. During follow-up, the incidence of MACE in groups 1-4 was 1.8%, 7.6%, 8.8%, and 13.1%, respectively. Compared to group 1, the cumulative rate by Kaplan-Meier analysis of MACE was not different for groups 2 and 3. However, group 4 had higher cumulative rate of MACE compared to group 1 (log-rank P = 0.013). In the multivariate Cox hazard models, only FFR (hazard ratio [HR], 0.95; P = 0.005) was independently associated with MACE among all participants. In contrast, previous history of percutaneous coronary intervention (HR, 2.37; P = 0.023) and diagnosis of acute coronary syndrome (ACS) (HR, 2.35; P = 0.015), but not FFR, were independent predictors for MACE in subjects with non-ischemic (FFR ≥ 0.81) deferred coronary lesions. Compared to subjects with ischemic deferred lesions, clinical outcomes in subjects with non-ischemic deferred lesions according to functional severity are favorable. However, longer-term follow-up may be necessary.

  2. Low density lipoprotein cholesterol level inversely correlated with coronary flow velocity reserve in patients with Type 2 diabetes

    Institute of Scientific and Technical Information of China (English)

    Jie Yu; Jiang-Li Han; Li-Yun He; Xin-Heng Feng; Wei-Hong Li; Jie-Ming Mao; Wei Gao; Guang Wang

    2013-01-01

    Objectives To evaluate the association of coronary artery endothelial function and plasma levels of low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) in patients with Type 2 Diabetes Mellitus (DM). Methods We investigated 90 participants from our institution between October 2007 to March 2010: non-DM (n = 60) and DM (n = 30). As an indicator of coronary endothelial dysfunction, we used non-invasive Doppler echocardiography to quantify coronary flow velocity reserve (CFVR) in the distal part of the left descending artery after rest and after intravenous adenosine administration. Results Plasma level of LDL-C was significantly higher in patients with DM than in non-DM (3.21 0.64 vs. 2.86 0.72 mmo/L, P < 0.05), but HDL-C level did not differ between the groups (1.01 0.17 vs. 1.05 0.19 mmo/L). Furthermore, the CFVR value was lower in DM patients than non-diabetics (2.45±0.62 vs. 2.98±0.68, P < 0.001). Plasma levels of LDL-C were negatively correlated with CFVR in all subjects (r = 0.35, P < 0.001; 95% confidence interval (CI): 0.52 -C0.15) and in the non-DM (r = 0.29, P < 0.05; 95% CI: 0.51–0.05), with an even stronger negative correlation in the DM group (r = 0.42, P < 0.05; 95% CI: 0.68 –0.06). Age (β = 0.019, s = 0.007, sβ = 0.435, 95% CI: 0.033 –0.005, P = 0.008), LDL-C (β = 0.217, s = 0.105, sβ = 0.282, 95% CI: 0.428 –0.005, P = 0.045) remained independently correlated with CFVR in the DM group. However, we found no correlation between HDL-C level and CFVR in any group. Conclusions Diabetes may contribute to coronary artery disease (CAD) by inducing dysfunction of the coronary artery endothelium. Increased LDL-C level may adversely impair coronary endothelial function in DM. HDL-C may lose its endothelial-protective effects, in part as a result of pathological conditions, especially under abnormal glucose metabolism.

  3. Optimization of flow reserve measurement using SPECT technology to evaluate the determinants of coronary microvascular dysfunction in diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Marini, Cecilia [CNR Institute of Bioimages and Molecular Physiology, Milan, Section of Genoa (Italy); Bezante, GianPaolo; Modonesi, Elisa; Rollando, Daniela; Balbi, Manrico; Brunelli, Claudio [University of Genoa, Department of Internal Medicine, Cardiology, Genoa (Italy); Gandolfo, Patrizia; Morbelli, Silvia D.; Armonino, Riccardo [University of Genoa, Department of Internal Medicine, Nuclear Medicine, Genoa (Italy); DePascale, Angelo; Maggi, Davide; Albertelli, Manuela; Cordera, Renzo [University of Genoa, Department of Endocrinological Metabolic Sciences, Diabetology, Genoa (Italy); Sambuceti, Gianmario [University of Genoa, Department of Internal Medicine, Nuclear Medicine, Genoa (Italy); Advanced Biotechnology Center, Genoa (Italy)

    2010-02-15

    The aim of this study was to validate a new method to measure regional myocardial perfusion reserve (MPR) with technetium-labelled tracers in patients with type 2 diabetes mellitus (DM2). A total of 40 consecutive DM2 patients without history of coronary artery disease (CAD) and 7 control subjects were recruited. Dipyridamole myocardial blood flow index (MBF) was assessed by measuring first transit counts in the pulmonary artery and myocardial count rate from gated SPECT images using {sup 99m}Tc-labelled tracers. The corresponding MBF index was estimated 2 h later according to the same procedure. Regional myocardial perfusion reserve (MPR) was defined as the ratio between dipyridamole and baseline MBF using a 17-segment left ventricular (LV) model. Coronary flow reserve (CFR) was estimated by transthoracic contrast echo Doppler monitoring of flow velocity in the left anterior descending coronary artery (LAD) during the same session. Estimated MPR was higher in control subjects than in patients (3.36 {+-} 0.66 vs 1.91 {+-} 0.61, respectively, p < 0.01). In patients, LAD CFR and LAD MPR were 2.01 {+-} 0.78 vs 1.93 {+-} 0.63, respectively (p = ns). The agreement between the two techniques was documented by their close correlation (r = 0.92, p < 0.001) and confirmed by the Bland-Altman analysis. Reversible perfusion defects occurred in 13 patients (32%) who showed similar MPR values as the remaining 27 (2.10 {+-} 0.71 vs 1.83 {+-} 0.71, respectively, p = ns). Finally, MPR was closely correlated with age (r = -0.50, p < 0.01) and time elapsed from the diagnosis of DM2 (r = -0.51, p < 0.01). LV regional MPR can be accurately estimated with the broadly available single photon technology. Application of this method to DM2 patients documents the presence of a microvascular dysfunction homogeneously distributed throughout the LV walls and most frequently not associated with reversible perfusion defects. (orig.)

  4. Diagnostic value of quantitative stenosis predictors with coronary CT angiography compared to invasive fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rui [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Renker, Matthias [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Kerckhoff Heart and Thorax Center, Benekestrasse 2-8, 61231 Bad Nauheim (Germany); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Wichmann, Julian L. [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Fuller, Stephen R.; Rier, Jeremy D.; Bayer, Richard R.; Steinberg, Daniel H. [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); De Cecco, Carlo N. [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Departments of Radiological Sciences, Oncology, and Pathology, University of Rome “Sapienza”-Polo Pontino, Latina, Viale Regina Elena, 324-00161 Roma (Italy); Baumann, Stefan [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); First Department of Medicine, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany)

    2015-08-15

    Highlights: • Evaluation of the diagnostic performance of CCTA predictors for coronary stenosis. • TAG was unable to detect hemodynamically significant coronary lesions. • CT-FFR, LL/MLD{sup 4} and CCO provide enhanced diagnostic performance over CCTA. • CT-FFR was the best parameter. - Abstract: Objective: To evaluate the diagnostic performance of CCTA-derived stenosis predictors including CT-FFR for the detection of ischemia-inducing stenosis compared to invasive FFR. Materials and methods: Stenosis parameters were assessed using dual-source CT (DSCT). All patients underwent both CCTA and invasive FFR within 3 months and were retrospectively analyzed. Observers visually assessed all CCTA studies and performed multiple lesion measurements. Lesion length/minimal luminal diameter{sup 4} (LL/MLD{sup 4}), transluminal attenuation gradient (TAG), corrected coronary attenuation (CCO) and CT-FFR were calculated. Results: The cohort included 32 patients (58 ± 12 years, 66%male). Among 32 coronary lesions, 8 (25%) were considered hemodynamically significant with an FFR <0.80. Compared to invasive FFR, the per-vessel sensitivity and specificity of CCTA, CT-FFR, LL/MLD{sup 4}, CCO and TAG for detecting hemodynamically significant lesions were 100% and 54%, 100% and 91%, 85% and 92%, 66% and 88%, 37% and 58%, respectively. Receiver operating characteristics analysis resulted in an area under the curve of 0.91 for CT-FFR (p = 0.0005), 0.88 for LL/MLD{sup 4} (p < 0.0001), 0.85 for CCO (p < 0.0001). TAG with an AUC of 0.67 (p = 0.152) was unable to discriminate between vessels with or without hemodynamically significant lesions. Conclusion: CT-FFR, LL/MLD{sup 4} and CCO provide enhanced diagnostic performance over CCTA analysis alone for discrimination of hemodynamically significant coronary stenosis.

  5. [Fractional flow reserve and instantaneous wave-free ratio for the physiological assessment of coronary artery stenosis in the catheterization laboratory: Practical tips].

    Science.gov (United States)

    Picard, F; Tadros, V X; Pighi, M; Spagnoli, V; De Hemptinne, Q; Ly, H Q

    2017-02-01

    In recent years, a large body of evidence has revealed the limitations of angiographic evaluation in determining the physiological significance of coronary stenosis, particularly when these are intermediate lesions. Percutaneous coronary interventions (PCI) guided by physiological assessment using fractional flow reserve (FFR) have been shown to reduce cardiovascular events when compared to angiography alone. Recently, another coronary physiologic parameter has been introduced: the "instantaneous wave-free ratio" (iFR). In this review, we will discuss the FFR, the iFR, and their use in the functional assessment of coronary stenosis in the cardiac catheterization laboratory. This review will cover theoretical aspects for non-interventional cardiologists, as well as practice points and common pitfalls related to coronary physiological assessment for interventional cardiologists.

  6. Prognostic Value of Coronary Flow Reserve Obtained on Dobutamine Stress Echocardiography and its Correlation with Target Heart Rate.

    Science.gov (United States)

    Abreu, José Sebastião de; Rocha, Eduardo Arrais; Machado, Isadora Sucupira; Parahyba, Isabelle O; Rocha, Thais Brito; Paes, Fernando José Villar Nogueira; Diogenes, Tereza Cristina Pinheiro; Abreu, Marília Esther Benevides de; Farias, Ana Gardenia Liberato Ponte; Carneiro, Marcia Maria; Paes, José Nogueira

    2017-05-01

    Normal coronary flow velocity reserve (CFVR) (≥ 2) obtained in the left anterior descending coronary artery (LAD) from transthoracic echocardiography is associated with a good prognosis, but there is no study correlating CFVR with submaximal target heart rate (HR). To evaluate the prognostic value of CFVR obtained in the LAD of patients with preserved (>50%) left ventricular ejection fraction (LVEF) who completed a dobutamine stress echocardiography (DSE), considering target HR. Prospective study of patients with preserved LVEF and CFVR obtained in the LAD who completed DSE. In Group I (GI = 31), normal CFVR was obtained before achieving target HR, and, in Group II (GII = 28), after that. Group III (G III=24) reached target HR, but CFVR was abnormal. Death, acute coronary insufficiency, coronary intervention, coronary angiography without further intervention, and hospitalization were considered events. In 28 ± 4 months, there were 18 (21.6%) events: 6% (2/31) in GI, 18% (5/28) in GII, and 46% (11/24) in GIII. There were 4 (4.8%) deaths, 6 (7.2%) coronary interventions and 8 (9.6%) coronary angiographies without further intervention. In event-free survival by regression analysis, GIII had more events than GI (p 50%) e ecocardiograma sob estresse com dobutamina (EED) concluído, considerando a FC alvo submáxima. studo prospectivo de pacientes com FEVE preservada e RVFC obtida na ADA durante EED concluído. No Grupo I (GI=31), a RVFC adequada foi obtida antes de se atingir a FC alvo, e no Grupo II (G II=28), após. O Grupo III (G III=24) atingiu a FC alvo, mas a RVFC foi inadequada. Foram considerados eventos: óbito, insuficiência coronariana aguda, intervenção coronariana, coronariografia sem intervenção subsequente e internamento hospitalar. Em 28 ± 4 meses, ocorreram 18 (21,6%) eventos, sendo 6% (2/31) no GI, 18% (5/28) no GII e 46% (11/24) no GIII. Foram 4 (4,8%) óbitos, 6 (7,2%) intervenções coronarianas e 8 (9,6%) coronariografias sem interven

  7. The effect of blood pressure on non-invasive fractional flow reserve derived from coronary computed tomography angiography

    Energy Technology Data Exchange (ETDEWEB)

    Kurata, Akira [Ehime University Graduate School of Medicine, Department of Radiology, Toon, Ehime (Japan); Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Coenen, Adriaan; Lubbers, Marisa M.; Nieman, Koen [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus University Medical Center, Departmenet of Cardiology, Rotterdam (Netherlands); Kido, Teruhito; Mochizuki, Teruhito [Ehime University Graduate School of Medicine, Department of Radiology, Toon, Ehime (Japan); Kido, Tomoyuki [Matsuyama Saiseikai Hospital, Department of Radiology, Matsuyama, Ehime (Japan); Yamashita, Natsumi [Clinical Research Center, National Hospital Organization Shikoku Cancer Center, Division of Clinical Biostatistics, Section of Cancer Prevention and Epidemiology, Matsuyama, Ehime (Japan); Watanabe, Kouki [Matsuyama Saiseikai Hospital, Department of Cardiology, Matsuyama, Ehime (Japan); Krestin, Gabriel P. [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands)

    2017-04-15

    The aim of this study is to assess the effect of blood pressure (BP) on coronary computed tomography angiography (CTA) derived computational fractional flow reserve (CTA-FFR). Twenty-one patients who underwent coronary CTA and invasive FFR were retrospectively identified. Ischemia was defined as invasive FFR ≤0.80. Using a work-in-progress computational fluid dynamics algorithm, CTA-FFR was computed with BP measured before CTA, and simulated BPs of 60/50, 90/60, 110/70, 130/80, 150/90, and 180/100 mmHg respectively. Correlation between CTA-FFR and invasive FFR was assessed using Pearson test. The repeated measuring test was used for multiple comparisons of CTA-FFR values by simulated BP inputs. Twenty-nine vessels (14 with invasive FFR ≤0.80) were assessed. The average CTA-FFR for measured BP (134 ± 20/73 ± 12 mmHg) was 0.77 ± 0.12. Correlation between CTA-FFR by measured BP and invasive FFR was good (r = 0.735, P < 0.001). For simulated BPs of 60/50, 90/60, 110/70, 130/80, 150/90, and 180/100 mmHg, the CTA-FFR increased: 0.69 ± 0.13, 0.73 ± 0.12, 0.75 ± 0.12, 0.77 ± 0.11, 0.79 ± 0.11, and 0.81 ± 0.10 respectively (P < 0.05). Measurement of the BP just before CTA is preferred for accurate CTA-FFR simulation. BP variations in the common range slightly affect CTA-FFR. However, inaccurate BP assumptions differing from the patient-specific BP could cause misinterpretation of borderline significant lesions. (orig.)

  8. Diagnostic performance of cardiac imaging methods to diagnose ischaemia-causing coronary artery disease when directly compared with fractional flow reserve as a reference standard

    DEFF Research Database (Denmark)

    Danad, Ibrahim; Szymonifka, Jackie; Twisk, Jos W R

    2016-01-01

    ), and cardiac magnetic resonance (MRI) imaging when directly compared with an FFR reference standard. METHOD AND RESULTS: PubMed and Web of Knowledge were searched for investigations published between 1 January 2002 and 28 February 2015. Studies performing FFR in at least 75% of coronary vessels......AIMS: The aim of this study was to determine the diagnostic performance of single-photon emission computed tomography (SPECT), stress echocardiography (SE), invasive coronary angiography (ICA), coronary computed tomography angiography (CCTA), fractional flow reserve (FFR) derived from CCTA (FFRCT...... for the diagnosis of ischaemic coronary artery disease (CAD) were included. Twenty-three articles reporting on 3788 patients and 5323 vessels were identified. Meta-analysis was performed for pooled sensitivity, specificity, likelihood ratios (LR), diagnostic odds ratio, and summary receiver operating characteristic...

  9. Persistent abnormal coronary flow reserve in association with abnormal glucose metabolism affects prognosis in acute myocardial infarction

    DEFF Research Database (Denmark)

    Løgstrup, Brian B; Høfsten, Dan E; Christophersen, Thomas B

    2011-01-01

    Objectives: To evaluate changes in coronary flow reserve (CFR) over time after acute myocardial infarction (AMI) in relation to left ventricular (LV) function and glucometabolic state and prognostic implication of abnormal CFR. Methods: 154 patients with first time AMI had a comprehensive...... baseline CFR (P = 0.004), S' (P = 0.045) and abnormal glucose metabolism (P = 0.001) were predictors of a decreased CFR at 3 months of follow-up. In multivariate analyses abnormal glucose metabolism (OR: 5.3; 95%CI: 1.9-14.4; P = 0.001) remained a predictor of decreased CFR at follow-up, furthermore...... baseline CFR (OR: 0.5; 95%CI: 0.25-0.94; P = 0.032) and S' (OR: 0.67; 95% CI: 0.47-0.94; P = 0.021) was predictors of decreased CFR. Finally, CFR was associated with a lower risk of cardiac events in patients with normal glucose metabolism (HR: 0.64; 95% CI: 0.22-1.9; P = 0.42) than in patients...

  10. Impairment of Coronary Flow Reserve Evaluated by Phase Contrast Cine-Magnetic Resonance Imaging in Patients With Heart Failure With Preserved Ejection Fraction.

    Science.gov (United States)

    Kato, Shingo; Saito, Naka; Kirigaya, Hidekuni; Gyotoku, Daiki; Iinuma, Naoki; Kusakawa, Yuka; Iguchi, Kohei; Nakachi, Tatsuya; Fukui, Kazuki; Futaki, Masaaki; Iwasawa, Tae; Kimura, Kazuo; Umemura, Satoshi

    2016-02-23

    Phase contrast (PC) cine-magnetic resonance imaging (MRI) of the coronary sinus allows for noninvasive evaluation of coronary flow reserve (CFR), which is an index of left ventricular microvascular function. The objective of this study was to investigate coronary flow reserve in patients with heart failure with preserved ejection fraction (HFpEF). We studied 25 patients with HFpEF (mean and SD of age: 73±7 years), 13 with hypertensive left ventricular hypertrophy (LVH) (67±10 years), and 18 controls (65±15 years). Breath-hold PC cine-MRI images of the coronary sinus were obtained to assess blood flow at rest and during ATP infusion. CFR was calculated as coronary sinus blood flow during ATP infusion divided by coronary sinus blood flow at rest. Impairment of CFR was defined as CFR <2.5 according to a previous study. The majority (76%) of HFpEF patients had decreased CFR. CFR was significantly decreased in HFpEF patients in comparison to hypertensive LVH patients and control subjects (CFR: 2.21±0.55 in HFpEF vs 3.05±0.74 in hypertensive LVH, 3.83±0.73 in controls; P<0.001 by 1-way ANOVA). According to multivariable linear regression analysis, CFR independently and significantly correlated with serum brain natriuretic peptide level (β=-68.0; 95% CI, -116.2 to -19.7; P=0.007). CFR was significantly lower in patients with HFpEF than in hypertensive LVH patients and controls. These results indicated that impairment of CFR might be a pathophysiological factor for HFpEF and might be related to HFpEF disease severity. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  11. Prediction of the true fractional flow reserve of left main coronary artery stenosis with concomitant downstream stenoses: in vitro and in vivo experiments.

    Science.gov (United States)

    Yamamoto, Erika; Saito, Naritatsu; Matsuo, Hitoshi; Kawase, Yoshiaki; Watanabe, Shin; Bao, Bingyuan; Watanabe, Hiroki; Higami, Hirooki; Nakatsuma, Kenji; Kimura, Takeshi

    2016-02-01

    The functional impact of downstream coronary stenoses on left main coronary artery (LMCA) stenosis has not been fully elucidated. This study therefore aimed to use in vitro and in vivo experiments to assess two novel equations that predict the true fractional flow reserve (FFR) of a left main coronary artery (LMCA) stenosis with concomitant downstream stenoses. Two novel equations were derived. One equation predicts the true fractional flow reserve (FFR) of an LMCA stenosis with a downstream stenosis (Equation A), and the other predicts the true FFR of an LMCA stenosis with downstream stenoses in both the left anterior descending and left circumflex arteries (Equation B). The equations were validated in both in vitro and in vivo models of the coronary circulation. The agreements between the apparent FFR (FFRapp), the predicted FFR (FFRpred) and the true FFR (FFRtrue) were assessed by Passing-Bablok regression analysis. Passing-Bablok regression analysis revealed that there were fixed proportional errors between FFRapp-m and FFRtrue-m, though a very small fixed error and no proportional errors between FFRpred-m and FFRtrue-m. The absolute differences between FFRpred and FFRtrue were significantly lower as compared to those between FFRapp and FFRtrue in all experiments. Two novel equations which predict the true FFR of LMCA stenosis were demonstrated to be correct. The study also revealed that the functional impact of downstream stenoses on the LMCA stenosis became stronger when the downstream stenoses became more severe.

  12. Quantitation of myocardial blood flow and myocardial flow reserve with {sup 99m}Tc-sestamibi dynamic SPECT/CT to enhance detection of coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Bailing [University of Missouri-Columbia, Nuclear Science and Engineering Institute, Columbia, MO (United States); Chen, Fu-Chung; Chen, Chien-Cheng [Show Chwan Memorial Hospital, Section of Cardiology, Department of Internal Medicine, Changhua (China); Wu, Tao-Cheng [Taipei Veterans General Hospital, Section of Cardiology, Department of Internal Medicine, Taipei (China); Huang, Wen-Sheng [Changhua Christian Hospital, Department of Medical Research and Department of Nuclear Medicine, Changhua (China); Hou, Po-Nien [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Lukong Town, Changhua Shien (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Lukong Town, Changhua Shien (China); Central Taiwan University of Science and Technology, Department of Medical Imaging and Radiological Science, Taichung (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China)

    2014-12-15

    Conventional dual-head single photon emission computed tomography (SPECT)/CT systems capable of fast dynamic SPECT (DySPECT) imaging have a potential for flow quantitation. This study introduced a new method to quantify myocardial blood flow (MBF) and myocardial flow reserve (MFR) with DySPECT scan and evaluated the diagnostic performance of detecting coronary artery disease (CAD) compared with perfusion using invasive coronary angiography (CAG) as the reference standard. This study included 21 patients with suspected or known CAD who had received DySPECT, ECG-gated SPECT (GSPECT), and CAG (13 with ≥50 % stenosis in any vessel; non-CAD group: 8 with patent arteries or <50 % stenosis). DySPECT and GSPECT scans were performed on a widely used dual-head SPECT/CT scanner. The DySPECT imaging protocol utilized 12-min multiple back-and-forth gantry rotations during injections of {sup 99m}Tc-sestamibi (MIBI) tracer at rest or dipyridamole-stress stages. DySPECT images were reconstructed with full physical corrections and converted to the physical unit of becquerels per milliliter. Stress MBF (SMBF), rest MBF (RMBF), and MFR were quantified by a one-tissue compartment flow model using time-activity curves derived from DySPECT images. Perfusion images were processed for GSPECT scan and interpreted to obtain summed stress score (SSS) and summed difference score (SDS). Receiver-operating characteristic (ROC) analyses were conducted to evaluate the diagnostic performance of flow and perfusion. Using the criteria of ≥50 % stenosis as positive CAD, areas under the ROC curve (AUCs) of flow assessment were overall significantly greater than those of perfusion. For patient-based analysis, AUCs for MFR, SMBF, SSS, and SDS were 0.91 ± 0.07, 0.86 ± 0.09, 0.64 ± 0.12, and 0.59 ± 0.13. For vessel-based analysis, AUCs for MFR, SMBF, SSS, and SDS were 0.81 ± 0.05, 0.76 ± 0.06, 0.62 ± 0.07, and 0.56 ± 0.08, respectively. The preliminary data suggest that MBF quantitation with a

  13. Meta-Analysis of Diagnostic Performance of Coronary Computed Tomography Angiography, Computed Tomography Perfusion, and Computed Tomography-Fractional Flow Reserve in Functional Myocardial Ischemia Assessment Versus Invasive Fractional Flow Reserve.

    Science.gov (United States)

    Gonzalez, Jorge A; Lipinski, Michael J; Flors, Lucia; Shaw, Peter W; Kramer, Christopher M; Salerno, Michael

    2015-11-01

    We sought to compare the diagnostic performance of coronary computed tomography angiography (CCTA), computed tomography perfusion (CTP), and computed tomography (CT)-fractional flow reserve (FFR) for assessing the functional significance of coronary stenosis as defined by invasive FFR in patients with known or suspected coronary artery disease (CAD). CCTA has proved clinically useful for excluding obstructive CAD because of its high sensitivity and negative predictive value (NPV); however, the ability of CTA to identify functionally significant CAD has remained challenging. We searched PubMed/Medline for studies evaluating CCTA, CTP, or CT-FFR for the noninvasive detection of obstructive CAD compared with catheter-derived FFR as the reference standard. Pooled sensitivity, specificity, PPV, NPV, likelihood ratios, and odds ratio of all diagnostic tests were assessed. Eighteen studies involving a total of 1,535 patients were included. CTA demonstrated a pooled sensitivity of 0.92, specificity 0.43, PPV of 0.56, and NPV of 0.87 on a per-patient level. CT-FFR and CTP increased the specificity to 0.72 and 0.77, respectively (p = 0.004 and p = 0.0009) resulting in higher point estimates for PPV 0.70 and 0.83, respectively. There was no improvement in the sensitivity. The CTP protocol involved more radiation (3.5 mSv CCTA vs 9.6 mSv CTP) and a higher volume of iodinated contrast (145 ml). In conclusion, CTP and CT-FFR improve the specificity of CCTA for detecting functionally significant stenosis as defined by invasive FFR on a per-patient level; both techniques could advance the ability to noninvasively detect the functional significance of coronary lesions.

  14. How good are experienced cardiologists at predicting the hemodynamic severity of coronary stenoses when taking fractional flow reserve as the gold standard.

    Science.gov (United States)

    Brueren, B R G; ten Berg, J M; Suttorp, M J; Bal, E T; Ernst, J M P G; Mast, E G; Plokker, H W M

    2002-04-01

    Coronary angioplasty should be based on documented ischemia. However, in daily clinical practice the indication for angioplasty is often based on eyeball assessment of the severity of the stenosis. This study was performed to assess the accuracy of eyeball estimation of coronary stenosis when taking functional flow reserve (FFR) as gold standard. Study lesions were where no mutual agreement on the severity of the stenosis was obtained. The procedure consisted of a repeat control angiogram, FFR measurement and in case of FFR<75% percutaneous coronary intervention. The eyeball assessment of the stenosis was written down before further execution of the procedure. FFR was measured with a pressure monitoring guide. Maximal myocardial hyperemia was induced by intravenous adenosine infusion. Fifty-two patients were studied. Agreement between eyeball assessment and FFR existed in a total of 36 cases (69.2%). Over estimation of hemodynamic severity occurred in six cases (11.5%) and under estimation in 10 cases (19.2%). Consequently, the positive predictive value of eyeball assessment for pressure-derived FFR was 63% and the negative predictive value 76%. The assessment of the hemodynamic severity of intermediate coronary stenosis should not be based on eyeball assessment even by experienced interventional cardiologists.

  15. Contrast-induced Hyperemia as an Alternative to Drug-induced Hyperemia in the Evaluation of the Fractional Flow Reserve in Coronary Lesions

    Science.gov (United States)

    Shiode, Nobuo; Okimoto, Tomokazu; Tamekiyo, Hiromichi; Kawase, Tomoharu; Yamane, Kenichi; Kagawa, Yuzo; Fujii, Yuto; Ueda, Yusuke; Hironobe, Naoya; Kato, Yasuko; Hayashi, Yasuhiko

    2017-01-01

    Objective Measuring the fractional flow reserve (FFR) requires the induction of coronary hyperemia, usually with adenosine, adenosine triphosphate (ATP), or papaverine. However, adenosine can induce rhythmic complications, and intracoronary boluses of papaverine that prolong the QT interval can cause ventricular tachycardia. Injection of contrast media, which is routinely performed to validate the FFR guidewire placement, also induces hyperemia and may be an alternative method of measuring the FFR. We evaluated the diagnostic accuracy of the FFR after contrast hyperemia (FFRcont) compared to FFR evaluated after intracoronary papaverine (FFRpp). Methods This study included 109 lesions in 93 patients (mean age 70.4±8.7 years) with stable coronary disease. The FFR was measured as follows: 1) baseline pressure value; 2) FFRcont after intracoronary contrast injection (iopamidol, 8 mL for left coronary artery [LCA] or 6 mL for right coronary artery [RCA]); 3) FFRpp after intracoronary injection of papaverine (12 mg for LCA or 8 mg for RCA). Results FFRcont values were strongly correlated with FFRpp (R=0.940, p<0.0001; FFRpp = FFRcont ×1.007-0.032). The best cut-off point in the receiver operator curve analysis for predicting a FFRpp <0.80 was 0.82 (area under the curve =0.980; sensitivity 95.1%, specificity 91.2%, positive predictive value 86.7%, negative predictive value 96.9%). Conclusion FFRcont is highly accurate for predicting FFRpp. An FFRcont threshold value of 0.82 provides excellent sensitivity and a negative predictive value. FFRcont is an alternative method of inducing hyperemia. PMID:28154267

  16. Comparison of Coronary CT Angiography, SPECT, PET, and Hybrid Imaging for Diagnosis of Ischemic Heart Disease Determined by Fractional Flow Reserve.

    Science.gov (United States)

    Danad, Ibrahim; Raijmakers, Pieter G; Driessen, Roel S; Leipsic, Jonathon; Raju, Rekha; Naoum, Chris; Knuuti, Juhani; Mäki, Maija; Underwood, Richard S; Min, James K; Elmore, Kimberly; Stuijfzand, Wynand J; van Royen, Niels; Tulevski, Igor I; Somsen, Aernout G; Huisman, Marc C; van Lingen, Arthur A; Heymans, Martijn W; van de Ven, Peter M; van Kuijk, Cornelis; Lammertsma, Adriaan A; van Rossum, Albert C; Knaapen, Paul

    2017-08-16

    At present, the choice of noninvasive testing for a diagnosis of significant coronary artery disease (CAD) is ambiguous, but nuclear myocardial perfusion imaging with single-photon emission tomography (SPECT) or positron emission tomography (PET) and coronary computed tomography angiography (CCTA) is predominantly used for this purpose. However, to date, prospective head-to-head studies are lacking regarding the diagnostic accuracy of these imaging modalities. Furthermore, the combination of anatomical and functional assessments configuring a hybrid approach may yield improved accuracy. To establish the diagnostic accuracy of CCTA, SPECT, and PET and explore the incremental value of hybrid imaging compared with fractional flow reserve. A prospective clinical study involving 208 patients with suspected CAD who underwent CCTA, technetium 99m/tetrofosmin-labeled SPECT, and [15O]H2O PET with examination of all coronary arteries by fractional flow reserve was performed from January 23, 2012, to October 25, 2014. Scans were interpreted by core laboratories on an intention-to-diagnose basis. Hybrid images were generated in case of abnormal noninvasive anatomical or functional test results. Hemodynamically significant stenosis in at least 1 coronary artery as indicated by a fractional flow reserve of 0.80 or less and relative diagnostic accuracy of SPECT, PET, and CCTA in detecting hemodynamically significant CAD. Of the 208 patients in the study (76 women and 132 men; mean [SD] age, 58 [9] years), 92 (44.2%) had significant CAD (fractional flow reserve ≤0.80). Sensitivity was 90% (95% CI, 82%-95%) for CCTA, 57% (95% CI, 46%-67%) for SPECT, and 87% (95% CI, 78%-93%) for PET, whereas specificity was 60% (95% CI, 51%-69%) for CCTA, 94% (95% CI, 88%-98%) for SPECT, and 84% (95% CI, 75%-89%) for PET. Single-photon emission tomography was found to be noninferior to PET in terms of specificity (P  .99) using the predefined absolute margin of 10%. Diagnostic accuracy was

  17. Effect of a single IV administration of L-propionylcarnitine on myocardial microcirculation assessed by coronary flow velocity reserve measurement in patients with systemic sclerosis: a pilot study.

    Science.gov (United States)

    Montisci, Roberta; Ruscazio, Massimo; Lai, Stefania; Vacca, Alessandra; Cauli, Alberto; Passiu, Giuseppe; Montisci, Massimo; Meloni, Luigi; Mathieu, Alessandro; Iliceto, Sabino

    2007-01-01

    Scleroderma-related cardiac involvement primarily affects coronary microvascular structures and function. The microvasculature disorder is responsible for impairment of coronary flow velocity reserve (CFVR), which has been reported in studies of patients with systemic sclerosis (SSc). L-propionylcarnitine (L-PC) is a metabolic substance that is associated with a beneficial effect on both microcirculation and myocyte function. The objective of this study was to determine whether or not CFVR was acutely improved or restored in patients with SSc after a single administration of IV L-PC. In this pilot study, we screened volunteers with SSc who had no clinical evidence of ischemic heart disease. CFVR was determined by a blinded investigator by evaluating the left anterior descending coronary artery (LADCA) by transthoracic echocardiography during adenosine infusion (140 microg/kg x min(-1) for 5 minutes), 30 minutes before and 15 minutes after administration of L-PC (300 mg IV in 5-minute bolus). Thirty-three patients were screened for this study. Fourteen patients (mean [SD] age, 54.3 [11.2] years; mean [SD] weight, 63.8 [14.5] kg; mean [SD] height, 156.3 [8.7] cm) with SSc and no evidence of coronary heart disease were included in the study; 13 women and 1 man (4 with the diffuse cutaneous form of SSc and 10 with the limited cutaneous form). After administration of L-PC to patients with SSc, median CFVR was significantly increased from 2.60 to 3.23 (P < 0.001), whereas peak diastolic velocity in the LADCA decreased significantly at the basal evaluation (30.0 vs 26.0, P = 0.009) and significantly increased (80.0 vs 87.5, P = 0.005) during adenosine infusion. No adverse events occurred before, during, or after L-PC infusion. Acute administration of L-PC was associated with a short-term beneficial effect on CFVR in this pilot study of patients with SSc. These results suggest that further, randomized, controlled, double-blind evaluation of longer-term administration to

  18. Number and function of bone-marrow derived angiogenic cells and coronary flow reserve in women without obstructive coronary artery disease: a substudy of the NHLBI-sponsored Women's Ischemia Syndrome Evaluation (WISE.

    Directory of Open Access Journals (Sweden)

    Rajesh Mohandas

    Full Text Available BACKGROUND: In women with ischemia and no obstructive coronary artery disease, the Women's Ischemic Syndrome Evaluation (WISE observed that microvascular coronary dysfunction (MCD is the best independent predictor of adverse cardiovascular events. Since coronary microvascular tone is regulated in part by endothelium, we hypothesized that circulating endothelial cells (CEC, which reflect endothelial injury, and the number and function of bone-marrow derived angiogenic cells (BMDAC, which could help repair damaged endothelium, may serve as biomarkers for decreased coronary flow reserve (CFR and MCD. METHODS: We studied 32 women from the WISE cohort. CFR measurements in response to intracoronary adenosine were taken as an index of MCD. We enumerated BMDAC colonies and CEC in peripheral blood samples. BMDAC function was assessed by assay of migration of CD34+ cells toward SDF-1 and measurement of bioavailable nitric oxide (NO. These findings were compared with a healthy reference group and also entered into a multivariable model with CFR as the dependent variable. RESULTS: Compared with a healthy reference group, women with MCD had lower numbers of BMDAC colonies [16 (0, 81 vs. 24 (14, 88; P = 0.01] and NO [936 (156, 1875 vs. 1168 (668, 1823; P = 0.02]. Multivariable regression analysis showed strong correlation of CFR to the combination of BMDAC colony count and CD34+ cell function (migration and NO (R(2 = 0.45; P<0.05. CONCLUSIONS: The BMDAC function and numbers of BMDAC colonies are decreased in symptomatic women with MCD and are independently associated with CFR. These circulating cells may provide mechanistic insights into MCD in women with ischemia.

  19. 320-row CT coronary angiography predicts freedom from revascularisation and acts as a gatekeeper to defer invasive angiography in stable coronary artery disease: a fractional flow reserve-correlated study

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Brian S.; Wong, Dennis T.L.; Cameron, James D.; Leung, Michael; Meredith, Ian T.; Nerlekar, Nitesh; Antonis, Paul; Harper, Richard; Malaiapan, Yuvaraj; Seneviratne, Sujith K. [Southern Health and Monash University, Monash Cardiovascular Research Centre, MonashHEART, Department of Medicine Monash Medical Centre (MMC), Melbourne (Australia); Leong, Darryl P. [University of Adelaide, Discipline of Medicine, Adelaide (Australia); Flinders University, Adelaide (Australia); Crossett, Marcus; Troupis, John [Southern Health and Monash University, Monash Cardiovascular Research Centre, MonashHEART, Department of Medicine Monash Medical Centre (MMC), Melbourne (Australia); Southern Health and Monash University, Department of Diagnostic Imaging, MMC, Melbourne (Australia)

    2014-03-15

    To determine the accuracy of 320-row multidetector coronary computed tomography angiography (M320-CCTA) to detect functional stenoses using fractional flow reserve (FFR) as the reference standard and to predict revascularisation in stable coronary artery disease. One hundred and fifteen patients (230 vessels) underwent M320-CCTA and FFR assessment and were followed for 18 months. Diameter stenosis on invasive angiography (ICA) and M320-CCTA were assessed by consensus by two observers and significant stenosis was defined as ≥50 %. FFR ≤0.8 indicated functionally significant stenoses. M320-CCTA had 94 % sensitivity and 94 % negative predictive value (NPV) for FFR ≤0.8. Overall accuracy was 70 %, specificity 54 % and positive predictive value 65 %. On receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) for CCTA to predict FFR ≤0.8 was 0.74 which was comparable with ICA. The absence of a significant stenosis on M320-CCTA was associated with a 6 % revascularisation rate. M320-CCTA predicted revascularisation with an AUC of 0.71 which was comparable with ICA. M320-CCTA has excellent sensitivity and NPV for functional stenoses and therefore may act as an effective gatekeeper to defer ICA and revascularisation. Like ICA, M320-CCTA lacks specificity for functional stenoses and only has moderate accuracy to predict the need for revascularisation. (orig.)

  20. N-terminal pro-brain natriuretic peptide is related with coronary flow velocity reserve and diastolic dysfunction in patients with asymmetric hypertrophic cardiomyopathy.

    Science.gov (United States)

    Tesic, Milorad; Seferovic, Jelena; Trifunovic, Danijela; Djordjevic-Dikic, Ana; Giga, Vojislav; Jovanovic, Ivana; Petrovic, Olga; Marinkovic, Jelena; Stankovic, Sanja; Stepanovic, Jelena; Ristic, Arsen; Petrovic, Milan; Mujovic, Nebojsa; Vujisic-Tesic, Bosiljka; Beleslin, Branko; Vukcevic, Vladan; Stankovic, Goran; Seferovic, Petar

    2017-10-01

    The relations of elevated N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and cardiac ischemia in hypertrophic cardiomyopathy (HCM) patients is uncertain. Therefore we designed the study with the following aims: (1) to analyze plasma concentrations of NT-pro-BNP in various subsets of HCM patients; (2) to reveal the correlations of NT-pro-BNP, myocardial ischemia, and diastolic dysfunction; (3) to assess predictors of the elevated plasma levels of NT-pro-BNP. In 61 patients (mean age 48.9±16.3 years; 26 male) with asymmetric HCM plasma levels of NT-pro-BNP were obtained. Standard transthoracic examination, tissue Doppler echocardiography with measurement of transthoracic coronary flow velocity reserve (CFVR) in left anterior descending artery (LAD) was done. Mean natural logarithm value of NT-pro-BNP was 7.11±0.95pg/ml [median value 1133 (interquartile range 561-2442)pg/ml]. NT-pro-BNP was significantly higher in patients with higher NYHA class, in obstructive HCM, more severe mitral regurgitation, increased left atrial volume index (LAVI), presence of calcified mitral annulus, elevated left ventricular (LV) filling pressure and in decreased CFVR. Levels of NT-pro-BNP significantly correlated with the ratio of E/e' (r=0.534, ppro-BNP. Plasma levels of NT-pro-BNP were significantly higher in HCM patients with more advanced disease. Elevated NT-pro-BNP not only reflects the diastolic impairment of the LV, but it might also be the result of cardiac ischemia in patients with HCM. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  1. Vascular and cardiac contractile reserve in the dog heart with chronic multiple coronary occlusions.

    Science.gov (United States)

    Schwarz, F; Flameng, W; Mack, B; Türschmann, W; Schaper, W

    1976-11-01

    Nineteen mongrel dogs survived chronic occlusion of the left circumflex and of the right coronary artery without infarction due to the timely development of a collateral circulation. Only 38 per cent of the conductance of the arteries before occlusion was restored by collateral vessels. In these animals and in 15 control dogs with normal coronary arteries myocardial contractility, contractility reserve, and myocardial blood flow were studied. The same was done in dogs with chronic coronary artery occlusion after aortocoronary bypass. Myocardial blood flow was determined woth the tracer microsphere technique. Contractility reserve was tested and defined as isovolumetric left ventricular pressure and dp/dt max with norepinephrine infusion and cross-clamping of the aorta. Contractile reserve was not significantly different between normal dogs and dogs with chronic coronary artery occlusion before and after aortocoronary bypass. Myocardial blood flow during control conditions was homogenously distributed in all three groups studied. The ratio of blood flow to the endocardium and the epicardium was not significantly different from inity. Coronary reserve was determined at peak reactive hyperemia following a 20 second period of coronary artery occlusion, with ongoing norepinephrine infusion. Under these conditions subendocardial fow in normal dogs rose by a factor of 7.9 while subepicardial flow increased 7.4 times. In dogs with chronic occlusion of two coronary arteries the increase of myocardial flow was nonnomogenous; subendocardial flow to areas supplied by a normal coronary artery rose by a factor of 7.0 while subepicardial flow increased 5.7 times control. Subendocardial collateral flow rose by a factor of 2.4 and subepicardial collateral flow increased 3.5 times control. In normal dogs norepinephrine alone did not result in maximal coronary flow but only 57 per cent thereof. Dogs with chronic coronary occlusion, however, required the entire coronary reserve in

  2. Clinical and experimental aspects of functional and flow reserve of the myocardium

    NARCIS (Netherlands)

    E.O. McFalls (Edward)

    1991-01-01

    textabstractBasic research over the past 50 years has provided the clinician with important concepts for understanding human coronary physiology. One such tool is the determination of coronary blood flow reserve. Defined as the ratio of maximal to resting coronary flow, flow reserve may be helpful i

  3. Diagnostic Performance of First-Pass Myocardial Perfusion Imaging without Stress with Computed Tomography (CT) Compared with Coronary CT Angiography Alone, with Fractional Flow Reserve as the Reference Standard.

    Science.gov (United States)

    Osawa, Kazuhiro; Miyoshi, Toru; Miki, Takashi; Koyama, Yasushi; Sato, Shuhei; Kanazawa, Susumu; Ito, Hiroshi

    2016-01-01

    Coronary computed tomography angiography (CCTA) in combination with first-pass CT myocardial perfusion imaging (MPI) has a better diagnostic performance than CCTA alone, compared with invasive coronary angiography as the reference standard. The aim of this study was to investigate the additional diagnostic value of first-pass CT-MPI without stress for detecting hemodynamic significance of coronary stenosis, compared with invasive fractional flow reserve (FFR). We recruited 53 patients with suspected coronary artery disease undergoing both CCTA and first-pass CT-MPI without stress and invasive FFR, and 75 vessels were analyzed. We used the same raw data for CCTA and CT-MPI. First-pass CT-MPI was reconstructed by examining the diastolic signal densities as a bull's eye map. Invasive FFR CT-MPI and CCTA alone was 0.81 (0.73-0.90) and 0.70 (0.61-0.81), respectively (P = 0.036). CCTA plus first-pass CT-MPI without stress showed 0.73 sensitivity, 0.74 specificity, 0.53 positive predictive value, and 0.87 negative predictive value for detecting hemodynamically significant coronary stenosis. First-pass CT-MPI without stress correctly reclassified 38% of CCTA false-positive vessels as true negative. First-pass CT-MPI without stress combined with CCTA demonstrated excellent diagnostic accuracy, compared with invasive FFR as the reference standard. This technique could complement CCTA for diagnosis of coronary artery disease.

  4. Effect of Fractional Flow Reserve (≤0.90 vs >0.90) on Long-Term Outcome (>10 Years) in Patients With Nonsignificant Coronary Arterial Narrowings.

    Science.gov (United States)

    Badoz, Marc; Chatot, Marion; Hechema, Rémy; Chopard, Romain; Meneveau, Nicolas; Schiele, François

    2016-08-15

    We assessed the long-term (>10 years) clinical course of patients with documented coronary lesions deemed nonsignificant according to fractional flow reserve (FFR) assessment and investigated whether the initial FFR value impacted on prognosis. From January 2000 to October 2003, all patients submitted to coronary angiography with FFR measurement were included in a single-center, prospective registry. Patients with an FFR value >0.80 were treated medically without revascularization. Major adverse cardiac events (MACE) (death, acute coronary syndrome (ACS), or coronary revascularization) were compared according to initial FFR value (absolute value and by category, ≤0.90 vs >0.90). Analyses were performed using a multivariable Cox model and propensity score matching. Among 257 patients (332 lesions) treated medically initially, 131 (51%, 143 lesions) had FFR ≤0.90 and 126 (49%, 189 lesions) >0.90. During follow-up (median duration, 11.6 years), 82 (31.9%) had a MACE, 38 (14.8%) died, 17 (6.6%) had ACS, 93 (36.2%) had repeat coronary angiography, and 27 (10.5%) had revascularization. There was no clinical, biologic or angiographic difference between patients with initial FFR value ≤0.90 versus >0.90. Adjusted Cox model showed no difference in relative risk of MACE, death, ACS, or revascularization. Coronary angiographies were numerically more frequent in patients with FFR ≤0.90, versus FFR >0.90. These findings were confirmed by propensity score-matched comparison. In patients with coronary narrowings left unrevascularized based on FFR, an FFR value between 0.80 and 0.90 has no impact on long-term outcome compared with those with FFR >0.90. In conclusion, patients with high FFR values should not be considered as having a lower risk of coronary event.

  5. 冠脉造影正常患者内皮功能与冠脉血流储备能力的研究%Clinical study of Endothelial Function and Coronary Flow Reserve in Patients with Normal Coronary Arteriograms

    Institute of Scientific and Technical Information of China (English)

    张勇; 唐小霞; 曹邦明; 任淑红; 王新宇; 陈兴新

    2014-01-01

    Objective Coronary Flow Reserve ( CFR ) of patients with normal coronary arteriograms were measured by the use of angiographic digital tracking and endothelial function were evaluated by intracoronary acetyl -choline(Ach) test and high-sensitivity C-reactive protein (hsCRP) levels.The change of CFR and endothelial function in patients with different risk factors were observed and analysed .Methods In selected 118 cases ( The mean age 61 ±11 years old ) with suspected coronary artery disease were divided into 6 groups according to different risk factors:hypertension , hypercholesterolemia , obesity , smoking , type 2 diabetes mellitus and ≥2 risk factors groups while 24 healthy subjects ( The mean age 56 ±12 years old ) as matched .CFR of patients with normal coro-nary arteriograms were measured by the use of angiographic digital tracking and endothelial function were evaluated by intracoronary Ach test and hsCRP levels .The change of CFR , positive rates of Ach test , hsCRP levels were ob-served and analysed .Results CFR in group of hypertension , smoking and≥2 risk factors were lower and positive rates of Ach test ,hsCRP levels were higher than those of the control group .CFR in group of hypercholesterolemia , Obesity , Type 2 Diabetes Mellitus groups were lower and positive rates of Ach test were higher than those of the control group but there were no significant differences between them .hsCRP levels of Type 2 Diabetes Mellitus group were higher than those of the control group .Conclusion Angiography digital tracking method can be easily used in measuring CFR .Lower CFR and endothelial dysfunction in people with different risk factors were observed in this reaserch .%目的:通过常规冠脉造影,运用数字跟踪技术软件测定冠脉造影正常患者冠脉血流储备( Coro-nary Flow Reserve,CFR),冠脉内注射乙酰胆碱(Acetylcholine,Ach)并检测高敏C反应蛋白( high Sensitivi-ty,hsCRP)含量评价内皮功能,

  6. MR assessment of absolute myocardial blood flow and vasodilator flow reserve in patients with hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Kawada, Nanaka; Sakuma, Hajime; Takeda, Kan; Nakagawa, Tsuyoshi; Yamakado, Tetsu; Nakano, Takeshi [Mie Univ., Tsu (Japan). School of Medicine

    1997-04-01

    Absolute coronary blood flow per myocardial mass and coronary flow reserve for the entire left ventricle were evaluated in normals and in patients with hypertrophic cardiomyopathy (HCM) by using fast cine MR imaging and fast velocity encoded cine (VENC) MR imaging. Nine healthy volunteers and 8 patients with HCM were studied with a 1.5 T imager. Breath-hold cine MR images encompassing the whole left ventricle were acquired on short axis imaging planes in order to evaluate myocardial mass. A fast VENC MR images were obtained to measure blood flow volume in the coronary sinus before and after dipyridamole administration (TR/TE=15/5 ms, FOV=28 x 22 cm, slice thickness=5 mm). Coronary flow reserve was calculated as a ratio of hyperemic to baseline coronary flow volumes. In the baseline state, coronary blood flow per myocardial mass was significantly lower in patients with HCM than in normal myocardium (0.56{+-}0.23 vs. 0.78{+-}0.27 ml/min/g, p<0.05). After dipyridamole administration, coronary blood flow per myocardial mass in patients with HCM increased substantially less than that in healthy subjects (0.99{+-}0.38 vs. 2.22{+-}0.55 ml/min/g, p<0.01), resulting in the significantly decreased coronary flow reserve ratio in HCM in comparison with that in normal myocardium (1.86{+-}0.56 vs. 3.11{+-}1.37, p<0.05). In conclusion, breath-hold velocity encoded cine MR imaging is a noninvasive technique which can provide assessments of altered coronary blood flow volume per myocardial mass and vasodilator flow reserve in patients with HCM. (author)

  7. Evaluation of myocardial blood flow and coronary flow reserve after implantation of a bioresorbable vascular scaffold versus metal drug-eluting stent: an interim one-month analysis of the VANISH trial.

    Science.gov (United States)

    Stuijfzand, Wijnand J; Raijmakers, Pieter G; Driessen, Roel S; Lammertsma, Adriaan A; van Rossum, Albert C; Nap, Alexander; Appelman, Yolande; Lemkes, Jorrit S; van Leeuwen, Maarten A; van Royen, Niels; Knaapen, Paul

    2016-08-05

    A randomised clinical trial of bioresorbable vascular scaffold (BVS) vs. metal drug-eluting stent (DES) was initiated, using positron emission tomography (PET) perfusion imaging to assess the effects of both treatments on (hyperaemic) myocardial blood flow (MBF) and coronary flow reserve (CFR) over a three-year period (VANISH trial). In the present study, early, i.e., after one month, MBF and CFR are reported. Sixty patients (45 men [75%], 55±7 years) with a documented single-vessel type A or B1 lesion were included in this single-blind randomised clinical trial. Patients were randomised to implantation of a BVS or DES in a one-to-one fashion. Approximately one month after percutaneous coronary intervention, patients underwent [15O]H2O PET to assess (hyperaemic) MBF, cold pressor test MBF, and CFR. One patient refused PET perfusion at one-month follow-up (in the DES arm). MBF of the treated myocardial territory during rest, CPT, and hyperaemia were not different in BVS-treated patients as compared to DES-treated patients (1.02±0.28 vs. 0.96±0.24 mL·min-1·g-1, p=0.38, 1.20±0.38 vs. 1.08±0.23 mL·min-1·g-1, p=0.16, and 3.04±0.80 vs. 3.33±0.77 mL·min-1·g-1, p=0.16, respectively). CFR of the treated myocardial territory was significantly lower in the BVS-treated patients (3.09±0.94 vs. 3.57±0.85, p<0.05). No differences in PET-derived absolute myocardial perfusion were observed between BVS-treated patients as compared to DES-treated patients at one-month follow-up. CFR was attenuated in BVS-treated patients, although still within the normal range.

  8. Clinical outcomes of fractional flow reserve by computed tomographic angiography-guided diagnostic strategies vs. usual care in patients with suspected coronary artery disease: the prospective longitudinal trial of FFRCT: outcome and resource impacts study

    Science.gov (United States)

    Douglas, Pamela S.; Pontone, Gianluca; Hlatky, Mark A.; Patel, Manesh R.; Norgaard, Bjarne L.; Byrne, Robert A.; Curzen, Nick; Purcell, Ian; Gutberlet, Matthias; Rioufol, Gilles; Hink, Ulrich; Schuchlenz, Herwig Walter; Feuchtner, Gudrun; Gilard, Martine; Andreini, Daniele; Jensen, Jesper M.; Hadamitzky, Martin; Chiswell, Karen; Cyr, Derek; Wilk, Alan; Wang, Furong; Rogers, Campbell; De Bruyne, Bernard

    2015-01-01

    Aims In symptomatic patients with suspected coronary artery disease (CAD), computed tomographic angiography (CTA) improves patient selection for invasive coronary angiography (ICA) compared with functional testing. The impact of measuring fractional flow reserve by CTA (FFRCT) is unknown. Methods and results At 11 sites, 584 patients with new onset chest pain were prospectively assigned to receive either usual testing (n = 287) or CTA/FFRCT (n = 297). Test interpretation and care decisions were made by the clinical care team. The primary endpoint was the percentage of those with planned ICA in whom no significant obstructive CAD (no stenosis ≥50% by core laboratory quantitative analysis or invasive FFR < 0.80) was found at ICA within 90 days. Secondary endpoints including death, myocardial infarction, and unplanned revascularization were independently and blindly adjudicated. Subjects averaged 61 ± 11 years of age, 40% were female, and the mean pre-test probability of obstructive CAD was 49 ± 17%. Among those with intended ICA (FFRCT-guided = 193; usual care = 187), no obstructive CAD was found at ICA in 24 (12%) in the CTA/FFRCT arm and 137 (73%) in the usual care arm (risk difference 61%, 95% confidence interval 53–69, P< 0.0001), with similar mean cumulative radiation exposure (9.9 vs. 9.4 mSv, P = 0.20). Invasive coronary angiography was cancelled in 61% after receiving CTA/FFRCT results. Among those with intended non-invasive testing, the rates of finding no obstructive CAD at ICA were 13% (CTA/FFRCT) and 6% (usual care; P = 0.95). Clinical event rates within 90 days were low in usual care and CTA/FFRCT arms. Conclusions Computed tomographic angiography/fractional flow reserve by CTA was a feasible and safe alternative to ICA and was associated with a significantly lower rate of invasive angiography showing no obstructive CAD. PMID:26330417

  9. Diagnostic performance of instantaneous wave-free ratio for the evaluation of coronary stenosis severity confirmed by fractional flow reserve: A PRISMA-compliant meta-analysis of randomized studies.

    Science.gov (United States)

    Man, Wanrong; Hu, Jianqiang; Zhao, Zhijing; Zhang, Mingming; Wang, Tingting; Lin, Jie; Duan, Yu; Wang, Ling; Wang, Haichang; Sun, Dongdong; Li, Yan

    2016-09-01

    The instantaneous wave-free ratio (iFR) is a new vasodilator-free index of coronary stenosis severity. The aim of this meta-analysis is to assess the diagnostic performance of iFR for the evaluation of coronary stenosis severity with fractional flow reserve as standard reference. We searched PubMed, EMBASE, CENTRAL, ProQuest, Web of Science, and International Clinical Trials Registry Platform (ICTRP) for publications concerning the diagnostic value of iFR. We used a random-effects covariate to synthesize the available data of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR). Overall test performance was summarized by the summary receiver operating characteristic curve (sROC) and the area under the curve (AUC). Eight studies with 1611 subjects were included in the meta-analysis. The pooled sensitivity, specificity, LR+, LR-, and DOR for iFR were respectively 73.3% (70.1-76.2%), 86.4% (84.3-88.3%), 5.71 (4.43-7.37), 0.29 (0.22-0.38), and 20.54 (16.11-26.20). The area under the summary receiver operating characteristic curves for iFR was 0.8786. No publication bias was identified. The available evidence suggests that iFR may be a new, simple, and promising technology for coronary stenosis physiological assessment.

  10. Image-based assessment of fractional flow reserve.

    Science.gov (United States)

    Tu, Shengxian; Bourantas, Christos V; Nørgaard, Bjarne L; Kassab, Ghassan S; Koo, Bon-Kwon; Reiber, Johan H C

    2015-01-01

    Pressure-derived fractional flow reserve (FFR) is an index of the haemodynamic significance of a coronary lesion. Numerous studies have provided robust evidence that FFR-guided percutaneous coronary intervention is associated with better clinical outcomes and reduces the need for repeat revascularisation. Although FFR is regarded as the gold standard for assessing lesion severity, it has limited clinical applications, mainly because it is a relatively expensive and time-consuming procedure. To overcome these limitations, several computational-based methodologies have been developed which enable estimation of the FFR in three-dimensional models derived from anatomic imaging data. Multislice computed tomographic coronary angiography and quantitative coronary angiography have been proposed for coronary reconstruction and computational evaluation of the FFR. In this review article, we describe the currently available methodologies for the computational estimation of FFR, present evidence derived from their clinical evaluations, stress their limitations, and discuss their potential value in clinical practice.

  11. Diagnostic performance of cardiac imaging methods to diagnose ischaemia-causing coronary artery disease when directly compared with fractional flow reserve as a reference standard: a meta-analysis

    Science.gov (United States)

    Danad, Ibrahim; Szymonifka, Jackie; Twisk, Jos W.R.; Norgaard, Bjarne L.; Zarins, Christopher K.; Knaapen, Paul

    2017-01-01

    Aims The aim of this study was to determine the diagnostic performance of single-photon emission computed tomography (SPECT), stress echocardiography (SE), invasive coronary angiography (ICA), coronary computed tomography angiography (CCTA), fractional flow reserve (FFR) derived from CCTA (FFRCT), and cardiac magnetic resonance (MRI) imaging when directly compared with an FFR reference standard. Method and results PubMed and Web of Knowledge were searched for investigations published between 1 January 2002 and 28 February 2015. Studies performing FFR in at least 75% of coronary vessels for the diagnosis of ischaemic coronary artery disease (CAD) were included. Twenty-three articles reporting on 3788 patients and 5323 vessels were identified. Meta-analysis was performed for pooled sensitivity, specificity, likelihood ratios (LR), diagnostic odds ratio, and summary receiver operating characteristic curves. In contrast to ICA, CCTA, and FFRCT reports, studies evaluating SPECT, SE, and MRI were largely retrospective, single-centre and with generally smaller study samples. On a per-patient basis, the sensitivity of CCTA (90%, 95% CI: 86–93), FFRCT (90%, 95% CI: 85–93), and MRI (90%, 95% CI: 75–97) were higher than for SPECT (70%, 95% CI: 59–80), SE (77%, 95% CI: 61–88), and ICA (69%, 95% CI: 65–75). The highest and lowest per-patient specificity was observed for MRI (94%, 95% CI: 79–99) and for CCTA (39%, 95% CI: 34–44), respectively. Similar specificities were noted for SPECT (78%, 95% CI: 68–87), SE (75%, 95% CI: 63–85), FFRCT (71%, 95% CI: 65–75%), and ICA (67%, 95% CI: 63–71). On a per-vessel basis, the highest sensitivity was for CCTA (pooled sensitivity, 91%: 88–93), MRI (91%: 84–95), and FFRCT (83%, 78–87), with lower sensitivities for ICA (71%, 69–74), and SPECT (57%: 49–64). Per-vessel specificity was highest for MRI (85%, 79–89), FFRCT (78%: 78–81), and SPECT (75%: 69–80), whereas ICA (66%: 64–68) and CCTA (58%: 55

  12. The Physics of Coronary Blood Flow

    CERN Document Server

    Zamir, M

    2005-01-01

    Coronary blood flow is blood flow to the heart for its own metabolic needs. In the most common form of heart disease there is a disruption in this flow because of obstructive disease in the vessels that carry the flow. The subject of coronary blood flow is therefore associated mostly with the pathophysiology of this disease, rarely with dynamics or physics. Yet, the system responsible for coronary blood flow, namely the "coronary circulation," is a highly sophisticated dynamical system in which the dynamics and physics of the flow are as important as the integrity of the conducting vessels. While an obstruction in the conducting vessels is a fairly obvious and clearly visible cause of disruption in coronary blood flow, any discord in the complex dynamics of the system can cause an equally grave, though less conspicuous, disruption in the flow. This book is devoted specifically to the dynamics and physics of coronary blood flow. While relevance to the clinical and pathophysiological issues is clearly maintaine...

  13. Impaired coronary flow reserve is the most important marker of viable myocardium in the myocardial segment-based analysis of dual-isotope gated myocardial perfusion single-photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Woo [Dept. of Nuclear Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); So, Young [Dept. of Nuclear Medicine, Konkuk University School of Medicine, Seoul (Korea, Republic of); Kim, Ki Bong; Lee, Dong Soo [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2014-04-15

    The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), {sup 201}Tl perfusion status at rest, {sup 201}Tl 24 hours redistribution and systolic wall thickening of {sup 99m}Tc-methoxyisobutylisonitrile using a dual isotope gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) who were re-vascularized with a coronary artery bypass graft (CABG) surgery. A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 ± 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG. The left ventricular ejection fraction (LVEF) significantly increased from 37.8 ± 9.0% to 45.5 ± 12.3% (p < 0.001) in 22 patients who had a pre-CABG LVEF lower than 50%. Among 590 myocardial segments in the re-vascularized area, 115 showed abnormal wall motion before CABG and 73.9% (85 of 115) had wall motion improvement after CABG. In the univariate analysis (n = 115 segments), stress/rest reversibility (p < 0.001) and {sup 201}Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001). Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.

  14. Anatomical and functional assessment of Tryton bifurcation stent before and after final kissing balloon dilatation: Evaluations by three-dimensional coronary angiography, optical coherence tomography imaging and fractional flow reserve.

    Science.gov (United States)

    Pyxaras, Stylianos A; Toth, Gabor G; Di Gioia, Giuseppe; Ughi, Giovanni J; Tu, Shengxian; Rusinaru, Dan; Adriaenssens, Tom; Reiber, Johan H C; Leon, Martin B; Bax, Jeroen J; Wijns, William

    2017-07-01

    To assess the anatomical and functional impact of final kissing balloon inflation (FKBI) after implantation of a dedicated bifurcation stent system. Current evidence suggests clinical benefit of FKBI in patients undergoing bifurcation dilatation using the Tryton side branch stent (Tryton-SBS). We hypothesized that FKBI improves anatomical reconstruction and functional results of bifurcation treated by Tryton-SBS. An unselected group of patients with complex bifurcation coronary lesions undergoing percutaneous coronary intervention (PCI) with Tryton-SBS underwent paired anatomical assessment with two- and three-dimensional quantitative coronary analysis (2D- and 3D-QCA), and optical coherence tomography (OCT), including 3D reconstruction before and after FKBI. Functional assessment by fractional flow reserve (FFR) was performed in the main branch (MB) and side branch (SB) before and after FKBI. Paired pre- and post-FKBI data were obtained in 10 patients. By OCT imaging, FKBI increased both the SB ostial area (4.93 ± 2.81 vs. 7.43 ± 2.87 mm(2) , P < 0.001) and the SB maximum diameter (3.12 ± 0.98 vs. 3.82 ± 1.10 mm, P = 0.003). These findings were associated with a significant increase in FFR in the SB (0.90 ± 0.05 vs. 0.94 ± 0.03; P = 0.011), with no significant change in the MB (0.91 ± 0.05 vs. 0.92 ± 0.04; P = 0.470). In patients with complex bifurcation stenosis undergoing PCI with a dedicated bifurcation system, FKBI is associated with improved anatomical and functional results at the SB level, without compromising the result at the MB. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Relationships between coronary flow vasodilator capacity and small artery remodelling in hypertensive patients.

    Science.gov (United States)

    Rizzoni, Damiano; Palombo, Carlo; Porteri, Enzo; Muiesan, Maria Lorenza; Kozàkovà, Michaela; La Canna, Giovanni; Nardi, Matilde; Guelfi, Daniele; Salvetti, Massimo; Morizzo, Carmela; Vittone, Francesca; Rosei, Enrico Agabiti

    2003-03-01

    Arterial hypertension is frequently associated with the presence of structural alterations in small arteries. Moreover, a reduced coronary flow reserve and vasodilator capacity has been observed in essential hypertensive patients, possibly due, at least in part, to microangiopathy of small coronary vessels. The aim of the present study was to evaluate a possible relationship between subcutaneous small artery structure and coronary flow reserve or vasodilator capacity in patients with essential hypertension. A total of 20 patients with mild to moderate essential hypertension were included in the study, and underwent a biopsy of the subcutaneous fat from the gluteal region. Small arteries were dissected and mounted on a micromyograph. The media thickness, the normalized internal diameter and the media:lumen ratio (M/L) were then calculated. In addition, a transesophageal Doppler echocardiographic study, which allows the measurement of coronary flow velocity before and during maximal pharmacological vasodilatation, was performed. Coronary flow reserve (CFR) was measured as the ratio of coronary flow velocity assessed during adenosine infusion and that measured in basal conditions. From blood pressure and coronary flow velocity during adenosine infusion, minimum coronary resistance was calculated. CFR as well as minimum coronary resistance were significantly correlated to both M/L and to normalized internal diameter of subcutaneous small arteries. Our results are consistent with the hypothesis of a generalized remodelling of small arteries in the body, including the coronary circulation; this remodelling may play an important role in the reduction of coronary vasodilator capacity in patients with mild to moderate essential hypertension.

  16. The coronary slow flow phenomenon: a new cardiac "Y" syndrome?

    Science.gov (United States)

    Leone, Maria Cristina; Gori, Tommaso; Fineschi, Massimo

    2008-01-01

    The coronary slow flow phenomenon (CSFP) is an angiographic finding that is characterised by delayed progression of the contrast medium during coronary angiography. The mechanism of this phenomenon remains unknown. In the present paper, we revise the current evidence regarding this phenomenon and discuss recent findings from our group reporting increased resting resistances in patients with the CSFP. We report that these patients had preserved blood flow responses to the intracoronary infusion of the vasodilator papaverine, demonstrating that the CSFP is not necessarily associated with an abnormal coronary flow reserve. Based on these findings and on the review of the current literature, we concur with the concept proposed by Beltrame et al. that the CSFP should be considered a separate clinical entity. Further studies are necessary to describe the clinical characteristics, including the prognosis, of these patients and to identify potential treatments.

  17. Positron Emission Tomography-Determined Hyperemic Flow, Myocardial Flow Reserve, and Flow Gradient—Quo Vadis?

    Science.gov (United States)

    Leucker, Thorsten M.; Valenta, Ines; Schindler, Thomas Hellmut

    2017-01-01

    Positron emission tomography/computed tomography (PET/CT) applied with positron-emitting flow tracers such as 13N-ammonia and 82Rubidium enables the quantification of both myocardial perfusion and myocardial blood flow (MBF) in milliliters per gram per minute for coronary artery disease (CAD) detection and characterization. The detection of a regional myocardial perfusion defect during vasomotor stress commonly identifies the culprit lesion or most severe epicardial narrowing, whereas adding regional hyperemic MBFs, myocardial flow reserve (MFR), and/or longitudinal flow decrease may also signify less severe but flow-limiting stenosis in multivessel CAD. The addition of regional hyperemic flow parameters, therefore, may afford a comprehensive identification and characterization of flow-limiting effects of multivessel CAD. The non-specific origin of decreases in hyperemic MBFs and MFR, however, prompts an evaluation and interpretation of regional flow in the appropriate context with the presence of obstructive CAD. Conversely, initial results of the assessment of a longitudinal hyperemic flow gradient suggest this novel flow parameter to be specifically related to increases in CAD caused epicardial resistance. The concurrent assessment of myocardial perfusion and several hyperemic flow parameters with PET/CT may indeed open novel avenues of precision medicine to guide coronary revascularization procedures that may potentially lead to a further improvement in cardiovascular outcomes in CAD patients. PMID:28770213

  18. Effect of intravenous infusion of iodinated contrast media on the coronary blood flow in dogs

    OpenAIRE

    Abd, Thura T; Asim I. Shafique; Hayder S. Yasir; Jung-Hee Seo; George, Richard T.; Rajat Mittal; Lardo, Albert C.

    2016-01-01

    Background: Coronary computed tomography angiography (CCTA) is obtained using peripheral intravenous iodinated contrast agents (ICA) injection. There is continuing attempts to derive coronary physiological information like coronary blood flow (CBF) and/or fractional flow reserve from CCTA images. However, no data is available regarding the effect of peripheral intravenous injection of ICA on CBF. Methods: A series of 4 experiments was performed using healthy mongrel dogs. All dogs underwen...

  19. A Case of Slow Coronary Flow Presented with Supraventricular Tachycardia and Troponin Positive Acute Coronary Syndrome

    Directory of Open Access Journals (Sweden)

    Mustafa Akçakoyun

    2009-12-01

    Full Text Available Slow coronary flow (SCF but normal epicardial coronary arteries phenomenon frequently have asymptomatic course, however, some reports have showed that this phenomenon may cause angina pectoris, myocardial ischemia and infarction. We described a patient presented with supraventricular tachycardia and Troponin elevation and whose coronary angiography’s had previously revealed slow flow in entire major epicardial coronary arteries.

  20. Evaluation of myocardial blood flow reserve in patients with chronic congestive heart failure due to idiopathic dilated cardiomyopathy.

    Science.gov (United States)

    Canetti, Menahem; Akhter, Mohammed W; Lerman, Amir; Karaalp, Ilyas S; Zell, Jason A; Singh, Harpreet; Mehra, Anilkumar; Elkayam, Uri

    2003-11-15

    This study demonstrates a significant impairment in coronary blood flow reserve in most patients with idiopathic dilated cardiomyopathy despite normal epicardial coronary arteries. This change may prevent appropriate increases in coronary blood flow and thus lead to myocardial ischemia and progression of disease. An association between decreased response to adenosine and acetylcholine supports previous observations indicating that adenosine-induced vasodilation of coronary microcirculation is dependent on endothelial nitric oxide production.

  1. Nonuniform loss of regional flow reserve during myocardial ischemia in dogs.

    Science.gov (United States)

    Coggins, D L; Flynn, A E; Austin, R E; Aldea, G S; Muehrcke, D; Goto, M; Hoffman, J I

    1990-08-01

    To determine whether coronary vasodilator reserve that persists during myocardial ischemia is present in all left ventricular regions, we measured regional blood flow in 192 left ventricular pieces (mean weight, 201 mg) in each of eight dogs by using radioactive microspheres while perfusing the left main coronary artery at 70, 50, 40, and 30 mm Hg. Flows were measured before and during adenosine infusion to determine flow reserve. Perfusion at 40 and 30 mm Hg produced ischemia in all dogs. At 70 mm Hg, 100% of left ventricular regions had significant flow reserve, compared with 92%, 55%, and 8% during perfusion at 50, 40, and 30 mm Hg, respectively. A greater amount of flow reserve and a greater number of regions responded to adenosine in the subepicardium than in the subendocardium at 50, 40, and 30 mm Hg. We conclude that coronary flow reserve persists in only a subset of left ventricular regions during ischemia and that the number of regions with persistent flow reserve decreases with perfusion pressure. These findings may best be explained by a model in which regional ischemia is a maximal coronary vasodilator and persistent pharmacological vasodilator reserve seen when global markers indicate ischemia simply reflects persistent endogenous flow reserve in myocardial regions not yet ischemic.

  2. Serum visfatin and omentin levels in slow coronary flow.

    Science.gov (United States)

    Ucgun, Taner; Başar, Cengiz; Memişoğulları, Ramazan; Demirin, Hilmi; Türker, Yasin; Aslantaş, Yusuf

    2014-12-01

    The adipocytokines visfatin and omentin have a direct effect on inflammation and endothelial injury. The expression of visfatin is closely associated with the expression of proinflammatory cytokines. Omentin has an anti-inflammatory effect and is inversely associated with coronary artery disease (CAD). The slow coronary flow phenomenon is an angiographic finding characterized by delayed distal vessel opacification in the absence of significant epicardial coronary disease. The pathophysiology of SCF has not been clearly identified, although multiple abnormalities including endothelial dysfunction, atherothrombosis and inflammation have been reported. However, the relationship between visfatin, omentin and SCF is still unknown. In this study, we aimed to investigate the relationship of these adipocytokines with SCF. The study included slow coronary flow (n=45) and normal coronary flow (n=55) subjects, according to the corrected TIMI frame count, who underwent angiography in the catheterization laboratory of Duzce University. Statistical analyses were performed with SPSS version 12. Visfatin levels were significantly higher in patients with SCF than in controls (p<0.001). Plasma omentin levels were lower in the SCF group than in controls, although without statistical significance. Visfatin, gender and platelet count were significant predictors of SCF in multivariate logistic regression analysis (OR 0.748, 95% CI 0.632-0.886, p=0.01; OR 30.016, 95% CI 4.355-206.8, p=0.01; OR1.028, 95% CI 1.006-1.050, p=0.011, respectively). Adipocytokines such as visfatin and omentin may play a role in the pathogenesis of coronary slow flow. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  3. Fractional flow reserve as a surrogate for inducible myocardial ischaemia.

    Science.gov (United States)

    van de Hoef, Tim P; Meuwissen, Martijn; Escaned, Javier; Davies, Justin E; Siebes, Maria; Spaan, Jos A E; Piek, Jan J

    2013-08-01

    Documentation of inducible myocardial ischaemia, related to the coronary stenosis of interest, is of increasing importance in lesion selection for percutaneous coronary intervention (PCI). Fractional flow reserve (FFR) is an easily understood, routine diagnostic modality that has become part of daily clinical practice, and is used as a surrogate technique for noninvasive assessment of myocardial ischaemia. However, the application of a single, discrete, cut-off value for FFR-guided lesion selection for PCI, and its adoption in contemporary revascularization guidelines, has limited the requirement for a thorough understanding of the physiological basis of FFR. This limitation constitutes an obstacle for the adequate use and interpretation of this technique, and also for the understanding of new and future modalities of physiological functional intracoronary testing. In this Review, we revisit the fundamental elements of coronary physiology in the absence or presence of coronary artery disease. We provide insight into three essential characteristics of FFR as a diagnostic tool in contemporary clinical practice--the theoretical framework of FFR and its associated limitations; the characteristics and role of FFR as a surrogate for noninvasively assessed myocardial ischaemia; and the requirement and associated caveats of potent vasodilatory drugs to induce maximal vasodilatation of the coronary vascular bed.

  4. Determination of fractional flow reserve (FFR) based on scaling laws: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Jerry T; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine-92697, CA (United States)], E-mail: symolloi@uci.edu

    2008-07-21

    Fractional flow reserve (FFR) provides an objective physiological evaluation of stenosis severity. A technique that can measure FFR using only angiographic images would be a valuable tool in the cardiac catheterization laboratory. To perform this, the diseased blood flow can be measured with a first pass distribution analysis and the theoretical normal blood flow can be estimated from the total coronary arterial volume based on scaling laws. A computer simulation of the coronary arterial network was used to gain a better understanding of how hemodynamic conditions and coronary artery disease can affect blood flow, arterial volume and FFR estimation. Changes in coronary arterial flow and volume due to coronary stenosis, aortic pressure and venous pressure were examined to evaluate the potential use of flow and volume for FFR determination. This study showed that FFR can be estimated using arterial volume and a scaling coefficient corrected for aortic pressure. However, variations in venous pressure were found to introduce some error in FFR estimation. A relative form of FFR was introduced and was found to cancel out the influence of pressure on coronary flow, arterial volume and FFR estimation. The use of coronary flow and arterial volume for FFR determination appears promising.

  5. RELATIONS OF ENDOTHELIAL FUNCTION AND BLOOD FLOW IN BRACHIAL ARTERY AND CORONARY ARTERY

    Institute of Scientific and Technical Information of China (English)

    孙寅光; 沈卫峰; 施仲伟; 张大东

    2003-01-01

    Objective To determine the relations between endothelium dependent vasodilator function and blood flow in the brachial and coronary arteries in patients with suspected coronary artery disease.MethodsTwenty eight patients with suspected coronary artery disease underwent brachial artery endothelial function test by using high resolution B mode ultrasound before coronary angiography (CAG) and coronary flow reserve (CFR) test by using intracoronary Doppler technique. The correlation of coronary artery dilatation induced by an increase in blood flow after intracoronary adenosine infusion and brachial artery flow mediated dilatation (FMD) following reactive hyperemia was evaluated. The relation between the change of brachial artery blood flow and CFR was also studied.ResultsThere was a positive correlation between brachial FMD and percent change of coronary diameter after adenosine infusion (12.50%±9.35% vs 11.38%±7.55%, r=0.425,P=0.02). There was also a weak negative relation between brachial flow change following reactive hyperemia and CFR (r=0.397, P=0.04).ConclusionThere is a correlation between the coronary endothelial function and the CFR by ultrasonic determination of brachial flow changes following reactive hyperemia.

  6. Clinical use of optical coherence tomography and fractional flow reserve

    Directory of Open Access Journals (Sweden)

    Ivanović Vladimir

    2016-01-01

    Full Text Available Introduction. The aim of each diagnostic method is to serve as a guide in deciding about the right patient treatment. During myocardial revascularization the decision to perform revascularization is usually not easy to make, especially in case of borderline stenosis. It has been proven that it is not enough to base morphological evaluation of coronary artery vessel stenosis solely on angiography. It is necessary to include additional modern diagnostic methods for functional analysis and detailed morphological analysis using fractional flow reserve (FFR and optical coherence tomography (OCT, respectively. Case reports. In the first case report we showed the significance of morphological analysis using OCT and proved that it was not lumen stenosis. The second and the third case reports showed the complementarity between functional analysis (FFR and morphological analysis (OCT of stenosis in solving a complex coronary disease. The fourth case report showed the significance of OCT in dealing with the recurrent stent restenosis. Conclusion. By these short case reports we confirmed that percutaneous coronary intervention (PCI guided by angiography is definitely not enough in deciding about myocardial revascularization especially in patients with a complex coronary disease. In certain cases FFR and OCT procedures can be complementary methods and improve quality of revascularization, particularly in the case of recurrent in-stent restenosis.

  7. Fractional flow reserve and instantaneous wave free ratio in 2015.

    Science.gov (United States)

    Kondareddy, S R; Singh, M; Stapleton, D; Rudzinski, W; Kaluski, E

    2015-06-01

    In the recent years it has become apparent that angiography-based assessment of coronary artery stenosis suffers from considerable inaccuracy and pitfalls. Besides interobserver variability in assessing stenosis severity, the correlation between angiographic severity and ischemia is suboptimal. Percutaneous coronary intervention (PCI) guided by the physiologic lesion assessment employing fractional flow reserve (FFR) is rendered superior to angiographic lesion assessment and proven to improve cardiovascular outcomes and reduce cost. In this manuscript we discuss the accepted and emerging clinical indications for FFR use. The correlation between FFR and symptoms, stress imaging and intravascular ultrasound are reviewed along with the inherent limitations and pitfalls of these diagnostic technologies. The data regarding the correlation between Instantaneous (vasodilator free) wave-free ratio (iFR) and conventional FFR is summarized.

  8. Quantitative relationship between coronary vasodilator reserve assessed by {sup 82}Rb PET imaging and coronary artery stenosis severity

    Energy Technology Data Exchange (ETDEWEB)

    Anagnostopoulos, Constantinos [Brigham and Women' s Hospital, Division of Nuclear Medicine/PET, Boston, MA (United States); Royal Brompton Hospital, Department of Nuclear Medicine, London (United Kingdom); Brigham and Women' s Hospital, Harvard Medical School, London (United Kingdom); Almonacid, Alexandra; Popma, Jeffrey J. [Brigham and Women' s Hospital, Division of Cardiovascular Medicine, Department of Medicine, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, London (United Kingdom); El Fakhri, Georges [Brigham and Women' s Hospital, Division of Nuclear Medicine/PET, Boston, MA (United States); Royal Brompton Hospital, Department of Cardiology, London (United Kingdom); Curillova, Zelmira; Dorbala, Sharmila; Di Carli, Marcelo F. [Brigham and Women' s Hospital, Division of Nuclear Medicine/PET, Boston, MA (United States); Brigham and Women' s Hospital, Cardiovascular Imaging, Department of Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Division of Cardiovascular Medicine, Department of Medicine, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, London (United Kingdom); Sitek, Arkadiusz [Brigham and Women' s Hospital, Division of Nuclear Medicine/PET, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, London (United Kingdom); Roughton, Michael [Royal Brompton Hospital, Department of Cardiology, London (United Kingdom)

    2008-09-15

    The relationship between myocardial blood flow (MBF) and stenosis severity has been determined previously using cyclotron-produced radiotracers such as {sup 15}O-H{sub 2}O and {sup 13}N-ammonia. An attractive alternative to overcome the limitations related to the use of cyclotron might be to use the generator-produced {sup 82}Rb as a flow tracer. The current study was undertaken to investigate the relationship between MBF and coronary vasodilator reserve (CVR) as measured by {sup 82}Rb positron emission tomography (PET) and the percent diameter stenosis as defined by quantitative coronary arteriography. We prospectively evaluated 22 individuals: 15 patients (60 {+-} 11 years of age) with angiographically documented coronary artery disease (CAD) and seven age-matched (56 {+-} 9 years) asymptomatic individuals without risk factors for CAD. Dynamic {sup 82}Rb PET was performed at rest and after dipyridamole vasodilation. MBF, CVR and an index of 'minimal coronary resistance' (MCR) were assessed in each of the three main coronary territories. Rest and stress MBF in regions subtended by vessels with less than 50% diameter stenosis was similar to that of the individuals with no risk factors for CAD. As a result, CVR was also similar in the two groups (1.9, interquartile [IQ] range from 1.7 to 2.7 vs. 2.2, IQ range from 2 to 3.4 respectively, p=0.09). CVR successfully differentiated coronary lesions with stenosis severity 70% to 89% from those with 50% to 69% stenosis (1, IQ range from 1 to 1.3 vs. 1.7, IQ range from 1.4 to 2), respectively, p=0.001. In addition, hyperaemic MBF (r{sup 2}=0.74, p<0.001), CVR (r {sup 2}=0.69, p<0.001) and MCR (r{sup 2}=0.78, p<0.001) measurements were inversely and non-linearly correlated to the percent diameter stenosis on angiography. MBF and CVR are inversely and non-linearly correlated to stenosis severity. Quantitative {sup 82}Rb PET can be a clinically useful tool for an accurate functional assessment of CAD. (orig.)

  9. Fractional Flow Reserve-Guided Multivessel Angioplasty in Myocardial Infarction.

    Science.gov (United States)

    Smits, Pieter C; Abdel-Wahab, Mohamed; Neumann, Franz-Josef; Boxma-de Klerk, Bianca M; Lunde, Ketil; Schotborgh, Carl E; Piroth, Zsolt; Horak, David; Wlodarczak, Adrian; Ong, Paul J; Hambrecht, Rainer; Angerås, Oskar; Richardt, Gert; Omerovic, Elmir

    2017-03-30

    Background In patients with ST-segment elevation myocardial infarction (STEMI), the use of percutaneous coronary intervention (PCI) to restore blood flow in an infarct-related coronary artery improves outcomes. The use of PCI in non-infarct-related coronary arteries remains controversial. Methods We randomly assigned 885 patients with STEMI and multivessel disease who had undergone primary PCI of an infarct-related coronary artery in a 1:2 ratio to undergo complete revascularization of non-infarct-related coronary arteries guided by fractional flow reserve (FFR) (295 patients) or to undergo no revascularization of non-infarct-related coronary arteries (590 patients). The FFR procedure was performed in both groups, but in the latter group, both the patients and their cardiologist were unaware of the findings on FFR. The primary end point was a composite of death from any cause, nonfatal myocardial infarction, revascularization, and cerebrovascular events at 12 months. Clinically indicated elective revascularizations performed within 45 days after primary PCI were not counted as events in the group receiving PCI for an infarct-related coronary artery only. Results The primary outcome occurred in 23 patients in the complete-revascularization group and in 121 patients in the infarct-artery-only group that did not receive complete revascularization, a finding that translates to 8 and 21 events per 100 patients, respectively (hazard ratio, 0.35; 95% confidence interval [CI], 0.22 to 0.55; Pratio, 0.80; 95% CI, 0.25 to 2.56), myocardial infarction in 7 and 28 patients, respectively (2.4% vs. 4.7%) (hazard ratio, 0.50; 95% CI, 0.22 to 1.13), revascularization in 18 and 103 patients (6.1% vs. 17.5%) (hazard ratio, 0.32; 95% CI, 0.20 to 0.54), and cerebrovascular events in 0 and 4 patients (0 vs. 0.7%). An FFR-related serious adverse event occurred in 2 patients (both in the group receiving infarct-related treatment only). Conclusions In patients with STEMI and multivessel

  10. Personal Computer System for Automatic Coronary Venous Flow Measurement

    OpenAIRE

    Dew, Robert B.

    1985-01-01

    We developed an automated system based on an IBM PC/XT Personal computer to measure coronary venous blood flow during cardiac catheterization. Flow is determined by a thermodilution technique in which a cold saline solution is infused through a catheter into the coronary venous system. Regional temperature fluctuations sensed by the catheter are used to determine great cardiac vein and coronary sinus blood flow. The computer system replaces manual methods of acquiring and analyzing temperatur...

  11. Transmural myocardial ischemia due to slow coronary flow

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Slow coronary flow phenomenon(SCFP) is an angiographic observation characterized by delayed distal vessel opacification in the absence of significant epicardial coronary disease. Only limited studies have been focused on the etiologies, clinical manifestations and treatment of this unique angiographic phenomenon. In our case report, we described an 85-year-old man who came with significant ST segment elevation in leads V1-V4 and V3R-V5R without increase in myocardial enzyme. The patient also developed respiratory failure requiring intubation and mechanical ventilation. Coronary angiography revealed only mild atherosclerosis without spasm or thromboembolic occlusion. Slow flow was seen in all coronary arteries, especially in the left anterior descending and right coronary arteries. This case speculated that transmural myocardial ischemia with ST segment elevation might be resulted from slow coronary flow. Transmural myocardial ischemia can occur owing to abnormalities of the coronary microcirculation.

  12. Does the quantitative assessment of coronary artery dimensions predict the physiologic significance of a coronary stenosis?

    NARCIS (Netherlands)

    F. Zijlstra (Felix); J.C.W. van Ommeren (Jan-Kees); J.H.C. Reiber (Johan); P.W.J.C. Serruys (Patrick)

    1987-01-01

    textabstractTo study the relationship between the quantitatively assessed coronary artery dimensions and the regional coronary flow reserve as measured by digital subtraction cineangiography, we investigated 17 coronary arteries with a single discrete proximal stenosis and 12 normal coronary

  13. Current status of assessment of fractional flow reserve

    Institute of Scientific and Technical Information of China (English)

    FANG Yi-min; Grisana Grootenhuijs-Triyasut; Pieter A. Doevendans; Yolande Appelman

    2009-01-01

    @@ Coronary angiography presently remains the main method for the diagnosis and instruction of epicardial coronary disease. However, precise characterization of the significance for any given stenosis is limited by the inability to identify intermediate coronary lesions responsible for ischemia.1-3 In clinical practice, in addition to the assessment of the anatomical details of vessel narrowing, a more precise assessment of the impediment to coronary blood flow has become extremely important. At present, several physiological parameters have been introduced to improve discrimination in functional coronary lesion severity during cardiac catheterization.

  14. Reserve, flowing electrolyte, high rate lithium battery

    Science.gov (United States)

    Puskar, M.; Harris, P.

    Flowing electrolyte Li/SOCl2 tests in single cell and multicell bipolar fixtures have been conducted, and measurements are presented for electrolyte flow rates, inlet and outlet temperatures, fixture temperatures at several points, and the pressure drop across the fixture. Reserve lithium batteries with flowing thionyl-chloride electrolytes are found to be capable of very high energy densities with usable voltages and capacities at current densities as high as 500 mA/sq cm. At this current density, a battery stack 10 inches in diameter is shown to produce over 60 kW of power while maintaining a safe operating temperature.

  15. Invasive and non-invasive fractional flow reserve index in validation of hemodynamic severity of intracoronary lesions.

    Science.gov (United States)

    Wasilewski, Jarosław; Mirota, Kryspin; Hawranek, Michał; Poloński, Lech

    2013-01-01

    This review discusses visual and functional evaluation of the hemodynamic significance of the degree of stenosis in coronary angiography, with respect to the indications for revascularization. The concept of the coronary flow reserve is defined, and the theoretical assumptions of the invasive measurement of the fractional flow reserve (FFR) are presented. In the following part, the publication describes the basic steps of numerical stimulations in terms of computational fluid dynamics (CFD) in calculating the fractional flow reserve based on computed tomography (CT) coronary angiography (FFRCT). The numerical FFRCT estimation in correlation with invasive measurements, as well as benefits deriving from FFRCT in the diagnosis of coronary artery disease, is presented in the example of the multicentre prospective DISCOVER-FLOW trial and the DeFACTO project. The CDF method enables to obtain hemodynamic significance of stenosis solely from the coronary anatomy vizualized by CT angiography. The calculation of FFRCT increases the diagnostic reliability of coronary flow reserve estimations. It contributes to the improvement in patients' qualification for contrast coronarography. If the accuracy of FFRCT is confirmed in clinical practice, and the time required for computational processing is shortened, it may turn out that the algorithms of coronary heart disease diagnosis will be verified and it will be to a greater extent based on the CT results.

  16. Coronary calcification with no flow limiting lesions: A potential cause for ischaemic dysfunction in syndrome X patients

    Directory of Open Access Journals (Sweden)

    Elisabetta Palmerini

    2015-12-01

    Conclusion: In symptomatic patients with no obstructive coronary lesions and with more than mild CAC, long axis disturbances and wall motion score index rise occur with stress, at the time of symptom development and correlate with severity of arterial calcification. These findings suggest CAC as a potential mechanism for coronary wall stiffness and consequently exertional ischaemic changes as a result of limited flow reserve.

  17. Quantification of coronary flow using dynamic angiography with 320-detector row CT and motion coherence image processing: Detection of ischemia for intermediate coronary stenosis.

    Science.gov (United States)

    Nagao, Michinobu; Yamasaki, Yuzo; Kamitani, Takeshi; Kawanami, Satoshi; Sagiyama, Koji; Yamanouchi, Torahiko; Shimomiya, Yamato; Matoba, Tetsuya; Mukai, Yasushi; Odashiro, Keita; Baba, Shingo; Maruoka, Yasuhiro; Kitamura, Yoshiyuki; Nishie, Akihiro; Honda, Hiroshi

    2016-05-01

    Anatomical coronary stenosis is not always indicative of functional stenosis, particularly for intermediate coronary lesions. The purpose of this study is to propose a new method for quantifying coronary flow using dynamic CT angiography for the whole heart (heart-DCT) and investigate its ability for detecting ischemia from intermediate coronary stenosis. Participants comprised 36 patients with coronary artery disease who underwent heart-DCT using 320-detector CT with tube voltage of 80kV and myocardial perfusion scintigraphy (MPS). Heart-DCT was continuously performed at mid-diastole throughout 15-25 cardiac cycles with prospective ECG-gating after bolus injection of contrast media (12-24ml). Dynamic datasets were computed into 90-100 data sets by motion coherence image processing (MCIP). Next, time-density curves (TDCs) for coronary arteries with a diameter >3mm were automatically calculated for all phases using MCIP. On the basis of the maximum slope method, coronary flow index (CFI) was defined as the ratio of the maximum upslope of coronary artery attenuation to the upslope of ascending aorta attenuation on the TDC, and was used to quantify coronary flow. CFIs for the proximal and distal sites of coronary arteries with mild-to-moderate stenosis were calculated. Coronary territories were categorized as non-ischemic or ischemic by MPS. Receiver-operating-characteristic (ROC) analysis was performed to determine the optimal cutoff for CFI to detect ischemia. Distal CFI was significantly lower for ischemia (0.26±0.08) than for non-ischemia (0.50±0.17, pcoronary flow quantification using heart-DCT. Distal CFI can detect myocardial ischemia derived from intermediate coronary stenosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Flow regulation in coronary vascular tree: a model study.

    Directory of Open Access Journals (Sweden)

    Xinzhou Xie

    Full Text Available Coronary blood flow can always be matched to the metabolic demand of the myocardium due to the regulation of vasoactive segments. Myocardial compressive forces play an important role in determining coronary blood flow but its impact on flow regulation is still unknown. The purpose of this study was to develop a coronary specified flow regulation model, which can integrate myocardial compressive forces and other identified regulation factors, to further investigate the coronary blood flow regulation behavior.A theoretical coronary flow regulation model including the myogenic, shear-dependent and metabolic responses was developed. Myocardial compressive forces were included in the modified wall tension model. Shear-dependent response was estimated by using the experimental data from coronary circulation. Capillary density and basal oxygen consumption were specified to corresponding to those in coronary circulation. Zero flow pressure was also modeled by using a simplified capillary model.Pressure-flow relations predicted by the proposed model are consistent with previous experimental data. The predicted diameter changes in small arteries are in good agreement with experiment observations in adenosine infusion and inhibition of NO synthesis conditions. Results demonstrate that the myocardial compressive forces acting on the vessel wall would extend the auto-regulatory range by decreasing the myogenic tone at the given perfusion pressure.Myocardial compressive forces had great impact on coronary auto-regulation effect. The proposed model was proved to be consistent with experiment observations and can be employed to investigate the coronary blood flow regulation effect in physiological and pathophysiological conditions.

  19. Evolution of Coronary Flow in an Experimental Slow Flow Model in Swines: Angiographic and Pathological Insights

    Directory of Open Access Journals (Sweden)

    Yupeng Bai

    2015-01-01

    Full Text Available Objective. Pathomechanism of coronary slow flow phenomenon remains largely unclear now. Present study observed the pathological and angiographic evolution in a pig model of coronary slow flow. Methods. Coronary slow flow was induced by repeat coronary injection of small doses of 40 µm microspheres in 18 male domestic pigs and angiographic and pathological changes were determined at 3 hours, 7 days, and 28 days after microspheres injection. Results. Compared to control group treated with coronary saline injection n=6 and baseline level, coronary flow was significantly reduced at 3 hours and 7 days but completely recovered at 28 days after coronary microsphere injection in slow flow group. Despite normal coronary flow at 28 days after microsphere injection, enhanced myocardial cytokine expression, left ventricular dysfunction, adverse remodelling, and ischemia/microembolism related pathological changes still persisted or even progressed from 3 hours to 28 days after coronary microsphere injection. Conclusions. Our results show that this large animal slow flow model could partly reflect the chronic angiographic, hemodynamic, and pathological changes of coronary slow flow and could be used to test new therapy strategies against the slow flow phenomenon.

  20. Coronary flow in a prosthetic aorto-coronary bypass graft: first report of Possis Perma-Flow graft physiology in a patient.

    Science.gov (United States)

    Mooney, M J; Emery, R; Kern, M J

    1997-03-01

    The coronary physiology of a prosthetic Perma-Flow coronary bypass graft conduit is demonstrated in the first patient at 1-yr follow-up. Coronary blood flow velocity was measured in the body of the graft and into the side-to-side anastomosis to the first diagonal branch. This case report demonstrates the first information on the coronary and prosthetic graft flow in a patient with atherosclerotic coronary disease.

  1. Noninvasive Fractional Flow Reserve for the Diagnosis of Lesion-specific Ischemia: A Case Example

    Directory of Open Access Journals (Sweden)

    Jesper Møller Jensen

    2015-01-01

    Full Text Available A physically active 52-year-old male with atypical chest pain was referred to our department. A coronary computed tomography angiography (CCTA showed a stenotic plaque in the mid left anterior descending coronary artery (LAD. A rest-stress Rubidium-82 myocardial perfusion was normal. One year later the patient sustained a cardiac arrest and percutaneous coronary intervention of the mid-LAD was successfully performed. The original CCTA data were submitted for noninvasive determination of fractional flow reserve (FFR CT revealing an ischemia-producing lesion in the mid-LAD. This case demonstrates the inherent limitations of assessing lesion-specific ischemia. FFR CT shows promise as a new method for future selection of patients for coronary angiography.

  2. Dynamic regulation of atrial coronary blood flow in healthy adult pigs.

    Science.gov (United States)

    van Bragt, Kelly A; Nasrallah, Hussein M; Kuiper, Marion; van Hunnik, Arne; Kuijpers, Nico H L; Schotten, Ulrich; Verheule, Sander

    2015-05-01

    There are several indications for a mismatch between atrial oxygen supply and demand during atrial fibrillation (AF), but atrial coronary flow regulation has not been investigated extensively. The purpose of this study was to characterize the dynamic regulation of atrial coronary flow in pigs. In anesthetized open-chest pigs, Doppler flow probes were placed around left atrial (LA) and left ventricular (LV) branches of the circumflex artery. Pressures and work indices were measured simultaneously. Systolic and diastolic flow contribution, flow response kinetics, and relationship between pressures, work, and flow were investigated during sinus rhythm, atrial pacing, and acute AF. During atrial systole, LA flow decreased. Only 2% of total LA flow occurred during atrial systole. Pacing with 2:1 AV block and infusion of acetylcholine revealed that atrial contraction itself impeded atrial coronary flow. The response to sudden changes in heart rate was slower in LA compared to LV. Both LA and LV vascular conductance were positively correlated with work. After the cessation of acute AF, the LA showed a more pronounced phase of supranormal vascular conductance than the LV, indicating a period of atrial reactive hyperemia. In healthy adult pigs, atrial coronary flow is impeded by atrial contraction. Although atrial coronary blood flow is positively correlated with atrial external work, it reacts more slowly to changes in rate than ventricular flow. The occurrence of a pronounced hyperemic phase after acute AF supports the notion of a significant supply-demand mismatch during AF. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  3. Simulation of Blood Flow Coronary Artery with Consecutive Stenosis and Coronary-Coronary Bypass

    Directory of Open Access Journals (Sweden)

    Omid Arjmandi-Tash

    2011-08-01

    Full Text Available Introduction: In this research the behavior of coronary arteries has been studied with symmetric and asymmetric consecutive stenosis, and grafted vessels. Methods: The incompressible Navier-Stokes and energy equations were discretized with second-order upwind method. Assumptions such as Newtonian fluid, wall rigidity and steady-flow were used. Results: All the calculations showed the same results with Newtonians and non-Newtonian fluids. It was found that the possibility of stenosis be reduced by increasing the graft angle. However, there exists further stenosis possibility. Among the three graft angles 20, 30 ̊ and 40, the 30 ̊ was found to be the reliable ones. Conclusion: Based on these findings, it can be deduced that there would be a high risk of further atherosclerosis when the first stenose has the maximum percentage.

  4. The effects of fenoldopam on coronary conduit blood flow after coronary artery bypass graft surgery.

    LENUS (Irish Health Repository)

    Halpenny, M

    2012-02-03

    OBJECTIVE: To quantify the effects of fenoldopam, 0.1 microg\\/kg\\/min, on left internal mammary artery (LIMA) and saphenous vein blood flow after coronary anastomosis. DESIGN: Prospective, randomized, double-blind, placebo-controlled trial. SETTING: University teaching hospital, single institution. PARTICIPANTS: Thirty-one American Society of Anesthesiologists III patients undergoing elective coronary revascularization. INTERVENTIONS: A perivascular ultrasonic flow probe (Linton Instrumentation, Norfolk, UK) was placed around the LIMA and saphenous vein graft after coronary anastomosis. MEASUREMENTS AND MAIN RESULTS: Immediately before and at 5-minute intervals for 15 minutes after starting the infusion, blood flow was measured in the LIMA and one saphenous vein graft using a transit time ultrasonic flow probe. Heart rate, blood pressure, and central venous pressure were documented at these time points. Administration of fenoldopam, 0.1 microg\\/kg\\/min, did not alter heart rate or blood pressure. A small, nonsignificant increase in LIMA blood flow occurred during the 15-minute study period (30 +\\/- 12 to 35 +\\/- 10 mL\\/min) in patients who received fenoldopam. No significant changes occurred in the placebo group. CONCLUSIONS: The findings indicate that fenoldopam, 0.1 microg\\/kg\\/min, did not influence coronary conduit blood flow to a clinically significant extent. The small increase in LIMA blood flow may be of greater importance in high-risk patients or in the prevention of coronary arterial spasm.

  5. Functional assessment of lesion severity without using the pressure wire: coronary imaging and blood flow simulation.

    Science.gov (United States)

    Papafaklis, Michail I; Mavrogiannis, Michail C; Siogkas, Panagiotis K; Lakkas, Lampros S; Katsouras, Christos S; Fotiadis, Dimitrios I; Michalis, Lampros K

    2017-09-19

    Hemodynamic indices derived from measurements with the pressure wire (primarily fractional flow reserve [FFR]) have been established as a reliable tool for assessing coronary stenoses and improving clinical decision making. However, the use of the pressure wire constitutes a hurdle for the universal adoption of physiology-guided patient management. Technological advancements have enabled the large-scale application of blood flow simulation (computational fluid dynamics [CFD]) to medical imaging, thereby enabling the virtual assessment of coronary physiology. Areas covered: This review summarizes the stand-alone non-invasive (coronary computed tomographic imaging) and invasive (coronary angiography) imaging approaches which were initially used for predicting FFR, and focuses on the use of blood flow modeling for functional assessment of coronary lesions in clinical practice. Expert commentary: Validation studies of CFD-derived methodologies for functional assessment have shown that virtual indices correlate well and have good diagnostic accuracy compared to pressure wire-FFR despite inherent limitations of spatial resolution and assumptions regarding boundary conditions in flow modeling. Beyond point-to-point agreement with FFR, further studies are needed to demonstrate the clinical safety/efficacy of these computational tools regarding patient outcomes. Such evidence base could support the incorporation of these methodologies into routine patient management for decision making and reliable risk stratification.

  6. Coronary blood flow during cardiopulmonary resuscitation in swine

    Energy Technology Data Exchange (ETDEWEB)

    Bellamy, R.F.; DeGuzman, L.R.; Pedersen, D.C.

    1984-01-01

    Recent papers have raised doubt as to the magnitude of coronary blood flow during closed-chest cardiopulmonary resuscitation. We will describe experiments that concern the methods of coronary flow measurement during cardiopulmonary resuscitation. Nine anesthetized swine were instrumented to allow simultaneous measurements of coronary blood flow by both electromagnetic cuff flow probes and by the radiomicrosphere technique. Cardiac arrest was caused by electrical fibrillation and closed-chest massage was performed by a Thumper (Dixie Medical Inc., Houston). The chest was compressed transversely at a rate of 66 strokes/min. Compression occupied one-half of the massage cycle. Three different Thumper piston strokes were studied: 1.5, 2, and 2.5 inches. Mean aortic pressure and total systemic blood flow measured by the radiomicrosphere technique increased as Thumper piston stroke was lengthened (mean +/- SD): 1.5 inch stroke, 23 +/- 4 mm Hg, 525 +/- 195 ml/min; 2 inch stroke, 33 +/- 5 mm Hg, 692 +/- 202 ml/min; 2.5 inch stroke, 40 +/- 6 mm Hg, 817 +/- 321 ml/min. Both methods of coronary flow measurement (electromagnetic (EMF) and radiomicrosphere (RMS)) gave similar results in technically successful preparations (data expressed as percent prearrest flow mean +/- 1 SD): 1.5 inch stroke, EMF 12 +/- 5%, RMS 16 +/- 5%; 2 inch stroke, EMF 30 +/- 6%, RMS 26 +/- 11%; 2.5 inch stroke, EMF 50 +/- 12%, RMS 40 +/- 20%. The phasic coronary flow signal during closed-chest compression indicated that all perfusion occurred during the relaxation phase of the massage cycle. We concluded that coronary blood flow is demonstrable during closed-chest massage, but that the magnitude is unlikely to be more than a fraction of normal.

  7. Angiographic coronary stenosis versus (15)O-water PET myocardial blood flow

    DEFF Research Database (Denmark)

    Thomassen, Anders; Braad, Poul-Erik; Johansen, Allan

    2013-01-01

    Purpose: To examine which of stress myocardial flow (MBF) and coronary flow reserve (CFR) determined by (15)-water-PET (PET) correspond most closely with diameter stenosis assessed by quantitative coronary angiography (QCA). Methods: Twenty-three patients with a C40% QCA stenosis underwent baseline...... and functional stenosis was poor, suggesting that the hemodynamic consequences of angiographically proven coronary stenoses should be examined by functional imaging like PET....... and adenosine stress PET. Baseline MBF measures were corrected for myocardial workload and stress MBF and CFR calculated in 17 standard AHA myocardial segments and reassigned to respective feeding vessels. If multiple stenoses, only the most severe stenosis was considered. Pearson’s correlation coefficients...

  8. Contractility is the main determinant of coronary systolic flow impediment.

    Science.gov (United States)

    Krams, R; Sipkema, P; Zegers, J; Westerhof, N

    1989-12-01

    We measured the relation between coronary flow amplitude (delta F = Fd-Fs; where d is diastolic and s is systolic) and developed left ventricular pressure (delta PLV = Ps-Pd) at a constant perfusion pressure of 75 mmHg (10 kPa) in the maximally vasodilated blood-perfused isolated cat heart for different steady-state levels of contractility (protocol A) and during transients in contractility (protocol B). Contractility was defined as the slope of the end-systolic pressure-volume relation (Emax). From protocol A it appeared that the coronary flow amplitude was only weakly related to left ventricular pressure at each steady-state level of contractility studied. However, the coronary flow amplitude was strongly related to the different levels of contractility. In protocol B, contractility was changed over a wide range of values (0-100%) but developed pressure and contractility changed simultaneously. Using multiple linear regression analysis, we found that contractility has approximately 10 times (range: 2.8-57.3) stronger effect than left ventricular pressure on coronary flow amplitude (n = 10 experiments). These data and our earlier observations suggest that it is the difference in stiffness of cardiac muscle between systole and diastole that determines coronary flow amplitude.

  9. Coronary blood flow in patients with cardiac syndrome X.

    Science.gov (United States)

    Sen, Nihat; Tavil, Yusuf; Yazici, Hüseyin Uğur; Abacl, Adnan; Cengel, Atiye

    2007-02-01

    Epicardial coronary arteries are normal in patients with cardiac syndrome X. It is, however, unclear whether there is an abnormality at the level of microvascular circulation. In this study, our aim was to evaluate the epicardial coronary blood flow and myocardial perfusion in patients with cardiac syndrome X. Two hundred and three patients (mean age 53+/-10 years, 85 men) were included in the study. The diagnosis of cardiac syndrome X was made in patients who had a complaint of typical anginal chest pain and had ischemic findings on either myocardial perfusion scintigraphy or a treadmill exercise test, and whose coronary angiograms did not reveal any pathology. Fifty patients (mean age 54+/-11 years, 24 men) who had a complaint of typical anginal chest pain and had a normal myocardial perfusion test and normal coronary arteries were recruited as the control group. Epicardial coronary blood flow was evaluated with the thrombolysis in myocardial infarction frame count method and myocardial perfusion was evaluated with the myocardial blush grade method. A myocardial blush grade of 0.05). We found that the epicardial coronary blood flow, as assessed by thrombolysis in myocardial infarction frame count, and myocardial perfusion, as assessed by myocardial blush grade, were normal in patients with cardiac syndrome X.

  10. Coronary artery ectasia and systolic flow cessation in a patient with hypertrophic cardiomyopathy: a case report.

    Science.gov (United States)

    Zografos, Theodoros; Kokladi, Maria; Katritsis, Demosthenes

    2010-12-01

    Coronary artery ectasia (CAE) is characterized by diffuse or localized inappropriate dilation of coronary arteries and is often associated with slow coronary blood flow. Although CAE has been described to coexist with several clinical entities there are only three reports of CAE in the presence of hypertrophic cardiomyopathy (HCM). We report a case of CAE and slow coronary flow with systolic flow cessation in a 61-year old male with coronary artery disease and HCM.

  11. MR angiography and determination of the flow reserve after minimal invasive direct coronary artery bypass (MIDCAB) surgery of the left internal mammary arteria in comparison to the multidetector-row CT; MR-Angiographie und Flussreservenbestimmung nach minimalinvasiver direkter Koronararterien-Bypass(MIDCAB)-Operation der linken Arteria mammaria interna im Vergleich zur Mehrzeilen-CT

    Energy Technology Data Exchange (ETDEWEB)

    Stauder, N.I.; Fenchel, M.; Kuettner, A.; Kramer, U.; Claussen, C.D.; Miller, S. [Abt. Radiologische Diagnostik, Universitaetsklinik Tuebingen (Germany); Stauder, H.; Scheule, A.M. [Abt. Thorax-, Herz- und Gefaesschirurgie, Universitaetsklinik Tuebingen (Germany)

    2005-08-01

    Purpose: To evaluate graft patency, flow and flow reserve in patients with minimal invasive direct coronary artery bypass (MIDCAB) of internal mammary artery (IMA) grafts using a combined MR protocol with phase-contrast technique and MR angiography. Material and methods: At a 1.5T Magnetom Sonata (SIEMENS), 19 symptomatic (angina CCS I-III, intermittent thoracic discomfort, scar disorders) patients (59.9{+-}7.9 years old) with 19 left internal mammary artery (LIMA) grafts implanted in minimal invasive technique were examined 6.9{+-}1.5 years post surgery. Contrast enhanced MR angiography (TR 2.5 ms, TE 1 ms, flip angle 20 , spatial resolution 1.4 x 0.9 x 1.0 mm{sup 3}, breath hold technique, no ECG-triggering, 25 ml Gd-DTPA) was performed to assess bypass patency. Phase-contrast flow measurements with retrospective gating (TR 41 msec, TE 3.2 msec, flip angle 30 , spatial resolution 1.1 x 1.1 x 5 mm{sup 3}, temporal resolution 42 msec, venc 90 cm/sec) were applied in the IMA grafts at rest and after stress induction with dipyridamole (0.56 mg/kg/BW). For comparison, graft patency was evaluated by multidetector-row computed tomography (16-row CT). In 9 patients a selective catheter angiography was performed. Results: MIDCAB grafts were occluded in 4/19 patients. In 4 patients the anastomosis to LAD was highly stenotic (>70%) at MDCT (2 experienced investigators in consensus reading). In MRA 9 grafts could be delineated completely including the distal anastomosis to LAD (47%). In 9 patients the distal part could not be evaluated. In patients with patent grafts (MDCT), a significant improvement of graft flow (at rest 75.4{+-}33.3 ml/min; after stress 202.7{+-}49.6; P<0.002) and flow reserve (patent grafts 3.0{+-}1.1; stenotic grafts 1.5{+-}0.2, P<0.02; occluded grafts 0.9{+-}0.2, P<0.01) after stress induction was detected. Diastolic-to-systolic peak velocity ratios (D/S-PVR) at baseline were not significant between patent and stenotic grafts. Mean flow at baseline and

  12. Coronary flow of the infarct artery assessed by transthoracic Doppler after primary percutaneous coronary intervention predicts final infarct size.

    Science.gov (United States)

    Trifunovic, Danijela; Sobic-Saranovic, Dragana; Beleslin, Branko; Stankovic, Sanja; Marinkovic, Jelena; Orlic, Dejan; Vujisic-Tesic, Bosiljka; Petrovic, Milan; Nedeljkovic, Ivana; Banovic, Marko; Djukanovic, Nina; Petrovic, Olga; Petrovic, Marija; Stepanovic, Jelena; Djordjevic-Dikic, Ana; Tesic, Milorad; Ostojic, Miodrag

    2014-12-01

    Coronary microcirculatory function after primary percutaneous coronary intervention (pPCI) in patients with acute myocardial infarction is important determinant of infarct size (IS). Our aim was to investigate the utility of coronary flow reserve (CFR) and diastolic deceleration time (DDT) of the infarct artery (IRA) assessed by transthoracic Doppler echocardiography after pPCI for final IS prediction. In 59 patients, on the 2nd day after pPCI for acute anterior myocardial infarction, transthoracic Doppler analysis of IRA blood flow was done including measurements of CFR, baseline DDT and DDT during adenosine infusion (DDT adeno). Killip class, myocardial blush grade, resolution of ST segment elevation, peak creatine kinase-myocardial band and conventional echocardiographic parameters were determined. Single-photon emission computed tomography myocardial perfusion imaging was done 6 weeks later to define final IS (percentage of myocardium with fixed perfusion abnormality). IS significantly correlated with CFR (r = -0.686, p 20 %), the best cut-off for CFR was <1.73 (sensitivity 65 %, specificity 96 %) and for DDT adeno ≤720 ms (sensitivity 81 %, specificity 96 %). CFR and DDT during adenosine are independent and powerful early predictors of final IS offering incremental prognostic information over conventional parameters of myocardial and microvascular damage and tissue reperfusion.

  13. Therapeutic effect of nicorandil on coronary slow flow intervention and endothelial function in elderly patients

    Institute of Scientific and Technical Information of China (English)

    王涛

    2013-01-01

    Objective To observe the effects of nicorandil on coronary slow flow phenomenon (CSFP) and endothelial function in elderly patients.Methods Totally 76 elderly patients diagnosed angiographically as coronary slow flow phenomenon were enrolled.All patients were randomly

  14. Submaximal exercise coronary artery flow increases in postmenopausal women without coronary artery disease after estrogen and atorvastatin.

    Science.gov (United States)

    Puntawangkoon, Chirapa; Morgan, Tim M; Herrington, David M; Hamilton, Craig A; Hundley, W Gregory

    2010-01-01

    The aim of this study was to determine the effect of statins and hormone therapy on submaximal exercise-induced coronary artery blood flow in postmenopausal women without a history of coronary artery disease. Hormone therapy or statin therapy in early postmenopausal women without coronary artery disease has been shown to enhance arterial endothelial function; we hypothesized that these agents would improve submaximal exercise-induced coronary artery blood flow. Sixty-four postmenopausal women, aged 50 to 65 years without documented coronary artery disease, were randomized in a double-blind, crossover fashion to receive 8 weeks of hormone therapy versus placebo, with or without 80 mg/day of atorvastatin. Before receipt of any therapy and after each treatment period, each woman underwent measures of coronary artery blood flow at rest and stress. The combination of hormone therapy and atorvastatin increased submaximal exercise-induced coronary artery blood flow (P = 0.04). In the subgroups of women compliant with treatment, resting coronary artery blood flow increased in those receiving hormone therapy (P = 0.03) or statin therapy (P = 0.02). In postmenopausal women aged 50 to 65 years without documented coronary artery disease, resting and submaximal exercise-induced coronary artery blood flow improves after receipt of high-dose atorvastatin and conjugated estrogens therapy.

  15. Hypertension as a predictor of adverse cardiac events in patients with borderline fractional flow reserve.

    Science.gov (United States)

    Arslan, Fatih; Kaya, Mehmet G; van der Heijden, Geert; Timurkaynak, Timur; Cengel, Atiye

    2007-08-01

    The cut-off value myocardial fractional flow reserve (FFRmyo) or = 0.75. Other clinical characteristics may affect such treatment decision. Therefore, we studied the association between baseline characteristics and clinical outcomes in an unselected patient cohort with coronary artery disease, with intermediate coronary stenosis, initially referred for PCI, but in whom the intervention was deferred on the basis of FFRmyo > or = 0.75. Angiographic analysis and follow-up were performed in 152 patients with stable or unstable angina pectoris with intermediate coronary stenosis severity and normal left ventricular function. A major adverse cardiac event (MACE) was defined as postprocedural acute myocardial infarction (AMI), target vessel revascularization (TVR) and verified cardiac death. More adverse cardiac events occurred in patients with 0.75 or = 0.80 (9/97) (P < 0.001). Hypertension, diabetes and hyperlipidaemia were significantly associated with the occurrence of MACE in the univariate analyses. Logistic regression analyses showed that only hypertension remained as a significant independent predictor of MACE for patients with 0.75 < or = FFRmyo < 0.80 (P < 0.10). In an unselected patient population with coronary artery disease, a FFRmyo cut-off value of 0.8 should be used in hypertensive patients to discriminate between clinically significant coronary stenosis.

  16. Comparison of instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) - First real world experience

    NARCIS (Netherlands)

    Haerle, Tobias; Bojara, Waldemar; Meyer, Sven; Elsaesser, Albrecht

    2015-01-01

    Background: The instantaneous wave-free ratio (iFR) is a new adenosine-independent index of coronary stenosis severity. Most published data have been based on off-line analyses of pressure recordings in a core laboratory. We prospectively compared real-time iFR and fractional flow reserve (FFR) meas

  17. Initial simulated FFR investigation using flow measurements in patient-specific 3D printed coronary phantoms

    Science.gov (United States)

    Shepard, Lauren; Sommer, Kelsey; Izzo, Richard; Podgorsak, Alexander; Wilson, Michael; Said, Zaid; Rybicki, Frank J.; Mitsouras, Dimitrios; Rudin, Stephen; Angel, Erin; Ionita, Ciprian N.

    2017-03-01

    Purpose: Accurate patient-specific phantoms for device testing or endovascular treatment planning can be 3D printed. We expand the applicability of this approach for cardiovascular disease, in particular, for CT-geometry derived benchtop measurements of Fractional Flow Reserve, the reference standard for determination of significant individual coronary artery atherosclerotic lesions. Materials and Methods: Coronary CT Angiography (CTA) images during a single heartbeat were acquired with a 320x0.5mm detector row scanner (Toshiba Aquilion ONE). These coronary CTA images were used to create 4 patientspecific cardiovascular models with various grades of stenosis: severe, stenosis using pressure transducers. Compliance chambers were used before and after the model to modulate the pressure wave. A flow sensor was used to ensure flow rates within physiological reported values. Results: 3D model based FFR measurements correlated well with stenosis severity. FFR measurements for each stenosis grade were: 0.8 severe, 0.7 moderate and 0.88 mild. Conclusions: 3D printed models of patient-specific coronary arteries allows for accurate benchtop diagnosis of FFR. This approach can be used as a future diagnostic tool or for testing CT image-based FFR methods.

  18. Effects of bileaflet mechanical heart valve orientation on coronary flow

    Science.gov (United States)

    Haya, Laura; Tavoularis, Stavros

    2015-11-01

    The aortic sinus is approximately tri-radially symmetric, but bileaflet mechanical heart valves (BMHVs), which are commonly used to replace diseased aortic valves, are bilaterally symmetric. This mismatch in symmetry suggests that the orientation in which a BMHV is implanted within the aortic sinus affects the flow characteristics downstream of it. This study examines the effect of BMHV orientation on the flow in the coronary arteries, which originate in the aortic sinus and supply the heart tissue with blood. Planar particle image velocimetry measurements were made past a BMHV mounted at the inlet of an anatomical aorta model under physiological flow conditions. The complex interactions between the valve jets, the sinus vortex and the flow in the right coronary artery were elucidated for three valve orientations. The coronary flow rate was directly affected by the size, orientation, and time evolution of the vortex in the sinus, all of which were sensitive to the valve's orientation. The total flow through the artery was highest when the valve was oriented with its axis of symmetry intersecting the artery's opening. The findings of this research may assist surgeons in choosing the best orientation for BMHV implantation. The bileaflet valve was donated by St. Jude Medical. Financial support was provided by the Natural Sciences and Engineering Research Council of Canada.

  19. Exploring Coronary Circulatory Response to Stenosis and Its Association with Invasive Physiologic Indices Using Absolute Myocardial Blood Flow and Coronary Pressure.

    Science.gov (United States)

    Lee, Joo Myung; Hwang, Doyeon; Park, Jonghanne; Zhang, Jinlong; Tong, Yaliang; Kim, Chee Hae; Bang, Ji-In; Suh, Minseok; Paeng, Jin Chul; Cheon, Gi Jeong; Koo, Bon-Kwon

    2017-08-29

    Background -Although invasive physiologic assessment for coronary stenosis has become a standard practice to guide treatment strategy, coronary circulatory response and changes in invasive physiologic indices, according to different anatomical and hemodynamic lesion severity, have not been fully demonstrated in patients with coronary artery disease. Methods -One hundred fifteen patients with left anterior descending artery stenosis who underwent both (13)N-ammonia positron emission tomography (PET) and invasive physiologic measurement were analyzed. Myocardial blood flow (MBF) measured using PET and invasively measured coronary pressures were used to calculate microvascular resistance (MVR) and stenosis resistance. Results -With progressive worsening of angiographic stenosis severity, both resting and hyperemic trans-stenotic pressure gradient and stenosis resistance increased (Pstenosis severity, stenosis resistance, and trans-stenotic pressure gradient increased, and hyperemic MBF decreased (all P valuescoronary flow reserve (CFR), the diagnostic accuracy of FFR and iFR did not differ, regardless of cut-off values of hyperemic MBF and CFR. Conclusions -This study demonstrated how the coronary circulation changes in response to increasing coronary stenosis severity using (13)N-ammonium PET-derived MBF and invasively measured pressure data. Currently used resting and hyperemic pressure-derived invasive physiologic indices have similar patterns of relationships to the different anatomic and hemodynamic lesion severity. Clinical Trial Registration -URL: https://clinicaltrials.gov Unique Identifier: NCT01366404.

  20. Flow characteristics in narrowed coronary bypass graft

    Energy Technology Data Exchange (ETDEWEB)

    Bernad, S. I. [Romanian Academy – Timisoara Branch, Mihai Viteazul Str. 24, RO-300223, Timisoara (Romania); Bosioc, A.; Totorean, A. F. [University Politehnica of Timisoara, Department of Hydraulic Machinery, Mihai Viteazul Str. 1, RO-300222, Timisoara (Romania); Bernad, E. S.; Petre, I. [University of Medicine and Pharmacy Victor Babes Timisoara, P-ta Eftimie Murgu, 2, Timisoara (Romania)

    2016-06-08

    Tortuous saphenous vein graft (SVG) hemodynamics was investigated using computational fluid dynamics (CFD) techniques. Computed tomography (CT) technology is used for non-invasive bypass graft assessment 7 days after surgery. CT investigation shown two regions with severe shape remodelling first is an elbow type contortion and second is a severe curvature with tortuous area reduction. In conclusion, the helical flow induced by vessel torsion may stabilize the blood flow in the distal part of the SVG, reducing the flow disturbance and suppressing the flow separation, but in the distal end of the graft, promote the inflammatory processes in the vessels.

  1. Flow characteristics in narrowed coronary bypass graft

    Science.gov (United States)

    Bernad, S. I.; Bosioc, A.; Bernad, E. S.; Petre, I.; Totorean, A. F.

    2016-06-01

    Tortuous saphenous vein graft (SVG) hemodynamics was investigated using computational fluid dynamics (CFD) techniques. Computed tomography (CT) technology is used for non-invasive bypass graft assessment 7 days after surgery. CT investigation shown two regions with severe shape remodelling first is an elbow type contortion and second is a severe curvature with tortuous area reduction. In conclusion, the helical flow induced by vessel torsion may stabilize the blood flow in the distal part of the SVG, reducing the flow disturbance and suppressing the flow separation, but in the distal end of the graft, promote the inflammatory processes in the vessels.

  2. Enhancement of canine coronary collateral flow by nafazatrom.

    Science.gov (United States)

    Fiedler, V B; Mardin, M

    1986-11-04

    The ability of oral nafazatrom treatment (10 mg/kg) 2 h preceding occlusion of the left anterior descending coronary artery for 6 h to limit expansion of myocardial injury was studied in anaesthetized canine hearts. Collateral blood flow was obtained with a load line analysis, employing aortic pressure, post-stenotic coronary pressure, and retrograde coronary flow from the occluded vessel. Contractile changes in the subendocardial ischemic perfused muscles were measured with ultrasonic techniques. Infarct size was determined post-mortem by a biochemical staining method and excision of necrosis. Post-stenotic coronary pressure was slightly below aortic pressure in both groups before coronary occlusion, and fell to 29 and 27% of aortic pressure in vehicle- and drug-treated hearts, respectively, after the insult. Retrograde flow was 2.4 +/- 0.6 vs. 4.1 +/- 0.7 ml/min in tylose- or nafazatrom-treated hearts. Collateral flow amounted to 1.5 +/- 0.06 vs. 2.5 +/- 0.04 ml/min in controls and drug-protected hearts. Contractility (dP/dtmax) and the %-segment shortening were greater in the ischaemic myocardium after nafazatrom treatment. Infarct size was 38 +/- 5.2 vs. 17 +/- 3.4 g/100 g left ventricle in the vehicle controls and nafazatrom group, respectively. Nafazatrom reduced infarct size by 46%. Besides other mechanisms, this was due to improved %-segment shortening and increased periinfarction collateral blood supply to jeopardized but viable myocardium. The drug may be of value in ischaemic heart disease as shown by the enhanced regional myocardial perfusion and improved contractility.

  3. Relationship between elevated serum gamma-glutamyltransferase activity and slow coronary flow

    DEFF Research Database (Denmark)

    Sen, Nihat; Ozlü, Mehmet F; Basar, Nurcan;

    2009-01-01

    OBJECTIVES: We evaluated the relationship between coronary blood flow and serum gamma-glutamyltransferase (GGT) activity in patients with slow coronary flow (SCF). STUDY DESIGN: The study included 90 patients (47 men, 43 women; mean age 50.8+/-9.4 years) with SCF and 88 patients (45 men, 43 women......; mean age 51.4+/-8.8 years) with coronary artery disease (CAD), whose diagnoses were made by coronary angiography. Patients with CAD had normal coronary flow. Coronary flow was quantified using the corrected TIMI frame count (TFC) method and serum levels of gamma-glutamyltransferase were measured....... The results were compared with those of a control group consisting of 86 age- and sex-matched patients who had normal coronary arteries and normal coronary flow. RESULTS: The three groups were similar with respect to body mass index, presence of hypertension and diabetes mellitus, lipid profiles, and fasting...

  4. Uncertainty quantification in coronary blood flow simulations: Impact of geometry, boundary conditions and blood viscosity.

    Science.gov (United States)

    Sankaran, Sethuraman; Kim, Hyun Jin; Choi, Gilwoo; Taylor, Charles A

    2016-08-16

    Computational fluid dynamic methods are currently being used clinically to simulate blood flow and pressure and predict the functional significance of atherosclerotic lesions in patient-specific models of the coronary arteries extracted from noninvasive coronary computed tomography angiography (cCTA) data. One such technology, FFRCT, or noninvasive fractional flow reserve derived from CT data, has demonstrated high diagnostic accuracy as compared to invasively measured fractional flow reserve (FFR) obtained with a pressure wire inserted in the coronary arteries during diagnostic cardiac catheterization. However, uncertainties in modeling as well as measurement results in differences between these predicted and measured hemodynamic indices. Uncertainty in modeling can manifest in two forms - anatomic uncertainty resulting in error of the reconstructed 3D model and physiologic uncertainty resulting in errors in boundary conditions or blood viscosity. We present a data-driven framework for modeling these uncertainties and study their impact on blood flow simulations. The incompressible Navier-Stokes equations are used to model blood flow and an adaptive stochastic collocation method is used to model uncertainty propagation in the Navier-Stokes equations. We perform uncertainty quantification in two geometries, an idealized stenosis model and a patient specific model. We show that uncertainty in minimum lumen diameter (MLD) has the largest impact on hemodynamic simulations, followed by boundary resistance, viscosity and lesion length. We show that near the diagnostic cutoff (FFRCT=0.8), the uncertainty due to the latter three variables are lower than measurement uncertainty, while the uncertainty due to MLD is only slightly higher than measurement uncertainty. We also show that uncertainties are not additive but only slightly higher than the highest single parameter uncertainty. The method presented here can be used to output interval estimates of hemodynamic indices

  5. Myocardial blood flow quantification for evaluation of coronary artery disease by computed tomography

    Science.gov (United States)

    Seitun, Sara; Clemente, Alberto; La Grutta, Ludovico; Toia, Patrizia; Runza, Giuseppe; Midiri, Massimo; Maffei, Erica

    2017-01-01

    During the last decade coronary computed tomography angiography (CTA) has become the preeminent non-invasive imaging modality to detect coronary artery disease (CAD) with high accuracy. However, CTA has a limited value in assessing the hemodynamic significance of a given stenosis due to a modest specificity and positive predictive value. In recent years, different CT techniques for detecting myocardial ischemia have emerged, such as CT-derived fractional flow reserve (FFR-CT), transluminal attenuation gradient (TAG), and myocardial CT perfusion (CTP) imaging. Myocardial CTP imaging can be performed with a single static scan during first pass of the contrast agent, with monoenergetic or dual-energy acquisition, or as a dynamic, time-resolved scan during stress by using coronary vasodilator agents (adenosine, dipyridamole, or regadenoson). A number of CTP techniques are available, which can assess myocardial perfusion in both a qualitative, semi-quantitative or quantitative manner. Once used primarily as research tools, these modalities are increasingly being used in routine clinical practice. All these techniques offer the substantial advantage of combining anatomical and functional evaluation of flow-limiting coronary stenosis in the same examination that would be beneficial for clinical decision-making. This review focuses on the state-of the-art and future trends of these evolving imaging modalities in the field of cardiology for the physiologic assessments of CAD. PMID:28540209

  6. Computed tomography derived fractional flow reserve testing in stable patients with typical angina pectoris

    DEFF Research Database (Denmark)

    Møller Jensen, Jesper; Erik Bøtker, Hans; Norling Mathiassen, Ole

    2017-01-01

    June 2016 all patients (N = 774) referred to non-emergent ICA or coronary CTA at Aarhus University Hospital on a suspicion of CAD had frontline CTA performed. Downstream testing and treatment within 3 months and adverse events ≥90 days were registered. Patients were divided into two groups according......Aims: To assess the use of downstream coronary angiography (ICA) and short-term safety of frontline coronary CT angiography (CTA) with selective CT-derived fractional flow reserve (FFRCT) testing in stable patients with typical angina pectoris. Methods and results: Between 1 January 2016 and 30...... to the presence of typical angina pectoris, which according to local practice would have resulted in referral to ICA, (low-intermediate-risk, n = 593 [76%]; high-risk, n = 181 [24%]) with mean pre-test probability of CAD of 31 ± 16% and 67 ± 16%, respectively. Coronary CTA was performed in 745 (96%) patients...

  7. Patient-specific coronary artery blood flow simulation using myocardial volume partitioning

    Science.gov (United States)

    Kim, Kyung Hwan; Kang, Dongwoo; Kang, Nahyup; Kim, Ji-Yeon; Lee, Hyong-Euk; Kim, James D. K.

    2013-03-01

    Using computational simulation, we can analyze cardiovascular disease in non-invasive and quantitative manners. More specifically, computational modeling and simulation technology has enabled us to analyze functional aspect such as blood flow, as well as anatomical aspect such as stenosis, from medical images without invasive measurements. Note that the simplest ways to perform blood flow simulation is to apply patient-specific coronary anatomy with other average-valued properties; in this case, however, such conditions cannot fully reflect accurate physiological properties of patients. To resolve this limitation, we present a new patient-specific coronary blood flow simulation method by myocardial volume partitioning considering artery/myocardium structural correspondence. We focus on that blood supply is closely related to the mass of each myocardial segment corresponding to the artery. Therefore, we applied this concept for setting-up simulation conditions in the way to consider many patient-specific features as possible from medical image: First, we segmented coronary arteries and myocardium separately from cardiac CT; then the myocardium is partitioned into multiple regions based on coronary vasculature. The myocardial mass and required blood mass for each artery are estimated by converting myocardial volume fraction. Finally, the required blood mass is used as boundary conditions for each artery outlet, with given average aortic blood flow rate and pressure. To show effectiveness of the proposed method, fractional flow reserve (FFR) by simulation using CT image has been compared with invasive FFR measurement of real patient data, and as a result, 77% of accuracy has been obtained.

  8. Coronary Artery Stenosis Flow: Experimental and Computational Investigation

    Science.gov (United States)

    Egelhoff, Carla; Budwig, Ralph; Hansen, Byron; Foster, Jonathan

    2000-11-01

    The effects of symmetry, flowrate, wall roughness and size are investigated using realistic pulsatile waveforms for flow viz and LDV experimental models as well as CFD models using original code. Distal to the stenosis flow is characterized by a high speed jet which is central for symmetric models and attached to the wall for eccentric models. The jet is accompanied by a low speed recirculation zone which persists while lengthening and shortening during most of the cardiac cycle. Of particular note is the downstream onset of flow instability and turbulence for high flow rate conditions in symmetric and eccentric severely occluded stenoses. The location and extent of the unstable flow region continually changes throughout the cycle, which may be a factor contributing to the thrombogenesis which coronary arteries experience.

  9. Quantifying coronary sinus flow and global LV perfusion at 3T

    Directory of Open Access Journals (Sweden)

    Bloch Karin

    2009-06-01

    Full Text Available Abstract Background Despite the large availability of 3T MR scanners and the potential of high field imaging, this technical platform has yet to prove its usefulness in the cardiac MR setting, where 1.5T remains the established standard. Global perfusion of the left ventricle, as well as the coronary flow reserve (CFR, can provide relevant diagnostic information, and MR measurements of these parameters may benefit from increased field strength. Quantitative flow measurements in the coronary sinus (CS provide one method to investigate these parameters. However, the ability of newly developed faster MR sequences to measure coronary flow during a breath-hold at 3T has not been evaluated. Methods The aim of this work was to measure CS flow using segmented phase contrast MR (PC MR on a clinical 3T MR scanner. Parallel imaging was employed to reduce the total acquisition time. Global LV perfusion was calculated by dividing CS flow with left ventricular (LV mass. The repeatability of the method was investigated by measuring the flow three times in each of the twelve volunteers. Phantom experiments were performed to investigate potential error sources. Results The average CS flow was determined to 88 ± 33 ml/min and the deduced LV perfusion was 0.60 ± 0.22 ml/min·g, in agreement with published values. The repeatability (1-error of the three repeated measurements in each subject was on average 84%. Conclusion This work demonstrates that the combination of high field strength (3T, parallel imaging and segmented gradient echo sequences allow for quantification of the CS flow and global perfusion within a breath-hold.

  10. The diastolic flow velocity-pressure gradient relation and dpv50 to assess the hemodynamic significance of coronary stenoses.

    Science.gov (United States)

    Marques, Koen M J; van Eenige, Machiel J; Spruijt, Hugo J; Westerhof, Nico; Twisk, Jos; Visser, Cees A; Visser, Frans C

    2006-12-01

    To evaluate the hemodynamic impact of coronary stenoses, the fractional (FFR) or coronary flow velocity reserve (CFVR) usually is measured. The combined measurement of instantaneous flow velocity and pressure gradient (v-dp relation) is rarely used in humans. We derived from the v-dp relation a new index, dp(v50) (pressure gradient at flow velocity of 50 cm/s), and compared the diagnostic performance of dp(v50), CFVR, and FFR. Before coronary angiography was performed, patients underwent noninvasive stress testing. In all coronary vessels with an intermediate or severe stenosis, the flow velocity, aortic, and distal coronary pressure were measured simultaneously with a Doppler and pressure guidewire after induction of hyperemia. After regression analysis of all middiastolic flow velocity and pressure gradient data, the dp(v50) was calculated. With the use of the results of noninvasive stress testing, the dp(v50) cutoff value was established at 22.4 mmHg. In 77 patients, 124 coronary vessels with a mean 39% (SD 19) diameter stenosis were analyzed. In 43 stenoses, ischemia was detected. We found a sensitivity, specificity, and accuracy of 56%, 86%, and 76% for CFVR; 77%, 99%, and 91% for FFR; and 95%, 95%, and 95% for dp(v50). To establish that dp(v50) is not dependent on maximal hyperemia, dp(v50) was recalculated after omission of the highest quartile of flow velocity data, showing a difference of 3%. We found that dp(v50) provided the highest sensitivity and accuracy compared with FFR and CFVR in the assessment of coronary stenoses. In contrast to CFVR and FFR, assessment of dp(v50) is not dependent on maximal hyperemia.

  11. Lesion flow coefficient: a combined anatomical and functional parameter for detection of coronary artery disease--a clinical study.

    Science.gov (United States)

    Peelukhana, Srikara V; Effat, Mohamed; Kolli, Kranthi K; Arif, Imran; Helmy, Tarek; Leesar, Massoud; Kerr, Hanan; Back, Lloyd H; Banerjee, Rupak

    2015-01-01

    Invasive diagnosis of coronary artery disease utilizes either anatomical or functional measurements. In this study, we tested a futuristic parameter, lesion flow coefficient (LFC, defined as the ratio of percent coronary area stenosis (%AS) to the square root of the ratio of the pressure drop across the stenosis to the dynamic pressure in the throat region), that combines both the anatomical (%AS) and functional measurements (pressure and flow) for application in a clinical setting. In 51 vessels, simultaneous pressure and flow readings were obtained using a 0.014" Combowire (Volcano Corporation). Anatomical details were assessed using quantitative coronary angiography (QCA). Fractional flow reserve (FFR), coronary flow reserve (CFR), hyperemic stenosis resistance index (HSR), and hyperemic microvascular index (HMR) were obtained at baseline and adenosine-induced hyperemia. QCA data were corrected for the presence of guidewire and then the LFC values were calculated. LFC was correlated with FFR, CFR, HSR, and HMR, individually and in combination with %AS, under both baseline and hyperemic conditions. Further, in 5 vessels, LFC group mean values were compared between pre-PCI and post-PCI groups. Panatomically measured %AS were combined (r = 0.64; Panatomical and functional endpoints, has potential for application in a clinical setting for stenosis evaluation, under both hyperemic and baseline conditions.

  12. Quantitative imaging of coronary blood flow

    Directory of Open Access Journals (Sweden)

    Adam M. Alessio

    2010-04-01

    Radiology. In 1979, he established a National Simulation Resource Facility in Circulatory Mass Transport and Exchange and in 1997, he initiated the Human Physiome Projects. He is a member of the US National Academy of Engineering. His research is on quantitative integration of cellular and cardiovascular systems.Positron emission tomography (PET is a nuclear medicine imaging modality based on the administration of a positron-emitting radiotracer, the imaging of the distribution and kinetics of the tracer, and the interpretation of the physiological events and their meaning with respect to health and disease. PET imaging was introduced in the 1970s and numerous advances in radiotracers and detection systems have enabled this modality to address a wide variety of clinical tasks, such as the detection of cancer, staging of Alzheimer's disease, and assessment of coronary artery disease (CAD. This review provides a description of the logic and the logistics of the processes required for PET imaging and a discussion of its use in guiding the treatment of CAD. Finally, we outline prospects and limitations of nanoparticles as agents for PET imaging.

  13. ASSESSMENT OF CORONARY FLOW RESERVE IN PATIENTS WITH ANGINA PECTORIS

    Institute of Scientific and Technical Information of China (English)

    沈卫峰; 蔡煦; 张大东; 张宪; 郑爱芳; 龚兰生

    1995-01-01

    ASSESSMENTOFCORONARYFLOWRESERVEINPATIENTSWITHANGINAPECTORISShengWeifeng(沈卫峰);CaiXu(蔡煦);ZhangDadong(张大东);ZhangXian(张宪);ZhengAi...

  14. Association between restless leg syndrom and slow coronary flow.

    Science.gov (United States)

    Erden, İsmail; Çakcak Erden, Emine; Durmuş, Hacer; Tıbıllı, Hakan; Tabakçı, Mustafa; Kalkan, Mehmet Emin; Türker, Yasin; Akçakoyun, Mustafa

    2014-11-01

    Restless legs syndrome (RLS) is a common sleep disorder in which patients feel unpleasent leg sensations and urge to move the legs during rest, especially at night, and symptoms are improved by leg movement. Prior studies analyzing the associations between cardiovascular disease and restless legs syndrome has shown controversial results. The goal of the study was to estimate the relationship between restless legs syndrome and slow coronary flow (SCF). The present study was cross-sectional and observational and consists of 176 individuals who underwent coronary angiography and had angiographically normal coronary arteries of varying coronary flow rates. The study included 86 patients with isolated SCF and 90 control participants with normal coronary flow (NCF). RLS was assessed the day after the coronry flow was evaluated, using a self-administered questionnaire based on the International Restless Legs Study Group criteria. The following question was asked: "Do you have unpleasant leg sensations (like crawling, paraesthesia, or pain) combined with motor restlessness and an urge to move?" The possible responses were as follows: no, less than once/month, 2-4 times/month, 5-14 times/month, and 15 or more times per month. Those who answered that they had these feelings were asked the following two more questions: 1) "Do these symptoms occur only at rest and does moving improve them?" and 2) "Are these symptoms worsen in the evening/at night compared with the morning?" RLS is considered to be probable if the participant has answered "yes" for all three of the above questions, and has a frequency of ≥5 times/month. Student's t-test, Mann-Whitney U test, multiple logistic regression analysis were used for statistical analysis. The prevalence of restless legs syndrome was 48 (27%) and increased significantly with age. Patients with SCF have more likely had RLS than the control group (p<0.001). The age-adjusted prevalence odds of SCF were 3.11 times higher (95% CI: 1

  15. Intracoronary Blood Flow Velocity and Transstenotic Pressure Drop in an Awake Human Being During Coronary Vasodilation

    NARCIS (Netherlands)

    F. Zijlstra (Felix); P.W.J.C. Serruys (Patrick)

    1988-01-01

    textabstractThe pressure drop over a coronary stenosis and the intracoronary Doppler blood flow velocity were measured at rest and during coronary vasodilation. We report the first observation that confirms the validity of fluid dynamic equations to describe the hemodynamics of a coronary stenosis b

  16. Myocardial blood flow quantification for evaluation of coronary artery disease by positron emission tomography, cardiac magnetic resonance imaging, and computed tomography.

    Science.gov (United States)

    Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond Y; Di Carli, Marcelo F

    2014-05-01

    The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging, and computed tomography, and its emerging clinical applications.

  17. Can transthoracic Doppler echocardiography be used to detect coronary slow flow phenomenon?

    Institute of Scientific and Technical Information of China (English)

    NIE Shao-ping; LUO Tai-yang; DONG Jian-zeng; LIU Xiao-hui; MA Chang-sheng; GENG Li-li; WANG Xiao; ZHANG Xiao-shan; YANG Ya; LIU Bai-qiu; LI Jun; QIAO Yan; LIU Xin-min

    2010-01-01

    Background Coronary slow flow phenomenon (CSFP) is an important, angiographic clinical entity but is lacking non-invasive detecting techniques. This study aimed to elucidate the value of transthoracic Doppler echocardiography (TTDE) in the diagnosis and monitoring of coronary slow flow in left anterior descending (LAD) coronary artery.Methods We consecutively enrolled 27 patients with CSFP in LAD detected by coronary arteriography from August 2009 to April 2010. Thirty-eight patients with angiographically normal coronary flow served as control. Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) was used to document coronary flow velocities. All subjects underwent TTDE within 24 hours after coronary angiography. LAD flow was detected and the coronary diastolic peak velocities (DPV) and diastolic mean velocities (DMV) were calculated.Results Sixty of 65 (92.3%) subjects successfully underwent TTDE. Baseline clinical characteristics were similar between the two groups. Coronary DPV and DMV of LAD were significantly lower in the CSFP group than in the control group ((0.228±0.029) m/s vs. (0.302±0.065) m/s, P=0.000; (0.176±0.028) m/s vs. (0.226±0.052) m/s, P=0.000,respectively). There was a high inverse correlation between CTFC and coronary DPV and DMV (r=-0.727, P=0.000;r=-0.671, P=0.000, respectively). Receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) was less than one half for coronary DPV (AUC=0.104) and DMV (AUC=0.204), respectively.Conclusions In patients with CSFP, there is a high inverse correlation between CTFC and coronary diastolic flow velocities in the LAD coronary artery, as measured by TTDE. The value of TTDE in the monitoring and evaluation of coronary flow in patients with CSFP deserves further investigation.

  18. Arterial bending angle and wall morphology correlate with slow coronary flow: Determination with multidetector CT coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Kantarci, Mecit, E-mail: akkanrad@hotmail.com [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Guendogdu, Fuat [Department of Cardiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Doganay, Selim [Department of Radiology, Medical Faculty, Erciyes University, Kayseri (Turkey); Duran, Cihan [Department of Radiology, Bilim University, Florence Nightingale Hospital, Istanbul (Turkey); Kalkan, M. Emin [Department of Cardiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Sagsoz, M. Erdem [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Kucuk, Osman [Department of Electronic Engineering, Engineering Faculty, Atatuerk University, Erzurum (Turkey); Karakaya, Afak [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Kucuk, Ahmet [Department of Mathematics, Science Faculty, Atatuerk University, Erzurum (Turkey); Akguen, Metin [Department of Chest, Medical Faculty, Atatuerk University, Erzurum (Turkey)

    2011-01-15

    Background and purpose: The purpose of this study was to assess angulations and vessel wall morphology that could lead to bending head loss in the RCA and LMCA arteries of patients with slow coronary flow (SCF) evaluated by MDCT coronary angiography. Methods: The study involved 51 patients (45 males, mean age: 59.6 years) who were diagnosed with SCF by coronary angiography. Diagnosis of SCF was based on thrombolysis in myocardial infarction (TIMI) frame count. Fifty-one patients with absence of slow flow were selected as the control group. The angulations of the main coronary arteries with the aorta were measured from the axial images obtained through MDCT coronary angiography, and the findings were recorded. In addition, the coronary artery walls of these patients were evaluated. For statistical analysis, SPSS for Windows 10.0 (SPSS Inc., Chicago, IL) was used. For comparisons of the angles, either independent samples t test or the Mann-Whitney U test was used where appropriate. Results: The results of the study indicated that 38 patients had SCF in the LAD. Comparisons of patients with SCF with the controls revealed that in the patients with SCF, the mean angle of the LMCA with the aorta (40.9 {+-} 20.5{sup o}) was statistically significantly smaller than the mean angle of the LMCA with the aorta in the control cases (71.8 {+-} 11{sup o}). In 12 patients, slow flow was detected in the RCA. Those with slow flow in the RCA had significantly smaller angles (mean: 33.2 {+-} 20.4{sup o}) than the other cases (mean: 78.9 {+-} 10.7{sup o}). Conclusion: A small angle of origin of the main coronary arteries from the aorta, measured on MDCT examinations is correlated with slow blood flow in those vessels, as calculated by the TIMI frame count in catheter coronary angiography.

  19. Inspiratory flow reserve in boys with Duchenne muscular dystrophy.

    Science.gov (United States)

    De Bruin, P F; Ueki, J; Bush, A; Y Manzur, A; Watson, A; Pride, N B

    2001-06-01

    Patients with advanced muscular dystrophy frequently develop ventilatory failure. Currently respiratory impairment usually is assessed by measuring vital capacity and the mouth pressure generated during a maximal inspiratory maneuver (PI,max), neither of which directly measures ventilatory capacity. We assessed inspiratory flow reserve in 26 boys [mean (SD) age 12.8 (3.8) years] with Duchenne muscular dystrophy (DMD) without ventilatory failure and in 28 normal boys [mean (SD) age 12.6 (1.9) years] by analyzing the ratio between the largest inspiratory flow during tidal breathing (V'I,max(t)) and during a forced vital capacity maneuver (V'I,max(FVC), (V'I,max(t)/V'I,maxFVC). We have compared this ratio with the forced vital capacity FVC and PI,max measured at functional residual capacity. Mean PI,max was -90(30)cmH2O, average 112% (range 57-179%) of predicted values in control boys and -31(11)cmH2O, average 40% predicted values in DMD boys (control vs DMD, P ratio was higher in DMD 0.22 (0.08) than in controls 0.12 (0.03) (P reserve in DMD. Inspiratory flow reserve was within the normal range in 8 of 19 DMD patients with PI,max less than 50% of predicted values. We conclude that measurement of inspiratory flow reserve (V'I,max(t)/V'I,maxFVC ratio) provides a simple and direct assessment of dynamic inspiratory muscle function which is not replicated by static measurement of PI,max or vital capacity and might be useful in assessment of respiratory impairment in boys with Duchenne muscular dystrophy. Follow-up studies are required to establish whether measures of inspiratory flow reserve are of clinical value in predicting subsequent ventilatory failure.

  20. Clinical evaluation of application of myocardial fractional flow reserve on elective percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction%心肌血流储备分数指导ST段抬高心肌梗死患者择期经皮冠状动脉介入的临床评价

    Institute of Scientific and Technical Information of China (English)

    邬冬梅; 王慧峰; 王凤群; 王鲲; 张永红

    2015-01-01

    目的:探讨心肌血流储备分数(FFRmyo)对ST段抬高心肌梗死(STEMI)患者择期经皮冠状动脉介入治疗(PCI)的意义。方法 STEMI行早期溶栓治疗或血栓自溶择期冠状动脉造影(CAG)的患者75例,其中FFRmyo<0.75者33例,行PCI治疗21例(A组),拒绝行PCI 治疗12例(B组),FFRmyo≥0.75者42例(C组)。记录患者一般临床资料,比较各组罪犯血管特点及临床事件发生情况。结果各组患者一般临床资料无统计学差异。随访一年,患者临床事件包括死亡、心肌梗死、靶血管血运重建及再住院的总发生率在A组及C组均显著低于B组(分别为P<0.05)。结论 FFRmyo测定对STEMI患者制定合理的治疗策略具有参考价值。%Objective To explore the application of myocardial fractional flow reserve (FFRmyo) on elective percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). Methods In all, 75 STEMI patients undergoing early thrombolysis treatment or spontaneous recanalization with elective PCI were recruited in this study. There were 33 patients with FFRmyo0.05). Fellowed one year, the total incidence of the clinical events including death, myocardial infarction, target vessel revascularization and rehospitalization was significantly lower in both Group A and Group C compared with Group B (P<0.05, respectively). Conclusion FFRmyo detection has a reference value on the establishment of treatment strategies for patients with STEMI.

  1. Reliability of fractional flow reserve on diagnosis of intermediate coronary stenosis in patients with diabetes%心肌血流储备分数评价糖尿病患者冠状动脉临界病变的可靠性

    Institute of Scientific and Technical Information of China (English)

    梁建文; 张东辉; 吴剑胜

    2015-01-01

    目的 通过测定冠状动脉中等程度狭窄的糖尿病和非糖尿病患者的心肌血流储备分数(fractional flow reserve,FFR)来评估糖尿病对FFR检测的影响.方法 本研究入组68例冠状动脉造影明确诊断为冠状动脉粥样硬化性心脏病(冠心病),且经量化冠状动脉造影(quantitative coronary angiography,QCA)诊断为中等程度狭窄的患者,分为糖尿病组和非糖尿病组;再根据病变处管腔狭窄程度进一步细分为50%~60%亚组和60%~70%亚组;根据糖化血红蛋白(glycated hemoglobin,GHb)水平分为GHb≥7.0亚组和GHb<7.0亚组.以三磷腺苷(ATP)为冠状动脉扩张剂.比较每两组间FFR的测量值(两次取平均值)及冠状动脉扩张前后的FFR差值.结果 冠状动脉狭窄程度相似的糖尿病组和非糖尿病组的FFR比较,差异无统计学意义[50%~60%亚组:(0.84±0.06)vs.(0.86±0.08),P=0.45;60%~70%亚组:[(0.76±0.09) vs.(0.81±0.07),P=0.061].糖尿病GHb≥7.0亚组的FFR高于糖尿病GHb<7.0亚组,差异有统计学意义[(0.77±0.06)ws.(0.72±0.11),P<0.05].结论 糖尿病对测定中等程度狭窄的冠状动脉的FFR没有明显影响,糖尿病且GHb≥7.0患者的FFR较GHb<7.0患者高.

  2. Fractional flow reserve: physiological basis, advantages and limitations, and potential gender differences.

    Science.gov (United States)

    Crystal, George J; Klein, Lloyd W

    2015-01-01

    Fractional flow reserve (FFR) is a physiological index of the severity of a stenosis in an epicardial coronary artery, based on the pressure differential across the stenosis. Clinicians are increasingly relying on this method because it is independent of baseline flow, relatively simple, and cost effective. The accurate measurement of FFR is predicated on maximal hyperemia being achieved by pharmacological dilation of the downstream resistance vessels (arterioles). When the stenosis causes FFR to be impaired by > 20%, it is considered to be significant and to justify revascularization. A diminished hyperemic response due to microvascular dysfunction can lead to a false normal FFR value, and a misguided clinical decision. The blunted vasodilation could be the result of defects in the signaling pathways modulated (activated or inhibited) by the drug. This might involve a downregulation or reduced number of vascular receptors, endothelial impairment, or an increased activity of an opposing vasoconstricting mechanism, such as the coronary sympathetic nerves or endothelin. There are data to suggest that microvascular dysfunction is more prevalent in post-menopausal women, perhaps due to reduced estrogen levels. The current review discusses the historical background and physiological basis for FFR, its advantages and limitations, and the phenomenon of microvascular dysfunction and its impact on FFR measurements. The question of whether it is warranted to apply gender-specific guidelines in interpreting FFR measurements is addressed.

  3. A laboratory model of the aortic root flow including the coronary arteries

    Science.gov (United States)

    Querzoli, Giorgio; Fortini, Stefania; Espa, Stefania; Melchionna, Simone

    2016-08-01

    Cardiovascular flows have been extensively investigated by means of in vitro models to assess the prosthetic valve performances and to provide insight into the fluid dynamics of the heart and proximal aorta. In particular, the models for the study of the flow past the aortic valve have been continuously improved by including, among other things, the compliance of the vessel and more realistic geometries. The flow within the sinuses of Valsalva is known to play a fundamental role in the dynamics of the aortic valve since they host a recirculation region that interacts with the leaflets. The coronary arteries originate from the ostia located within two of the three sinuses, and their presence may significantly affect the fluid dynamics of the aortic root. In spite of their importance, to the extent of the authors' knowledge, coronary arteries were not included so far when modeling in vitro the transvalvular aortic flow. We present a pulse duplicator consisting of a passively pulsing ventricle, a compliant proximal aorta, and coronary arteries connected to the sinuses of Valsalva. The coronary flow is modulated by a self-regulating device mimicking the physiological mechanism, which is based on the contraction and relaxation of the heart muscle during the cardiac cycle. Results show that the model reproduces satisfyingly the coronary flow. The analysis of the time evolution of the velocity and vorticity fields within the aortic root reveals the main characteristics of the backflow generated through the aorta in order to feed the coronaries during the diastole. Experiments without coronary flow have been run for comparison. Interestingly, the lifetime of the vortex forming in the sinus of Valsalva during the systole is reduced by the presence of the coronaries. As a matter of fact, at the end of the systole, that vortex is washed out because of the suction generated by the coronary flow. Correspondingly, the valve closure is delayed and faster compared to the case with

  4. Effect of Diltiazem on Coronary Artery Flow and Myocardial Perfusion in Patients With Isolated Coronary Artery Ectasia and Either Stable Angina Pectoris or Positive Myocardial Ischemic Stress Test.

    Science.gov (United States)

    Ozcan, Ozgur Ulas; Atmaca, Yusuf; Goksuluk, Huseyin; Akbulut, Irem Muge; Ozyuncu, Nil; Ersoy, Nedret; Erol, Cetin

    2015-10-15

    Isolated coronary artery ectasia (CAE) may be associated with stable or unstable coronary events despite the absence of epicardial coronary stenosis. Impaired coronary flow dynamics and myocardial perfusion have been demonstrated in stable patients with ectatic coronary arteries. We aimed to assess whether epicardial flow and tissue-level perfusion would be improved by diltiazem in myocardial regions subtended by the ectatic coronary arteries in patients with isolated CAE. A total of 60 patients with isolated CAE were identified of 9,780 patients who underwent elective coronary angiography. Patients were randomized to 5 mg of intracoronary diltiazem or saline. Coronary blood flow of the microvascular network was assessed using myocardial blush grade (MBG) technique. The thrombolysis in myocardial infarction (TIMI) flow grade and TIMI frame count (TFC) were used to assess epicardial coronary flow. MBG (from 2.4 to 2.6, p = 0.02), TIMI flow grades (from 2.4 to 2.8, p flow grade; and from 35 to 33, p = 0.43 for TFC). Diltiazem provided amelioration of the altered coronary flow dynamics, which was suggested as the pathophysiological influence of CAE. In conclusion, the favorable effects of the diltiazem on myocardial perfusion were observed at both epicardial and tissue levels.

  5. Impaired myocardial blood flow reserve in subjects with metabolic syndrome analyzed using positron emission tomography and N-13 labeled ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Teragawa, Hiroki; Kihara, Yasuki [Hiroshima University Graduate School of Biomedical Sciences, Department of Cardiovascular Medicine, Hiroshima (Japan); Morita, Koichi; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Shishido, Hiroki; Otsuka, Nobuaki; Hirokawa, Yutaka [Hiroshima Heiwa Clinic, Hiroshima (Japan); Chayama, Kazuaki [Hiroshima University Graduate School of Biomedical Sciences, Department of Molecular Science and Medicine, Hiroshima (Japan)

    2010-02-15

    Coronary vasomotor response might be impaired in metabolic syndrome (MS); however, the precise abnormality has not been elucidated. The aim of this study was to assess coronary-vasomotor response in MS subjects using N-13 labeled ammonia and positron emission tomography. Myocardial blood flow (MBF) was measured at rest and during adenosine infusion in MS subjects (n = 13, MS group) with no definite evidence of heart disease and in subjects without MS (n = 14, non-MS group). Coronary vascular resistance (CVR) was calculated by dividing the mean aortic blood pressure by MBF. Myocardial blood flow reserve (MFR) was calculated as the ratio of the MBF during adenosine infusion to that during rest. Blood chemical parameters were measured to evaluate their relationship with MFR. During adenosine infusion, MBF was lower (p = 0.0085) and CVR higher (p = 0.0128) in the MS group than in the non-MS group and MFR was significantly lower in the MS group than in the non-MS group (2.13 {+-} 0.99 vs. 3.38 {+-} 0.95, p = 0.0027). Multivariate analysis demonstrated that the homeostasis model assessment-insulin resistance (p < 0.05) and the presence of hypertension (p < 0.05) were independent determinants of MFR. The results indicate that MFR was impaired in MS subjects, suggesting that an abnormal coronary microvascular response occurred in these subjects. This abnormality may have been partially due to insulin resistance and hypertension. (orig.)

  6. Autoregulation of coronary blood flow in the isolated beating pig heart.

    Science.gov (United States)

    Schampaert, Stéphanie; van 't Veer, Marcel; Rutten, Marcel C M; van Tuijl, Sjoerd; de Hart, Jurgen; van de Vosse, Frans N; Pijls, Nico H J

    2013-08-01

    The isolated beating pig heart model is an accessible platform to investigate the coronary circulation in its truly morphological and physiological state, whereas its use is beneficial from a time, cost, and ethical perspective. However, whether the coronary autoregulation is still intact is not known. Here, we study the autoregulation of coronary blood flow in the working isolated pig heart in response to brief occlusions of the coronary artery, to step-wise changes in left ventricular loading conditions and contractile states, and to pharmacologic vasodilating stimuli. Six slaughterhouse pig hearts (473 ± 40 g) were isolated, prepared, and connected to an external circulatory system. Through coronary reperfusion and controlled cardiac loading, physiological cardiac performance was achieved. After release of a coronary occlusion, coronary blood flow rose rapidly to an equal (maximum) level as the flow during control beats, independent of the duration of occlusion. Moreover, a linear relation was found between coronary blood flow and coronary driving pressure for a wide variation of preload, afterload, and contractility. In addition, intracoronary administration of papaverine did not yield a transient increase in blood flow indicating the presence of maximum coronary hyperemia. Together, this indicates that the coronary circulation in the isolated beating pig heart is in a permanent state of maximum hyperemia. This makes the model excellently suitable for testing and validating cardiovascular devices (i.e., heart valves, stent grafts, and ventricular assist devices) under well-controlled circumstances, whereas it decreases the necessity of sacrificing large mammalians for performing classical animal experiments. © 2013, Copyright the Authors. Artificial Organs © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

  7. Recruitable collateral blood flow index predicts coronary instent restenosis after percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Lassen, Jens Flensted

    2007-01-01

    in patients undergoing PCI with bare metal stents and using optimal antithrombotic treatment. METHODS AND RESULTS: In 95 patients, 95 de novo lesions were treated with PCI and a bare metal stent. Fractional flow reserve (FFR) at maximum hyperaemia induced by intravenous adenosine was determined. The pressure.......25) had a lower pre-interventional FFR (0.50 +/- 0.14 vs. 0.72 +/- 0.18, P ratio 1.07, 95% CI 1...

  8. Instantaneous Wave-free Ratio versus Fractional Flow Reserve to Guide PCI.

    Science.gov (United States)

    Götberg, Matthias; Christiansen, Evald H; Gudmundsdottir, Ingibjörg J; Sandhall, Lennart; Danielewicz, Mikael; Jakobsen, Lars; Olsson, Sven-Erik; Öhagen, Patrik; Olsson, Hans; Omerovic, Elmir; Calais, Fredrik; Lindroos, Pontus; Maeng, Michael; Tödt, Tim; Venetsanos, Dimitrios; James, Stefan K; Kåregren, Amra; Nilsson, Margareta; Carlsson, Jörg; Hauer, Dario; Jensen, Jens; Karlsson, Ann-Charlotte; Panayi, Georgios; Erlinge, David; Fröbert, Ole

    2017-03-18

    Background The instantaneous wave-free ratio (iFR) is an index used to assess the severity of coronary-artery stenosis. The index has been tested against fractional flow reserve (FFR) in small trials, and the two measures have been found to have similar diagnostic accuracy. However, studies of clinical outcomes associated with the use of iFR are lacking. We aimed to evaluate whether iFR is noninferior to FFR with respect to the rate of subsequent major adverse cardiac events. Methods We conducted a multicenter, randomized, controlled, open-label clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2037 participants with stable angina or an acute coronary syndrome who had an indication for physiologically guided assessment of coronary-artery stenosis were randomly assigned to undergo revascularization guided by either iFR or FFR. The primary end point was the rate of a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization within 12 months after the procedure. Results A primary end-point event occurred in 68 of 1012 patients (6.7%) in the iFR group and in 61 of 1007 (6.1%) in the FFR group (difference in event rates, 0.7 percentage points; 95% confidence interval [CI], -1.5 to 2.8%; P=0.007 for noninferiority; hazard ratio, 1.12; 95% CI, 0.79 to 1.58; P=0.53); the upper limit of the 95% confidence interval for the difference in event rates fell within the prespecified noninferiority margin of 3.2 percentage points. The results were similar among major subgroups. The rates of myocardial infarction, target-lesion revascularization, restenosis, and stent thrombosis did not differ significantly between the two groups. A significantly higher proportion of patients in the FFR group than in the iFR group reported chest discomfort during the procedure. Conclusions Among patients with stable angina or an acute coronary syndrome, an iFR-guided revascularization strategy was

  9. Transient integral boundary layer method to calculate the translesional pressure drop and the fractional flow reserve in myocardial bridges

    Directory of Open Access Journals (Sweden)

    Möhlenkamp Stefan

    2006-06-01

    Full Text Available Abstract Background The pressure drop – flow relations in myocardial bridges and the assessment of vascular heart disease via fractional flow reserve (FFR have motivated many researchers the last decades. The aim of this study is to simulate several clinical conditions present in myocardial bridges to determine the flow reserve and consequently the clinical relevance of the disease. From a fluid mechanical point of view the pathophysiological situation in myocardial bridges involves fluid flow in a time dependent flow geometry, caused by contracting cardiac muscles overlying an intramural segment of the coronary artery. These flows mostly involve flow separation and secondary motions, which are difficult to calculate and analyse. Methods Because a three dimensional simulation of the haemodynamic conditions in myocardial bridges in a network of coronary arteries is time-consuming, we present a boundary layer model for the calculation of the pressure drop and flow separation. The approach is based on the assumption that the flow can be sufficiently well described by the interaction of an inviscid core and a viscous boundary layer. Under the assumption that the idealised flow through a constriction is given by near-equilibrium velocity profiles of the Falkner-Skan-Cooke (FSC family, the evolution of the boundary layer is obtained by the simultaneous solution of the Falkner-Skan equation and the transient von-Kármán integral momentum equation. Results The model was used to investigate the relative importance of several physical parameters present in myocardial bridges. Results have been obtained for steady and unsteady flow through vessels with 0 – 85% diameter stenosis. We compare two clinical relevant cases of a myocardial bridge in the middle segment of the left anterior descending coronary artery (LAD. The pressure derived FFR of fixed and dynamic lesions has shown that the flow is less affected in the dynamic case, because the distal

  10. [Mechanisms of coronary flow recovery in the isolated heart during reperfusion with cardioprotective liposomal emoxipin form].

    Science.gov (United States)

    Toropova, Ia G; Antonova, L V; Mukhamadiiarov, R A; Bogdanov, M V; Golovkin, A S

    2013-06-01

    In the experiments on the isolated perfused rat heart the effects of liposomes, containing different concentrations (0.25 and 0.1 mg/mL) of emoxipine, on coronary flow restoration after total normothermic ischemia and reperfusion were studied. The coronary flow, levels of nitrates and nitrites in the outflowing perfusate from heart and level of free radical processes were assessed, The obtained results showed that 0.1 mg/mL liposomal emoxipine provide with stronger increase coronary flow during reperfusion mostly due to the increase concentration of endothelial nitric oxide compare with treatments at 0.25 mg/mL.

  11. Angiographic characteristics of intermediate stenosis of the left anterior descending artery for determination of lesion significance as identified by fractional flow reserve

    DEFF Research Database (Denmark)

    Biasco, Luigi; Pedersen, Frants; Lønborg, Jacob

    2015-01-01

    Previous studies have shown a poor correlation between angiographic assessment of stenosis grade (%) and its functional assessment by fractional flow reserve (FFR). This study aimed to investigate whether a more comprehensive evaluation of the coronary angiogram may contribute to a better...... identification of flow-limiting stenoses. Coronary angiograms of 1,350 patients (1,883 lesions) were retrospectively analyzed for stenosis grade (eyeballing, %) and matched with FFR values. Angiography-derived optimal cut-off values and intervals delineating the [90% sensitivity-90% specificity] range were 50...... wrap" of LAD, and (5) collaterals to an occluded LCX/RCA. Based on these results, a risk score (P20-DAC2) for prediction of flow limitation in intermediate LAD lesions was derived. In conclusion, a comprehensive evaluation of the coronary angiogram-in which besides stenosis grade also other lesion...

  12. [Diffuse atherosclerotic disease unmasked by invasive physiologic assessment of coronary flow].

    Science.gov (United States)

    Sant'Anna, Fernando Mendes; Silva, Expedito E Ribeiro da; Batista, Leonardo Alves; Ventura, Fábio Machado; Barrozo, Carlos Alberto Mussel; Pijls, Nico H J

    2005-08-01

    It is known that coronary atherosclerosis is a diffuse process, very little visible at angiography. This article describes a stable angina patient, three months after acute myocardial infarction (AMI), and a severe lesion in anterior descending artery (ADA), evinced by coronariography. Myocardial fractional flow reserve (FFR), obtained through intracoronary pressure measurements, was 0.37 during maximum hyperemia, clearly showing the presence of ischemia. A stent was implanted in ADA and, despite the excellent angiographic result, post-stent FFR was only 0.75, the minimum limit, below which there is ischemia. When the pressure wire (PW) was slowly drawn back from the distal portion of ADA to its proximal portion, a continuous and gradual increase in intracoronary pressure was noted, which clearly indicates diffuse atherosclerosis and not focal stenosis. A gradient was not observed at the stent place. The patient was kept under medical treatment and has been asymptomatic so far.

  13. Coronary pressure and flow relationships in humans: phasic analysis of normal and pathological vessels and the implications for stenosis assessment: a report from the Iberian–Dutch–English (IDEAL) collaborators

    Science.gov (United States)

    Nijjer, Sukhjinder S.; de Waard, Guus A.; Sen, Sayan; van de Hoef, Tim P.; Petraco, Ricardo; Echavarría-Pinto, Mauro; van Lavieren, Martijn A.; Meuwissen, Martijn; Danad, Ibrahim; Knaapen, Paul; Escaned, Javier; Piek, Jan J.; Davies, Justin E.; van Royen, Niels

    2016-01-01

    Background Our understanding of human coronary physiological behaviour is derived from animal models. We sought to describe physiological behaviour across a large collection of invasive pressure and flow velocity measurements, to provide a better understanding of the relationships between these physiological parameters and to evaluate the rationale for resting stenosis assessment. Methods and results Five hundred and sixty-seven simultaneous intracoronary pressure and flow velocity assessments from 301 patients were analysed for coronary flow velocity, trans-stenotic pressure gradient (TG), and microvascular resistance (MVR). Measurements were made during baseline and hyperaemic conditions. The whole cardiac cycle and the diastolic wave-free period were assessed. Stenoses were assessed according to fractional flow reserve (FFR) and quantitative coronary angiography DS%. With progressive worsening of stenoses, from unobstructed angiographic normal vessels to those with FFR ≤ 0.50, hyperaemic flow falls significantly from 45 to 19 cm/s, Ptrend stenosis severity and was consistent across all strata of stenosis (Ptrend > 0.05 for all). Trans-stenotic pressure gradient rose with stenosis severity for both rest and hyperaemic measures (Ptrend stenosis severity under resting conditions (Ptrend stenosis severity, TG rises. However, while hyperaemic flow falls significantly, resting coronary flow is maintained by compensatory reduction of MVR, demonstrating coronary auto-regulation. These data support the translation of coronary physiological concepts derived from animals to patients with coronary artery disease and furthermore, suggest that resting pressure indices can be used to detect the haemodynamic significance of coronary artery stenoses. PMID:26612582

  14. The deep hydrogeologic flow system underlying the Oak Ridge Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Nativ, R. [Hebrew Univ., Jerusalem (IL); Hunley, A.E. [Oak Ridge National Lab., TN (United States)

    1993-07-01

    The deep hydrogeologic system underlying the Oak Ridge Reservation contains some areas contaminated with radionuclides, heavy metals, nitrates, and organic compounds. The groundwater at that depth is saline and has previously been considered stagnant. On the basis of existing and newly collected data, the nature of flow of the saline groundwater and its potential discharge into shallow, freshwater systems was assessed. Data used for this purpose included (1) spatial and temporal pressures and hydraulic heads measured in the deep system, (2) hydraulic parameters of the formations in question, (3) spatial temperature variations, and (4) spatial and temporal chemical and isotopic composition of the saline groundwater. In addition, chemical analyses of brine in adjacent areas in Tennessee, Kentucky, Ohio, Pennsylvania, and West Virginia were compared with the deep water underlying the reservation to help assess the origin of the brine. Preliminary conclusions suggest that the saline water contained at depth is old but not isolated (in terms of recharge and discharge) from the overlying active and freshwater-bearing units. The confined water (along with dissolved solutes) moves along open fractures (or man-made shortcuts) at relatively high velocity into adjacent, more permeable units. Groundwater volumes involved in this flow probably are small.

  15. Contribution of KV7 Channels to Basal Coronary Flow and Active Response to Ischemia

    DEFF Research Database (Denmark)

    Khanamiri, Saereh; Soltysinska, Ewa; Jepps, Thomas A

    2013-01-01

    .5 activators produced relaxations, which were considerably less in arteries from hypertensive rats and were not mimicked by the KV7.1-specific activator R-L3. In isolated, perfused heart preparations, coronary flow rate increased in response to the KV7.2 to 7.5 activator (S)-1 and was diminished......The goal of the present study was to determine the role of KCNQ-encoded KV channels (KV7 channels) in the passive and active regulation of coronary flow in normotensive and hypertensive rats. In left anterior descending coronary arteries from normotensive rats, structurally different KV7.2 to 7....... Application of adenosine or A2A receptor agonist CGS-21680 produced concentration-dependent relaxations of coronary arteries from normotensive rats, which were attenuated by application of KV7 inhibitors. KV7 blockers also attenuated the ischemia-induced increase in coronary perfusion in Langendorff studies...

  16. Use of the Instantaneous Wave-free Ratio or Fractional Flow Reserve in PCI.

    Science.gov (United States)

    Davies, Justin E; Sen, Sayan; Dehbi, Hakim-Moulay; Al-Lamee, Rasha; Petraco, Ricardo; Nijjer, Sukhjinder S; Bhindi, Ravinay; Lehman, Sam J; Walters, Darren; Sapontis, James; Janssens, Luc; Vrints, Christiaan J; Khashaba, Ahmed; Laine, Mika; Van Belle, Eric; Krackhardt, Florian; Bojara, Waldemar; Going, Olaf; Härle, Tobias; Indolfi, Ciro; Niccoli, Giampaolo; Ribichini, Flavo; Tanaka, Nobuhiro; Yokoi, Hiroyoshi; Takashima, Hiroaki; Kikuta, Yuetsu; Erglis, Andrejs; Vinhas, Hugo; Canas Silva, Pedro; Baptista, Sérgio B; Alghamdi, Ali; Hellig, Farrel; Koo, Bon-Kwon; Nam, Chang-Wook; Shin, Eun-Seok; Doh, Joon-Hyung; Brugaletta, Salvatore; Alegria-Barrero, Eduardo; Meuwissen, Martijin; Piek, Jan J; van Royen, Niels; Sezer, Murat; Di Mario, Carlo; Gerber, Robert T; Malik, Iqbal S; Sharp, Andrew S P; Talwar, Suneel; Tang, Kare; Samady, Habib; Altman, John; Seto, Arnold H; Singh, Jasvindar; Jeremias, Allen; Matsuo, Hitoshi; Kharbanda, Rajesh K; Patel, Manesh R; Serruys, Patrick; Escaned, Javier

    2017-03-18

    Background Coronary revascularization guided by fractional flow reserve (FFR) is associated with better patient outcomes after the procedure than revascularization guided by angiography alone. It is unknown whether the instantaneous wave-free ratio (iFR), an alternative measure that does not require the administration of adenosine, will offer benefits similar to those of FFR. Methods We randomly assigned 2492 patients with coronary artery disease, in a 1:1 ratio, to undergo either iFR-guided or FFR-guided coronary revascularization. The primary end point was the 1-year risk of major adverse cardiac events, which were a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization. The trial was designed to show the noninferiority of iFR to FFR, with a margin of 3.4 percentage points for the difference in risk. Results At 1 year, the primary end point had occurred in 78 of 1148 patients (6.8%) in the iFR group and in 83 of 1182 patients (7.0%) in the FFR group (difference in risk, -0.2 percentage points; 95% confidence interval [CI], -2.3 to 1.8; Pratio, 0.95; 95% CI, 0.68 to 1.33; P=0.78). The risk of each component of the primary end point and of death from cardiovascular or noncardiovascular causes did not differ significantly between the groups. The number of patients who had adverse procedural symptoms and clinical signs was significantly lower in the iFR group than in the FFR group (39 patients [3.1%] vs. 385 patients [30.8%], P<0.001), and the median procedural time was significantly shorter (40.5 minutes vs. 45.0 minutes, P=0.001). Conclusions Coronary revascularization guided by iFR was noninferior to revascularization guided by FFR with respect to the risk of major adverse cardiac events at 1 year. The rate of adverse procedural signs and symptoms was lower and the procedural time was shorter with iFR than with FFR. (Funded by Philips Volcano; DEFINE-FLAIR ClinicalTrials.gov number, NCT02053038 .).

  17. Impact of local flow haemodynamics on atherosclerosis in coronary artery bifurcations.

    Science.gov (United States)

    Antoniadis, Antonios P; Giannopoulos, Andreas A; Wentzel, Jolanda J; Joner, Michael; Giannoglou, George D; Virmani, Renu; Chatzizisis, Yiannis S

    2015-01-01

    Coronary artery bifurcations are susceptible to atherosclerosis as a result of the unique local flow patterns and the subsequent endothelial shear stress (ESS) environment that are conducive to the development of plaques. Along the lateral walls of the main vessel and side branches, a distinct flow pattern is observed with local low and oscillatory ESS, while high ESS develops at the flow divider (carina). Histopathologic studies have shown that the distribution of plaque at bifurcation regions is related to the local ESS patterns. The local ESS profile also influences the outcome of percutaneous coronary interventions in bifurcation lesions. A variety of invasive and non-invasive imaging modalities have enabled 3D reconstruction of coronary bifurcations and thereby detailed local ESS assessment by computational fluid dynamics. Highly effective strategies for treatment and ultimately prevention of atherosclerosis in coronary bifurcations are anticipated with the use of advanced imaging and computational fluid dynamic techniques.

  18. Severe familial hypercholesterolemia impairs the regulation of coronary blood flow and oxygen supply during exercise.

    Science.gov (United States)

    Bender, Shawn B; de Beer, Vincent J; Tharp, Darla L; Bowles, Douglas K; Laughlin, M Harold; Merkus, Daphne; Duncker, Dirk J

    2016-11-01

    Accelerated development of coronary atherosclerosis is a defining characteristic of familial hypercholesterolemia (FH). However, the recent data highlight a significant cardiovascular risk prior to the development of critical coronary stenosis. We, therefore, examined the hypothesis that FH produces coronary microvascular dysfunction and impairs coronary vascular control at rest and during exercise in a swine model of FH. Coronary vascular responses to drug infusions and exercise were examined in chronically instrumented control and FH swine. FH swine exhibited ~tenfold elevation of plasma cholesterol and diffuse coronary atherosclerosis (20-60 % plaque burden). Similar to our recent findings in the systemic vasculature in FH swine, coronary smooth muscle nitric oxide sensitivity was increased in vivo and in vitro with maintained endothelium-dependent vasodilation in vivo in FH. At rest and during exercise, FH swine exhibited increased myocardial O2 extraction resulting in reduced coronary venous SO2 and PO2 versus control. During exercise in FH swine, the transmural distribution of coronary blood flow was unchanged; however, a shift toward anaerobic cardiac metabolism was revealed by increased coronary arteriovenous H(+) concentration gradient. This shift was associated with a worsening of cardiac efficiency (relationship between cardiac work and O2 consumption) in FH during exercise owing, in part, to a generalized reduction in stroke volume which was associated with increased left atrial pressure in FH. Our data highlight a critical role for coronary microvascular dysfunction as a contributor to impaired myocardial O2 balance, cardiac ischemia, and impaired cardiac function prior to the development of critical coronary stenosis in FH.

  19. Influence of anatomical dominance and hypertension on coronary conduit arterial and microcirculatory flow patterns: a multiscale modeling study.

    Science.gov (United States)

    Mynard, Jonathan P; Smolich, Joseph J

    2016-07-01

    Coronary hemodynamics are known to be affected by intravascular and extravascular factors that vary regionally and transmurally between the perfusion territories of left and right coronary arteries. However, despite clinical evidence that left coronary arterial dominance portends greater cardiovascular risk, relatively little is known about the effects of left or right dominance on regional conduit arterial and microcirculatory blood flow patterns, particularly in the presence of systemic or pulmonary hypertension. We addressed this issue using a multiscale numerical model of the human coronary circulation situated in a closed-loop cardiovascular model. The coronary model represented left or right dominant anatomies and accounted for transmural and regional differences in vascular properties and extravascular compression. Regional coronary flow dynamics of the two anatomical variants were compared under normotensive conditions, raised systemic or pulmonary pressures with maintained flow demand, and after accounting for adaptations known to occur in acute and chronic hypertensive states. Key findings were that 1) right coronary arterial flow patterns were strongly influenced by dominance and systemic/pulmonary hypertension; 2) dominance had minor effects on left coronary arterial and all microvascular flow patterns (aside from mean circumflex flow); 3) although systemic hypertension favorably increased perfusion pressure, this benefit varied regionally and transmurally and was offset by increased left ventricular and septal flow demands; and 4) pulmonary hypertension had a substantial negative effect on right ventricular and septal flows, which was exacerbated by greater metabolic demands. These findings highlight the importance of interactions between coronary arterial dominance and hypertension in modulating coronary hemodynamics.

  20. Flow disturbances in stent-related coronary evaginations

    DEFF Research Database (Denmark)

    Radu, Maria D; Pfenniger, Aloïs; Räber, Lorenz

    2014-01-01

    Aims: Angiographic ectasias and aneurysms in stented segments have been associated with late stent thrombosis. Using optical coherence tomography (OCT), some stented segments show coronary evaginations reminiscent of ectasias. The purpose of this study was to explore, using computational fluid...

  1. Improved assessment of functional severity of coronary artery stenosis by analysis of combined intracoronary pressure and flow velocity signals

    NARCIS (Netherlands)

    Nolte, F.

    2014-01-01

    Coronary artery disease (CAD) accounts for almost 2 million deaths per year within the EU. CAD is often characterized by focal narrowing of epicardial arteries, limiting coronary arterial flow and myocardial perfusion. Treatment of critical lesions by percutaneous coronary intervention (PCI) can be

  2. Usefulness of BMIPP SPECT to evaluate myocardial viability, contractile reserve and coronary stenotic progression after reperfusion in acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Katsunuma, Eita; Kurokawa, Shingo; Takahashi, Motoi; Fukuda, Naoto; Kurosawa, Toshiro; Izumi, Tohru [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine

    2001-07-01

    Using combined {sup 123}I-BMIPP (BMIPP), {sup 201}Tl (Tl) and {sup 99m}Tc-PYP (PYP) myocardial SPECT imaging, risk areas of acute myocardial infarction were documented in the acute stage, and then these images were evaluated for how well they reflected muscle viability, contractile reserve and coronary stenotic progression subsequent to reperfusion therapy. Patients who only experienced a first attack of myocardial infarction were enrolled. In total, 36 cases who had had the occluded artery successfully reperfused were examined during the past year. They had no significant vessel disease except for the culprit single artery. The patients were comprised of 32 men and 4 women. The mean age was 59.5 years. All patients underwent coronary angiography and left ventricular (LV) angiography in the emergency room. BMIPP/Tl and PYP myocardial SPECT were conducted in the acute stage and chronic stage. In the chronic stage LV angiography was repeated to assess the improvement of LV wall motion. The response to postextrasystolic potentiation (PESP) testing was performed to estimate myocardial contractile reserve. The risk area of acute myocardial infarction (AMI) was documented by reduced BMIPP accumulation. The size of reduced BMIPP accumulation was larger than that of PYP accumulation. A BMIPP/Tl discrepancy and PYP accumulation were documented to assess myocardial viability. Both improvement in LV wall motion and augmentation of PESP response were more closely related to a BMIPP/Tl discrepancy in the presence or absence of PYP accumulation. Therefore, it would be possible to evaluate myocardial viability and contractile reserve by the BMIPP/Tl discrepancy. In patients with good viability, it is important to predict whether there is coronary stenotic progression or not. In this study, we demonstrated that most patients with improved BMIPP images had no significant progression at the site of intervention. Serial observation of BMIPP images from the acute stage to the chronic

  3. Chest pain with myocardial ischemia in a child: should we think about coronary slow flow phenomenon?

    Science.gov (United States)

    Kocabaş, Abdullah; Kardelen, Fırat; Akçurin, Gayaz; Ertuğ, Halil

    2013-10-01

    The coronary slow flow phenomenon (CSFP) is an angiographic finding characterized by delayed opacification of epicardial coronary arteries in the absence of stenotic lesion. Herein, we present a 13-year-old boy with recurrent chest pain who was diagnosed with acute ST-segment elevation myocardial infarction associated with CSFP, which has not been reported previously in the pediatric age group. Coronary angiography revealed only the presence of slow flow in the left anterior descending (LAD) coronary artery. Myocardial perfusion scintigraphy revealed a reversible perfusion defect in the LAD territory, which regressed partially at rest and showed complete improvement after dipyridamole infusion. All the symptoms, electrocardiogram abnormalities and cardiac markers returned to normal after dipyridamole treatment during the follow-up. We conclude that CSFP should be kept in mind in the differential diagnosis of chest pain with myocardial ischemia in the pediatric age group.

  4. Relationship between elevated serum gamma-glutamyltransferase activity and slow coronary flow

    DEFF Research Database (Denmark)

    Sen, Nihat; Ozlü, Mehmet F; Basar, Nurcan

    2009-01-01

    . The results were compared with those of a control group consisting of 86 age- and sex-matched patients who had normal coronary arteries and normal coronary flow. RESULTS: The three groups were similar with respect to body mass index, presence of hypertension and diabetes mellitus, lipid profiles, and fasting...... was found as the only independent predictor of the mean TFC (beta=0.309; pphysiopathologic role of serum GGT activity in SCF....

  5. Risk model for estimating the 1-year risk of deferred lesion intervention following deferred revascularization after fractional flow reserve assessment.

    Science.gov (United States)

    Depta, Jeremiah P; Patel, Jayendrakumar S; Novak, Eric; Gage, Brian F; Masrani, Shriti K; Raymer, David; Facey, Gabrielle; Patel, Yogesh; Zajarias, Alan; Lasala, John M; Amin, Amit P; Kurz, Howard I; Singh, Jasvindar; Bach, Richard G

    2015-02-21

    Although lesions deferred revascularization following fractional flow reserve (FFR) assessment have a low risk of adverse cardiac events, variability in risk for deferred lesion intervention (DLI) has not been previously evaluated. The aim of this study was to develop a prediction model to estimate 1-year risk of DLI for coronary lesions where revascularization was not performed following FFR assessment. A prediction model for DLI was developed from a cohort of 721 patients with 882 coronary lesions where revascularization was deferred based on FFR between 10/2002 and 7/2010. Deferred lesion intervention was defined as any revascularization of a lesion previously deferred following FFR. The final DLI model was developed using stepwise Cox regression and validated using bootstrapping techniques. An algorithm was constructed to predict the 1-year risk of DLI. During a mean (±SD) follow-up period of 4.0 ± 2.3 years, 18% of lesions deferred after FFR underwent DLI; the 1-year incidence of DLI was 5.3%, while the predicted risk of DLI varied from 1 to 40%. The final Cox model included the FFR value, age, current or former smoking, history of coronary artery disease (CAD) or prior percutaneous coronary intervention, multi-vessel CAD, and serum creatinine. The c statistic for the DLI prediction model was 0.66 (95% confidence interval, CI: 0.61-0.70). Patients deferred revascularization based on FFR have variation in their risk for DLI. A clinical prediction model consisting of five clinical variables and the FFR value can help predict the risk of DLI in the first year following FFR assessment. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  6. Moderate exercise training promotes adaptations in coronary blood flow and adenosine production in normotensive rats

    Directory of Open Access Journals (Sweden)

    Fernanda R. Roque

    2011-01-01

    Full Text Available OBJECTIVES: Aerobic exercise training prevents cardiovascular risks. Regular exercise promotes functional and structural adaptations that are associated with several cardiovascular benefits. The aim of this study is to investigate the effects of swimming training on coronary blood flow, adenosine production and cardiac capillaries in normotensive rats. METHODS: Wistar rats were randomly divided into two groups: control (C and trained (T. An exercise protocol was performed for 10 weeks and 60 min/day with a tail overload of 5% bodyweight. Coronary blood flow was quantified with a color microsphere technique, and cardiac capillaries were quantified using light microscopy. Adenine nucleotide hydrolysis was evaluated by enzymatic activity, and protein expression was evaluated by western blot. The results are presented as the means ± SEMs (p<0.05. RESULTS: Exercise training increased the coronary blood flow and the myocardial capillary-to-fiber ratio. Moreover, the circulating and cardiac extracellular adenine nucleotide hydrolysis was higher in the trained rats than in the sedentary rats due to the increased activity and protein expression of enzymes, such as E-NTPDase and 59- nucleotidase. CONCLUSIONS: Swimming training increases coronary blood flow, number of cardiac capillaries, and adenine nucleotide hydrolysis. Increased adenosine production may be an important contributor to the enhanced coronary blood flow and angiogenesis that were observed in the exercise-trained rats; collectively, these results suggest improved myocardial perfusion.

  7. Cell-cell interaction in blood flow in patients with coronary heart disease (in vitro study)

    Science.gov (United States)

    Malinova, Lidia I.; Simonenko, Georgy V.; Denisova, Tatyana P.; Tuchin, Valery V.

    2007-02-01

    Blood cell-cell and cell-vessel wall interactions are one of the key patterns in blood and vascular pathophysiology. We have chosen the method of reconstruction of pulsative blood flow in vitro in the experimental set. Blood flow structure was studied by PC integrated video camera with following slide by slide analysis. Studied flow was of constant volumetric blood flow velocity (1 ml/h). Diameter of tube in use was comparable with coronary arteries diameter. Glucose solution and unfractured heparin were used as the nonspecial irritants of studied flow. Erythrocytes space structure in flow differs in all groups of patients in our study (men with stable angina pectoris (SAP), myocardial infarction (MI) and practically healthy men (PHM). Intensity of erythrocytes aggregate formation was maximal in patients with SAP, but time of their "construction/deconstruction" at glucose injection was minimal. Phenomena of primary clotting formation in patients with SAP of high function class was reconstructed under experimental conditions. Heparin injection (10 000 ED) increased linear blood flow velocity both in patients with SAP, MI and PHP but modulated the cell profile in the flow. Received data correspond with results of animal model studies and noninvasive blood flow studies in human. Results of our study reveal differences in blood flow structure in patients with coronary heart disease and PHP under irritating conditions as the possible framework of metabolic model of coronary blood flow destabilization.

  8. Abnormalities in myocardial contractility, metabolism and perfusion reserve in non-stenotic coronary segments in heart failure patients

    NARCIS (Netherlands)

    van den Heuvel, AFM; Bax, JJ; Blanksma, PK; Vaalburg, W; Crijns, HJGM; van Veldhuisen, DJ

    2002-01-01

    Objective: Myocardial blood flow (MBF) reserve is impaired in congestive heart failure (CHF), while fluorine-18-deoxyglucose ((18)FDG) uptake is relatively preserved. To determine whether this mismatch could be interpreted as ischemia, we performed dobutamine stress echocardiography (DSE). Methods:

  9. Detection of severe left anterior descending coronary artery stenosis by transthoracic evaluation of resting coronary flow velocity dynamics

    Directory of Open Access Journals (Sweden)

    Edward G. Abinader

    2010-09-01

    Full Text Available In the presence of severe stenosis, coronary artery flow may be reduced at rest. Recent advances in echocardiography have made non-invasive sampling of velocities in the left an­terior descending coronary artery (LAD possible. The aim of our study was to evaluate feasi­bility and capability of transthoracic Doppler to detect severe stenosis of the LAD. The study population consisted of 42 subjects with suspected coronary artery disease scheduled for coronary angiography. All had complete transthoracic echocardiography and Doppler sampling of LAD velocities. Quantitative cor­onary angiography was performed within 24 hours of the echocardiogram. Correlations between LAD velocity profile, measurements and calculations, and the angiographic results were performed. Six subjects had LAD occlusion, 10 had severe (>80% diameter LAD stenosis, and 26 had normal or non-occlusive LAD disease. In all six subjects with LAD occlusion, distal LAD velocities were not detectable, while in the other 36 subjects, LAD velocities were recorded indicating the vessels were patent. In the 10 subjects with severe LAD stenosis, the diastolic/systolic velocity ratio was <1.5, while in those with non-signifi­cant LAD disease, the diastolic/systolic velocity ratio was >1.5 (P<0.005. Diastolic LAD flow was 21.8±13 mL/min in the presence of severe stenosis as compared to 48.5±20 mL/min in subjects without severe stenosis (P<0.0013. LAD velocities had high sensitiv­ity and specificity for the prediction of severe angiographic stenosis. Thus transthoracic Doppler measurement of LAD velocities is feas­ible and can predict the presence of severe LAD stenosis or occlusion.

  10. Prolonged ischemic heart disease and coronary artery bypass - relation to contractile reserve

    DEFF Research Database (Denmark)

    Kofoed, Klaus F; Bangsgaard, Regitze; Carstensen, Steen;

    2002-01-01

    OBJECTIVE: A major effect of coronary artery bypass grafting (CABG) in patients with ischemic heart disease and impaired left ventricular (LV) contractile function is believed to be an improvement in LV function due to recovery of dysfunctional, but viable myocardium. However, recent studies have...

  11. Measurement of coronary flow response to cold pressor stress in asymptomatic women with cardiovascular risk factors using spiral velocity-encoded cine MRI at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Maroules, Christopher D.; Peshock, Ronald M. (Dept. of Radiology, Univ. of Texas Southwestern Medical Center, Dallas, TX (United States)), e-mail: Ron.Peshock@UTSouthwestern.edu; Chang, Alice Y.; Kontak, Andrew (Dept. of Internal Medicine, Univ. of Texas Southwestern Medical Center, Dallas, TX (United States)); Dimitrov, Ivan; Kotys, Melanie (Dept. of Philips Medical Systems, Cleveland, OH (United States))

    2010-05-15

    Background: Coronary sinus (CS) flow in response to a provocative stress has been used as a surrogate measure of coronary flow reserve, and velocity-encoded cine (VEC) magnetic resonance imaging (MRI) is an established technique for measuring CS flow. In this study, the cold pressor test (CPT) was used to measure CS flow response because it elicits an endothelium-dependent coronary vasodilation that may afford greater sensitivity for detecting early changes in coronary endothelial function. Purpose: To investigate the feasibility and reproducibility of CS flow reactivity (CSFR) to CPT using spiral VEC MRI at 3 Tesla in a sample of asymptomatic women with cardiovascular risk factors. Material and Methods: Fourteen asymptomatic women (age 38 years +- 10) with cardiovascular risk factors were studied using 3D spiral VEC MRI of the CS at 3 T. The CPT was utilized as a provocative stress to measure changes in CS flow. CSFR to CPT was calculated from the ratio of CS flow during peak stress to baseline CS flow. Results: CPT induced a significant hemodynamic response as measured by a 45% increase in rate-pressure product (P<0.01). A significant increase in CS volume flow was also observed (baseline, 116 +- 26 ml/min; peak stress, 152 +- 34 ml/min, P=0.01). CSFR to CPT was 1.31 +- 0.20. Test-retest variability of CS volume flow was 5% at baseline and 6% during peak stress. Conclusion: Spiral CS VEC MRI at 3 T is a feasible and reproducible technique for measuring CS flow in asymptomatic women at risk for cardiovascular disease. Significant changes in CSFR to CPT are detectable, without demanding pharmacologic stress

  12. Coronary flow and hemorrhagic complications after alteplase and streptokinase administration in patients with acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Kostić Tomislav

    2009-01-01

    Full Text Available Background/Aim. Up-to-date treatment of acute myocardial infarction (AIM has been based on as early as possible establishment of circulation in ischemic myocardium whether by the use of fibrinolythic therapy and/or urgent coronary intervention which significantly changes the destiny of patients with AMI, but also increases the risk of bleeding. The aim of this study was to compare coronary flow and bleeding complications in patients with acute myocardial infarction with ST-elevation (STEMI after administration of alteplase or streptokinase. Methods. The study included 254 patients with STEMI. The group I (n = 174 received streptokinase, and the group II (n = 80 received alteplase. We followed frequency of complications such as bleeding and hypotension in the investigated groups of patients, based on the TIMI classification of bleeding, as well as the transience of infarction artery in accordance with TIMI flow. Results. The patients with myocardial infarction after administration of alteplase had statistically significantly higher coronary flow (TIMI- 3, 72.5% as compared to the patients who received streptokinase, 39.2%. Hypotension as complication of fibrynolythic therapy administration occurred in a significantly higher percentage in the group of patients who received streptokinase. There was no statistically significant difference in the appearance of major bleeding in the groups of patients who received streptokinasis and alteplase (6.9% and 7.5%, respectively. Also, there was no difference in the appearance of minor and minimal bleeding among the investigated groups of patients. Conclusion. It was shown that alteplase in a higher number of patients provided TIMI-3 coronary flow as compared to streptokinese. In comparison with streptokinase, a combination of alteplase, enoxaparin and double antiplatelet therapy enabled earlier achievement of coronary flow through previously blocked coronary artery that was more complete (higher frequency of

  13. Open-loop (feed-forward) and feedback control of coronary blood flow during exercise, cardiac pacing, and pressure changes.

    Science.gov (United States)

    Pradhan, Ranjan K; Feigl, Eric O; Gorman, Mark W; Brengelmann, George L; Beard, Daniel A

    2016-06-01

    A control system model was developed to analyze data on in vivo coronary blood flow regulation and to probe how different mechanisms work together to control coronary flow from rest to exercise, and under a variety of experimental conditions, including cardiac pacing and with changes in coronary arterial pressure (autoregulation). In the model coronary flow is determined by the combined action of a feedback pathway signal that is determined by the level of plasma ATP in coronary venous blood, an adrenergic open-loop (feed-forward) signal that increases with exercise, and a contribution of pressure-mediated myogenic control. The model was identified based on data from exercise experiments where myocardial oxygen extraction, coronary flow, cardiac interstitial norepinephrine concentration, and arterial and coronary venous plasma ATP concentrations were measured during control and during adrenergic and purinergic receptor blockade conditions. The identified model was used to quantify the relative contributions of open-loop and feedback pathways and to illustrate the degree of redundancy in the control of coronary flow. The results indicate that the adrenergic open-loop control component is responsible for most of the increase in coronary blood flow that occurs during high levels of exercise. However, the adenine nucleotide-mediated metabolic feedback control component is essential. The model was evaluated by predicting coronary flow in cardiac pacing and autoregulation experiments with reasonable fits to the data. The analysis shows that a model in which coronary venous plasma adenine nucleotides are a signal in local metabolic feedback control of coronary flow is consistent with the available data.

  14. Fractional Flow Reserve-Guided Deferred Versus Complete Revascularization in Patients With Diabetes Mellitus.

    Science.gov (United States)

    Kennedy, Mark W; Hermanides, Rik S; Kaplan, Emel; Hemradj, Veemal; Fabris, Enrico; Koopmans, Petra C; Dambrink, Jan-Henk E; Gosselink, A T Marcel; Van't Hof, Arnoud W J; Ottervanger, Jan Paul; Roolvink, Vincent; Remkes, Wouter S; van der Sluis, Aize; Suryapranata, Harry; Kedhi, Elvin

    2016-11-01

    To assess the safety and efficacy of deferred versus complete revascularization using a fractional flow reserve (FFR)-guided strategy in patients with diabetes mellitus (DM), we analyzed all DM patients who underwent FFR-guided revascularization from January 1, 2010, to December 12, 2013. Patients were divided into 2 groups: those with ≥1 remaining FFR-negative (>0.80) medically treated lesions [FFR(-)MT] and those with only FFR-positive lesions (≤0.80) who underwent complete revascularization [FFR(+)CR] and were followed until July 1, 2015. The primary end point was the incidence of major adverse cardiovascular events (MACE), a composite of death, myocardial infarction (MI), target lesion (FFR assessed) revascularization, and rehospitalization for acute coronary syndrome. A total of 294 patients, 205 (69.7%) versus 89 (30.3%) in FFR(-)MT and FFR(+)CR, respectively, were analyzed. At a mean follow-up of 32.6 ± 18.1 months, FFR(-)MT was associated with higher MACE rate 44.0% versus 26.6% (log-rank p = 0.02, Cox regression-adjusted hazard ratio [HR] 2.01, 95% confidence interval [CI] 1.21 to 3.33, p required to guide our treatment strategy in these patients with high-risk, fast-progressing atherosclerosis.

  15. SPECT myocardial perfusion versus fractional flow reserve for evaluation of functional ischemia: A meta analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Tao; Yang, Lin-feng [Department of Medical Imaging, Jinan Military General Hospital, No, 25, Shifan Road, Jinan, Shandong Province, China. 250031 (China); Zhai, Ji-liang [Department of Medical Imaging, The Branch of TaiAn Central Hospital, Middle of Changcheng Road, Shandong Province, China. 271000 (China); Li, Jiang [Department of Medical Imaging, Affiliated Hospital of Taishan Medical University, No, 706, Taishan Road, Shandong Province, China. 271000 (China); Wang, Qi-meng [Department of Medical Imaging, Taishan Hospital of Traditional Chinese Medicine, No, 216, Yingxuan Street, Shandong Province, China. 271000. (China); Zhang, Rui-jie; Wang, Sen; Peng, Zhao-hui [Department of Medical Imaging, Jinan Military General Hospital, No, 25, Shifan Road, Jinan, Shandong Province, China. 250031 (China); Li, Min, E-mail: liminyingxiang@163.com [Department of Medical Imaging, Jinan Military General Hospital, No, 25, Shifan Road, Jinan, Shandong Province, China. 250031 (China); Sun, Gang, E-mail: cjr.sungang@vip.163.com [Department of Medical Imaging, Jinan Military General Hospital, No, 25, Shifan Road, Jinan, Shandong Province, China. 250031 (China)

    2014-06-15

    Purpose: The present meta-analysis illustrates the accuracy of myocardial perfusion SPECT (MPS) to diagnose functional stenotic coronary artery disease (CAD) with fractional flow reserve (FFR) as standard reference. Methods: All investigators screened and selected studies that compared MPS with FFR in symptomatic patients with suspected CAD. Patients and study characteristics were independently extracted by two investigators; differences were resolved by consensus. Results: 13 articles, including 1,017 patients, 699 vessels were included in the study. No significant publication bias was detected (P = 0.65). At the patient level, the summary sensitivity and specificity were 77% (95% confidence interval [CI], 70–83%) and 77% (95%CI, 67–84%) for MPS. Vessel-level pooled sensitivity was 66% (95%CI, 57–74%) and specificity was 81% (95%CI, 70–89%). The overall diagnostic performance of MPS was moderate. [The area under the summary receiver operating characteristic (sROC) curve was 0.83]. No study influenced the pooled results larger than 0.03. Conclusions: The accuracy between FFR and MPS SPECT was moderate.

  16. Fantofarone (SR33557): effects on myocardial oxygen consumption and coronary blood flow.

    Science.gov (United States)

    Hodeige, D; Chatelain, P; Manning, A

    1994-01-01

    We have investigated the effects of a novel calcium antagonist, fantofarone (SR 33557) on myocardial oxygen consumption (MO2C) and coronary blood flow in anaesthetized dogs during periods of normal and elevated heart rate. 25 micrograms/kg i.v. fantofarone induced a transient increase in coronary blood flow (+25% after 2 min; p MO2C (-50% after 5 min; p MO2C was reduced by 67% after 5 min (p MO2C was observed during the pacing periods (32% after 10 min; p MO2C consumption during periods of elevated heart rate.

  17. Computerized flow and vessel wall analyses of coronary arteries for detection of non-calcified plaques in coronary CT angiography

    Science.gov (United States)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Hadjiiski, Lubomir; Kazerooni, Ella

    2016-03-01

    The buildup of non-calcified plaques (NCP) that are vulnerable to rupture in coronary arteries is a risk for myocardial infarction. We are developing a computer-aided detection (CADe) system to assist radiologists in detecting NCPs in cCTA. A major challenge of NCP detection is the large number of false positives (FPs) caused by the small sized coronary arteries, image noise and artifacts. In this study, our purpose is to design new image features to reduce FPs. A data set of 98 cCTA scans was retrospectively collected from patient files. We first used vessel wall analysis, in which topological features were extracted from vessel wall and fused with a support-vector machine, to identify the NCP candidates from the segmented coronary tree. Computerized flow dynamic (CFD) features that characterize the change in blood flow due to the presence of plaques and a vascular cross-sectional (VCS) feature that quantifies the presence of low attenuation region at the vessel wall were designed for FP reduction. Using a leave-one-out resampling method, a support vector machine classifier was trained to merge the features into a NCP likelihood score using the vessel wall features alone or in combination with the new CDF and VCS features. The performance of the new features in classification of true NCPs and FPs was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC). Without the new CFD and VCS features, the test AUC was 0.84+/-0.01. The AUC was improved to 0.88+/-0.01 with the addition of the new features. The improvement was statistically significant (p < 0.001). The study indicated that the new flow dynamic and vascular cross-sectional features were useful for differentiation of NCPs from FPs in cCTA.

  18. Effect of adrenergic agonists on coronary blood flow: a laboratory study in healthy volunteers.

    Science.gov (United States)

    Vargas Pelaez, Alvaro F; Gao, Zhaohui; Ahmad, Tariq A; Leuenberger, Urs A; Proctor, David N; Maman, Stephan R; Muller, Matthew D

    2016-05-01

    Myocardial oxygen supply and demand mismatch is fundamental to the pathophysiology of ischemia and infarction. The sympathetic nervous system, through α-adrenergic receptors and β-adrenergic receptors, influences both myocardial oxygen supply and demand. In animal models, mechanistic studies have established that adrenergic receptors contribute to coronary vascular tone. The purpose of this laboratory study was to noninvasively quantify coronary responses to adrenergic receptor stimulation in humans. Fourteen healthy volunteers (11 men and 3 women) performed isometric handgrip exercise to fatigue followed by intravenous infusion of isoproterenol. A subset of individuals also received infusions of phenylephrine (n = 6), terbutaline (n = 10), and epinephrine (n = 4); all dosages were based on fat-free mass and were infused slowly to achieve steady-state. The left anterior descending coronary artery was visualized using Doppler echocardiography. Beat-by-beat heart rate (HR), blood pressure (BP), peak diastolic coronary velocity (CBVpeak), and coronary velocity time integral were calculated. Data are presented as M ± SD Isometric handgrip elicited significant increases in BP, HR, and CBVpeak (from 23.3 ± 5.3 to 34.5 ± 9.9 cm/sec). Isoproterenol raised HR and CBVpeak (from 22.6 ± 4.8 to 43.9 ± 12.4 cm/sec). Terbutaline and epinephrine evoked coronary hyperemia whereas phenylephrine did not significantly alter CBVpeak. Different indices of coronary hyperemia (changes in CBVpeak and velocity time integral) were significantly correlated (R = 0.803). The current data indicate that coronary hyperemia occurs in healthy humans in response to isometric handgrip exercise and low-dose, steady-state infusions of isoproterenol, terbutaline, and epinephrine. The contribution of β1 versus β2 receptors to coronary hyperemia remains to be determined. In this echocardiographic study, we demonstrate that coronary blood flow increases when

  19. Diagnostic Performance of a Lattice Boltzmann-Based Method for Fast CT-Fractional Flow Reserve.

    Science.gov (United States)

    Giannopoulos, Andreas; Tang, Anji; Ge, Yin; Cheezum, Michael; Steigner, Michael; Fujimoto, Shinichiro; Kumamaru, Kanako; Chiappino, Dante; Della Latta, Daniele; Berti, Sergio; Chiappino, Sara; Rybicki, Frank; Melchionna, Simone; Mitsouras, Dimitrios

    2017-06-27

    Fractional flow reserve (FFR) estimated from coronary computed tomography angiography (CT-FFR) offers non-invasive detection of lesion-specific ischemia. We developed and validated a fast CT-FFR algorithm utilizing the Lattice-Boltzmann Method for blood flow simulation (LBM CT-FFR). 64 patients from 3 institutions with clinically-indicated CTA and invasive FFR measurement were retrospectively analyzed. CT-FFR was performed using an on-site tool interfacing with a commercial Lattice-Boltzmann fluid dynamics cloud-based platform. Diagnostic accuracy of LBM CT-FFR≤0.8 and percent diameter stenosis >50% by CTA to detect invasive FFR≤0.8 were compared using area under the receiver operating characteristic curve (AUC). 60 patients successfully underwent LBM CT-FFR analysis; 29 of 73 lesions in 69 vessels had invasive FFR≤0.8. Total time to perform LBM CT-FFR was 40±10 min. Compared to invasive FFR, LBM CT-FFR had good correlation (r=0.64), small bias (0.009) and good limits of agreement (-0.223 to 0.206). The AUC of LBM CT-FFR (AUC=0.894, 95% confidence interval [CI]: 0.792- 0.996) was significantly higher than CTA (AUC=0.685, 95% CI: 0.576-0.794) to detect FFR≤0.8 (p=0.0021). Per-lesion specificity, sensitivity, accuracy of LBM CT-FFR were 97.7%, 79.3%, and 90.4%, respectively. LBM CT-FFR has very good diagnostic accuracy to detect lesion-specific ischemia (FFR≤0.8) and can be performed in less than 1 hour.

  20. Coronary Microvascular Function and Cardiovascular Risk Factors in Women With Angina Pectoris and No Obstructive Coronary Artery Disease

    DEFF Research Database (Denmark)

    Mygind, Naja Dam; Michelsen, Marie Mide; Peña, Adam

    2016-01-01

    artery stenosis (coronary flow velocity reserve......BACKGROUND: The majority of women with angina-like chest pain have no obstructive coronary artery disease when evaluated with coronary angiography. Coronary microvascular dysfunction is a possible explanation and associated with a poor prognosis. This study evaluated the prevalence of coronary...... microvascular dysfunction and the association with symptoms, cardiovascular risk factors, psychosocial factors, and results from diagnostic stress testing. METHODS AND RESULTS: After screening 3568 women, 963 women with angina-like chest pain and a diagnostic coronary angiogram without significant coronary...

  1. Coronary flow velocity analysis during short term follow up after coronary reperfusion: use of transthoracic Doppler echocardiography to predict regional wall motion recovery in patients with acute myocardial infarction

    OpenAIRE

    Hozumi, T; Kanzaki, Y; Ueda, Y.; Yamamuro, A; Takagi, T; Akasaka, T; Homma, S; Yoshida, K.; Yoshikawa, J

    2003-01-01

    Background: A recent study using a Doppler guide wire showed that coronary flow velocity measurements immediately after coronary reperfusion were useful in predicting recovery of regional left ventricular function. The value of coronary flow velocity analyses during follow up after reperfusion has not been established in the clinical setting.

  2. Numerical Simulation and Clinical Implications of Stenosis in Coronary Blood Flow

    Science.gov (United States)

    Zhong, Liang; Luo, Tong; Huo, Yunlong; Tan, Swee Yaw; Wong, Aaron Sung Lung; Su, Boyang; Zhao, Xiaodan; Kassab, Ghassan S.; Khoo, Boo Cheong; Kang, Chang-Wei; Tan, Ru San

    2014-01-01

    Fractional flow reserve (FFR) is the gold standard to guide coronary interventions. However it can only be obtained via invasive angiography. The objective of this study is to propose a noninvasive method to determine FFRCT by combining computed tomography angiographic (CTA) images and computational fluid dynamics (CFD) technique. Utilizing the method, this study explored the effects of diameter stenosis (DS), stenosis length, and location on FFRCT. The baseline left anterior descending (LAD) model was reconstructed from CTA of a healthy porcine heart. A series of models were created by adding an idealized stenosis (with DS from 45% to 75%, stenosis length from 4 mm to 16 mm, and at 4 locations separately). Through numerical simulations, it was found that FFRCT decreased (from 0.89 to 0.74), when DS increased (from 45% to 75%). Similarly, FFRCT decreased with the increase of stenosis length and the stenosis located at proximal position had lower FFRCT than that at distal position. These findings are consistent with clinical observations. Applying the same method on two patients' CTA images yielded FFRCT close to the FFR values obtained via invasive angiography. The proposed noninvasive computation of FFRCT is promising for clinical diagnosis of CAD. PMID:24987691

  3. Estimating the accuracy of a reduced-order model for the calculation of fractional flow reserve (FFR).

    Science.gov (United States)

    Boileau, Etienne; Pant, Sanjay; Roobottom, Carl; Sazonov, Igor; Deng, Jingjing; Xie, Xianghua; Nithiarasu, Perumal

    2017-06-09

    Image-based noninvasive fractional flow reserve (FFR) is an emergent approach to determine the functional relevance of coronary stenoses. The present work aimed to determine the feasibility of using a method based on coronary computed tomography angiography (CCTA) and reduced-order models (0D-1D) for the evaluation of coronary stenoses. The reduced-order methodology (cFFRRO ) was kept as simple as possible and did not include pressure drop or stenosis models. The geometry definition was incorporated into the physical model used to solve coronary flow and pressure. cFFRRO was assessed on a virtual cohort of 30 coronary artery stenoses in 25 vessels and compared with a standard approach based on 3D computational fluid dynamics (cFFR3D ). In this proof-of-concept study, we sought to investigate the influence of geometry and boundary conditions on the agreement between both methods. Performance on a per-vessel level showed a good correlation between both methods (Pearson's product-moment R=0.885, P<0.01), when using cFFR3D  as the reference standard. The 95% limits of agreement were -0.116 and 0.08, and the mean bias was -0.018 (SD =0.05). Our results suggest no appreciable difference between cFFRRO  and cFFR3D with respect to lesion length and/or aspect ratio. At a fixed aspect ratio, however, stenosis severity and shape appeared to be the most critical factors accounting for differences in both methods. Despite the assumptions inherent to the 1D formulation, asymmetry did not seem to affect the agreement. The choice of boundary conditions is critical in obtaining a functionally significant drop in pressure. Our initial data suggest that this approach may be part of a broader risk assessment strategy aimed at increasing the diagnostic yield of cardiac catheterisation for in-hospital evaluation of haemodynamically significant stenoses. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Cholinergic Regulation of Resting Coronary Blood Flow in the Domestic Swine

    Science.gov (United States)

    1989-03-17

    37 • 43 •51,73 Administration of phentolamine , a mixed alpha adrenergic antagonist, blocks the sympathetic vasoconstriction which limits active...blockers, prazosin and trimazosin, with phentolamine . Neither phentolamine , nor prazosin produced significant changes in coronary blood flow. Trimazosin...blockade of sympathetic input through section of the left stellate ganglia. Similar results were obtained following alpha1 , 2 blockade with phentolamine

  5. The use of a Perma-Flow graft for coronary artery bypass surgery.

    Science.gov (United States)

    Schmid, C; Weyand, M; Kerber, S; Breithardt, G; Scheld, H H

    1996-01-01

    We report on our first clinical use of a Perma-Flow graft for coronary artery bypass surgery (CABG). It may well be that repeated successful use of this graft will offer a chance for revascularization to patients who might otherwise have been denied for lack of appropriate vessels.

  6. Effect of Coronary Slow Flow on the Longitudinal Left Ventricular Function Assessed by 2-Dimensional Speckle-Tracking Echocardiography.

    Science.gov (United States)

    Narimani, Sima; Hosseinsabet, Ali; Pourhosseini, Hamidreza

    2016-04-01

    The coronary slow flow phenomenon is defined as the slow progression of an angiographic contrast agent to the distal part of the coronary arteries on selective coronary angiography in the absence of stenosis. There are some studies with different results about the effect of this phenomenon on left ventricular (LV) function. The aim of our study was to evaluate the longitudinal LV function in the coronary slow flow phenomenon using 2-dimensional (2D) speckle-tracking echocardiography. In a study with a patient-to-patient matched design, 36 patients with the coronary slow flow phenomenon and 36 individuals with normal coronary flow matched for age (±5 years), sex, hypertension, and diabetes mellitus were compared in terms of the longitudinal LV systolic and diastolic functions by pulsed wave tissue Doppler echocardiography and 2D speckle-tracking echocardiography-derived indices. Lateral s' and e' waves were lower in the patients with the coronary slow flow phenomenon, but there were no statistically significant differences between the groups regarding the other tissue Doppler echocardiographic indices and longitudinal systolic strain and systolic and diastolic strain rates derived by 2D speckle-tracking echocardiography. Our results showed that the coronary slow flow phenomenon could not impair the longitudinal LV systolic and diastolic functions. © 2016 by the American Institute of Ultrasound in Medicine.

  7. Computed tomography myocardial perfusion vs {sup 15}O-water positron emission tomography and fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Michelle C.; Dweck, Marc R.; Golay, Saroj K. [University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Edinburgh (United Kingdom); Mirsadraee, Saeed; Weir, Nicholas W.; Fletcher, Alison; Lucatelli, Christophe; Reid, John H. [University of Edinburgh, Clinical Research Imaging Centre, Edinburgh (United Kingdom); MacGillivray, Tom; Van Beek, Edwin J.R.; Newby, David E. [University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Edinburgh (United Kingdom); University of Edinburgh, Clinical Research Imaging Centre, Edinburgh (United Kingdom); Cruden, Nicholas L.; Henriksen, Peter A.; Uren, Neal [Edinburgh Heart Centre, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom); McKillop, Graham; Patel, Dilip [Department of Radiology, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom); Lima, Joao A.C. [Johns Hopkins Hospital, Departments of Medicine and Radiology, Baltimore, MD (United States)

    2017-03-15

    Computed tomography (CT) can perform comprehensive cardiac imaging. We compared CT coronary angiography (CTCA) and CT myocardial perfusion (CTP) with {sup 15}O-water positron emission tomography (PET) and invasive coronary angiography (ICA) with fractional flow reserve (FFR). 51 patients (63 (61-65) years, 80 % male) with known/suspected coronary artery disease (CAD) underwent 320-multidetector CTCA followed by ''snapshot'' adenosine stress CTP. Of these 22 underwent PET and 47 ICA/FFR. Obstructive CAD was defined as CTCA stenosis >50 % and CTP hypoperfusion, ICA stenosis >70 % or FFR <0.80. PET hyperaemic myocardial blood flow (MBF) was lower in obstructive than non-obstructive territories defined by ICA/FFR (1.76 (1.32-2.20) vs 3.11 (2.44-3.79) mL/(g/min), P < 0.001) and CTCA/CTP (1.76 (1.32-2.20) vs 3.12 (2.44-3.79) mL/(g/min), P < 0.001). Baseline and hyperaemic CT attenuation density was lower in obstructive than non-obstructive territories (73 (71-76) vs 86 (84-88) HU, P < 0.001 and 101 (96-106) vs 111 (107-114) HU, P 0.001). PET hyperaemic MBF corrected for rate pressure product correlated with CT attenuation density (r = 0.579, P < 0.001). There was excellent per-patient sensitivity (96 %), specificity (85 %), negative predictive value (90 %) and positive predictive value (94 %) for CTCA/CTP vs ICA/FFR. CT myocardial attenuation density correlates with {sup 15}O-water PET MBF. CTCA and CTP can accurately identify obstructive CAD. (orig.)

  8. Association of Indicators of Dehydration and Haemoconcentration with the Coronary Slow Flow Phenomenon

    Directory of Open Access Journals (Sweden)

    Suzan Hatipoğlu

    2010-08-01

    Full Text Available Objectives: The coronary slow flow phenomenon (CSFP, characterized by decreased distal progression of dye to coronary arteries, is a distinct angiographic phenomenon and little is known about its pathophysiology. Although several hypotheses have been suggested, the underlying mechanism of CSFP has not been well established yet.The aim of this study was to determine the roles of indicators of dehydration and haemoconcentration in CSFP which have blood flow abnormality effects. Methods: The study consisted of 33 patients with CSFP (group 1, and 31 normal subjects as control group (group 2 detected by coronary angiography. CSFP was diagnosed by the TIMI frame count method. Serum electrolytes, osmolarity and haematological parameters were measured. Results: Compared with control subjects, patient with CSFP had increased levels of calculated osmolarity, tonicity, sodium, glucose and blood urea nitrogen (BUN. Significant differences were also observed in the haematocrit, haemoglobin concentration, and calculated osmolarity but not in total cholesterol and albumin. Conclusions: The results of the present study indicate that the markers of haemoconcentration and dehydration are significantly associated with CSFP. The markers may be important in the coronary blood flow anomaly.

  9. Complete blood cell count components and coronary slow-flow phenomenon

    Directory of Open Access Journals (Sweden)

    Arjmand N

    2016-12-01

    Full Text Available Nasim Arjmand, Mohammad Reza Dehghani Department of Cardiology, Seyyed-al-Shohada Heart Center, Urmia University of Medical Sciences, Urmia, IranDespite the implementation of preventive strategies, ischemic heart disease and stroke remain the main causes of mortality and morbidity worldwide.1,2 Of the cardiovascular diseases, coronary slow-flow phenomenon (CSFP, with a prevalence rate of 1%–7% among patients undergoing diagnostic coronary angiography, has been found to be associated with cardiovascular events, including cardiac arrhythmia and acute coronary syndrome.3–5 However, the potential mechanisms involved in the pathogenesis of CSFP remain unknown. Microvascular and endothelial dysfunctions, inflammation, diffuse atherosclerosis, and increased platelet aggregability have been reported to be the main possible etiologies for CSFP.6,7View original paper by Atlas and colleagues.

  10. Quantification of coronary microvascular resistance using angiographic images for volumetric blood flow measurement: in vivo validation.

    Science.gov (United States)

    Zhang, Zhang; Takarada, Shigeho; Molloi, Sabee

    2011-06-01

    Structural coronary microcirculation abnormalities are important prognostic determinants in clinical settings. However, an assessment of microvascular resistance (MR) requires a velocity wire. A first-pass distribution analysis technique to measure volumetric blood flow has been previously validated. The aim of this study was the in vivo validation of the MR measurement technique using first-pass distribution analysis. Twelve anesthetized swine were instrumented with a transit-time ultrasound flow probe on the proximal segment of the left anterior descending coronary artery (LAD). Microspheres were injected into the LAD to create a model of microvascular dysfunction. Adenosine (400 μg·kg(-1)·min(-1)) was used to produce maximum hyperemia. A region of interest in the LAD arterial bed was drawn to generate time-density curves using angiographic images. Volumetric blood flow measurements (Q(a)) were made using a time-density curve and the assumption that blood was momentarily replaced with contrast agent during the injection. Blood flow from the flow probe (Q(p)), coronary pressure (P(a)), and right atrium pressure (P(v)) were continuously recorded. Flow probe-based normalized MR (NMR(p)) and angiography-based normalized MR (NMR(a)) were calculated using Q(p) and Q(a), respectively. In 258 measurements, Q(a) showed a strong correlation with the gold standard Q(p) (Q(a) = 0.90 Q(p) + 6.6 ml/min, r(2) = 0.91, P measure NMR without using a velocity wire, which can potentially be used to evaluate microvascular conditions during coronary arteriography.

  11. A Methodology for Modeling the Flow of Military Personnel Across Air Force Active and Reserve Components

    Science.gov (United States)

    2016-01-01

    for pilots will depend on the • number of active component pilots who separate • fraction of separating pilots who affiliate with the reserve ...when tracking economic output over a period of time. GDP data were collected from the Federal Reserve Economic Data (FRED), Federal Reserve Bank of St...C O R P O R A T I O N Research Report A Methodology for Modeling the Flow of Military Personnel Across Air Force Active and Reserve Components

  12. Measurements Of Coronary Mean Transit Time And Myocardial Tissue Blood Flow By Deconvolution Of Intravasal Tracer Dilution Curves

    Science.gov (United States)

    Korb, H.; Hoeft, A.; Hellige, G.

    1984-10-01

    Previous studies have shown that intramyocardial blood volume does not vary to a major extent even during extreme variation of hemodynamics and coronary vascular tone. Based on a constant intramyocardial blood volume it is therefore possible to calculate tissue blood flow from the mean transit time of an intravascular tracer. The purpose of this study was to develop a clinically applicable method for measurement of coronary blood flow. The new method was based on indocyanine green, a dye which is bound to albumin and intravasally detectable by means of a fiberoptic catheter device. One fiberoptic catheter was placed in the aortic root and another in the coronary sinus. After central venous dye injection the resulting arterial and coronary venous dye dilution curves were processed on-line by a micro-computer. The mean transit time as well as myocardial blood flow were calculated from the step response function of the deconvoluted arterial and coronary venous signals. Reference flow was determined with an extracorporeal electromagnetic flowprobe within a coronary sinus bypass system. 38 steady states with coronary blood flow ranging from 49 - 333 ml/min*100g were analysed in 5 dogs. Mean transit times varied from 2.9 to 16.6 sec. An average intracoronary blood volume of 13.9 -7 1.8 m1/100g was calculated. The correlation between flow determined by the dye dilution technique and flow measured with the reference method was 0.98. According to these results determination of coronary blood flow with a double fiberoptic system and indocyanine green should be possible even under clinical conditions. Furthermore, the arterial and coronary venous oxygen saturation can be monitored continuously by the fiberoptic catheters. Therefore, additional information about the performance of the heart such as myocardial oxygen consumption and myocardial efficiency is available with the same equipment.

  13. Marine Forces Reserve: Accelerating Knowledge Flow through Asynchronous Learning Technologies

    Science.gov (United States)

    2014-12-19

    pedagogic techniques that are infeasible in the classroom , and they suggest that in some respects technologically intermediated learning can be even better...frameworks and technologies to examine I-I knowledge flows, and from the practitioner perspective, we bring to bear deep inside knowledge of the focal...ASYNCHRONOUS LEARNING TECHNOLOGIES by Mark Nissen, Robert McGuiness and Anthony Davis December 2014 Further distribution of all or part of this

  14. The non-invasive documentation of coronary microcirculation impairment: role of transthoracic echocardiography

    Directory of Open Access Journals (Sweden)

    Galderisi Maurizio

    2005-08-01

    Full Text Available Abstract Transthoracic Doppler echocardiographic-derived coronary flow reserve is an useful hemodynamic index to assess dysfunction of coronary microcirculation. Isolated coronary microvascular abnormalities are overt by reduced coronary flow reserve despite normal epicardial coronary arteries. These abnormalities may occur in several diseases (arterial hypertension, diabetes mellitus, hypercholesterolemia, syndrome X, aortic valve disease, hypertrophic cardiomyopathy and idiopathic dilated cardiomyopathy. The prognostic role of impaired microvascular coronary flow reserve has been shown unfavourable especially in hypertrophic or idiopathic dilated cardiomyopathies. Coronary flow reserve reduction may be reversible, for instance after regression of left ventricular hypertrophy subsequent to valve replacement in patients with aortic stenosis, after anti-hypertensive treatment or using cholesterol lowering drugs. Coronary flow reserve may increase by 30% or more after pharmacological therapy and achieve normal level >3.0. In contrast to other non invasive tools as positron emission tomography, very expensive and associated with radiation exposure, transthoracic Doppler-derived coronary flow reserve is equally non invasive but cheaper, very accessible and prone to a reliable exploration of coronary microvascular territories, otherwise not detectable by invasive coronary angiography, able to visualize only large epicardial arteries.

  15. The correlation between coronary flow reserve and clinical outcomes in patients with primary ;angioplasty for acute myocardial infarction with high baseline white blood cell count%基础白细胞计数增高的急性心肌梗死患者冠状动脉介入术后冠状动脉血流储备降低对远期预后的影响

    Institute of Scientific and Technical Information of China (English)

    郑振国; 周旭晨; 朱皓; 尹达; 张妍

    2014-01-01

    Objective Both abnormal coronary flow reserve (CFR) following percutaneous coronary intervention (PCI) and elevated white blood cell (WBC) count in acute myocardial infarction (AMI) are known as useful predictors for adverse outcomes. We evaluated the value of abnormal CFR for prediction of adverse outcomes in AMI patients with high baseline WBC count following primary PCI. Methods We studied 72 consecutive patients (mean age 56±12, male 55) presenting with AMI who were admitted to our institution. Analyze of CFR was performed following PCI by intra-coronary Doppler wire. All enroll patents’ baseline WBC count was obtained at admission and WBC count≥10.4×109/L. The occurrence of major adverse cardiac events (MACE) were analyzed during clinical follow up (12.7±7.1 months). According to the best cutoff value of CFR for predicting MACE, the patients were divided into 2 groups:group 1 with CFR<1.4, group 2 with CFR≥1.4. Results Baseline CK and CK-MB in group 1 were significantly higher than in group 2[(4 109±407)U/L vs. (2 685±562)U/L, P<0.05; (290.8± 26.6)ng/ml vs. (255.7±65.6)ng/ml, P<0.05 respectively]; Percent of post PCI MBG grade3 were more often in group 2 than in group 1(25.9%vs. 38.9%, P<0.05). MACE rate were significantly higher in group 1 than in group 2(40.7%vs. 27.8%, P<0.05), the mortality rate was significantly higher in group 1 than in group 2(13.0% vs. 0, P<0.05). Conclusions Abnormal CFR following PCI with high baseline WBC count in patients with AMI were associated with a higher incidence of adverse long-term clinical outcomes. This observation may provide a potential explanation that links of microvascular dysfunction and vascular inflammation in patients with AMI.%目的:急性心肌梗死(AMI)患者在接受了冠状动脉介入术(PCI)后,即刻冠状动脉血流储备(CFR)的降低,以及AMI急性期基础血液中白细胞计数的增加均被视为AMI患者远期预后不良的预测因子。我们现将这

  16. Myocardial perfusion imaging with a cadmium zinc telluride-based gamma camera versus invasive fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Mouden, Mohamed [Isala klinieken, Department of Cardiology, Zwolle (Netherlands); Isala klinieken, Department of Nuclear Medicine, Zwolle (Netherlands); Ottervanger, Jan Paul; Timmer, Jorik R. [Isala klinieken, Department of Cardiology, Zwolle (Netherlands); Knollema, Siert; Reiffers, Stoffer; Oostdijk, Ad H.J.; Jager, Pieter L. [Isala klinieken, Department of Nuclear Medicine, Zwolle (Netherlands); Boer, Menko-Jan de [University Medical Centre Nijmegen, Department of Cardiology, Nijmegen (Netherlands)

    2014-05-15

    Recently introduced ultrafast cardiac SPECT cameras with cadmium zinc telluride-based (CZT) detectors may provide superior image quality allowing faster acquisition with reduced radiation doses. Although the level of concordance between conventional SPECT and invasive fractional flow reserve (FFR) measurement has been studied, that between FFR and CZT-based SPECT is not yet known. Therefore, we aimed to assess the level of concordance between CZT SPECT and FFR in a large patient group with stable coronary artery disease. Both invasive FFR and myocardial perfusion imaging with a CZT-based SPECT camera, using Tc-tetrofosmin as tracer, were performed in 100 patients with stable angina and intermediate grade stenosis on invasive coronary angiography. A cut-off value of <0.75 was used to define abnormal FFR. The mean age of the patients was 64 ± 11 years, and 64 % were men. SPECT demonstrated ischaemia in 31 % of the patients, and 20 % had FFR <0.75. The concordance between CZT SPECT and FFR was 73 % on a per-patient basis and 79 % on a per-vessel basis. Discordant findings were more often seen in older patients and were mainly (19 %) the result of ischaemic SPECT findings in patients with FFR ≥0.75, whereas only 8 % had an abnormal FFR without ischaemia as demonstrated by CZT SPECT. Only 20 - 30 % of patients with intermediate coronary stenoses had significant ischaemia as assessed by CZT SPECT or invasive FFR. CZT SPECT showed a modest degree of concordance with FFR, which is comparable with previous results with conventional SPECT. Further investigations are particularly necessary in patients with normal SPECT and abnormal FFR, especially to determine whether these patients should undergo revascularization. (orig.)

  17. Hyperglycemia is an important predictor of impaired coronary flow before reperfusion therapy in ST-segment elevation myocardial infarction

    NARCIS (Netherlands)

    Timmer, [No Value; Ottervanger, JP; de Boer, MJ; Hoorntje, JCA; Gosselink, ATM; Suryapranata, H; Zijlstra, F; van't Hof, AWJ; Dambrink, Jan Hendrik Everwijn

    2005-01-01

    OBJECTIVES This study was designed to investigate whether elevated glucose is associated with impaired Thrombolysis In Myocardial Infarction (TIMI) flow before primary percutaneous coronary intervention (PCI). BACKGROUND Reperfusion before primary PCI in patients with ST-segment elevation myocardial

  18. Systolic and diastolic changes in human coronary blood flow during Valsalva manoeuvre.

    Science.gov (United States)

    Federici, A; Ciccone, M; Gattullo, D; Losano, G

    2000-01-01

    Valsalva manoeuvre is reported to be sometimes successful for the relief of angina pectoris. The present study investigated how haemodynamic changes produced by Valsalva manoeuvre can interact to improve the relationship between cardiac work and coronary blood flow. Ten male subjects aged 53 +/- 12 years (SD) were considered. Blood velocity in the internal mammary artery, previously anastomosed to the left descending coronary artery, was studied with Doppler technique. The subjects performed Valsalva manoeuvres by expiring into a tube connected to a mercury manometer, to develop a pressure of 40 mmHg. The arterial blood pressure curve was continuously monitored with a Finapres device from a finger of the left hand. During expiratory effort, an increase in heart rate and a decrease in arterial pulse pressure were followed by a more delayed and progressive increase in mean and diastolic pressures. Systolic blood velocity markedly decreased along with the reduction in pulse pressure and increase in heart rate. By contrast, diastolic and mean coronary blood velocities did not show any significant change. Since it is known that the Valsalva manoeuvre strongly reduces stroke volume and cardiac output, it is likely that a reduction in cardiac work also takes place. Since in diastole, i.e. when the myocardial wall is better perfused, coronary blood velocity did not show any significant reduction, it is likely that unchanged perfusion in the presence of reduced cardiac work is responsible for the relief from angina sometimes observed during Valsalva manoeuvre. It is also likely that the increase in heart rate prevents the diastolic and mean blood coronary velocity from decreasing during the expiratory strain, when an increased sympathetic discharge could cause vasoconstriction through the stimulation of the coronary alpha-receptors.

  19. Dopexamine increases internal mammary artery blood flow following coronary artery bypass grafting.

    LENUS (Irish Health Repository)

    Flynn, Michael J

    2012-02-03

    OBJECTIVE: Vasoactive agents and inotropes influence conduit-coronary blood flow following coronary artery bypass grafting (CABG). It was hypothesized that dopexamine hydrochloride, a dopamine A-1 (DA-1) and beta(2) agonist would increase conduit-coronary blood flow. A prospective randomized double blind clinical trial was carried out to test this hypothesis. DA-1 receptors have previously been localized to human left ventricle. METHODS: Twenty-six American Society of Anaesthesiology class 2-3 elective coronary artery bypass graft patients who did not require inotropic support on separation from cardiopulmonary bypass (CPB) were studied. According to a randomized allocation patients received either dopexamine (1 microg\\/kg per min) or placebo (saline) by intravenous infusion for 15 min. Immediately prior to and at 5,10 and 15 min of infusion, blood flow through the internal mammary and vein grafts (Transit time flow probes, Transonic Ltd.), heart rate, cardiac index, mean arterial pressure and pulmonary haemodynamics were noted. The data were analysed using multivariate analysis of variance. RESULTS: Low-dose dopexamine (1 microg\\/kg per min) caused a significant increase in mammary graft blood flow compared to placebo at 15 min of infusion (P=0.028, dopexamine group left internal mammary artery (LIMA) flow of 43.3+\\/-14.2 ml\\/min, placebo group LIMA flow at 26.1+\\/-16.3 ml\\/min). Dopexamine recipients demonstrated a non-significant trend to increased saphenous vein graft flow (P=0.059). Increased heart rate was the only haemodynamic change induced by dopexamine (P=0.004, dopexamine group at 85.2+\\/-9.6 beats\\/min and placebo group at 71.1+\\/-7.6 beats\\/min after 15 min of infusion). CONCLUSION: This study demonstrates that administration of dopexamine (1 microg\\/kg per min) was associated with a significant increase in internal mammary artery graft blood flow with mild increase in heart rate being the only haemodynamic change. Low-dose dopexamine may

  20. Coronary grafts flow and cardiac pacing modalities: how to improve perioperative myocardial perfusion.

    LENUS (Irish Health Repository)

    D'Ancona, Giuseppe

    2012-02-03

    OBJECTIVE: Aim of this study was to investigate modifications of coronary grafts flow during different pacing modalities after CABG. MATERIALS AND METHODS: Two separate prospective studies were conducted in patients undergoing CABG and requiring intraoperative epicardial pacing. In a first study (22 patients) coronary grafts flows were measured during dual chamber pacing (DDD) and during ventricular pacing (VVI). In a second study (10 patients) flows were measured during DDD pacing at different atrio-ventricular (A-V) delay periods. A-V delay was adjusted in 25 ms increments from 25 to 250 ms and flow measurements were performed for each A-V delay increment. A transit time flowmeter was used for the measurements. RESULTS: An average of 3.4 grafts\\/patient were performed. In the first study, average coronary graft flow was 47.4+\\/-20.8 ml\\/min during DDD pacing and 41.8+\\/-18.2 ml\\/min during VVI pacing (P = 0.0004). Furthermore average systolic pressure was 94.3+\\/-10.1 mmHg during DDD pacing and 89.6+\\/-12.2 mmHg during VVV pacing (P = 0.0007). No significant differences in diastolic pressure were recorded during the two different pacing modalities. In the second study, maximal flows were achieved during DDD pacing with an A-V delay of 175 ms (54+\\/-9.6 ml\\/min) and minimal flows were detected at 25 ms A-V delay (38.1+\\/-4.7 ml\\/min) (P=ns). No significant differences in systolic or diastolic blood pressure were noticed during the different A-V delays. CONCLUSION: Grafts flowmetry provides an extra tool to direct supportive measures such as cardiac pacing after CABG. DDD mode with A-V delay around 175 ms. should be preferred to allow for maximal myocardial perfusion via the grafts.

  1. Coronary microembolization.

    Science.gov (United States)

    Skyschally, Andreas; Leineweber, Kkirsten; Gres, Petra; Haude, Michael; Erbel, Raimund; Heusch, Gerd

    2006-09-01

    Atherosclerotic plaque rupture is the key event in the pathogenesis of acute coronary syndromes and it also occurs during coronary interventions. Atherosclerotic plaque rupture does not always result in complete thrombotic occlusion of the epicardial coronary artery with subsequent impending myocardial infarction, but may in milder forms result in the embolization of atherosclerotic and thrombotic debris into the coronary microcirculation. This review summarizes the present experimental pathophysiology of coronary microembolization in animal models of acute coronary syndromes and highlights the main consequences of coronary microembolization--reduced coronary reserve, microinfarction, inflammation and oxidative modification of contractile proteins, contractile dysfunction and perfusion-contraction mismatch.Furthermore, the review presents the available clinical evidence for coronary microembolization in patients and compares the clinical observations with observations in the experimental model.

  2. Evaluation of coronary blood flow velocity during cardiac arrest with circulation maintained through mechanical chest compressions in a porcine model

    Directory of Open Access Journals (Sweden)

    Wagner Henrik

    2011-12-01

    Full Text Available Abstract Background Mechanical chest compressions (CCs have been shown capable of maintaining circulation in humans suffering cardiac arrest for extensive periods of time. Reports have documented a visually normalized coronary blood flow during angiography in such cases (TIMI III flow, but it has never been actually measured. Only indirect measurements of the coronary circulation during cardiac arrest with on-going mechanical CCs have been performed previously through measurement of the coronary perfusion pressure (CPP. In this study our aim was to correlate average peak coronary flow velocity (APV to CPP during mechanical CCs. Methods In a closed chest porcine model, cardiac arrest was established through electrically induced ventricular fibrillation (VF in eleven pigs. After one minute, mechanical chest compressions were initiated and then maintained for 10 minutes upon which the pigs were defibrillated. Measurements of coronary blood flow in the left anterior descending artery were made at baseline and during VF with a catheter based Doppler flow fire measuring APV. Furthermore measurements of central (thoracic venous and arterial pressures were also made in order to calculate the theoretical CPP. Results Average peak coronary flow velocity was significantly higher compared to baseline during mechanical chests compressions and this was observed during the entire period of mechanical chest compressions (12 - 39% above baseline. The APV slowly declined during the 10 min period of mechanical chest compressions, but was still higher than baseline at the end of mechanical chest compressions. CPP was simultaneously maintained at > 20 mmHg during the 10 minute episode of cardiac arrest. Conclusion Our study showed good correlation between CPP and APV which was highly significant, during cardiac arrest with on-going mechanical CCs in a closed chest porcine model. In addition APV was even higher during mechanical CCs compared to baseline. Mechanical

  3. Noninvasive Nuclear SPECT Myocardial Blood Flow Quantitation to Guide Management for Coronary Artery Disease.

    Science.gov (United States)

    Chen, Lung-Ching; Jong, Bor-Hsin; Lin, Sheng-Che; Ku, Chi-Tai; Chen, Ing-Jou; Chen, Yen-Kung; Hsu, Bailing

    2017-09-01

    Recently, myocardial blood flow quantitation with dynamic SPECT has been validated to enhance the detection of multivessel coronary artery disease (CAD) and conclude equivocal SPECT myocardial perfusion study. This advance opened an important clinical application to utilize the tool in guiding CAD management for area where myocardial perfusion tracers for PET are unavailable or unaffordable. We present a clinical patient with ongoing recursive angina who underwent multiple nuclear stress tests for a sequence of CAD evaluation in 26 months and demonstrated that SPECT myocardial blood flow quantitation properly guided CAD management to warrant patient outcome.

  4. PIV-validated numerical modeling of pulsatile flows in distal coronary end-to-side anastomoses.

    Science.gov (United States)

    Xiong, F L; Chong, C K

    2007-01-01

    This study employed particle image velocimetry (PIV) to validate a numerical model in a complementary approach to quantify hemodynamic factors in distal coronary anastomoses and to gain more insights on their relationship with anastomotic geometry. Instantaneous flow fields and wall shear stresses (WSS) were obtained from PIV measurement in a modified life-size silastic anastomosis model adapted from a conventional geometry by incorporating a smooth graft-artery transition. The results were compared with those predicted by a concurrent numerical model. The numerical method was then used to calculate cycle-averaged WSS (WSS(cyc)) and spatial wall shear stress gradient (SWSSG), two critical hemodynamic factors in the pathogenesis of intimal thickening (IT), to compare the conventional and modified geometries. Excellent qualitative agreement and satisfactory quantitative agreement with averaged normalized error in WSS between 0.8% and 8.9% were achieved between the PIV experiment and numerical model. Compared to the conventional geometry, the modified geometry produces a more uniform WSS(cyc) distribution eliminating both high and low WSS(cyc) around the toe, critical in avoiding IT. Peak SWSSG on the artery floor of the modified model is less than one-half that in the conventional case, and high SWSSG at the toe is eliminated. The validated numerical model is useful for modeling unsteady coronary anastomotic flows and elucidating the significance of geometry regulated hemodynamics. The results suggest the clinical relevance of constructing smooth graft-artery transition in distal coronary anastomoses to improve their hemodynamic performance.

  5. Net Capital Flows, Macroeconomic Shocks and Reserve Assets. The Case of Argentina (1994-2013

    Directory of Open Access Journals (Sweden)

    Luis N. Lanteri

    2014-06-01

    Full Text Available International reserves have been used as a source of protection against the vulnerability of the balance of payments, or alternatively, as an attempt to keep a competitive real exchange rate and to promote exports. This paper explores the correlation between the net capital flows and reserves. Similarly, the impact of some macroeconomic shocks on that variable is assessed. Estimates are carried out through both, the VEC (Vector Error Correction models and quarterly data of the Argentine economy for the period 1994-2013. Results show a negative correlation between international reserves and net capital flows (reserve accumulation through current account surpluses. At the same time, the expansionary fiscal policies and the continuing and widespread price increases would adversely affect the reserves.

  6. Determination of Flow Conditions in Coronary Bifurcation Lesions in the Context of the Medina Classification

    Directory of Open Access Journals (Sweden)

    Marjan Molavi Zarandi

    2012-01-01

    Full Text Available Coronary artery bifurcation lesions are complex and several classifications are presented to describe them. Recently, the Medina classification has been proposed. This classification uses binary values for characterization of stenosis. Flow conditions according to Medina classification have not been described. In this paper, bifurcation lesions corresponding to anatomical Medina lesion classification are compared on the basis of flow and Wall Shear Stress (WSS. Computational models of healthy and stenosed coronary artery bifurcations ((1, 1, 1, (0, 1, 1 and (1, 0, 1 with moderate and severe stenoses of 50% and 75% diameter were analyzed. The results showed that, flow conditions vary in bifurcation lesion types according to the clinically-oriented Medina classification. The flow in SB of bifurcation was dependent of the Medina lesion type and was more affected in lesion type (1, 0, 1. The magnitudes of WSS on the inner and outer walls of SB of bifurcation lesion (1, 0, 1 in post-stenotic region and along the arterial wall were smaller than bifurcations lesions (0, 1, 1 and (1, 1, 1 respectively. Our results suggest that SB of bifurcation lesion (1, 0, 1 is more prone to atherosclerosis progression compared to types (0, 1, 1 and (1, 1, 1.

  7. Impact of pacing modality and biventricular pacing on cardiac output and coronary conduit flow in the post-cardiotomy patient.

    LENUS (Irish Health Repository)

    Healy, David G

    2012-02-03

    We have previously demonstrated the role of univentricular pacing modalities in influencing coronary conduit flow in the immediate post-operative period in the cardiac surgery patient. We wanted to determine the mechanism of this improved coronary conduit and, in addition, to explore the possible benefits with biventricular pacing. Sixteen patients undergoing first time elective coronary artery bypass grafting who required pacing following surgery were recruited. Comparison of cardiac output and coronary conduit flow was performed between VVI and DDD pacing with a single right ventricular lead and biventricular pacing lead placement. Cardiac output was measured using arterial pulse waveform analysis while conduit flow was measured using ultrasonic transit time methodology. Cardiac output was greatest with DDD pacing using right ventricular lead placement only [DDD-univentricular 5.42 l (0.7), DDD-biventricular 5.33 l (0.8), VVI-univentricular 4.71 l (0.8), VVI-biventricular 4.68 l (0.6)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.023) and VVI-biventricular pacing (P=0.001) but there was no significant advantage to DDD-biventricular pacing (P=0.45). In relation to coronary conduit flow, DDD pacing again had the highest flow [DDD-univentricular 55 ml\\/min (24), DDD-biventricular 52 ml\\/min (25), VVI-univentricular 47 ml\\/min (23), VVI-biventricular 50 ml\\/min (26)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.006) pacing but not significantly different to VVI-biventricular pacing (P=0.109) or DDD-biventricular pacing (P=0.171). Pacing with a DDD modality offers the optimal coronary conduit flow by maximising cardiac output. Biventricular lead placement offered no significant benefit to coronary conduit flow or cardiac output.

  8. Impact of top end anastomosis design on patency and flow stability in coronary artery bypass grafting.

    Science.gov (United States)

    Koyama, Sachi; Kitamura, Tadashi; Itatani, Keiichi; Yamamoto, Tadashi; Miyazaki, Shohei; Oka, Norihiko; Nakashima, Kouki; Horai, Tetsuya; Ono, Minoru; Miyaji, Kagami

    2016-05-01

    For coronary artery bypass grafting (CABG), free grafts such as a saphenous vein or radial artery are often used for grafts to the lateral and posterior walls. However, the relationship between top-end anastomosis design and long-term patency remains unknown. Because coronary artery blood flow is dominant during diastole, top-end anastomosis may work better if the graft is directed towards the apex, whereas the shortest graft pathway appears to be most efficient. Using computational fluid dynamic models, we evaluated the hemodynamic variables that were affected by the angle of the top-end anastomosis. We created three-dimensional geometries of the aortic root with coronary arteries that involved 75 % stenosis in the obtuse marginal and postero-lateral branches. Two bypass models under vasodilator administration were created: in a"Model A", the top-end anastomosis is parallel to the long axis of the ascending aorta and the graft passed over the conus directed towards the apex; in a "Model B", the top-end anastomosis is directed toward the shortest pathway, and form near the right angles to the long axis of the ascending aorta. Wall shear stress (WSS) and its fluctuation, an oscillatory shear index (OSI) were evaluated to predict fibrosis progression at the anastomosis site and graft flow. Graft flow was 197.3 ml/min and 207.3 ml/min in the "Model A" and "Model B", respectively. The minimal WSS value inside the graft with the "Model A" and "Model B" was 0.53 Pa and 4.09 Pa, respectively, and the OSI value was 0.46 and 0.04, respectively. The top-end anastomosis of a free graft should be directed vertically towards the aorta to achieve the shortest graft pathway to maintain a high graft flow rate and to avoid the risks of endothelial fibrosis and plaque progression over the long-term after CABG.

  9. Assessment of endothelial function and myocardial flow reserve using {sup 15}O-water PET without attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Tuffier, Stephane; Joubert, Michael; Bailliez, Alban [EA 4650, Normandie Universite, Caen (France); Legallois, Damien [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Cardiology, Caen (France); Belin, Annette [Caen University Hospital, Department of Cardiac Surgery, Caen (France); Redonnet, Michel [Rouen University Hospital, Department of Cardiac Surgery, Rouen (France); Agostini, Denis [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Nuclear Medicine, Caen (France); Manrique, Alain [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Nuclear Medicine, Caen (France); Cyceron PET Centre, Caen (France)

    2016-02-15

    Myocardial blood flow (MBF) measurement using positron emission tomography (PET) from the washout rate of {sup 15}O-water is theoretically independent of tissue attenuation. The aim of this study was to evaluate the impact of not using attenuation correction in the assessment of coronary endothelial function and myocardial flow reserve (MFR) using {sup 15}O-water PET. We retrospectively processed 70 consecutive {sup 15}O-water PET examinations obtained at rest and during cold pressor testing (CPT) in patients with dilated cardiomyopathy (n = 58), or at rest and during adenosine infusion in heart transplant recipients (n = 12). Data were reconstructed with attenuation correction (AC) and without attenuation correction (NAC) using filtered backprojection, and MBF was quantified using a single compartmental model. The agreement between AC and NAC data was assessed using Lin's concordance correlation coefficient followed by Bland-Altman plot analysis. Regarding endothelial function, NAC PET showed poor reproducibility and poor agreement with AC PET data. Conversely, NAC PET demonstrated high reproducibility and a strong agreement with AC PET for the assessment of MFR. Non-attenuation-corrected {sup 15}O-water PET provided an accurate measurement of MFR compared to attenuation-corrected PET. However, non-attenuation-corrected PET data were less effective for the assessment of endothelial function using CPT in this population. (orig.)

  10. [Myocardial ischemia during exertion. Correlations between blood levels of thromboxane B2 and changes in coronary flow and resistance].

    Science.gov (United States)

    De Servi, S; Vidale, E; Mussini, A; Cafiso, A; Gavazzi, A; Falcone, C; Bramucci, E; Angoli, L; Ferrario, M; Ghio, S

    1985-01-01

    Platelet activation, with the subsequent generation of Thromboxane (Tx) A2, has been implied as a possible cause of resting as well as exercise induced myocardial ischemia. To verify the latter hypothesis, we measured the exercise release of TxB2, the stable metabolite of TxA2, in 9 patients with exertional angina and left anterior descending coronary artery disease. Three of the patients also suffered from angina at rest, due to coronary vasospasm. The great cardiac vein flow, venous efflux from the myocardial territory supplied by the left anterior descending, was determined by the thermodilution technique in the basal conditions, at peak exercise when angina and/or significant ST changes occurred, and 20 min after exercise. Simultaneous blood samples were drawn from the great cardiac vein and a peripheral artery for TxB2 measurements. Regional coronary resistances were calculated as the ratio of mean arterial pressure and coronary flow. At peak exercise the great cardiac vein flow increased and regional coronary resistances decreased in all patients, except in one who showed exercise induced coronary spasm. An increase in TxB2 release was found in 3 patients, a decrease in 3, while the remaining 3 patients did not show significant changes. After exercise the great cardiac vein flow and regional coronary resistances returned to control values in all, whereas both great cardiac vein and arterial TxB2 levels were increased in 6 patients. Our data show that no apparent relation exists between exercise-induced changes in coronary resistances and generation of TxB2.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. A combination of thermal methods to assess coronary pressure and flow dynamics with a pressure-sensing guide wire.

    Science.gov (United States)

    van der Horst, Arjen; Van't Veer, Marcel; van der Sligte, Robin A M; Rutten, Marcel C M; Pijls, Nico H J; van de Vosse, Frans N

    2013-03-01

    Measurement of coronary pressure and absolute flow dynamics have shown great potential in discerning different types of coronary circulatory disease. In the present study, the feasibility of assessing pressure and flow dynamics with a combination of two thermal methods, developed in combination with a pressure-sensor-tipped guide wire, was evaluated in an in vitro coronary model. A continuous infusion thermodilution method was employed to determine the average flow, whereas a thermal anemometric method was utilized to assess the pressure and flow dynamics, simultaneously. In the latter method, the electrical power supplied to an element, kept at constant temperature above ambient temperature, was used as a measure for the shear rate. It was found that, using a single calibration function, the method was able to assess coronary pressure and flow dynamics for different flow amplitudes, heart rates, and different pressure wires. However, due to the fact that the thermal anemometric method cannot detect local shear rate reversal, the method was unable to reliably measure flow dynamics close to zero. Nevertheless, the combined methodology was able to reliably assess diastolic hemodynamics. The diastolic peak flow and average diastolic resistance could be determined with a small relative error of (8 ± 7)% and (7 ± 5)%, respectively.

  12. The presence of fragmented QRS on 12-lead ECG in patients with coronary slow flow.

    Science.gov (United States)

    Yilmaz, Hale; Gungor, Baris; Kemaloglu, Tugba; Sayar, Nurten; Erer, Betul; Yilmaz, Mehmet; Cakmak, Nazmiye; Gurkan, Ufuk; Oz, Dilaver; Bolca, Osman

    2014-01-01

    Coronary slow flow (CSF) is characterised by delayed opacification of coronary arteries in the absence of epicardial occlusive disease. It has been reported that CSF may cause angina, myocardial ischaemia, and infarction. Fragmentation of QRS complex (fQRS) is an easily evaluated non-invasive electrocardiographic parameter. It has been associated with alternation of myocardial activation due to myocardial scar and/or ischaemia. Whether CSF is associated with fQRS is unknown. The presence of fQRS on ECG may be an indicator of myocardial damage in patients with CSF. To investigate the presence of fQRS in patients with CSF. Sixty patients (mean age 55.5 ± 10.5 years) with CSF and 44 patients with normal coronary arteries without associated CSF (mean age 53 ± 8.4 years) were included in this study. The fQRS was defined as the presence of an additional R wave or notching of R or S wave or the presence of fragmentation in two contiguous leads corresponding to a major coronary artery territory. The presence of fQRS was higher in the CSF group than in the controls (p = 0.005). Hypertension was significantly more common in the CSF group (p < 0.001). There was no significant association between the presence of fQRS and an increasing number of vessel involvements. Logistic regression analysis demonstrated that the presence of CSF was the independent determinant of fQRS (OR = 10.848; 95% CI 2.385-49.347; p = 0.002). Fragmented QRS, indicating increased risk for arrhythmias and cardiovascular mortality, was found to be significantly higher in patients with CSF. We have not found an association between the presence of fragmented QRS and the degree of CSF. Further prospective studies are needed to establish the significance as a possible new risk factor in patients with CSF.

  13. Value of Echocardiography for Evaluation of the Flow-dependent Epicardial Coronary Vasodilation In Vivo

    Institute of Scientific and Technical Information of China (English)

    LI Tianliang; DENG Youbin; WANG Lin; YANG Haoyi; BI Xiaojun; ZHANG Qingyang; LIU Jinghua; CHANG Qing; LI Chunlei

    2005-01-01

    To assess the value of echocardiography for detection of the flow-dependent epicardial coronary vasodilation, the changes in internal diameter of the left anterior descending coronary arteries (LAD) induced by reactive hyperemia were studied by echocardiography in 12 health anesthetized open-chest dogs. Reactive hyperemia was induced by brief occlusion of the left anterior descending coronary artery for 30 s followed by rapid release. The two- dimensional images of the left anterior descending coronary artery before and after reactive hyperemia with and without intracoronary infusion of NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase(NOS) were investigated. The internal diameter of LAD was measured and its percent change induced by reactive hyperemia was calculated. Our results showed that the internal diameter of LAD was 2.23±0.19 mm before intracoronary infusion of L-NAME (baseline). The internal diameter of LAD significantly increased to 2.52±0.24 mm (P<0.01) after reactive hyperemia at baseline, and the percent change in internal diameter of LAD was (13. 10±3.59) %. The internal diameter of LAD before and after reactive hyperemia under the condition of intracoronary infusion of L-NAME was not different from that before reactive hyperemia at baseline. The percent change in internal diameter of LAD was (1.07±2.97) %, and it was significantly lower than that at baseline (P<0.001). We are led to conclude that the change in internal diameter of LAD responding to reactive hyperemia was detected sensitively by echocardiography, and this change was associated with endothelium-derived nitric oxide.

  14. Endocardial-epicardial distribution of myocardial perfusion reserve assessed by multidetector computed tomography in symptomatic patients without significant coronary artery disease

    DEFF Research Database (Denmark)

    Kühl, Jørgen Tobias; George, Richard T; Mehra, Vishal C

    2016-01-01

    (MPR) in humans. We aimed to test the hypothesis that MPR in all myocardial layers is determined by age, gender, and cardiovascular risk profile in patients with ischaemic symptoms or equivalent but without obstructive coronary artery disease (CAD). METHODS AND RESULTS: A total of 149 patients enrolled...... in endocardial-epicardial distribution of perfusion reserve may be demonstrated with static CT perfusion. Low MPR in all myocardial layers was observed specifically in obese patients....

  15. The Effects Of L-Arginine And L-Name On Coronary Flow And Oxidative Stress In Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Sobot Tanja

    2015-12-01

    Full Text Available The aim of this experimental study was to assess the effects of the acute administration of L-arginine alone and in combination with L-NAME (a non-selective NO synthase inhibitor on the coronary flow and oxidative stress markers in isolated rat hearts. The experimental study was performed on hearts isolated from Wistar albino rats (n=12, male, 8 weeks old, body mass of 180-200 g. Retrograde perfusion of the isolated preparations was performed using a modified method according to the Langendorff technique with a gradual increase in the perfusion pressure (40–120 cmH2O. The following values were measured in the collected coronary effluents: coronary flow, released nitrites (NO production marker, superoxide anion radical and the index of lipid peroxidation (measured as thiobarbiturate reactive substances. The experimental protocol was performed under controlled conditions, followed by the administration of L-arginine alone (1 mmol and L-arginine (1 mmol + L-NAME (30 μmol. The results indicated that L-arginine did not significantly increase the coronary flow or the release of NO, TBARS and the superoxide anion radical. These effects were partially blocked by the joint administration of L-arginine + L-NAME, which indicated their competitive effect. Hence, the results of our study do not demonstrate significant effects of L-arginine administration on the coronary flow and oxidative stress markers in isolated rat hearts.

  16. Effect of intra-aortic balloon pump on coronary blood flow during different balloon cycles support: A computer study.

    Science.gov (United States)

    Aye, Thin Pa Pa; Htet, Zwe Lin; Singhavilai, Thamvarit; Naiyanetr, Phornphop

    2015-01-01

    Intra-aortic balloon pump (IABP) has been used in clinical treatment as a mechanical circulatory support device for patients with heart failure. A computer model is used to study the effect on coronary blood flow (CBF) with different balloon cycles under both normal and pathological conditions. The model of cardiovascular and IABP is developed by using MATLAB SIMULINK. The effect on coronary blood flow has been studied under both normal and pathological conditions using different balloon cycles (balloon off; 1:4; 1:2; 1:1). A pathological heart is implemented by reducing the left ventricular contractility. The result of this study shows that the rate of balloon cycles is related to the level of coronary blood flow.

  17. In-vitro investigation for blood flow characteristics in stenotic right coronary artery

    Science.gov (United States)

    Park, S. M.; Min, Y. U.; Kang, M. J.; Ji, H. S.; Kim, K. C.

    2010-03-01

    It is very important to investigate hemodynamic and hemorheologic features of blood flow from fluid mechanical point of view because they play major roles in understanding the pathogenesis on cardiovascular disorders. Generally, hemorheologic characteristics of blood flow near the vessel wall are well-known as the most important factor in thrombosis generation according to several hypotheses. To investigate the hemodynamic and hemorheological features related to circulatory diseases, in-vitro experiments were carried out using Micro-PIV technique. Numerical simulation methods using conventional CFD codes were also used to compare with experimental results. The vessel models with stenotic lesion and clinical stent implantation were made of PDMS channel based on Right Coronary Artery (RCA) from clinical angiogram for the patient with stenotic lesion. The hemodynamic and hemorheologic behaviors for control volume near stenotic lesion were evaluated by velocity profiles.

  18. Normal Myocardial Flow Reserve in HIV-Infected Patients on Stable Antiretroviral Therapy

    DEFF Research Database (Denmark)

    Knudsen, Andreas; Christensen, Thomas E; Ghotbi, Adam Ali

    2015-01-01

    ), which can quantify the coronary microvascular function. MFR has proved highly predictive of future coronary artery disease and cardiovascular events in the general population.In a prospective cross-sectional study, HIV-infected patients all receiving antiretroviral therapy (ART) with full viral....... The HIV-infected patients had a mean age of 53 years (range 37-68 years) with 23% active smokers. The controls had a mean age of 52 years (range 36-68 years) and 26% active smokers. In the HIV-infected group 73% had a normal MFR, 17% borderline, and 10% low values of MFR. Among controls these values were...... 71%, 19%, and 10%, respectively (P = 0.99). However, the HIV-infected group had lower values of stress myocardial blood flow (MBF) (2.63 ± 0.09 mL/g/min vs 2.99 ± 0.14 mL/g/min; P = 0.03). We found no evidence of decreased MFR as assessed by 82Rb PET among HIV-infected patients on stable ART...

  19. Evaluation of laser Doppler flowmetry for measuring coronary band and laminar microcirculatory blood flow in clinically normal horses.

    Science.gov (United States)

    Adair, H S; Goble, D O; Shires, G M; Sanders, W L

    1994-04-01

    Once daily for 3 days, laser Doppler flowmetry was used in 5 healthy, nonsedated adult horses to evaluate coronary band and laminar microcirculatory blood flow (MBF) in both forelimbs. The coronary band had significantly (P measurement period in any one site. Significant (P laminar MBF. On occlusion of the digital arteries at the level of the fetlock, marked decrease in coronary band and laminar MBF was observed. Twenty minutes after IV administration of acetylpromazine, marked increase in coronary band and laminar MBF was observed. The technique was easily performed in standing nonsedated horses, did not inflict discomfort, lacked complications, and measurements were repeatable. This technique provides an index of digital MBF, either intermittently or continuously, avoiding introduction of invasive variables associated with other techniques.

  20. Anatomy and function relation in the coronary tree: from bifurcations to myocardial flow and mass.

    Science.gov (United States)

    Kassab, Ghassan S; Finet, Gerard

    2015-01-01

    The study of the structure-function relation of coronary bifurcations is necessary not only to understand the design of the vasculature but also to use this understanding to restore structure and hence function. The objective of this review is to provide quantitative relations between bifurcation anatomy or geometry, flow distribution in the bifurcation and degree of perfused myocardial mass in order to establish practical rules to guide optimal treatment of bifurcations including side branches (SB). We use the scaling law between flow and diameter, conservation of mass and the scaling law between myocardial mass and diameter to provide geometric relations between the segment diameters of a bifurcation, flow fraction distribution in the SB, and the percentage of myocardial mass perfused by the SB. We demonstrate that the assessment of the functional significance of an SB for intervention should not only be based on the diameter of the SB but also on the diameter of the mother vessel as well as the diameter of the proximal main artery, as these dictate the flow fraction distribution and perfused myocardial mass, respectively. The geometric and flow rules for a bifurcation are extended to a trifurcation to ensure optimal therapy scaling rules for any branching pattern.

  1. Coronary artery flow measurement using navigator echo gated phase contrast magnetic resonance velocity mapping at 3.0 T.

    Science.gov (United States)

    Johnson, Kevin; Sharma, Puneet; Oshinski, John

    2008-01-01

    A validation study and early results for non-invasive, in vivo measurement of coronary artery blood flow using phase contrast magnetic resonance imaging (PC-MRI) at 3.0T is presented. Accuracy of coronary artery blood flow measurements by phase contrast MRI is limited by heart and respiratory motion as well as the small size of the coronary arteries. In this study, a navigator echo gated, cine phase velocity mapping technique is described to obtain time-resolved velocity and flow waveforms of small diameter vessels at 3.0T. Phantom experiments using steady, laminar flow are presented to validate the technique and show flow rates measured by 3.0T phase contrast MRI to be accurate within 15% of true flow rates. Subsequently, in vivo scans on healthy volunteers yield velocity measurements for blood flow in the right, left anterior descending, and left circumflex arteries. Measurements of average, cross-sectional velocity were obtainable in 224/243 (92%) of the cardiac phases. Time-averaged, cross-sectional velocity of the blood flow was 6.8+/-4.3cm/s in the LAD, 8.0+/-3.8cm/s in the LCX, and 6.0+/-1.6cm/s in the RCA.

  2. Impaired Coronary Autoregulation Is Associated With Long-term Fatal Events in Patients With Stable Coronary Artery Disease

    NARCIS (Netherlands)

    van de Hoef, Tim P.; Bax, Matthijs; Damman, Peter; Delewi, Ronak; Hassell, Mariella E. C. J.; Piek, Martijn A.; Chamuleau, Steven A. J.; Voskuil, Michiel; van Eck-Smit, Berthe L. F.; Verberne, Hein J.; Henriques, Jose P. S.; Koch, Karel T.; de Winter, Robbert J.; Tijssen, Jan G. P.; Piek, Jan J.; Meuwissen, Martijn

    2013-01-01

    Background-Abnormalities in the coronary microcirculation are increasingly recognized as an elementary component of ischemic heart disease, which can be accurately assessed by coronary flow velocity reserve in reference vessels (refCFVR). We studied the prognostic value of refCFVR for long-term mort

  3. Transit-time flow measurement as a predictor of coronary bypass graft failure at one year angiographic follow-up

    DEFF Research Database (Denmark)

    Lehnert, Per; Møller, Christian H; Damgaard, Sune

    2015-01-01

    BACKGROUND: Transit-time flow measurement (TTFM) is a commonly used intraoperative method for evaluation of coronary artery bypass graft (CABG) anastomoses. This study was undertaken to determine whether TTFM can also be used to predict graft patency at one year postsurgery. METHODS: Three hundred...... forty-five CABG patients with intraoperative graft flow measurements and one year angiographic follow-up were analyzed. Graft failure was defined as more than 50% stenosis including the "string sign." Logistic regression analysis was used to analyze the risk of graft failure after one year based...... on graft vessel type, anastomatic configuration, and coronary artery size. RESULTS: Nine hundred eighty-two coronary anastomoses were performed of which 12% had signs of graft failure at one year angiographic follow-up. In internal mammary arteries (IMAs), analysis showed a 4% decrease in graft failure...

  4. Comparative study of graft flow between on-pump and off-pump coronary bypass surgery for patients with multivessel coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    Xin Chen; Ming Xu; Zhibing Qiu; Yinshuo Jiang; Liming Wang; Liqiong Xiao

    2006-01-01

    Objective: To Comparatively study grafts flow between on-pump and off-pump coronary bypass surgery for patients with triple coronary artery disease. Methods: The grafts flow was studied in 100 patients of OPCAB and compared with100 cases of CCABG by means of Medi-Stim Butterfly Flowmeter measurement intraoperatively. Results: The mean number of the distal anastomosis was 3.78+ 1.11 in CCABG group, and 3.83 + 0.93 in OPCAB group. The index of completeness of revascularization in CCABG group was 1.01 + 0.08, and 1.10+ 0.09 in OPCAB group. The flow of grafts was satisfied in all patients. The PI values were all under 5. There was no significant difference in the mean graft flow and PI value between two groups.Conclusion: OPCAB can provide the same grafts flow and similar completeness of revascularization when compared with CCABG which indicates the similar anastomosis quality of grafts in OPCAB and CCABG groups.

  5. Influence of acute renal failure on coronary vasoregulation in dogs.

    Science.gov (United States)

    Kingma, John G; Vincent, Chantal; Rouleau, Jacques R; Kingma, Iris

    2006-05-01

    Impaired renal function is associated with an increased risk for cardiovascular events and death, but the pathophysiology is poorly defined. The hypothesis that coronary blood flow regulation and distribution of ventricular blood flow could be compromised during acute renal failure (ARF) was tested. In two separate groups (n = 14 each) of dogs with ARF, (1) coronary autoregulation (pressure-flow relations), vascular reserve (reactive hyperemia), and myocardial blood flow distribution (microspheres) and (2) coronary vessel responses to intracoronary infusion of select endothelium-dependent and -independent vasodilators were evaluated. In addition, coronary pressure-flow relations and vascular reserve after inhibition of nitric oxide and prostaglandin release were evaluated. Under resting conditions, myocardial oxygen consumption increased in dogs with ARF compared with no renal failure (NRF; 11.8 +/- 9.2 versus 5.0 +/- 1.5 ml O(2)/min per 100 g; P = 0.01), and the autoregulatory break point of the coronary pressure-flow relation was shifted to higher diastolic coronary pressures (60 +/- 17 versus 52 +/- 8 mmHg in NRF; P = 0.003); the latter was shifted further rightward after inhibition of both nitric oxide and prostaglandin release. The endocardial/epicardial blood flow ratio was comparable for both groups, suggesting preserved ventricular distribution of blood flow. In dogs with ARF, coronary vascular conductance also was reduced (P = 0.001 versus NRF), but coronary zero-flow pressure was unchanged. Vessel reactivity to each endothelium-dependent/independent compound also was blunted significantly. In conclusion, under resting conditions, coronary vascular tone, reserve, and vessel reactivity are markedly diminished with ARF, suggesting impaired vascular function. Consequently, during ARF, small increases in myocardial oxygen demand would induce subendocardial ischemia as a result of a limited capacity to increase oxygen supply and thereby contribute to higher

  6. Simulation of the regional groundwater-flow system of the Menominee Indian Reservation, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Dunning, Charles P.

    2015-01-01

    A regional, two-dimensional, steady-state groundwater-flow model was developed to simulate the groundwater-flow system and groundwater/surface-water interactions within the Menominee Indian Reservation. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Menominee Indian Tribe of Wisconsin, to contribute to the fundamental understanding of the region’s hydrogeology. The objectives of the regional model were to improve understanding of the groundwater-flow system, including groundwater/surface-water interactions, and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate groundwater/surface-water interactions, provide a framework for simulating regional groundwater-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate groundwater-flow patterns at multiple scales. Simulations made with the regional model reproduce groundwater levels and stream base flows representative of recent conditions (1970–2013) and illustrate groundwater-flow patterns with maps of (1) the simulated water table and groundwater-flow directions, (2) probabilistic areas contributing recharge to high-capacity pumped wells, and (3) estimation of the extent of infiltrated wastewater from treatment lagoons.

  7. Numerical investigation of blood flow in a deformable coronary bifurcation and non-planar branch

    Science.gov (United States)

    Razavi, Seyed Esmail; Omidi, Amir Ali; Saghafi Zanjani, Massoud

    2014-01-01

    Introduction: Among cardiovascular diseases, arterials stenosis is recognized more commonly than the others. Hemodynamic characteristics of blood play a key role in the incidence of stenosis. This paper numerically investigates the pulsatile blood flow in a coronary bifurcation with a non-planar branch. To create a more realistic analysis, the wall is assumed to be compliant. Furthermore, the flow is considered to be three-dimensional, incompressible, and laminar. Methods: The effects of non-Newtonian blood, compliant walls and different angles of bifurcation on hemodynamic characteristics of flow were evaluated. Shear thinning of blood was simulated with the Carreau-Yasuda model. The current research was mainly focused on the flow characteristics in bifurcations since atherosclerosis occurs mostly in bifurcations. Moreover, as the areas with low shear stresses are prone to stenosis, these areas were identified. Results: Our findings indicated that the compliant model of the wall, bifurcation’s angle, and other physical properties of flow have an impact on hemodynamics of blood flow. Lower wall shear stress was observed in the compliant wall than that in the rigid wall. The outer wall of bifurcation in all models had lower wall shear stress. In bifurcations with larger angles, wall shear stress was higher in outer walls, and lower in inner walls. Conclusion: The non-Newtonian blood vessels and different angles of bifurcation on hemodynamic characteristics of flow evaluation confirmed a lower wall shear stress in the compliant wall than that in the rigid wall, while the wall shear stress was higher in outer walls but lower in inner walls in the bifurcation regions with larger angles. PMID:25671176

  8. Measurement of pulmonary flow reserve and pulmonary index of microcirculatory resistance for detection of pulmonary microvascular obstruction.

    Directory of Open Access Journals (Sweden)

    Rahn Ilsar

    Full Text Available BACKGROUND: The pulmonary microcirculation is the chief regulatory site for resistance in the pulmonary circuit. Despite pulmonary microvascular dysfunction being implicated in the pathogenesis of several pulmonary vascular conditions, there are currently no techniques for the specific assessment of pulmonary microvascular integrity in humans. Peak hyperemic flow assessment using thermodilution-derived mean transit-time (T(mn facilitate accurate coronary microcirculatory evaluation, but remain unvalidated in the lung circulation. Using a high primate model, we aimed to explore the use of T(mn as a surrogate of pulmonary blood flow for the purpose of measuring the novel indices Pulmonary Flow Reserve [PFR = (maximum hyperemic/(basal flow] and Pulmonary Index of Microcirculatory Resistance [PIMR = (maximum hyperemic distal pulmonary artery pressurex(maximum hyperemic T(mn]. Ultimately, we aimed to investigate the effect of progressive pulmonary microvascular obstruction on PFR and PIMR. METHODS AND RESULTS: Temperature- and pressure-sensor guidewires (TPSG were placed in segmental pulmonary arteries (SPA of 13 baboons and intravascular temperature measured. T(mn and hemodynamics were recorded at rest and following intra-SPA administration of the vasodilator agents adenosine (10-400 microg/kg/min and papaverine (3-24 mg. Temperature did not vary with intra-SPA sensor position (0.010+/-0.009 v 0.010+/-0.009 degrees C; distal v proximal; p = 0.1, supporting T(mn use in lung for the purpose of hemodynamic indices derivation. Adenosine (to 200 microg/kg/min & papaverine (to 24 mg induced dose-dependent flow augmentations (40+/-7% & 35+/-13% T(mn reductions v baseline, respectively; p<0.0001. PFR and PIMR were then calculated before and after progressive administration of ceramic microspheres into the SPA. Cumulative microsphere doses progressively reduced PFR (1.41+/-0.06, 1.26+/-0.19, 1.17+/-0.07 & 1.01+/-0.03; for 0, 10(4, 10(5 & 10(6 microspheres; p

  9. Rationale, design and goals of the HeartFlow assessing diagnostic value of non-invasive FFRCT in Coronary Care (ADVANCE) registry

    DEFF Research Database (Denmark)

    Chinnaiyan, Kavitha M; Akasaka, Takashi; Amano, Tetsuya

    2017-01-01

    reserve by CT (FFRCT) can accurately predict the hemodynamic significance of coronary lesions. The primary objective of this registry is to determine whether the integration of FFRCT as an adjunct to coronary CTA will lead to a significant change in the management of CAD in patients with stable angina...... up to 50 sites in Europe, USA, Canada and Asia. Requirement for enrollment is the presence of atherosclerosis on coronary CTA. For each enrolled patient, a clinical management review committee will use data from coronary CTA and FFRCT to determine the management plan using the following criteria: (a......) optimal medical therapy, (b) percutaneous coronary intervention, (c) coronary artery bypass graft surgery, or (d) more information required. The primary endpoint of the registry is the reclassification rate between the management plan based on coronary CTA alone versus CTA plus FFRCT. The secondary...

  10. Qualitative evaluation of coronary flow during anesthetic induction using thallium-201 perfusion scans

    Energy Technology Data Exchange (ETDEWEB)

    Kleinman, B.; Henkin, R.E.; Glisson, S.N.; el-Etr, A.A.; Bakhos, M.; Sullivan, H.J.; Montoya, A.; Pifarre, R.

    1986-02-01

    Qualitative distribution of coronary flow using thallium-201 perfusion scans immediately postintubation was studied in 22 patients scheduled for elective coronary artery bypass surgery. Ten patients received a thiopental (4 mg/kg) and halothane induction. Twelve patients received a fentanyl (100 micrograms/kg) induction. Baseline thallium-201 perfusion scans were performed 24 h prior to surgery. These scans were compared with the scans performed postintubation. A thallium-positive scan was accepted as evidence of relative hypoperfusion. Baseline hemodynamic and ECG data were obtained prior to induction of anesthesia. These data were compared with the data obtained postintubation. Ten patients developed postintubation thallium-perfusion scan defects (thallium-positive scan), even though there was no statistical difference between their baseline hemodynamics and hemodynamics at the time of intubation. There was no difference in the incidence of thallium-positive scans between those patients anesthetized by fentanyl and those patients anesthetized with thiopental-halothane. The authors conclude that relative hypoperfusion, and possibly ischemia, occurred in 45% of patients studied, despite stable hemodynamics, and that the incidence of these events was the same with two different anesthetic techniques.

  11. Transesophageal echocardiography evaluation of the coronary blood flow and cardiac function in laparoscopic surgery and their correlation with operative wound

    Institute of Scientific and Technical Information of China (English)

    Xin-Sheng Chen

    2016-01-01

    Objective:To analyze the transesophageal echocardiography evaluation of the coronary blood flow and cardiac function in laparoscopic surgery and their correlation with operative wound.Methods:A total of 80 patients undergoing laparoscopic surgery in our hospital were randomly divided into standard pneumoperitoneum pressure group (12-15 mmHg) and high pneumoperitoneum pressure group (>15 mmHg) (n=40), and the differences in the levels of coronary blood flow and cardiac function parameters under transesophageal echocardiography as well as the content of stress hormones and acute phase proteins in serum were compared between two groups of patients.Results: Coronary blood flow parameters D, Q, PDV, MDV and DAR levels of standard pneumoperitoneum pressure group were significantly higher than those of high pneumoperitoneum pressure group; cardiac function parameters COLVOT, LVEF and LVFAC levels were significantly higher than those of high pneumoperitoneum pressure group; stress hormones Cor, Ang-Ⅰ, Ang-Ⅱ, NE, Glucagon and C-peptide as well as acute phase proteins CRP, YKL-40 and HMGB1 content in serum were significantly lower than those of high pneumoperitoneum pressure group while the acute phase protein PA content was significantly higher than that of high pneumoperitoneum pressure group.Conclusions:Transesophageal echocardiography can timely detect the excessive pneumoperitoneum damage in laparoscopic surgery to the coronary blood flow and cardiac function in patients, and also prevent the occurrence of excessive operative wound.

  12. Absolute Versus Relative Myocardial Blood Flow by Dynamic CT Myocardial Perfusion Imaging in Patients With Anatomic Coronary Artery Disease

    NARCIS (Netherlands)

    Wichmann, Julian L.; Meinel, Felix G.; Schoepf, U. Joseph; Lo, Gladys G.; Choe, Yeon Hyeon; Wang, Yining; Vliegenthart, Rozemarijn; Varga-Szemes, Akos; Muscogiuri, Giuseppe; Cannao, Paola M.; De Cecco, Carlo N.

    2015-01-01

    OBJECTIVE. The purpose of this study was to evaluate differences in the diagnostic accuracy of absolute and relative territorial myocardial blood flow (MBF) derived from stress dynamic CT myocardial perfusion imaging (MPI) for the detection of significant coronary artery stenosis. MATERIALS AND METH

  13. Differential effects of androgens on coronary blood flow regulation and arteriolar diameter in intact and castrated swine

    Directory of Open Access Journals (Sweden)

    O’Connor Erin K

    2012-05-01

    Full Text Available Abstract Background Low endogenous testosterone levels have been shown to be a risk factor for the development of cardiovascular disease and cardiovascular benefits associated with testosterone replacement therapy are being advocated; however, the effects of endogenous testosterone levels on acute coronary vasomotor responses to androgen administration are not clear. The objective of this study was to compare the effects of acute androgen administration on in vivo coronary conductance and in vitro coronary microvascular diameter in intact and castrated male swine. Methods Pigs received intracoronary infusions of physiologic levels (1–100 nM of testosterone, the metabolite 5α-dihydrotestosterone, and the epimer epitestosterone while left anterior descending coronary blood flow and mean arterial pressure were continuously monitored. Following sacrifice, coronary arterioles were isolated, cannulated, and exposed to physiologic concentrations (1–100 nM of testosterone, 5α-dihydrotestosterone, and epitestosterone. To evaluate effects of the androgen receptor on acute androgen dilation responses, real-time PCR and immunohistochemistry for androgen receptor were performed on conduit and resistance coronary vessels. Results In vivo, testosterone and 5α-dihydrotestosterone produced greater increases in coronary conductance in the intact compared to the castrated males. In vitro, percent maximal dilation of microvessels was similar between intact and castrated males for testosterone and 5α-dihydrotestosterone. In both studies epitestosterone produced significant increases in conductance and microvessel diameter from baseline in the intact males. Androgen receptor mRNA expression and immunohistochemical staining were similar in intact and castrated males. Conclusions Acute coronary vascular responses to exogenous androgen administration are increased by endogenous testosterone, an effect unrelated to changes in androgen receptor expression.

  14. Performance Analysis of the United States Marine Corps War Reserve Materiel Program Process Flow

    Science.gov (United States)

    2016-12-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA MBA PROFESSIONAL REPORT PERFORMANCE ANALYSIS OF THE UNITED STATES MARINE CORPS...PERFORMANCE ANALYSIS OF THE UNITED STATES MARINE CORPS WAR RESERVE MATERIEL PROGRAM PROCESS FLOW 5. FUNDING NUMBERS 6. AUTHOR(S) Nathan A. Campbell...an item is requested but not maintained in the WRM inventory. By conducting a process analysis and using computer modeling, our recommendations are

  15. Microvascular Coronary Artery Spasm Presents Distinctive Clinical Features With Endothelial Dysfunction as Nonobstructive Coronary Artery Disease

    Science.gov (United States)

    Ohba, Keisuke; Sugiyama, Seigo; Sumida, Hitoshi; Nozaki, Toshimitsu; Matsubara, Junichi; Matsuzawa, Yasushi; Konishi, Masaaki; Akiyama, Eiichi; Kurokawa, Hirofumi; Maeda, Hirofumi; Sugamura, Koichi; Nagayoshi, Yasuhiro; Morihisa, Kenji; Sakamoto, Kenji; Tsujita, Kenichi; Yamamoto, Eiichiro; Yamamuro, Megumi; Kojima, Sunao; Kaikita, Koichi; Tayama, Shinji; Hokimoto, Seiji; Matsui, Kunihiko; Sakamoto, Tomohiro; Ogawa, Hisao

    2012-01-01

    Background Angina without significant stenosis, or nonobstructive coronary artery disease, attracts clinical attention. Microvascular coronary artery spasm (microvascular CAS) can cause nonobstructive coronary artery disease. We investigated the clinical features of microvascular CAS and the therapeutic efficacy of calcium channel blockers. Methods and Results Three hundred seventy consecutive, stable patients with suspected angina presenting nonobstructive coronary arteries (<50% diameter) in coronary angiography were investigated with the intracoronary acetylcholine provocation test, with simultaneous measurements of transcardiac lactate production and of changes in the quantitative coronary blood flow. We diagnosed microvascular CAS according to lactate production and a decrease in coronary blood flow without epicardial vasospasm during the acetylcholine provocation test. We prospectively followed up the patients with calcium channel blockers for microvascular coronary artery disease. We identified 50 patients with microvascular CAS who demonstrated significant impairment of the endothelium-dependent vascular response, which was assessed by coronary blood flow during the acetylcholine provocation test. Administration of isosorbide dinitrate normalized the abnormal coronary flow pattern in the patients with microvascular CAS. Multivariate logistic regression analysis indicated that female sex, a lower body mass index, minor–borderline ischemic electrocardiogram findings at rest, limited–baseline diastolic-to-systolic velocity ratio, and attenuated adenosine triphosphate–induced coronary flow reserve were independently correlated with the presence of microvascular CAS. Receiver-operating characteristics curve analysis revealed that the aforementioned 5-variable model showed good correlation with the presence of microvascular CAS (area under the curve: 0.820). No patients with microvascular CAS treated with calcium channel blockers developed cardiovascular

  16. Coronary flow and reactivity, but not arrhythmia vulnerability, are affected by cardioplegia during cardiopulmonary bypass in piglets

    DEFF Research Database (Denmark)

    Liuba, Petru; Johansson, Sune; Pesonen, Erkki;

    2013-01-01

    Background: Surgery under cardiopulmonary bypass (CPB) is still associated with significant cardiovascular morbidity in both pediatric and adult patients but the mechanisms are not fully understood. Abnormalities in coronary flow and function have been suggested to play an important role. Prior...... velocity (cPFV) rose significantly after surgery especially in the cardioplegia group (p0.4). There was no difference in systolic myocardial function between groups at any time point.Conclusion: In piglets, CPB with cardioplegia was associated with profound abnormalities in coronary vasomotor tone...

  17. Quantification of myocardial blood flow and blood flow reserve in the presence of arterial dispersion: a simulation study.

    Science.gov (United States)

    Schmitt, Melanie; Viallon, Magalie; Thelen, Manfred; Schreiber, Wolfgang G

    2002-04-01

    Myocardial blood flow (MBF) can be quantified using dynamic T1-weighted MRI of diffusible tracers and a mathematical model of underlying vasculature. Quantification of MBF by means of T1- weighted MRI requires knowledge of the arterial input function (AIF). The AIF can be estimated from the left ventricular (LV) cavity. However, dispersion may occur between the LV and the tissue of interest because of the laminar blood flow profiles, branching of venules, and because of stenosis. To evaluate the influence of dispersion on the results of MBF quantification, a simulation study was performed. The dispersion was described as a convolution of the AIF with an exponential residue function. Synthetic tissue and AIF curves were analyzed and the derived parameters fit to the simulated parameters. The results show that an unaccounted dispersion may result in a systematic underestimation of MBF up to approximately 50%. Underestimation increases with increasing dispersion and with increasing MBF. Assuming equal dispersion at rest and during hyperemia, myocardial perfusion reserve (MPR) estimates are also susceptible to underestimation of approximately 20%. An unaccounted dispersion therefore can lead to systematic underestimation of both blood flow and perfusion reserve.

  18. Plasma soluble urokinase-type plasminogen activator receptor level is independently associated with coronary microvascular function in patients with non-obstructive coronary artery disease

    DEFF Research Database (Denmark)

    Mekonnen, Girum; Corban, Michel T; Hung, Olivia Y;

    2015-01-01

    , medications profiles and hs-CRP, suPAR remained an independent predictor of CFR (B = -0.30, p = 0.04), indicating an independent association between suPAR level and coronary microvascular function. CONCLUSIONS: In this cross-sectional study, plasma suPAR level was an independent predictor of coronary......BACKGROUND: Soluble urokinase-type plasminogen activator receptor (suPAR) is a novel biomarker released from leukocytes and endothelial cells that has been associated with atherosclerotic cardiovascular disease. We hypothesized that plasma suPAR level is an independent predictor of coronary...... microvascular function. METHODS: Coronary blood flow velocity and plasma suPAR levels were evaluated in patients with non-obstructive coronary artery disease. Coronary flow reserve (CFR) was calculated as the ratio of hyperemic to basal average peak blood flow velocity and coronary microvascular dysfunction...

  19. Usefulness of fractional flow reserve measurements to defer revascularization in patients with stable or unstable angina pectoris, non-ST-elevation and ST-elevation acute myocardial infarction, or atypical chest pain.

    Science.gov (United States)

    Potvin, Jean-Michel; Rodés-Cabau, Josep; Bertrand, Olivier F; Gleeton, Onil; Nguyen, Can Nanh; Barbeau, Gerald; Proulx, Guy; De Larochellière, Robert; Déry, Jean-Pierre; Batalla, Nuria; Dana, Ali; Facta, Alvaro; Roy, Louis

    2006-08-01

    This study determined the safety of deferring coronary revascularization based on a fractional flow reserve (FFR) value > or = 0.75 in a series of consecutive unselected coronary patients with moderate coronary lesions, including patients with unstable angina, myocardial infarction (MI), and/or positive noninvasive test findings. The study included 201 consecutive coronary patients (mean age 62 +/- 10 years; 65% men) with 231 lesions evaluated by FFR measurement for which revascularization was deferred based on a FFR value > or = 0.75. Lesions associated with a positive noninvasive test result were those located in an artery supplying a myocardial territory in which myocardial ischemia was demonstrated by a noninvasive test. Cardiac events (cardiac death, MI, revascularization) and Canadian Cardiovascular Society angina class were evaluated at follow-up. Indications for coronary angiography included unstable angina or MI (62%), stable angina (30%), or atypical chest pain (8%). Forty-four patients (22%) had > or = 1 coronary lesion associated with a positive noninvasive test result in which FFR was evaluated. Mean FFR value was 0.87 +/- 0.06 and mean lesion percent diameter stenosis was 41 +/- 8%. At 11 +/- 6 months of follow-up, cardiac events occurred in 20 patients (10%), and no significant differences were observed between patients with unstable angina or MI and those with stable angina (9% vs 13%, p = 0.44) or between patients with and without lesions associated with positive noninvasive test results (9% vs 10%, p = 1.00). At the end of follow-up, 88% of patients were asymptomatic in angina class 0 or I, with no differences across various groups. In conclusion, these results suggest that patients with moderate coronary lesions can be safely managed without revascularization on the basis of FFR measurements, irrespective of clinical presentation and/or presence of positive noninvasive test results.

  20. A novel framework for fluid/structure interaction in rapid subject specific simulations of blood flow in coronary artery bifurcations

    Directory of Open Access Journals (Sweden)

    Blagojević Milan

    2014-01-01

    Full Text Available Background/Aim. Practical difficulties, particularly long model development time, have limited the types and applicability of computational fluid dynamics simulations in numerical modeling of blood flow in serial manner. In these simulations, the most revealing flow parameters are the endothelial shear stress distribution and oscillatory shear index. The aim of this study was analyze their role in the diagnosis of the occurrence and prognosis of plaque development in coronary artery bifurcations. Methods. We developed a novel modeling technique for rapid cardiovascular hemodynamic simulations taking into account interactions between fluid domain (blood and solid domain (artery wall. Two numerical models that represent the observed subdomains of an arbitrary patient-specific coronary artery bifurcation were created using multi-slice computed tomography (MSCT coronagraphy and ultrasound measurements of blood velocity. Coronary flow using an in-house finite element solver PAK-FS was solved. Results. Overall behavior of coronary artery bifurcation during one cardiac cycle is described by: velocity, pressure, endothelial shear stress, oscillatory shear index, stress in arterial wall and nodal displacements. The places where (a endothelial shear stress is less than 1.5, and (b oscillatory shear index is very small (close or equal to 0 are prone to plaque genesis. Conclusion. Finite element simulation of fluid-structure interaction was used to investigate patient-specific flow dynamics and wall mechanics at coronary artery bifurcations. Simulation model revealed that lateral walls of the main branch and lateral walls distal to the carina are exposed to low endothelial shear stress which is a predilection site for development of atherosclerosis. This conclusion is confirmed by the low values of oscillatory shear index in those places.

  1. Inter-observer agreement and diagnostic accuracy of myocardial perfusion reserve quantification by cardiovascular magnetic resonance at 3 Tesla in comparison to quantitative coronary angiography.

    Science.gov (United States)

    Ikuye, Katharina; Buckert, Dominik; Schaaf, Lisa; Walcher, Thomas; Rottbauer, Wolfgang; Bernhardt, Peter

    2013-03-27

    Quantification of cardiovascular magnetic resonance (CMR) myocardial perfusion reserve (MPR) at 1.5 Tesla has been shown to correlate to invasive evaluation of coronary artery disease (CAD) and to yield good inter-observer agreement. However, little is known about quantitative adenosine-perfusion CMR at 3 Tesla and no data about inter-observer agreement is available. Aim of our study was to evaluate inter-observer agreement and to assess the diagnostic accuracy in comparison to quantitative coronary angiography (QCA). Fifty-three patients referred for coronary x-ray angiography were previously examined in a 3 Tesla whole-body scanner. Adenosine and rest perfusion CMR were acquired for the quantification of MPR in all segments. Two blinded and independent readers analyzed all images. QCA was performed in case of coronary stenosis. QCA data was used to assess diagnostic accuracy of the MPR measurements. Inter-observer agreement was high for all myocardial perfusion territories (ρ = 0.92 for LAD, ρ = 0.93 for CX and RCA perfused segments). Compared to QCA receiver-operating characteristics yielded an area under the curve of 0.78 and 0.73 for RCA, 0.66 and 0.69 for LAD, and 0.52 and 0.53 for LCX perfused territories. Inter-observer agreement of MPR quantification at 3 Tesla CMR is very high for all myocardial segments. Diagnostic accuracy in comparison to QCA yields good values for the RCA and LAD perfused territories, but moderate values for the posterior LCX perfused myocardial segments.

  2. Energy loss and coronary flow simulation following hybrid stage I palliation: a hypoplastic left heart computational fluid dynamic model.

    Science.gov (United States)

    Shuhaiber, Jeffrey H; Niehaus, Justin; Gottliebson, William; Abdallah, Shaaban

    2013-08-01

    The theoretical differences in energy losses as well as coronary flow with different band sizes for branch pulmonary arteries (PA) in hypoplastic left heart syndrome (HLHS) remain unknown. Our objective was to develop a computational fluid dynamic model (CFD) to determine the energy losses and pulmonary-to-systemic flow rates. This study was done for three different PA band sizes. Three-dimensional computer models of the hybrid procedure were constructed using the standard commercial CFD softwares Fluent and Gambit. The computer models were controlled for bilateral PA reduction to 25% (restrictive), 50% (intermediate) and 75% (loose) of the native branch pulmonary artery diameter. Velocity and pressure data were calculated throughout the heart geometry using the finite volume numerical method. Coronary flow was measured simultaneously with each model. Wall shear stress and the ratio of pulmonary-to-systemic volume flow rates were calculated. Computer simulations were compared at fixed points utilizing echocardiographic and catheter-based metric dimensions. Restricting the PA band to a 25% diameter demonstrated the greatest energy loss. The 25% banding model produced an energy loss of 16.76% systolic and 24.91% diastolic vs loose banding at 7.36% systolic and 17.90% diastolic. Also, restrictive PA bands had greater coronary flow compared with loose PA bands (50.2 vs 41.9 ml/min). Shear stress ranged from 3.75 Pascals with restrictive PA banding to 2.84 Pascals with loose banding. Intermediate PA banding at 50% diameter achieved a Qp/Qs (closest to 1) at 1.46 systolic and 0.66 diastolic compared with loose or restrictive banding without excess energy loss. CFD provides a unique platform to simulate pressure, shear stress as well as energy losses of the hybrid procedure. PA banding at 50% provided a balanced pulmonary and systemic circulation with adequate coronary flow but without extra energy losses incurred.

  3. A randomised trial comparing the effect of exercise training and weight loss on microvascular function in coronary artery disease

    DEFF Research Database (Denmark)

    Olsen, Rasmus Huan; Pedersen, Lene Rørholm; Jürs, Anders

    2015-01-01

    BACKGROUND: Coronary microvascular function is associated with outcome and is reduced in coronary artery disease (CAD) and obesity. We compared the effect of aerobic interval training (AIT) and weight loss on coronary flow reserve (CFR) and peripheral vascular function in revascularised obese CAD...... might impact prognosis of CAD through improvement of coronary microvascular function. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01724567....

  4. The Aberrant Coronary Artery - The Management Approach.

    Science.gov (United States)

    King, Nina-Marie; Tian, David D; Munkholm-Larsen, Stine; Buttar, Sana N; Chow, Vincent; Yan, Tristan

    2017-07-03

    An aberrant coronary artery is a rare clinical occurrence with an incidence of 0.05-1.2%. Often it is an incidental finding detected on coronary angiography or at autopsy. However, symptomatic patients can experience angina, arrhythmia, sudden death or non-specific symptoms such as dyspnoea and syncope. At present, there are no guidelines or dedicated studies assessing the treatment of an aberrant coronary artery leaving management options for these patients controversial. Selected international cardiothoracic surgeons were surveyed electronically in November 2016 to determine whether consensus exists on different management aspects for patients with an aberrant coronary artery arising from the contralateral sinus with an interarterial course. For asymptomatic patients with either an aberrant left main coronary artery (ALMCA) arising from the contralateral sinus or an aberrant right main coronary artery (ARMCA) arising from the contralateral sinus, there was no consensus on surgical correction of the anomaly. If myocardial ischaemia was demonstrated on either coronary angiography with fractional flow reserve measurements and/or stress myocardial perfusion scan, surgical correction was the consensus between the surveyed surgeons. If surgery was deemed appropriate, coronary artery bypass surgery utilising the internal mammary artery was marginally preferred by the respondents in patients with an ALMCA whilst unroofing of the coronary ostium was preferred in patients with an ARMCA. Although no consensus was reached, a large proportion of respondents would not treat a patient over the age of 30 years differently compared to those under 30 years old. For symptomatic patients or if myocardial ischaemia is demonstrated on either coronary angiography with fractional flow reserve measurements and/or stress myocardial perfusion scan, surgical correction is indicated. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the

  5. Coronary vasomotor function assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo, Hokkaido (Japan); Yoshinaga, Keiichiro [Hokkaido University Graduate School of Medicine, Department of Molecular Imaging, Sapporo (Japan); Naya, Masanao [Hokkaido University Graduate School of Medicine, Department of Cardiovascular Medicine, Sapporo (Japan)

    2010-06-15

    Cardiac PET has the unique ability to assess coronary flow reserve and coronary endothelial function on the basis of response of blood flow to pharmacological stress and the cold pressor test. Quantitative analysis of coronary vasomotor function is valuable for precise assessment of function and treatment monitoring in the presence of various coronary risk factors. In addition, recent data have shown prognostic value of PET assessment of coronary vasomotor imaging in patients with suspected coronary artery disease. Thus, quantitative analysis of PET has a great potential for wide application in identifying microcirculatory dysfunction and ''individualized'' monitoring of the effects of primary or preventive medical intervention to optimize cardiovascular outcome. (orig.)

  6. Relationship between HgbA1c and Myocardial Blood Flow Reserve in Patients with Type 2 Diabetes Mellitus: Noninvasive Assessment Using Real-Time Myocardial Perfusion Echocardiography

    Directory of Open Access Journals (Sweden)

    Runqing Huang

    2014-01-01

    Full Text Available To study the relationship between glycosylated hemoglobin (HgbA1c and myocardial perfusion in type 2 diabetes mellitus (T2DM patients, we prospectively enrolled 24 patients with known or suspected coronary artery disease (CAD who underwent adenosine stress by real-time myocardial perfusion echocardiography (RTMPE. HgbA1c was measured at time of RTMPE. Microbubble velocity (β min−1, myocardial blood flow (MBF, mL/min/g, and myocardial blood flow reserve (MBFR were quantified. Quantitative MCE analysis was feasible in all patients (272/384 segments, 71%. Those with HgbA1c > 7.1% had significantly lower βreserve and MBFR than those with HgbA1c ≤ 7.1% (P 2 as normal, HgbA1c > 7.1% significantly increased the risk for abnormal MBFR, (adjusted odds ratio: 1.92, 95% CI: 1.12–3.35, P=0.02. Optimal glycemic control is associated with preservation of MBFR as determined by RTMPE, in T2DM patients at risk for CAD.

  7. Compliant model of a coupled sequential coronary arterial bypass graft: effects of vessel wall elasticity and non-Newtonian rheology on blood flow regime and hemodynamic parameters distribution.

    Science.gov (United States)

    Kabinejadian, Foad; Ghista, Dhanjoo N

    2012-09-01

    We have recently developed a novel design for coronary arterial bypass surgical grafting, consisting of coupled sequential side-to-side and end-to-side anastomoses. This design has been shown to have beneficial blood flow patterns and wall shear stress distributions which may improve the patency of the CABG, as compared to the conventional end-to-side anastomosis. In our preliminary computational simulation of blood flow of this coupled sequential anastomoses design, the graft and the artery were adopted to be rigid vessels and the blood was assumed to be a Newtonian fluid. Therefore, the present study has been carried out in order to (i) investigate the effects of wall compliance and non-Newtonian rheology on the local flow field and hemodynamic parameters distribution, and (ii) verify the advantages of the CABG coupled sequential anastomoses design over the conventional end-to-side configuration in a more realistic bio-mechanical condition. For this purpose, a two-way fluid-structure interaction analysis has been carried out. A finite volume method is applied to solve the three-dimensional, time-dependent, laminar flow of the incompressible, non-Newtonian fluid; the vessel wall is modeled as a linearly elastic, geometrically non-linear shell structure. In an iteratively coupled approach the transient shell equations and the governing fluid equations are solved numerically. The simulation results indicate a diameter variation ratio of up to 4% and 5% in the graft and the coronary artery, respectively. The velocity patterns and qualitative distribution of wall shear stress parameters in the distensible model do not change significantly compared to the rigid-wall model, despite quite large side-wall deformations in the anastomotic regions. However, less flow separation and reversed flow is observed in the distensible models. The wall compliance reduces the time-averaged wall shear stress up to 32% (on the heel of the conventional end-to-side model) and somewhat

  8. 3D flow study in a mildly stenotic coronary artery phantom using a whole volume PIV method.

    Science.gov (United States)

    Brunette, J; Mongrain, R; Laurier, J; Galaz, R; Tardif, J C

    2008-11-01

    Blood flow dynamics has an important role in atherosclerosis initiation, progression, plaque rupture and thrombosis eventually causing myocardial infarction. In particular, shear stress is involved in platelet activation, endothelium function and secondary flows have been proposed as possible variables in plaque erosion. In order to investigate these three-dimensional flow characteristics in the context of a mild stenotic coronary artery, a whole volume PIV method has been developed and applied to a scaled-up transparent phantom. Experimental three-dimensional velocity data was processed to estimate the 3D shear stress distributions and secondary flows within the flow volume. The results show that shear stress reaches values out of the normal and atheroprotective range at an early stage of the obstructive pathology and that important secondary flows are also initiated at an early stage of the disease. The results also support the concept of a vena contracta associated with the jet in the context of a coronary artery stenosis with the consequence of higher shear stresses in the post-stenotic region in the blood domain than at the vascular wall.

  9. Effects of nicardipine on coronary blood flow, left ventricular inotropic state and myocardial metabolism in patients with angina pectoris.

    Science.gov (United States)

    Rousseau, M F; Vincent, M F; Cheron, P; van den Berghe, G; Charlier, A A; Pouleur, H

    1985-01-01

    The effects of intravenous nicardipine (2.5 mg) on the left ventricular (LV) inotropic state, LV metabolism, and coronary haemodynamics were analysed in 22 patients with angina pectoris. Measurements were made at fixed heart rate (atrial pacing), under basal state, and during a cold pressor test. After nicardipine, coronary blood flow and oxygen content in the coronary sinus increased significantly. The indices of inotropic state increased slightly, and the rate of isovolumic LV pressure fall improved. Myocardial oxygen consumption was unchanged despite the significant reduction in pressure-rate product, but LV lactate uptake increased, particularly during the cold pressor test. When nicardipine was administered after propranolol, the indices of inotropic state were unaffected. The lack of direct effect of nicardipine on LV inotropic state was further confirmed by intracoronary injection of 0.1 and 0.2 mg in a separate group of 10 patients. It is concluded that the nicardipine-induced coronary dilatation seems to improve perfusion and aerobic metabolism in areas with chronic ischaemia, resulting in reduced lactate production and augmented oxygen consumption.

  10. In-vivo measurements of coronary blood flow using 16-slice multidetector spiral computed tomography (MDCT) in a porcine model

    Energy Technology Data Exchange (ETDEWEB)

    Krug, Kathrin Barbara; Bovenschulte, H. [Klinikum der Koeln Univ. (Germany). Inst. fuer Radiologische Diagnostik; Geissler, H.J. [Klinikum der Koeln Univ. (DE). Klinik und Poliklinik fuer Herz- und Thoraxchirurgie] (and others)

    2009-03-15

    To determine whether CTCA supplemented with CT flow measurements can be used to demonstrate and semiquantitatively evaluate poststenotic coronary blood flow in a porcine model. In 10 thoracotomized pigs, transit time flow meter probes were attached to the aorta and left anterior descending artery (LAD) for real-time blood flow volumetry. A vascular silicone occluder was deployed around the LAD proximal to the probe to create medium-grade (MGS) and high-grade stenoses (HGS). The blood flow was measured by CT without vessel occlusion and distal to the stenoses. Time-density curves were generated from CT data. The curves were evaluated by calculating and cross-plotting the variables ''slope of the density increase'', ''peak density'' and ''slope of the post-peak density decrease'' from the LAD and aortic CT data. The flow in the LAD dropped to 41 % {+-} 9 % (mean {+-} SD) for MGS and 12 % {+-} 6 % for HGS of the baseline. Coronary time-density curves plateaued proportional to luminal narrowing. Unimpaired flow could be differentiated statistically significant from poststenotic flow adjacent to MGS and HGS (p < 0.000 and p < 0.002, respectively). Flow adjacent to MGS and HGS was successfully differentiated for ''slope of the density increase'' and ''slope of the post-peak density decrease'' (p < 0.003 and p < 0.030, respectively). (orig.)

  11. Transthoracic Doppler echocardiography compared with positron emission tomography for assessment of coronary microvascular dysfunction

    DEFF Research Database (Denmark)

    Michelsen, Marie Mide; Mygind, Naja Dam; Pena, Adam

    2017-01-01

    stenosis at invasive coronary angiography, TTDE CFVR by dipyridamole induced stress and MBFR by rubidium-82 PET with adenosine was successfully measured in 107 subjects. Repeatability of TTDE CFVR was assessed in 10 symptomatic women and in 10 healthy individuals. RESULTS: MBFR was systematically higher......BACKGROUND: Coronary microvascular function can be assessed by transthoracic Doppler echocardiography as a coronary flow velocity reserve (TTDE CFVR) and by positron emission tomography as a myocardial blood flow reserve (PET MBFR). PET MBFR is regarded the noninvasive reference standard...... for measuring coronary microvascular function but has limited availability. We compared TTDE CFVR with PET MBFR in women with angina pectoris and no obstructive coronary artery disease and assessed repeatability of TTDE CFVR. METHODS: From a cohort of women with angina and no obstructive coronary artery...

  12. Fogarty Maneuver to Restore Coronary Flow in ST-Segment Elevation Myocardial Infarction: Desperate Times Call for Desperate Measures.

    Science.gov (United States)

    Larralde, Mark J; Afzal, Ashwad; Brener, Sorin J

    2016-01-01

    Nonatherosclerotic embolism is a rare cause (4%-7%) of coronary occlusion in ST-segment elevation myocardial infarction (STEMI) patients, approximately half of which occur in inadequately anticoagulated patients with prosthetic valves. We report a rare case of a patient with severe rheumatic heart disease and 3 mechanical valves presenting with STEMI that was successfully managed by Fogarty maneuver thrombus extraction after failed thrombus aspiration and balloon angioplasty. A 56-year-old woman presented with an acute anterior STEMI and Killip class III heart failure. She had severe rheumatic heart disease with mechanical tricuspid, mitral and aortic valve prostheses, and atrial fibrillation on warfarin anticoagulation. The international normalized ratio on admission was 1.1. Emergency coronary angiography revealed normal right and circumflex coronary arteries and a total occlusion in the mid left anterior descending artery with a meniscus appearance. Multiple attempts at thrombus aspiration and balloon angioplasty failed to restore flow in the left anterior descending artery. Ultimately, a Fogarty maneuver using a compliant balloon inflated at a low pressure was performed successfully, removing the thrombus into the guiding catheter. There was Thrombolysis in Myocardial Infarction flow grade 3 and near-normal myocardial blush at the end of the procedure. Signs and symptoms of heart failure resolved quickly.

  13. Direct visualization of a significant stenosis of the right coronary artery by transthoracic echocardiography. A case report

    Directory of Open Access Journals (Sweden)

    Wiseth Rune

    2007-10-01

    Full Text Available Abstract Non-invasive imaging of coronary arteries by transthoracic echocardiography is an emerging diagnostic tool to study the left main (LM, left descending artery (LAD, circumflex (Cx and right coronary artery (RCA. Impaired coronary circulation can be assessed by measuring coronary velocity flow reserve (CVFR by transthoracic Doppler echocardiography. Coronary artery stenoses can be identified as localized colour aliasing and accelerated flow velocities. We report a case with an acute coronary syndrome (ACS of a 46-year-old man. With non-invasive imaging of coronary arteries by transthoracic echocardiography (TTE, we identified a segment of the mid right coronary artery (RCA suggestive of stenosis with localized colour aliasing and accelerated flow velocity. We found a high ratio between the stenotic peak velocity and the prestenotic peak velocity, and a pathologic coronary flow velocity reserve (CFVR distal to the stenosis in the posterior interventricular descending branch (RDP. Subsequent coronary angiography demonstrated one vessel disease with a stenosis in segment 3 of RCA, which was successfully treated with percutaneos coronary intervention PCI. Two weeks following the PCI procedure he was readmitted to hospital with chest pain. A subacute stent thrombosis was questioned, and repeated echocardiography was preformed. The mid portion of RCA showed normal and laminar flow. The CVFR of RCA measured in the RDP showed normal vasodilatory response, confirming an open RCA without any flow limitation. A repeated coronary angiogram demonstrated only a mild in stent intimal hyperplasia. This case illustrates the value of transthoracic echocardiography as a tool both in the diagnosis and the follow-up of chest pain disorders and coronary flow problems. Transthoracic echocardiography allows both direct visualization of the various coronary segments and assessment of the CVFR.

  14. 36. Clinical profile of coronary slow flow phenomena – A cardiac Y syndrome

    Directory of Open Access Journals (Sweden)

    Toufiqur Rahman

    2015-10-01

    Conclusion: CSFP was prevalent in wide spectrum if Ischemic Heart Disease presenting as CSA and Acute Coronary Syndrome. Most of the patients presented with CSFP were smokers and had uncontrolled Hypertension.

  15. Coronary blood flow dynamics during transcutaneous electrical nerve stimulation for stable angina pectoris associated with severe narrowing of one major coronary artery

    NARCIS (Netherlands)

    Jessurun, GAJ; Tio, RA; De Jongste, MJL; Hautvast, RWM; Den Heijer, P; Crijns, HJGM

    1998-01-01

    To study the effect of transcutaneous electrical nerve stimulation (TENS) on coronary vasomotion, patients with New York Heart Association class III angina pectoris and significant single-vessel left coronary artery disease and who were also scheduled for elective percutaneous transluminal coronary

  16. Coronary blood flow dynamics during transcutaneous electrical nerve stimulation for stable angina pectoris associated with severe narrowing of one major coronary artery

    NARCIS (Netherlands)

    Jessurun, GAJ; Tio, RA; De Jongste, MJL; Hautvast, RWM; Den Heijer, P; Crijns, HJGM

    1998-01-01

    To study the effect of transcutaneous electrical nerve stimulation (TENS) on coronary vasomotion, patients with New York Heart Association class III angina pectoris and significant single-vessel left coronary artery disease and who were also scheduled for elective percutaneous transluminal coronary

  17. Effects of dipyridamole and aminophylline on hemodynamics, regional myocardial blood flow and thallium-201 washout in the setting of a critical coronary stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Granato, J.E.; Watson, D.D.; Belardinelli, L.; Cannon, J.M.; Beller, G.A. (Univ. of Virginia Health Sciences Center, Charlottesville (USA))

    1990-12-01

    Experiments were performed to characterize the interaction of intravenous dipyridamole and aminophylline on thallium-201 transport kinetics, regional myocardial blood flow and systemic hemodynamics in the presence of a critical coronary artery stenosis. In 12 dogs with a critical left anterior descending coronary artery stenosis, arterial pressure decreased from a mean value (+/- SEM) of 107 +/- 6 to 94 +/- 3 mm Hg and distal left anterior descending artery pressure decreased from 70 +/- 7 to 55 +/- 4 mm Hg after intravenous administration of dipyridamole. In the left anterior descending perfusion zone, the endocardial/epicardial flow ratio decreased from 0.70 to 0.36 and the intrinsic thallium washout rate was significantly prolonged. Intravenous aminophylline reversed the dipyridamole-induced systemic hypotension and transmural coronary steal and restored the thallium washout rate to baseline values. In six other dogs, aminophylline alone resulted in no alterations in systemic and coronary hemodynamics or regional myocardial blood flow. As expected, dipyridamole-induced vasodilation and coronary steal were prevented by aminophylline pretreatment. These data show that in a canine model of partial coronary stenosis, systemic hypotension, adverse regional flow effects and prolonged thallium-201 washout consequent to intravenously administered dipyridamole are promptly reversed by intravenous aminophylline administration. Aminophylline alone had no significant hemodynamic and coronary flow effects. This study provides further insight into the altered thallium kinetics occurring as a consequence of dipyridamole-induced vasodilation and suggests that the prompt reversal of symptoms and signs of ischemia with aminophylline in patients receiving intravenous dipyridamole for clinical imaging studies probably reflects the reversal of transmural coronary steal.

  18. Coronary and peripheral endothelial function in HIV patients studied with positron emission tomography and flow-mediated dilation: relation to hypercholesterolemia

    Energy Technology Data Exchange (ETDEWEB)

    Lebech, Anne-Mette [Copenhagen University Hospital, Department of Infectious Diseases, Hvidovre (Denmark); Hvidovre University Hospital, Department of Infectious Diseases, Hvidovre (Denmark); Kristoffersen, Ulrik Sloth; Kjaer, Andreas [Rigshospitalet University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen (Denmark); University of Copenhagen, Cluster for Molecular Imaging, Copenhagen (Denmark); Wiinberg, Niels; Petersen, Claus Leth [Frederiksberg University Hospital, Department of Clinical Physiology and Nuclear Medicine, Frederiksberg (Denmark); Kofoed, Kristian; Andersen, Ove [Copenhagen University Hospital, Department of Infectious Diseases, Hvidovre (Denmark); Copenhagen University Hospital, Clinical Research Unit, Hvidovre (Denmark); Hesse, Birger [Rigshospitalet University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen (Denmark); Gerstoft, Jan [Rigshospitalet University Hospital, Department of Infectious Diseases, Copenhagen (Denmark)

    2008-11-15

    The mechanisms underlying increased cardiovascular risk in HIV patients in antiretroviral therapy (ART) are not known. Our aim was to study the endothelial function of the coronary arteries by cardiac perfusion positron emission tomography (PET), in HIV patients with normal or high cholesterol levels. Flow mediated dilation (FMD) of the brachial artery and circulating endothelial markers were also assessed. HIV patients in ART with total cholesterol {<=} 5.5 mmol/L (215 mg/dL; n = 13) or total cholesterol {>=} 6.5 mmol/L (254 mg/dL; n = 12) and healthy controls (n = 14) were included. {sup 13}NH{sub 3} perfusion PET, FMD, and measurement of plasma levels of E-Selectin, ICAM-1, VCAM-1, tPAI-1, and hs-CRP were performed. Baseline myocardial perfusion and the coronary flow reserve measured by PET (3.2 {+-} 0.3, 3.2 {+-} 0.3 and 3.0 {+-} 0.3; ns) was similar in HIV patients with normal or high total cholesterol and controls. FMD did not differ between the groups and was 4.6 {+-} 1.1%, 5.1 {+-} 1.2%, and 4.6 {+-} 0.8%, respectively. Increased levels of plasma E-Selectin, ICAM-1, tPAI-1, and hs-CRP were found in HIV patients when compared to controls (p < 0.05). E-Selectin and ICAM-1 levels were higher in HIV patients receiving protease inhibitors (PI) compared to those not receiving PI (p < 0.05). None of the measured endothelial biomarkers differed between the normal and high cholesterol HIV groups. In ART-treated HIV patients with a low overall cardiovascular risk, no sign of endothelial dysfunction was found not even in hypercholesterolemic patients. Also, the increased level of plasma endothelial markers found in HIV patients was not related to hypercholesterolemia. (orig.)

  19. Blood flow, flow reserve, and glucose utilization in viable and nonviable myocardium in patients with ischemic cardiomyopathy.

    Science.gov (United States)

    Zhang, Xiaoli; Schindler, Thomas H; Prior, John O; Sayre, James; Dahlbom, Magnus; Huang, Sung-Cheng; Schelbert, Heinrich R

    2013-04-01

    The aim of the study was to determine whether glucose uptake in viable myocardium of ischemic cardiomyopathy patients depends on rest myocardial blood flow (MBF) and the residual myocardial flow reserve (MFR). Thirty-six patients with ischemic cardiomyopathy (left ventricular ejection fraction 25 ± 10 %) were studied with (13)N-ammonia and (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET). Twenty age-matched normals served as controls. Regional MBF was determined at rest and during dipyridamole hyperemia and regional FDG extraction was estimated from regional FDG to (13)N-ammonia activity ratios. Rest MBF was reduced in viable (0.42 ± 0.18 ml/min per g) and nonviable regions (0.32 ± 0.09 ml/min per g) relative to remote regions (0.68 ± 0.23 ml/min per g, p MFRs did not differ significantly (p > 0.05). Compared to MFR in remote myocardium, MFRs in viable regions were similar (1.39 ± 0.56 vs 1.70 ± 0.45, p > 0.05) but were significantly lower in nonviable regions (1.23 ± 0.43, p MFRs (r =-0.424, p MFRs in viable myocardium are associated with increasing glucose extraction that likely reflects a metabolic adaptation of remodeling hibernating myocytes.

  20. Role of coronary physiology in the contemporary management of coronary artery disease.

    Science.gov (United States)

    Ruparelia, Neil; Kharbanda, Rajesh K

    2015-02-16

    Coronary artery disease (CAD) remains the leading cause of death worldwide with approximately 1 in 30 patients with stable CAD experiencing death or acute myocardial infarction each year. The presence and extent of resultant myocardial ischaemia has been shown to confer an increased risk of adverse outcomes. Whilst, optimal medical therapy (OMT) forms the cornerstone of the management of patients with stable CAD, a significant number of patients present with ischaemia refractory to OMT. Historically coronary angiography alone has been used to determine coronary lesion severity in both stable and acute settings. It is increasingly clear that this approach fails to accurately identify the haemodynamic significance of lesions; especially those that are visually "intermediate" in severity. Revascularisation based upon angiographic appearances alone may not reduce coronary events above OMT. Technological advances have enabled the measurement of physiological indices including the fractional flow reserve, the index of microcirculatory resistance and the coronary flow reserve. The integration of these parameters into the routine management of patients presenting to the cardiac catheterization laboratory with CAD represents a critical adjunctive tool in the optimal management of these patients by identifying patients that would most benefit from revascularisation and importantly also highlighting patients that would not gain benefit and therefore reducing the likelihood of adverse outcomes associated with coronary revascularisation. Furthermore, these techniques are applicable to a broad range of patients including those with left main stem disease, proximal coronary disease, diabetes mellitus, previous percutaneous coronary intervention and with previous coronary artery bypass grafting. This review will discuss current concepts relevant to coronary physiology assessment, its role in the management of both stable and acute patients and future applications.

  1. Improvement of myocardial perfusion reserve detected by cardiovascular magnetic resonance after direct endomyocardial implantation of autologous bone marrow cells in patients with severe coronary artery disease

    Directory of Open Access Journals (Sweden)

    Lau Chu-Pak

    2010-01-01

    Full Text Available Abstract Background Recent studies suggested that bone marrow (BM cell implantation in patients with severe chronic coronary artery disease (CAD resulted in modest improvement in symptoms and cardiac function. This study sought to investigate the functional changes that occur within the chronic human ischaemic myocardium after direct endomyocardial BM cells implantation by cardiovascular magnetic resonance (CMR. Methods and Results We compared the interval changes of left ventricular ejection fraction (LVEF, myocardial perfusion reserve and the extent of myocardial scar by using late gadolinium enhancement CMR in 12 patients with severe CAD. CMR was performed at baseline and at 6 months after catheter-based direct endomyocardial autologous BM cell (n = 12 injection to viable ischaemic myocardium as guided by electromechanical mapping. In patients randomized to receive BM cell injection, there was significant decrease in percentage area of peri-infarct regions (-23.6%, P = 0.04 and increase in global LVEF (+9.0%, P = 0.02, the percentage of regional wall thickening (+13.1%, P= 0.04 and MPR (+0.25%, P = 0.03 over the target area at 6-months compared with baseline. Conclusions Direct endomyocardial implantation of autologous BM cells significantly improved global LVEF, regional wall thickening and myocardial perfusion reserve, and reduced percentage area of peri-infarct regions in patients with severe CAD.

  2. The effect of exercise and antioxidant enzyme levels in syndrome X and coronary slow flow phenomenon: an observational study.

    Science.gov (United States)

    Kaplan, Ozgür; Meriç, Murat; Acar, Zeydin; Kale, Abdurrahman; Demircan, Sabri; Yılmaz, Ozcan; Demircan, Günnur; Yılmaz Miroğlu, Yeliz

    2013-11-01

    In this study the antioxidant enzyme [catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) ] levels at rest in patients with syndrome X and coronary slow flow are measured. Then it has been investigated whether there is any enzymatic difference between the normal controls and syndrome X patients or patients with coronary slow flow and ascertain if exercise has any effects on the antioxidant enzyme levels. Fifty-five patients were included in this prospective observational controlled study. Patients were divided into 3 groups: Group 1- normal controls (n=20); Group 2-patients with coronary slow flow (n=20); and Group 3-patients diagnosed with syndrome X (n=15). In all patients, blood samples were collected at rest and after maximal exercise. The antioxidant enzymes (SOD, CAT, Gpx) in the erythrocytes were studied for these three groups of blood sample. Statistical analysis was performed using Student t-test, Mann-Whitney U and Chi-square tests, Kruskal-Wallis variance analysis and ANOVA. Under basal conditions the lowest SOD and GPx levels were measured in the 2nd Group, whereas significant differences in paired comparisons were observed only between the 2nd and 3rd Groups (p=0.024 vs. plevels were decreased significantly in the 3rd Groups when compared with the basal concentrations (p=0.014), however no significant pre- and post-exercise differences were observed in the CAT and GPx concentrations (p>0.05). The post-exercise SOD level when compared with basal SOD levels were decreased significantly in the syndrome X group, however no differences were observed between the other groups. This can be interpreted as the reduction in the exercise related symptoms and ischemic findings are resulting from the decrease of SOD activity.

  3. Environmental flow calculation for the maintenance of the water reserve of the Piaxtla River, Sinaloa, Mexico

    Directory of Open Access Journals (Sweden)

    Guadalupe de la Lanza Espino

    2014-03-01

    status to be achieved within the watershed to maintain the integrity of existing ecosystems or when they believe that they are degraded, contributing to the recovery or rehabilitation; and annual percentage rate recommended for environmental protection. Based on this, the purpose of this study was to quantify the river flow of the Piaxtla river, in the state of Sinaloa. The river runoff data bases for 36 and nine years were compared, showed differences mainly between the frequency of maximum runoff and its origin, and indicated that it is advisable to use a data base of more than 20 years. However, results were similar in the final calculation of the environmental or ecological river flows; that is to say, total runoff volume was 62.1% considering 36 years and 57.7% for nine years of information. We conclude that the ecological importance of Piaxtla river was very high and the use of water pressure was low (considering that database runoff only included until 1999 and did not take into account population growth and activities. To determine the final volume reserved for the environment or ecological flow, could be estimated not only with a database of 36 years, but for nine years also confirming that those rivers that have databases of 10 years can the methodology used hydrological indicated by the NMX said. Particularly in this study it was determined that for parameters more detailed as the volume of the base rate of the annual volume, according to the frequency of occurrence, both very dry years, dry, average and wet, and influence of meteorological events that determine periods separate return, it is advisable to use minimum data bases as brand NMX 20 years.

  4. Roles of myocardial blood volume and flow in coronary artery disease: an experimental MRI study at rest and during hyperemia

    Energy Technology Data Exchange (ETDEWEB)

    McCommis, Kyle S.; Goldstein, Thomas A.; Pilgram, Thomas [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Abendschein, Dana R. [Washington University School of Medicine, Center for Cardiovascular Research, St. Louis, MO (United States); Misselwitz, Bernd [Bayer Schering Pharma AG, Berlin (Germany); Gropler, Robert J. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Washington University School of Medicine, Center for Cardiovascular Research, St. Louis, MO (United States); Zheng, Jie [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Cardiovascular Imaging Lab, St. Louis, MO (United States)

    2010-08-15

    To validate fast perfusion mapping techniques in a setting of coronary artery stenosis, and to further assess the relationship of absolute myocardial blood volume (MBV) and blood flow (MBF) to global myocardial oxygen demand. A group of 27 mongrel dogs were divided into 10 controls and 17 with acute coronary stenosis. On 1.5-T MRI, first-pass perfusion imaging with a bolus injection of a blood-pool contrast agent was performed to determine myocardial perfusion both at rest and during either dipyridamole-induced vasodilation or dobutamine-induced stress. Regional values of MBF and MBV were quantified by using a fast mapping technique. Color microspheres and {sup 99m}Tc-labeled red blood cells were injected to obtain respective gold standards. Microsphere-measured MBF and {sup 99m}Tc-measured MBV reference values correlated well with the MR results. Given the same changes in MBF, changes in MBV are twofold greater with dobutamine than with dipyridamole. Under dobutamine stress, MBV shows better association with total myocardial oxygen demand than MBF. Coronary stenosis progressively reduced this association in the presence of increased stenosis severity. MR first-pass perfusion can rapidly estimate regional MBF and MBV. Absolute quantification of MBV may add additional information on stenosis severity and myocardial viability compared with standard qualitative clinical evaluations of myocardial perfusion. (orig.)

  5. TU-G-204-01: BEST IN PHYSICS (IMAGING): Dynamic CT Myocardial Perfusion Measurement and Its Comparison to Fractional Flow Reserve

    Energy Technology Data Exchange (ETDEWEB)

    Ziemer, B; Hubbard, L; Groves, E; Sadeghi, B; Javan, H; Lipinski, J; Molloi, S [University of California, Irvine, CA (United States)

    2015-06-15

    Purpose: To evaluate a first pass analysis (FPA) technique for CT perfusion measurement in a swine animal and its validation using fractional flow reserve (FFR) as a reference standard. Methods: Swine were placed under anesthesia and relevant physiologic parameters were continuously recorded. Intra-coronary adenosine was administered to induce maximum hyperemia. A pressure wire was advanced distal to the first diagonal branch of the left anterior descending (LAD) artery for FFR measurements and a balloon dilation catheter was inserted over the pressure wire into the proximal LAD to create varying levels of stenosis. Images were acquired with a 320-row wide volume CT scanner. Three main coronary perfusion beds were delineated in the myocardium using arteries extracted from CT angiography images using a minimum energy hypothesis. The integrated density in the perfusion bed was used to calculate perfusion using the FPA technique. The perfusion in the LAD bed over a range of stenosis severity was measured. The measured fractional perfusion was compared to FFR and linear regression was performed. Results: The measured fractional perfusion using the FPA technique (P-FPA) and FFR were related as P-FPA = 1.06FFR – 0.06 (r{sup 2} = 0.86). The perfusion measurements were calculated with only three to five total CT volume scans, which drastically reduces the radiation dose as compared with the existing techniques requiring 15–20 volume scans. Conclusion: The measured perfusion using the first pass analysis technique showed good correlation with FFR measurements as a reference standard. The technique for perfusion measurement can potentially make a substantial reduction in radiation dose as compared with the existing techniques.

  6. Vascular flow reserve as a link between long-term blood pressure level and physical performance capacity in mammals

    DEFF Research Database (Denmark)

    Poulsen, Christian B; Damkjær, Mads; Hald, Bjørn O

    2016-01-01

    function producing a high precapillary resistance and thus a high vascular flow reserve is associated with an increase in network inlet pressure. Assuming that network properties are independent of body mass, and that inlet pressure of the microvascular network is a proxy for arterial pressure, the study......Mean arterial pressure (MAP) is surprisingly similar across different species of mammals, and it is, in general, not known which factors determine the arterial pressure level. Mammals often have a pronounced capacity for sustained physical performance. This capacity depends on the vasculature...... having a flow reserve that comes into play as tissue metabolism increases. We hypothesize that microvascular properties allowing for a large vascular flow reserve is linked to the level of the arterial pressure.To study the interaction between network properties and network inlet pressure, we developed...

  7. Myocardial blood flow and left ventricular functional reserve in hypertrophic cardiomyopathy: a {sup 13}NH{sub 3} gated PET study

    Energy Technology Data Exchange (ETDEWEB)

    Sciagra, Roberto; Calabretta, Raffaella; Passeri, Alessandro; Castello, Angelo; Pupi, Alberto [University of Florence, Nuclear Medicine Unit, Department of Experimental and Clinical Biomedical Sciences ' ' Mario Serio' ' , Florence (Italy); Cipollini, Fabrizio [University of Florence, Department of Statistics, Florence (Italy); Cecchi, Franco; Olivotto, Iacopo [Careggi University Hospital, Referral Centre for Myocardial Diseases, Florence (Italy)

    2017-05-15

    Ischemia in hypertrophic cardiomyopathy (HCM) is caused by coronary microvascular dysfunction (CMD), which is detected by measuring myocardial blood flow (MBF) with PET. Whether CMD may be associated with ischemic left ventricular (LV) dysfunction is unclear. We therefore assessed LV ejection fraction (EF) reserve in HCM patients undergoing dipyridamole (Dip) PET. Resting and stress {sup 13}NH{sub 3} dynamic as well as gated PET were performed in 34 HCM patients. Segmental MBF and transmural perfusion gradient (TPG = subendocardial / subepicardial MBF) were assessed. LVEF reserve was considered abnormal if Dip LVEF decreased more than 5 units as compared to rest. Eighteen patients had preserved (group A) and 16 abnormal LVEF reserve (group B; range -7 to -32). Group B patients had greater wall thickness than group A, but resting volumes, LVEF, resting and Dip MBF, and myocardial flow reserve were similar. Group B had slightly higher summed stress score and summed difference score in visual analysis than group A, and a significantly higher summed stress wall motion score. In group B, resting TPG was slightly lower (1.31 ± 0.29 vs. 1.37 ± 0.34, p <0.05), and further decreased after Dip, whilst in group A it increased (B = 1.20 ± 0.39, p < 0.0001 vs. rest and vs. A = 1.40 ± 0.43). The number of segments per patient with TPG <1 was higher than in group A (p < 0.001) and was a significant predictor of impaired LVEF reserve (OR 1.86, p < 0.02), together with wall thickness (OR 1.3, p < 0.02). Abnormal LVEF response is common in HCM patients following Dip, and is related to abnormal TPG, suggesting that subendocardial ischemia might occur under Dip and cause transient LV dysfunction. Although in vivo this effect may be hindered by the adrenergic drive associated with effort, these findings may have relevance in understanding exercise limitation and heart failure symptoms in HCM. (orig.)

  8. In vitro blood flow model with physiological wall shear stress for hemocompatibility testing-An example of coronary stent testing.

    Science.gov (United States)

    Engels, Gerwin Erik; Blok, Sjoerd Leendert Johannes; van Oeveren, Willem

    2016-09-18

    Hemocompatibility of blood contacting medical devices has to be evaluated before their intended application. To assess hemocompatibility, blood flow models are often used and can either consist of in vivo animal models or in vitro blood flow models. Given the disadvantages of animal models, in vitro blood flow models are an attractive alternative. The in vitro blood flow models available nowadays mostly focus on generating continuous flow instead of generating a pulsatile flow with certain wall shear stress, which has shown to be more relevant in maintaining hemostasis. To address this issue, the authors introduce a blood flow model that is able to generate a pulsatile flow and wall shear stress resembling the physiological situation, which the authors have coined the "Haemobile." The authors have validated the model by performing Doppler flow measurements to calculate velocity profiles and (wall) shear stress profiles. As an example, the authors evaluated the thrombogenicity of two drug eluting stents, one that was already on the market and one that was still under development. After identifying proper conditions resembling the wall shear stress in coronary arteries, the authors compared the stents with each other and often used reference materials. These experiments resulted in high contrast between hemocompatible and incompatible materials, showing the exceptional testing capabilities of the Haemobile. In conclusion, the authors have developed an in vitro blood flow model which is capable of mimicking physiological conditions of blood flow as close as possible. The model is convenient in use and is able to clearly discriminate between hemocompatible and incompatible materials, making it suitable for evaluating the hemocompatible properties of medical devices.

  9. Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats

    OpenAIRE

    Weytjens Caroline; Garbar Christian; Degaillier Céline; Hernot Sophie; Droogmans Steven; Cosyns Bernard; Roosens Bram; Schoors Danny; Lahoutte Tony; Franken Philippe R; Van Camp Guy

    2008-01-01

    Abstract The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with Streptozotocin-induced diabetic rats using contrast echocardiography. Methods We prospectively studied 40 Wistar rats. Diabetes was induced by ...

  10. Quantitative analysis of arterial flow properties for detection of non-calcified plaques in ECG-gated coronary CT angiography

    Science.gov (United States)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2015-03-01

    We are developing a computer-aided detection system to assist radiologists in detection of non-calcified plaques (NCPs) in coronary CT angiograms (cCTA). In this study, we performed quantitative analysis of arterial flow properties in each vessel branch and extracted flow information to differentiate the presence and absence of stenosis in a vessel segment. Under rest conditions, blood flow in a single vessel branch was assumed to follow Poiseuille's law. For a uniform pressure distribution, two quantitative flow features, the normalized arterial compliance per unit length (Cu) and the normalized volumetric flow (Q) along the vessel centerline, were calculated based on the parabolic Poiseuille solution. The flow features were evaluated for a two-class classification task to differentiate NCP candidates obtained by prescreening as true NCPs and false positives (FPs) in cCTA. For evaluation, a data set of 83 cCTA scans was retrospectively collected from 83 patient files with IRB approval. A total of 118 NCPs were identified by experienced cardiothoracic radiologists. The correlation between the two flow features was 0.32. The discriminatory ability of the flow features evaluated as the area under the ROC curve (AUC) was 0.65 for Cu and 0.63 for Q in comparison with AUCs of 0.56-0.69 from our previous luminal features. With stepwise LDA feature selection, volumetric flow (Q) was selected in addition to three other luminal features. With FROC analysis, the test results indicated a reduction of the FP rates to 3.14, 1.98, and 1.32 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. The study indicated that quantitative blood flow analysis has the potential to provide useful features for the detection of NCPs in cCTA.

  11. Topical negative pressure effects on coronary blood flow in a sternal wound model

    DEFF Research Database (Denmark)

    Lindstedt, Sandra; Malmsjö, Malin; Gesslein, Bodil

    2008-01-01

    Several studies have suggested that mediastinitis is a strong predictor for poor long-term survival after coronary artery bypass surgery (CABG). In those studies, several conventional wound-healing techniques were used. Previously, we have shown no difference in long-term survival between CABG...

  12. Regional myocardial shortening in relation to graft-reactive hyperemia and flow after coronary bypass surgery

    NARCIS (Netherlands)

    R.W. Brower (Ronald); P.W.J.C. Serruys (Patrick); E. Bos (Egbert); J. Nauta (Jan)

    1979-01-01

    textabstractExtent of regional shortening of myocardium in areas newly perfused by bypass grafting was determined in 56 patients by a new technique employing four to six radiopaque markers sutured in pairs to the epicardium near the coronary anastomosis. Paradoxical systolic expansion (PSE) was mani

  13. [Flow rates of roentgen contrast media of different viscosity in 4.1 Charrière coronary catheters].

    Science.gov (United States)

    Jung, F; Schmitt, R M; Scheller, B; Bach, R; Heidmann, D; Spitzer, S; Schieffer, H

    1996-08-01

    The studies presented here investigated the obtainable flows of different contrast media (Iopromide 370 mg iodine/ml, ZK 119 095 370 mg iodine/ml, ZK 139 129 370 mg iodine/ml, Iopamidol 370 mg iodine/ml, Iopromide 300 mg iodine/ml, ZK 119 095 300 mg iodine/ml, ZK 139 129 300 mg iodine/ml, Iopamidol 300 mg iodine/ml, aqua dest.) in 4.1 Charrière coronary catheters. The measurements of the flow achieved by a standardised power of 100 N show that the highest values are reached with the substance ZK 119 095 (both for 300 mg iodine/ml and 370 mg iodine/ml). On comparison of the catheter types there are no differences in the delivery rate. The x-ray contrast-media, however, are significantly different: the lowest iodine delivery rate is found for iopromide 370 with 384.5 mg iodine/s; the highest rate for the test substance ZK 119 095 with 648.9 mg iodine/s. Although contrast media with low viscosity contain considerably less iodine/ml it is possible to achieve an iodine density in coronary vessels by about 86% higher than that achieved by contrast media with 370 mg iodine/ml. Therefore, the possibility to choose a viscosity-adapted x-ray contrast-medium allows the use of very thin cardiac catheter systems without leading to a worsening of picture quality.

  14. Structural alterations of the coronary arterial wall are associated with myocardial flow heterogeneity in type 2 diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Thomas H. [California Univ., Los Angeles, CA (United States). Dept. of Moelecular and Medical Pharmacology, Radiological Science]|[University Hospital of Geneva, Department of Internal Medicine, Cardiovascular Center, Nuclear Cardiology, Geneva (Switzerland); Facta, Alvaro D.; Prior, John O.; Cadenas, Jerson; Zhang, Xiao-Li; Sayre, James; Goldin, Jonathan; Schelbert, Heinrich R. [California Univ., Los Angeles, CA (United States). Dept. of Moelecular and Medical Pharmacology, Radiological Science; Li, Yanjie [University of Southern California, Atherosclerosis Research Unit, Keck School of Medicine, Los Angeles, CA (United States)

    2009-02-15

    To determine the relationship between carotid intima-media thickness (IMT), coronary artery calcification (CAC), and myocardial blood flow (MBF) at rest and during vasomotor stress in type 2 diabetes mellitus (DM). In 68 individuals, carotid IMT was measured using high-resolution vascular ultrasound, while the presence of CAC was determined with electron beam tomography (EBT). Global and regional MBF was determined in milliliters per gram per minute with {sup 13}N-ammonia and positron emission tomography (PET) at rest, during cold pressor testing (CPT), and during adenosine (ADO) stimulation. There was neither a relationship between carotid IMT and CAC (r = 0.10, p = 0.32) nor between carotid IMT and coronary circulatory function in response to CPT and during ADO (r = -0.18, p = 0.25 and r = 0.10, p = 0.54, respectively). In 33 individuals, EBT detected CAC with a mean Agatston-derived calcium score of 44 {+-} 18. There was a significant difference in regional MBFs between territories with and without CAC at rest and during ADO-stimulated hyperemia (0.69 {+-} 0.24 vs. 0.74 {+-} 0.23 and 1.82 {+-} 0.50 vs. 1.95 {+-} 0.51 ml/g/min; p {<=} 0.05, respectively) and also during CPT in DM but less pronounced (0.81 {+-} 0.24 vs. 0.83 {+-} 0.23 ml/g/min; p = ns). The increase in CAC was paralleled with a progressive regional decrease in resting as well as in CPT- and ADO-related MBFs (r = -0.36, p {<=} 0.014; r = -0.46, p {<=} 0.007; and r = -0.33, p {<=} 0.041, respectively). The absence of any correlation between carotid IMT and coronary circulatory function in type 2 DM suggests different features and stages of early atherosclerosis in the peripheral and coronary circulation. PET-measured MBF heterogeneity at rest and during vasomotor stress may reflect downstream fluid dynamic effects of coronary artery disease (CAD)-related early structural alterations of the arterial wall. (orig.)

  15. [Coronary artery blood flow velocity non-invasively measured using a vessel-tracking pulsed Doppler system].

    Science.gov (United States)

    Tateishi, O; Aizawa, O; Okamura, T; Yoshida, T; Furuhata, H; Seo, Y; Iinuma, K; Shiki, E

    1988-09-01

    A newly-developed noninvasive method was used to measure left coronary blood flow during phantom experiments. Two techniques were used in which: (1) the sample position can always be set in a fluctuating vessel using a wall echo-tracking method with a phase-locked-loop, and (2) the Doppler reference signal was generated separately synchronous with the wall echo signal. These techniques were combined, using a commercially available pulsed Doppler apparatus (SSH-40B: Toshiba). Basic experiments were performed using a blood vessel phantom to verify the validity of these systems. Blood flow velocity in the fluctuating tube could be measured clearly using a vessel-tracking method. The blood flow velocity of the left anterior descending artery was measured in three normal subjects and in seven patients from the third intercostal space along the left sternal border. The velocity pattern was characterized by a crescendo-decrescendo shape in diastole. The peak velocity which appeared in diastole ranged from 19 to 69 cm/sec, with no difference by disease entity. However, in all cases, the blood flow velocity signals were marred by extraneous signals, making it impossible to measure blood flow velocity during systole. Further improvement of the system is mandatory in order to use this flowmeter clinically.

  16. Modeling of Stenotic Coronary Artery and Implications of Plaque Morphology on Blood Flow

    Directory of Open Access Journals (Sweden)

    Carlos Moreno

    2013-01-01

    Full Text Available A diseased coronary artery has been modeled to study the implications of plaque morphology on the fluid dynamics. In our previous study, we have successfully classified the coronary plaques of 42 patients who underwent intravascular ultrasound (IVUS into four-types (Type I, Type II, Type III, and Type IV based on the plaque morphology. In this study, we demonstrate that, for the same degree of stenosis (height of the plaques, hemodynamics parameters are strongly dependent on the plaque shape. This study is the first one to clearly demonstrate that in addition to wall shear stress, presence of turbulence and location of transition from laminar to turbulence state are additional hemodynamics parameters to identify plaques vulnerable to rupture.

  17. Angiography and coronary function, a clinical approach

    NARCIS (Netherlands)

    Stoel, Martin Gerrit

    2013-01-01

    Coronary angiography has the potential to determine coronary function in addition to merely showing coronary anatomy. In this thesis, we describe several facets of angiographic evaluation of coronary flow velocity and function. Measurement of the length of the coronary vessels by means of a guide

  18. Echocardiographic assessment of coronary artery flow in normal canines and model dogs with myocardial infarction.

    Science.gov (United States)

    Park, Nohwon; Kim, Jaehwan; Lee, Miyoung; Lee, Soyun; Song, Sunhye; Lee, Seungjun; Kim, Soyoung; Park, Yangwoo; Eom, Kidong

    2014-01-01

    This study was conducted to evaluate the usefulness of coronary arterial profiles from normal dogs (11 animals) and canines (six dogs) with experimental myocardial infarction (MI) induced by ligation of the left coronary artery (LCA). Blood velocity of the LCA and right coronary artery (RCA) were evaluated following transthoracic pulsed-wave Doppler echocardiography. The LCA was observed as an infundibular shape, located adjacent to the sinus of Valsalva. The RCA appeared as a tubular structure located 12 o'clock relative to the aorta. In normal dogs, the LCA and RCA mean peak diastolic velocities were 20.84 ± 3.24 and 19.47 ± 2.67 cm/sec, respectively. The LCA and RCA mean diastolic deceleration times were 0.91 ± 0.14 sec and 1.13 ± 0.20 sec, respectively. In dogs with MI, the LCA had significantly (p < 0.01) lower peak velocities (14.82 ± 1.61 cm/sec) than the RCA (31.61 ± 2.34 cm/sec). The RCA had a significantly (p < 0.01) rapid diastolic deceleration time (0.71 ± 0.06 sec) than that found in the LCA (1.02 ± 0.22 sec) of MI dogs. In conclusion, these profiles may serve as a differential factor for evaluating cardiomyopathy in dogs.

  19. Effects of respiratory alkalosis and acidosis on myocardial blood flow and metabolism in patients with coronary artery disease.

    Science.gov (United States)

    Kazmaier, S; Weyland, A; Buhre, W; Stephan, H; Rieke, H; Filoda, K; Sonntag, H

    1998-10-01

    Variation of the arterial carbon dioxide partial pressure (PaCO2) is not uncommon in anesthetic practice. However, little is known about the myocardial consequences of respiratory alkalosis and acidosis, particularly in patients with coronary artery disease. The aim of the current study was to investigate the effects of variation in PaCO2 on myocardial blood flow (MBF), metabolism, and systemic hemodynamics in patients before elective coronary artery bypass graft surgery. In 10 male anesthetized patients, measurements of MBF, myocardial contractility, metabolism, and systemic hemodynamics were made in a randomized sequence at PaCO2 levels of 30, 40, and 50 mmHg, respectively. The MBF was measured using the Kety-Schmidt technique with argon as a tracer. End-diastolic left ventricular pressure and the maximal increase of left ventricular pressure were assessed using a manometer-tipped catheter. The cardiac index significantly changed with varying PaCO2 levels (hypocapnia, - 9%; hypercapnia, 13%). This reaction was associated with inverse changes in systemic vascular resistance index levels. The MBF significantly increased by 15% during hypercapnia, whereas no change was found during hypocapnia. Myocardial oxygen and glucose uptake and the maximal increase of left ventricular pressure were not affected by varying PaCO2 levels. In anesthetized patients with coronary artery disease, short-term variations in PaCO2 have significant effects on MBF but do not influence global myocardial oxygen and glucose uptake. Changes in systemic hemodynamics associated with respiratory alkalosis and acidosis are caused by changes in systemic vascular resistance rather than by alterations in myocardial contractility.

  20. Quantitative assessment of blood flow reserve using {sup 99m}Tc-HMPAO in carotid stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Garai, I.; Varga, J.; Galuska, L. [Department of Nuclear Medicine, University of Debrecen Medical and Health Centre, Debrecen (Hungary); Szomjak, E. [3. Department of Internal Medicine, University of Debrecen Medical and Health Centre, Debrecen (Hungary); Toth, C.; Olvaszto, S. [1. Department of Surgery, University of Debrecen Medical and Health Centre, Debrecen (Hungary); Bank, J. [Department of Neurology, Kenezy Hospital (Hungary); Ficzere, A. [Department of Neurology, University of Debrecen Medical and Health Centre, Debrecen (Hungary)

    2002-02-01

    Dynamic imaging of the inflow of technetium-99m hexamethylpropylene amine oxime (HMPAO) to the brain has been proved to allow estimation of the hemispherical cerebral blood flow (CBF) using the Patlak plot. In this study, we compared the hemispherical CBF (in ml/min/100 g) of different patient groups. A total of 25 patients (comprising 13 with migraine and 12 scheduled for endarterectomy owing to angiographically confirmed severe stenosis of the internal carotid artery on at least one side) underwent baseline and acetazolamide {sup 99m}Tc-HMPAO brain perfusion studies. In addition, acetazolamide {sup 99m}Tc-HMPAO studies were performed in 12 healthy subjects (no baseline study was performed for ethical reasons.) Dynamic studies were acquired by means of a dual-detector gamma camera with a large field of view (HELIX, Elscint). Special difference images were created to make definition of the aortic arch and hemispherical brain regions easier and more reproducible. A semi-automatic method was developed to determine the transit time from the aorta to the brain, making the generation of the Patlak plot even more robust. The baseline CBF values did not significantly depend on the disease (P>0.1), whereas the CBF values obtained after acetazolamide provocation did do so (ANOVA, P<0.001). Patients suffering from migraine showed a significant increase in global CBF values after acetazolamide provocation (paired t test, P<0.05), but we could not find any effect of the provocation in patients awaiting carotid endarterectomy, indicating a lack of cerebrovascular reserve capacity. Comparison of the results of the acetazolamide study in patients and the control group revealed the CBF values to be significantly lower in patients with carotid stenosis (two-sample t-test, P<0.001), but not in those with migraine (P>0.1). In summary, using quantitative analysis of {sup 99m}Tc-HMPAO brain studies we could objectively compare the CBF of patients suffering from different diseases

  1. Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

    NARCIS (Netherlands)

    A. Coenen (Adriaan); M. Lubbers (Marisa); A. Kurata (Akira); A.K. Kono (Atsushi K.); A. Dedic (Admir); R.G. Chelu (Raluca Gabriela); M.L. Dijkshoorn (Marcel); Rossi, A. (Alexia); R.J.M. van Geuns (Robert Jan); K. Nieman (Koen)

    2016-01-01

    textabstractObjectives: To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). Methods: Subjects with suspected or known coro

  2. Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

    Science.gov (United States)

    Gewirtz, Henry; Dilsizian, Vasken

    2016-05-31

    In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted.

  3. Effect of a distal protection device on epicardial blood flow and myocardial perfusion in primary percutaneous coronary intervention

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: The beneficial effect of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) has been well established, but there is the problem of no-reflow phenomenon which is an adverse prognostic factor in primary PCI. In the present study the effect of a distal protection device (PercuSurge GuardWire; GW) on epicardial blood flow and myocardial perfusion was evaluated. Methods and Results: Patients with AMI were randomly divided into 2 groups, the GW and the control groups. The GW group included 52 patients with AMI who underwent primary PCI with GW protection and the control group included 60 patients who underwent primary PCI without GW protection. Epicardial blood flow in the infarct-related artery (IRA) and myocardial perfusion were evaluated according to the thrombolysis in myocardial infarction (TIMI) flow grade and the myocardial blush grade (MBG). We found TIMI score of 3 was obtained significantly more frequently in the GW group (96%) than in the control group (80%). The MBG score of 3 was obtained also significantly greater in the GW group (65%) than in the control group (33%). Conclusion: Primary PCI with GW protection can significantly improve epicardial blood flow and myocardial perfusion.

  4. Simulation of groundwater flow and interaction of groundwater and surface water on the Lac du Flambeau Reservation, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Fienen, Michael N.; Hunt, Randall J.

    2014-01-01

    The Lac du Flambeau Band of Lake Superior Chippewa and Indian Health Service are interested in improving the understanding of groundwater flow and groundwater/surface-water interaction on the Lac du Flambeau Reservation (Reservation) in southwest Vilas County and southeast Iron County, Wisconsin, with particular interest in an understanding of the potential for contamination of groundwater supply wells and the fate of wastewater that is infiltrated from treatment lagoons on the Reservation. This report describes the construction, calibration, and application of a regional groundwater flow model used to simulate the shallow groundwater flow system of the Reservation and water-quality results for groundwater and surface-water samples collected near a system of waste-water-treatment lagoons. Groundwater flows through a permeable glacial aquifer that ranges in thickness from 60 to more than 200 feet (ft). Seepage and drainage lakes are common in the area and influence groundwater flow patterns on the Reservation. A two-dimensional, steady-state analytic element groundwater flow model was constructed using the program GFLOW. The model was calibrated by matching target water levels and stream base flows through the use of the parameter-estimation program, PEST. Simulated results illustrate that groundwater flow within most of the Reservation is toward the Bear River and the chain of lakes that feed the Bear River. Results of analyses of groundwater and surface-water samples collected downgradient from the wastewater infiltration lagoons show elevated levels of ammonia and dissolved phosphorus. In addition, wastewater indicator chemicals detected in three downgradient wells and a small downgradient stream indicate that infiltrated wastewater is moving southwest of the lagoons toward Moss Lake. Potential effects of extended wet and dry periods (within historical ranges) were evaluated by adjusting precipitation and groundwater recharge in the model and comparing the

  5. Early changes in contractility and coronary blood flow in the normal areas of the ischemic porcine heart.

    Science.gov (United States)

    Pashkow, F; Holland, R; Brooks, H

    1977-03-01

    The regional responses of normal myocardium distant from an ischemic area were studied during acute anterior descending occlusion in the open-chest chloralose-anesthetized pig. Three markers of regional response in both normal and ischemic areas were used: surface ECG electrode, a force gauge in series with left ventricular outer wall fibers, and coronary blood inflow to each region as determined by electromagnetic cuff-probes. Following brief anterior descending artery occlusion (120 sec)., a characteristic rapid decline in contractile force and evolution of TQ-ST segment changes was observed in the ischemic area. In contrast, in the distant area increases in contractil force (p less than 0.001) and coronary blood flow (p less than 0.002) occurred. These distant responses were essentially obliterated following transection and cannulation of the artery supplying this region (p less than 0.05). The findings are consistent with a reflex neurovascular mechanism operating within the intact heart. This reflex is rapidly activated in order to maintain adequate levels of cardiac performance despite sudden loss of functional myocardial mass.

  6. Association of glomerular filtration rate with slow coronary flow in patients with normal to mildly impaired renal function.

    Science.gov (United States)

    Akin, Fatih; Celik, Omer; Ayça, Burak; Yalçin, Ahmet Arif; Altun, Ibrahim; Köse, Nuri

    2014-10-01

    We evaluated the association between estimated glomerular filtration rate (eGFR) and slow coronary flow (SCF) in patients with normal to mildly impaired renal function; 211 patients with angiographically proven SCF and 219 controls were studied. Patients were categorized based on the angiographic findings as with or without SCF. We used the Modification of Diet in Renal Disease equation to calculate eGFR. The frequency of mildly decreased eGFR, serum uric acid levels, and eGFR was higher in the SCF group. Patients with mildly impaired renal function had higher thrombolysis in myocardial infarction frame counts in 3 major coronary arteries. In logistic regression analysis, uric acid (odds ratio [OR] = 1.323, 95% confidence interval [CI] = 1.109-1.572, P = .002) and eGFR (OR = 0.972, 95% CI = 0.957-0.987, P < .001) were independent correlates of SCF. In conclusion, eGFR was significantly correlated with SCF in patients with normal to mildly impaired renal function.

  7. Association of Monocyte-to-HDL Cholesterol Ratio with Slow Coronary Flow is Linked to Systemic Inflammation.

    Science.gov (United States)

    Canpolat, Ugur; Çetin, Elif Hande; Cetin, Serkan; Aydin, Selahattin; Akboga, Mehmet Kadri; Yayla, Cagri; Turak, Osman; Aras, Dursun; Aydogdu, Sinan

    2016-07-01

    Previous studies proposed that both inflammation, oxidative stress, and impaired endothelial dysfunction have a significant role in occurrence of slow coronary flow (SCF). monocyte-to-high density lipoprotein cholesterol ratio (MHR) is a recently emerged indicator of inflammation and oxidative stress, which have been studied only in patients with chronic kidney disease. We aimed to assess the relationship between MHR and SCF. Patients who had angiographically normal coronary arteries were enrolled in this retrospective study (n = 253 as SCF group and n = 176 as control group). Patients who had corrected thrombolysis in myocardial infarction frame counts (cTFCs) above the normal cutoffs were defined as with SCF. The MHR and high-sensitivity C-reactive protein (hsCRP) were significantly higher in the SCF group. In correlation analysis, MHR has a significantly positive correlation with cTFC and serum hsCRP levels (P MHR was found as independently associated with the presence of SCF (odds ratio: 1.24, P MHR which indicates an enhanced inflammation and oxidative stress was significantly and independently associated with the presence of SCF. Besides, MHR was positively correlated with serum hsCRP level as a conventional marker for systemic inflammation. © The Author(s) 2015.

  8. Treatment of a coronary artery to superior vena cava fistula resulting from early closure of a Possis Perma-Flow graft.

    Science.gov (United States)

    Graham, M M; Kells, C M; Sullivan, J; O'Neill, B J

    1999-06-01

    The Perma-Flow graft used in bypass surgery achieves more complete revascularization when paucity of native conduits exists. We report a coronary artery to superior vena cava fistula as a complication of this graft, leading to severe right heart failure. The fistula was successfully occluded percutaneously, improving the patient's clinical situation.

  9. Intracoronary genistein acutely increases coronary blood flow in anesthetized pigs through beta-adrenergic mediated nitric oxide release and estrogenic receptors.

    Science.gov (United States)

    Grossini, Elena; Molinari, Claudio; Mary, David A S G; Uberti, Francesca; Caimmi, Philippe Primo; Surico, Nicola; Vacca, Giovanni

    2008-05-01

    Various studies have suggested that the phytoestrogen genistein has beneficial cardioprotective and vascular effects. However, there has been scarce information regarding the primary effect of genistein on coronary blood flow and its mechanisms including estrogen receptors, autonomic nervous system, and nitric oxide (NO). The present study was planned to determine the primary effect of genistein on coronary blood flow and the mechanisms involved. In anesthetized pigs, changes in left anterior descending coronary artery caused by intracoronary infusion of genistein at constant heart rate and arterial pressure were assessed using ultrasound flowmeters. In 25 pigs, genistein infused at 0.075 mg/min increased coronary blood flow by about 16.3%. This response was graded in a further five pigs by increasing the infused dose of the genistein between 0.007 and 0.147 mg/min. In the 25 pigs, blockade of cholinergic receptors (iv atropine; five pigs) and alpha-adrenergic receptors (iv phentolamine; five pigs) did not abolish the coronary response to genistein, whose effects were prevented by blockade of beta(2)-adrenergic receptors (iv butoxamine; five pigs), nitric oxide synthase (intracoronary N(omega)-nitro-L-arginine methyl ester; five pigs) and estrogenic receptors (ERs; ERalpha/ERbeta; intracoronary fulvestrant; five pigs). In porcine aortic endothelial cells, genistein induced the phosphorylation of endothelial nitric oxide synthase and NO production through ERK 1/2, Akt, and p38 MAPK pathways, which was prevented by the concomitant treatment by butoxamine and fulvestrant. In conclusion, genistein primarily caused coronary vasodilation the mechanism of which involved ERalpha/ERbeta and the release of NO through vasodilatory beta(2)-adrenoreceptor effects.

  10. COMPUTER SIMULATION OF NON-NEWTONIAN FLOW AND MASS TRANSPORT THROUGH CORONARY ARTERIAL STENOSIS

    Institute of Scientific and Technical Information of China (English)

    李新宇; 温功碧; 李丁

    2001-01-01

    A numerical analysis of Newtonian and non-Newtonian flow in an axi-symmetric tube with a local constriction simulating a stenosed artery under steady and pulsatile flow conditions was carried out. Based on these results, the concentration fields of LDL ( low density lipoprotein ) and Albumin were discussed. According to the results, in great details the macromolecule transport influences of wall shear stress, non-Newtonian fluid character and the scale of the molecule etc are given. The results of Newtonian fluid flow and non Newtonian fluid flow , steady flow and pulsatile flow are compared. These investigations can provide much valuable information about the correlation between the flow properties, the macromolecule transport and the development of atherosclerosis.

  11. Absolute coronary blood flow measurement and microvascular resistance in ST-elevation myocardial infarction in the acute and subacute phase

    Energy Technology Data Exchange (ETDEWEB)

    Wijnbergen, Inge; Veer, Marcel van ' t [Department of Cardiology, Catharina Hospital, Eindhoven (Netherlands); Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven (Netherlands); Lammers, Jeroen; Ubachs, Joey [Department of Cardiology, Catharina Hospital, Eindhoven (Netherlands); Pijls, Nico H.J., E-mail: nico.pijls@cze.nl [Department of Cardiology, Catharina Hospital, Eindhoven (Netherlands); Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven (Netherlands)

    2016-03-15

    Background/Purpose: In a number of patients with acute myocardial infarction (AMI), myocardial hypoperfusion, known as the no-reflow phenomenon, persists after primary percutaneous intervention (PPCI). The aim of this study was to evaluate the feasibility and safety of a new quantitative method of measuring absolute blood flow and resistance within the perfusion bed of an infarct-related artery. Furthermore, we sought to study no-reflow by correlating these measurements to the index of microvascular resistance (IMR) and the area at risk (AR) as determined by cardiac magnetic resonance imaging (CMR). Methods: Measurements of absolute flow and myocardial resistance were performed in 20 patients with ST-segment elevation myocardial infarction (STEMI), first immediately following PPCI and then again after 3–5 days. These measurements used the technique of thermodilution during a continuous infusion of saline. Flow was expressed in ml/min per gram of tissue within the area at risk. Results: The average time needed for measurement of absolute flow, resistance and IMR was 20 min, and all measurements could be performed without complication. A higher flow supplying the AR correlated with a lower IMR in the acute phase. Absolute flow increased from 3.14 to 3.68 ml/min/g (p = 0.25) and absolute resistance decreased from 1317 to 1099 dyne.sec.cm-5/g (p = 0.40) between the first day and fifth day after STEMI. Conclusions: Measurement of absolute flow and microvascular resistance is safe and feasible in STEMI patients and may allow for a better understanding of microvascular (dys)function in the early phase of AMI. - Highlights: • We measured absolute coronary blood flow and microvascular resistance in STEMI patients in the acute phase and in the subacute phase, using the technique of thermodilution with low grade intracoronary continuous infusion of saline. • These measurements are safe and feasible during PPCI in STEMI patients. • In STEMI patients, absolute flow

  12. Flow and wall shear stress in end-to-side and side-to-side anastomosis of venous coronary artery bypass grafts

    Directory of Open Access Journals (Sweden)

    Poulikakos Dimos

    2007-09-01

    Full Text Available Abstract Purpose Coronary artery bypass graft (CABG surgery represents the standard treatment of advanced coronary artery disease. Two major types of anastomosis exist to connect the graft to the coronary artery, i.e., by using an end-to-side or a side-to-side anastomosis. There is still controversy because of the differences in the patency rates of the two types of anastomosis. The purpose of this paper is to non-invasively quantify hemodynamic parameters, such as mass flow and wall shear stress (WSS, in end-to-side and side-to-side anastomoses of patients with CABG using computational fluid dynamics (CFD. Methods One patient with saphenous CABG and end-to-side anastomosis and one patient with saphenous CABG and side-to-side anastomosis underwent 16-detector row computed tomography (CT. Geometric models of coronary arteries and bypasses were reconstructed for CFD analysis. Blood flow was considered pulsatile, laminar, incompressible and Newtonian. Peri-anastomotic mass flow and WSS were quantified and flow patterns visualized. Results CFD analysis based on in-vivo CT coronary angiography data was feasible in both patients. For both types of CABG, flow patterns were characterized by a retrograde flow into the native coronary artery. WSS variations were found in both anastomoses types, with highest WSS values at the heel and lowest WSS values at the floor of the end-to-side anastomosis. In contrast, the highest WSS values of the side-to-side anastomosis configuration were found in stenotic vessel segments and not in the close vicinity of the anastomosis. Flow stagnation zones were found in end-to-side but not in side-to-side anastomosis, the latter also demonstrating a smoother stream division throughout the cardiac cycle. Conclusion CFD analysis of venous CABG based on in-vivo CT datasets in patients was feasible producing qualitative and quantitative information on mass flow and WSS. Differences were found between the two types of anastomosis

  13. Rubidium-82 PET-CT for quantitative assessment of myocardial blood flow: validation in a canine model of coronary artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Lautamaeki, Riikka; Higuchi, Takahiro; Merrill, Jennifer; Voicu, Corina; Bengel, Frank M. [Johns Hopkins Medical Institutions, Department of Radiology, Division of Nuclear Medicine, Baltimore, MD (United States); George, Richard T.; Kitagawa, Kakuya; DiPaula, Anthony; Lima, Joao A.C. [Johns Hopkins Medical Institutions, Department of Medicine, Division of Cardiology, Baltimore, MD (United States); Nekolla, Stephan G. [Technischen Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Lardo, Albert C. [Johns Hopkins Medical Institutions, Department of Medicine, Division of Cardiology, Baltimore, MD (United States); Johns Hopkins Medical Institutions, Department of Biomedical Engineering, Baltimore, MD (United States)

    2009-04-15

    Absolute quantification of myocardial blood flow expands the diagnostic potential of PET for assessment of coronary artery disease. {sup 82}Rb has significantly contributed to increasing utilization of PET; however, clinical studies are still mostly analysed qualitatively. The aim of this study was to reevaluate the feasibility of {sup 82}Rb for flow quantification, using hybrid PET-CT in an animal model of coronary stenosis. Nine dogs were prepared with experimental coronary artery stenosis. Dynamic PET was performed for 8 min after {sup 82}Rb(1480-1850 MBq) injection during adenosine-induced vasodilation. Microspheres were injected simultaneously for reference flow measurements. CT angiography was used to determine the myocardial regions related to the stenotic vessel. Two methods for flow calculation were employed: a two-compartment model including a spill-over term, and a simplified retention index. The two-compartment model data were in good agreement with microsphere flow (y=0.84x+0.20; r=0.92, p<0.0001), although there was variability in the physiological flow range <3 ml/g per minute (y=0.54x+0.53; r=0.53, p=0.042). Results from the retention index also correlated well with microsphere flow (y=0.47x+0.52; r=0.75, p=0.0004). Error increased with higher flow, but the correlation was good in the physiological range (y=0.62x+0.29; r=0.84, p=0.0001). Using current state-of-the-art PET-CT systems, quantification of myocardial blood flow is feasible with {sup 82}Rb. A simplified approach based on tracer retention is practicable in the physiological flow range. These results encourage further testing of the robustness and usefulness in the clinical context of cardiac hybrid imaging. (orig.)

  14. Safety of guidewire-based measurement of fractional flow reserve and the index of microvascular resistance using intravenous adenosine in patients with acute or recent myocardial infarction.

    Science.gov (United States)

    Ahmed, Nadeem; Layland, Jamie; Carrick, David; Petrie, Mark C; McEntegart, Margaret; Eteiba, Hany; Hood, Stuart; Lindsay, Mitchell; Watkins, Stuart; Davie, Andrew; Mahrous, Ahmed; Carberry, Jaclyn; Teng, Vannesa; McConnachie, Alex; Curzen, Nick; Oldroyd, Keith G; Berry, Colin

    2016-01-01

    Coronary guidewire-based diagnostic assessments with hyperemia may cause iatrogenic complications. We assessed the safety of guidewire-based measurement of coronary physiology, using intravenous adenosine, in patients with an acute coronary syndrome. We prospectively enrolled invasively managed STEMI and NSTEMI patients in two simultaneously conducted studies in 6 centers (NCT01764334; NCT02072850). All of the participants underwent a diagnostic coronary guidewire study using intravenous adenosine (140 μg/kg/min) infusion for 1-2 min. The patients were prospectively assessed for the occurrence of serious adverse events (SAEs) and symptoms and invasively measured hemodynamics were also recorded. 648 patients (n=298 STEMI patients in 1 hospital; mean time to reperfusion 253 min; n=350 NSTEMI in 6 hospitals; median time to angiography from index chest pain episode 3 (2, 5) days) were included between March 2011 and May 2013. Two NSTEMI patients (0.3% overall) experienced a coronary dissection related to the guidewire. No guidewire dissections occurred in the STEMI patients. Chest symptoms were reported in the majority (86%) of patient's symptoms during the adenosine infusion. No serious adverse events occurred during infusion of adenosine and all of the symptoms resolved after the infusion ceased. In this multicenter analysis, guidewire-based measurement of FFR and IMR using intravenous adenosine was safe in patients following STEMI or NSTEMI. Self-limiting symptoms were common but not associated with serious adverse events. Finally, coronary dissection in STEMI and NSTEMI patients was noted to be a rare phenomenon. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  15. Effects of Rosuvastatin on Coronary Flow Reserve and Metabolic Mismatch in Patients With Heart Failure (from the CORONA Study)

    NARCIS (Netherlands)

    van der Harst, Pim; Slart, Riemer H. J. A.; Tio, Rene A.; Dunselman, Peter H. J. M.; Willemsen, Antoon T. M.; van den Heuvel, Ad F. M.; Voors, Adriaan A.; van Veldhuisen, Dirk J.

    2010-01-01

    In patients with heart failure (HF), statin treatment might improve myocardial perfusion, but could also have detrimental effects on myocardial metabolism. A predefined substudy of the Controlled Rosuvastatin Multinational Trial in Heart Failure (CORONA) trial sought to determine the effects of stat

  16. The relation between endothelial dependent flow mediated dilation of the brachial artery and coronary collateral development – a cross sectional study

    Directory of Open Access Journals (Sweden)

    Ozdemir Aydan

    2009-06-01

    Full Text Available Abstract Background Endothelial dysfunction is thought to be a potential mechanism for the decreased presence of coronary collaterals. The aim of the study was to investigate the association between systemic endothelial function and the extent of coronary collaterals. Methods We investigated the association between endothelial function assessed via flow mediated dilation (FMD of the brachial artery following reactive hyperemia and the extent of coronary collaterals graded from 0 to 3 according to Rentrop classification in a cohort of 171 consecutive patients who had high grade coronary stenosis or occlusion on their angiograms. Results Mean age was 61 years and 75% were males. Of the 171 patients 88 (51% had well developed collaterals (grades of 2 or 3 whereas 83 (49% had impaired collateral development (grades of 0 or 1. Patients with poor collaterals were significantly more likely to have diabetes (p = 0.001, but less likely to have used statins (p = 0.083. FMD measurements were not significantly different among good and poor collateral groups (11.5 ± 5.6 vs. 10.4 ± 6.2% respectively, p = 0.214. Nitroglycerin mediated dilation was also similar (13.4 ± 5.9 vs. 12.8 ± 6.5%, p = 0.521. Conclusion No significant association was found between the extent of angiographically visible coronary collaterals and systemic endothelial function assessed by FMD of the brachial artery.

  17. Transition in the mechanism of flow-mediated dilation with aging and development of coronary artery disease.

    Science.gov (United States)

    Beyer, Andreas M; Zinkevich, Natalya; Miller, Bradley; Liu, Yanping; Wittenburg, April L; Mitchell, Michael; Galdieri, Ralph; Sorokin, Andrey; Gutterman, David D

    2017-01-01

    In microvessels of patients with coronary artery disease (CAD), flow-mediated dilation (FMD) is largely dependent upon the endothelium-derived hyperpolarizing factor H2O2. The goal of this study is to examine the influence of age and presence or absence of disease on the mechanism of FMD. Human coronary or adipose arterioles (~150 µm diameter) were prepared for videomicroscopy. The effect of inhibiting COX [indomethacin (Indo) or NOS (L-NAME), eliminating H2O2 (polyethylene glycol-catalase (PEG-CAT)] or targeting a reduction in mitochondrial ROS with scavengers/inhibitors [Vitamin E (mtVitamin E); phenylboronic acid (mtPBA)] was determined in children aged 0-18 years; young adults 19-55 years; older adults >55 years without CAD, and similarly aged adults with CAD. Indo eliminated FMD in children and reduced FMD in younger adults. This response was mediated mainly by PGI2, as the prostacyclin-synthase-inhibitor trans-2-phenyl cyclopropylamine reduced FMD in children and young adults. L-NAME attenuated dilation in children and younger adults and eliminated FMD in older adults without CAD, but had no effect on vessels from those with CAD, where mitochondria-derived H2O2 was the primary mediator. The magnitude of dilation was reduced in older compared to younger adults independent of CAD. Exogenous treatment with a sub-dilator dose of NO blocked FMD in vessels from subjects with CAD, while prolonged inhibition of NOS in young adults resulted in a phenotype similar to that observed in disease. The mediator of coronary arteriolar FMD evolves throughout life from prostacyclin in youth, to NO in adulthood. With the onset of CAD, NO-inhibitable release of H2O2 emerges as the exclusive mediator of FMD. These findings have implications for use of pharmacological agents, such as nonsteroidal anti-inflammatory agents in children and the role of microvascular endothelium in cardiovascular health.

  18. Cerebral blood flow and cerebrovascular reserve capacity: estimation by dynamic magnetic resonance imaging.

    Science.gov (United States)

    Schreiber, W G; Gückel, F; Stritzke, P; Schmiedek, P; Schwartz, A; Brix, G

    1998-10-01

    We have developed a new method for estimation of regional CBF (rCBF) and cerebrovascular reserve capacity on a pixel-by-pixel basis by means of dynamic magnetic resonance imaging (MRI). Thirteen healthy volunteers, 8 patients with occlusion and/or high grade stenosis of the internal carotid artery (ICA), and 2 patients with acute stroke underwent dynamic susceptibility-weighted contrast enhanced MRI. Using principles of indicator dilution theory and deconvolution analysis, maps of rCBF, regional cerebral blood volume, and of the mean transit time (MTT) were calculated. In patients with ICA occlusion/stenosis, cerebrovascular reserve capacity was assessed by the rCBF increase after acetazolamide stimulation. Mean gray and white matter rCBF values in normals were 67.1 and 23.7 mL x 100 g(-1) x min(-1), respectively. Before acetazolamide stimulation, six of eight patients with ICA occlusions showed decreased rCBF values; and in seven patients increased MTT values were observed in tissue ipsilateral to the occlusion. After acetazolamide stimulation, decreased cerebrovascular reserve capacity was observed in five of eight patients with ICA occlusion. In acute stroke, rCBF in the central core of ischemia was less than 8 mL x 100 g(-1) x min(-1). In peri-infarct tissue, rCBF and MTT were higher than in unaffected tissue but rCBF was normal. Dynamic MRI provides important clinical information on the hemodynamic state of brain tissue in patients with occlusive cerebrovascular disease or acute stroke.

  19. 瘦素在冠状动脉慢血流现象中的研究进展%Research Progress of Leptin in Coronary Slow Flow Phenomenon

    Institute of Scientific and Technical Information of China (English)

    吴高祥(综述); 楚天舒; 武力勇(审校)

    2016-01-01

    瘦素是肥胖基因编码的一种蛋白,由脂肪细胞分泌,通过与瘦素受体结合发挥生物活性效应,其主要作用是调节营养物质代谢如糖类、脂类,调节能量平衡,促使机体抑制食欲,促进能量消耗,减少脂肪细胞合成,降低体质量。冠状动脉慢血流现象是指在冠状动脉造影过程中,冠状动脉无明显狭窄病变,而远端血流灌注延迟的现象。诸多研究表明瘦素可能参与冠状动脉慢血流现象的发生、发展,现就近年来瘦素参与冠状动脉慢血流的发病机制做一综述。%Leptin is a protein coded by obesity gene,which is secreted by adipose cells and plays an important biological activity role by binding to specific leptin receptors.Its main functions are to regulate metabolism of nutrients such as sugar and fat.It can regulate energy metabolism,suppress the appetite, promote energy consumption and decrease adipose cell synthesis thereby enabling weight loss.Coronary slow flow phenomenon is characterized by delayed opacification of coronary vessels in a normal coronary angiogram.Many studies have indica-ted that leptin may participate in the occurrence and development of coronary slow flow phenomenon.This article reviews the recent findings that leptin involved the pathogenic mechanism of coronary slow flow phenomenon.

  20. Resource Flows of Villages with Contrasting Lifestyles in Nanda Devi Biosphere Reserve, Central Himalaya, India

    Institute of Scientific and Technical Information of China (English)

    K. S. Rao; S. Nautiyal; R. K. Maikhuri; K. G. Saxena

    2005-01-01

    Resource use efficiency analyses of village ecosystem are necessary for effective and efficient planning of resource utilization. This paper deals with economic and energy input-output analyses of different components of village ecosystem in representative buffer zone villages, which are practicing transhumance and settled way of lifestyles in Nanda Devi Biosphere Reserve (NDBR) of Garhwal Himalaya. While the villages practicing transhumance used various natural resources spatially segregated,the villages practicing settled way of lifestyle have to manage resources from a limited spatial area through rotation and varied extraction intensities. Forests subsidized the production activity in both type of villages and the per capita resource extractions were found to be greater in transhumance village than settled village. Though crops provided maximum energy, in terms of economic criteria, animal husbandry played important role in both settled and transhumance villages. As villages representing both the situations showed different ways of adjustments to the conservation oriented land use changes,management authority needs to address the eco-development plans fulfilling the aspirations of all people traditionally using the resources of the Reserve to reduce the conflicts and encourage their participation in the conservation of the area.

  1. Maximal blood flow acceleration analysis in the early diastolic phase for in situ internal thoracic artery bypass grafts: a new transit-time flow measurement predictor of graft failure following coronary artery bypass grafting.

    Science.gov (United States)

    Handa, Takemi; Orihashi, Kazumasa; Nishimori, Hideaki; Fukutomi, Takashi; Yamamoto, Masaki; Kondo, Nobuo; Tashiro, Miwa

    2015-04-01

    Maximal graft flow acceleration (max df/dt) determined by transit-time flowmetry (TTFM) in the diastolic phase was assessed as a possible predictor of graft failure in coronary artery bypass patients. Max df/dt was retrospectively measured in 57 in situ left internal thoracic artery grafts. TTFM data were fitted to a 5-polynomial curve, which was derived from the first-derivative curve to measure max df/dt (5-polymial max df/dt). Abnormal TTFM was defined as a mean flow of 5 or diastolic filling ratio of polynomial max df/dt between each group pair (P polynomial max df/dt was significantly lower in the Ab-N/F group compared with the other groups (Ab-N/F: 0.89 ± 0.41 vs N/P: 4.74 ± 3.18, N/F: 2.23 ± 0.65, Ab-N/P: 2.70 ± 1.31 ml/s(2), P polynomial max df/dt were, respectively, 72.7 and 80.4% (cut-off value, 1.918 ml/s(2)) for all grafts and 100 and 88.2% (cut-off value, 1.273 ml/s(2)) for abnormal TTFM grafts. The TTFM 5-polymial max df/dt value in the early diastolic phase may be a promising predictor of future graft failure. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  2. [Effect of different concentrations liposomal emoxipine on coronary flow, contractive and pump function of the isolated rat heart after normotermic ischema and further reperfusion].

    Science.gov (United States)

    Toropova, Ia G; Mukhamadiiarov, R A; Golovkin, A S

    2013-07-01

    In the experiments on the isolated perfused rat heart we studied the effects of liposomes containing different concentrations (0.25 and 0.1 mg/ml) of emoxipine on coronary flow, contractive and pump function of the isolated heart, which was effected by total normothermical ischemia and reperfusion. The parameters of the contractile activity of hearts, coronary flow and pump function of the hearts were assessed. It was detected that the introduction of the liposomal emoxipine during ischemia provides a protective effect against ischemic and reperfusion myocardial damage and smaller concentration of the emoxipin (0.1 mg/ml) in composition with the liposomes promote the best recovery of contractile activity and the pumping function of the ischemic heart in the period of the reperfusion.

  3. Instantaneous wave-free ratio derived from coronary computed tomography angiography in evaluation of ischemia-causing coronary stenosis

    Science.gov (United States)

    Ma, Yue; Liu, Hui; Hou, Yang; Qiao, Aike; Hou, Yingying; Yang, Qingqing; Guo, Qiyong

    2017-01-01

    Abstract The instantaneous wave-free ratio (iFR) closely related to fractional flow reserve (FFR) is a adenosine-independent physiologic index of coronary stenosis severity. We sought to evaluate whether iFR derived from coronary computed tomographic angiography (iFRCT) can be used as a novel noninvasive method for diagnosis of ischemia-causing coronary stenosis. We retrospectively enrolled 33 patients (47 lesions) with coronary artery disease (CAD) and examined with coronary computed tomographic angiography (CTA), invasive coronary angiography (ICA), and FFR. Patient-specific anatomical model of the coronary artery was built by original resting end-diastolic CTA images. Based on the model and computational fluid dynamics, individual boundary conditions were set to calculate iFRCT as the mean pressure distal to the stenosis divided by the mean aortic pressure during the diastolic wave-free period of rest state. Ischemia was assessed by an FFR of up to 0.8, while anatomically obstructive CAD was defined by a stenosis of at least 50% by ICA. The correlation between iFRCT and FFR was evaluated. The receiver operating characteristic (ROC) curve was used to select the cut-off value of iFRCT for diagnosis of ischemia-causing stenosis. The diagnostic performances of iFRCT, coronary CTA, and iFRCT plus CTA for ischemia-causing stenosis were compared with ROC curve and Delong method. On a per-vessel basis, iFRCT and FFR had linear correlation (r = 0.75, p coronary CTA (AUC = 0.60), iFRCT yielded diagnostic improvement over stenosis assessment with AUC increasing from 0.6 by CTA to 0.87 (P coronary CTA for detection of ischemia-causing coronary stenosis. PMID:28121952

  4. Effects of Provinols on Cardiodynamics and Coronary Flow in Islodated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Popovic Ana

    2016-06-01

    Full Text Available Provinols are an alcohol-free extract of red wine that contains a wide range of polyphenols. Polyphenols are a group of chemical compounds found in diverse plants. Polyphenols are considered to protect against cardiovascular disease. Although some older epidemiological studies have indicated that the positive effects of red wine on heart disease can be attributed to the alcohol content alone, there is now powerful evidence that polyphenols present in red wine are responsible for these positive effects. The hearts of male Wistar albino rats (n = 36, 12 in each experimental group, 10 weeks old, body mass 250 ± 30 g were excised and retrogradely perfused according to the Langendorff technique at a gradually increasing perfusion pressure (40-120 cmH2O. Parameters of cardiac function (dp/dt max, dp/dt min, SLVP, DLVP, HR, CF were measured after perfusion with three different concentrations of provinols (5 μg/ml, 10 μg/ml and 50 μg/ml. Administration of the highest dose (50 μg/ml induced a significant increase in dp/dt max, dp/dt min, HR and CF compared with control conditions at CPP = 40 cmH2O, while an intermediate dose increased dp/dt max at the same CPP. Generally viewed, the results of the present study suggest that provinols may have a beneficial effect on the intact myocardium and coronary circulation. These findings could constitute an important step in further investigation of these polyphenols under different representative experimental conditions in the heart, as well as providing a good basis for potential clinical studies in this field.

  5. Effects of first and second generation calcium channel blockers on diastolic function of the failing hamster heart: relationship with coronary flow changes.

    Science.gov (United States)

    Beaucage, Pierre; Massicotte, Julie; Boileau, Jean-François; Dumont, Louis

    2003-07-01

    Calcium channel blockers (CCBs) have variable efficacy in the treatment of heart failure. We hypothesized that modulation of left ventricular diastolic pressure (LVDP) may play a role in the variable efficacy of CCBs in this condition. Isolated perfused hearts from 200- to 250-day-old UM-X7.1 cardiomyopathic hamsters (failing hearts) and age-matched Syrian hamsters (normal hearts) were studied. After recording of heart rate, coronary flow (CF), LVDP and left ventricular systolic pressure (LVSP), hearts were exposed either to verapamil or diltiazem (1 nM-10 microM), mibefradil (1 nM-1 microM) or clentiazem (1 nM-10 microM). Mechanical increase in CF (+2 to +10 ml/min) was carried out using a roller pump. Mechanically-augmented flow led to an increase in coronary perfusion pressure (+40 to +90 mm Hg), LVSP (+5 to +40 mm Hg) and LVDP (+5 to +25 mm Hg). CCBs-induced increment of coronary flow led to a difference in their cardiac response. In normal hearts, the negative inotropic response was more important with diltiazem and verapamil. Failing hearts did not demonstrate increased inotropic sensitivity to first-generation CCBs. On the contrary, at clinically relevant concentrations, verapamil resulted in the most pronounced impairment of LVDP followed by diltiazem while mibefradil and clentiazem, at clinically relevant concentrations, preserved LVDP. Such findings provide an additional explanation for the variable efficacy of CCBs in heart failure.

  6. Effects of rat urotensin II on coronary flow and myocardial eNOS protein expression in isolated rat heart

    Institute of Scientific and Technical Information of China (English)

    LingLI; Wen-junYUAN; Ding-fengSU

    2004-01-01

    AIM: To examine the effects of urotensin Ⅱ, a recently discovered endogenous peptide, on coronary flow (CF),cardiac function, and endothelial nitric oxide synthase (eNOS) expression in isolated rat hearts. METHODS: Heart was isolated and perfused retrogradely via the aorta in Langendorff mode. Rat urotensin Ⅱ was administered in the perfusion solution. The eNOS content in myocardium was determined by Western blot. RESULTS: Rat urotensin Ⅱ had no effect on the heart rate, left ventricular systolic pressure, left ventricular end-diastolic pressure, or±dp/dt max. While rat urotensin Ⅱ dose-dependently increased CF. CF was increased by 11.43%, 6.67%, 6.62%,6.56%, 6.36%, and 5.86% respectively in a time-dependent manner at 5, 10, 15, 20, 25, and 30 min after injection of rat urotensin Ⅱ 6.66×10-2μg. The maximal effect on CF was found at 5 min following urotensin Ⅱ administration.NG-nitro-L-arginine methyl ester (L-NAME) did not prevent the increased CF in response to urotensin Ⅱ. Rat urotensin Ⅱ dose-dependently increased the cardiac eNOS protein expression and this effect was not inhibited by L-NAME. CONCLUSION: Rat urotensin Ⅱ did not alter cardiac function but increased CF and the amount of myocardial eNOS protein in the isolated rat heart. The increased CF was independent of the involvement of eNOS.

  7. Effects of nicardipine and nisoldipine on myocardial metabolism, coronary blood flow and oxygen supply in angina pectoris.

    Science.gov (United States)

    Rousseau, M F; Vincent, M F; Van Hoof, F; Van den Berghe, G; Charlier, A A; Pouleur, H

    1984-12-01

    The effects of the calcium antagonists nicardipine and nisoldipine on left ventricular (LV) metabolism were analyzed in 32 patients with angina pectoris. Measurements were made at a fixed heart rate under the basal state and during a cold pressor test (CPT). After administration of the drugs, coronary blood flow increased significantly and the mean aortic pressure decreased by 10% (p less than 0.01) in the basal state and by 11% (p less than 0.01) during CPT. Despite the reduction in pressure-rate product, myocardial oxygen consumption was unchanged in the basal state (18 +/- 4 vs 19 +/- 4 ml/min, difference not significant) and during CPT (21 +/- 5 vs 21 +/- 5 ml/min, difference not significant); this discrepancy between a reduced pressure-rate product and an unchanged oxygen consumption was also noted when nicardipine was given after propranolol (0.1 mg/kg; 12 patients). Both agents also increased LV lactate uptake, particularly during CPT (+13 mumol/min, p less than 0.05 vs control CPT) and reduced LV glutamine production. In 10 patients in whom 14C-lactate was infused, the chemical LV lactate extraction ratio increased more than the 14C-lactate extraction ratio after administration of the drugs, indicating a reduction in LV lactate production. The data are consistent with the hypothesis that nicardipine and nisoldipine improve perfusion and aerobic metabolism in chronically ischemic areas, resulting in an augmented oxygen consumption and in a reduced lactate production.

  8. Absolute coronary blood flow measurement and microvascular resistance in ST-elevation myocardial infarction in the acute and subacute phase.

    Science.gov (United States)

    Wijnbergen, Inge; van 't Veer, Marcel; Lammers, Jeroen; Ubachs, Joey; Pijls, Nico H J

    2016-03-01

    In a number of patients with acute myocardial infarction (AMI), myocardial hypoperfusion, known as the no-reflow phenomenon, persists after primary percutaneous intervention (PPCI). The aim of this study was to evaluate the feasibility and safety of a new quantitative method of measuring absolute blood flow and resistance within the perfusion bed of an infarct-related artery. Furthermore, we sought to study no-reflow by correlating these measurements to the index of microvascular resistance (IMR) and the area at risk (AR) as determined by cardiac magnetic resonance imaging (CMR). Measurements of absolute flow and myocardial resistance were performed in 20 patients with ST-segment elevation myocardial infarction (STEMI), first immediately following PPCI and then again after 3-5days. These measurements used the technique of thermodilution during a continuous infusion of saline. Flow was expressed in ml/min per gram of tissue within the area at risk. The average time needed for measurement of absolute flow, resistance and IMR was 20min, and all measurements could be performed without complication. A higher flow supplying the AR correlated with a lower IMR in the acute phase. Absolute flow increased from 3.14 to 3.68ml/min/g (p=0.25) and absolute resistance decreased from 1317 to 1099 dyne.sec.cm-5/g (p=0.40) between the first day and fifth day after STEMI. Measurement of absolute flow and microvascular resistance is safe and feasible in STEMI patients and may allow for a better understanding of microvascular (dys)function in the early phase of AMI. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Impact of thermodilution-derived coronary blood flow patterns after percutaneous coronary intervention on mid-term left ventricular remodeling in patients with ST elevation myocardial infarction.

    Science.gov (United States)

    Sumiyoshi, Akinori; Fujii, Kenichi; Fukunaga, Masashi; Shibuya, Masahiko; Imanaka, Takahiro; Kawai, Kenji; Miki, Kojiro; Tamaru, Hiroto; Horimatsu, Tetsuo; Saita, Ten; Nishimura, Machiko; Masuyama, Tohru; Ishihara, Masaharu

    2017-01-01

    We recently reported the coronary thermodilution curve can be evaluated by analyzing the thermodilution curve obtained from a pressure sensor/thermistor-tipped guidewire, and presence of a bimodal-shaped thermodilution curve following primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI) patients was associated with worse outcomes. This study evaluated whether the bimodal-shaped thermodilution curve predicts left ventricular (LV) remodeling after STEMI. The coronary thermodilution curve patterns were evaluated for 75 patients treated by pPCI for their first STEMI using a pressure sensor/thermistor-tipped guidewire, and classified into the three groups according to the thermodilution curve shape: narrow unimodal (n = 39), wide unimodal (n = 26), and bimodal pattern (n = 10). Echocardiography was performed at baseline and 6 months after STEMI. LV remodeling was defined as a >20 % increase in LV end-diastolic volumes (LVEDV). LVEDV at 6-month follow-up was greater in the bimodal group than in the other groups (p remodeling was highest in the bimodal group than in the narrow and wide unimodal groups (60, 12, and 15 %, respectively; p = 0.003). Multivariate analysis revealed a bimodal-shaped thermodilution curve as an independent predictor of the prevalence of LV remodeling. A bimodal-shaped thermodilution curve is associated with LV remodeling after STEMI. This easily assessable coronary thermodilution curve pattern is useful to predict mid-term LV remodeling for STEMI patients at the catheterization laboratory.

  10. Noninvasive Physiologic Assessment of Coronary Stenoses Using Cardiac CT

    Directory of Open Access Journals (Sweden)

    Lei Xu

    2015-01-01

    Full Text Available Coronary CT angiography (CCTA has become an important noninvasive imaging modality in the diagnosis of coronary artery disease (CAD. CCTA enables accurate evaluation of coronary artery stenosis. However, CCTA provides limited information on the physiological significance of stenotic lesions. A noninvasive “one-stop-shop” diagnostic test that can provide both anatomical significance and functional significance of stenotic lesions would be beneficial in the diagnosis and management of CAD. Recently, with the introduction of novel techniques, such as myocardial CT perfusion, CT-derived fractional flow reserve (FFRCT, and transluminal attenuation gradient (TAG, CCTA has emerged as a noninvasive method for the assessment of both anatomy of coronary lesions and its physiological consequences during a single study. This review provides an overview of the current status of new CT techniques for the physiologic assessments of CAD.

  11. Concordance between myocardial perfusion scan assessed by SPECT and fractional flow reserve findings for detection of significant ischemia

    Directory of Open Access Journals (Sweden)

    Morteza Safi

    2016-09-01

    Conclusion: FFR and MPI with SPECT techniques showed significant concordance for detection of myocardial ischemia, regardless of the type of diseased coronary arteries. In this context, SPECT has high sensitivity and NPV for detection of ischemia compared with FFR.

  12. The effects of verapamil and its combinations with glutamate and glycine on cardiodynamics, coronary flow and oxidative stress in isolated rat heart.

    Science.gov (United States)

    Stojic, Isidora; Srejovic, Ivan; Zivkovic, Vladimir; Jeremic, Nevena; Djuric, Marko; Stevanovic, Ana; Milanovic, Tamara; Djuric, Dragan; Jakovljevic, Vladimir

    2017-02-01

    The role of N-methyl-D-aspartate receptor (NMDA-R) in heart is still unclear. For these ionotropic glutamate receptors is characteristic the necessity of both co-agonists, glutamate and glycine, for their activation, which primarily allows influx of calcium. The aim of the present study was to examine the effects of verapamil, as a calcium channel blocker, alone and its combination with glycine and/or glutamate on cardiac function, coronary flow, and oxidative stress in isolated rat heart or to examine the effects of potential activation of NMDA-R in isolated rat heart. The hearts of male Wistar albino rats were excised and perfused according to Langendorff technique, and cardiodynamic parameters and coronary flow were determined during the administration of verapamil and its combinations with glutamate and/or glycine. The oxidative stress biomarkers, including thiobarbituric acid-reactive substances, nitrites, superoxide anion radical, and hydrogen peroxide, were each determined spectrophotometrically from coronary venous effluent. The greatest decline in parameters of cardiac contractility and systolic pressure was in the group that was treated with verapamil only, while minimal changes were observed in group treated with all three tested substances. Also, the largest changes in coronary flow were in the group treated only with verapamil, and at least in the group that received all three tested substances, as well as the largest increase in oxidative stress parameters. Based on the obtained results, it can be concluded that NMDA-R activation allows sufficient influx of calcium to increase myocardial contractility and systolic pressure, as well as short-term increase of oxidative stress.

  13. Incidence of severe coronary stenosis in asymptomatic patients with peripheral arterial disease scheduled for major vascular surgery.

    Science.gov (United States)

    Hromadka, Milan; Baxa, Jana; Seidlerova, Jitka; Suchy, David; Sedivy, Jakub; Stepankova, Lucie; Rajdl, Daniel; Rokyta, Richard

    2016-08-01

    Peripheral arterial disease (PAD) has the risk equivalent of coronary heart disease. The biochemical parameters associated with functionally significant coronary artery stenosis were investigated in asymptomatic patients with PAD who were scheduled for major vascular intervention. A total of 50 PAD patients asymptomatic for coronary heart disease were examined using coronary computed tomography angiography (CTA). A stress myocardial CT perfusion (CTP) test was performed in patients who exhibited coronary stenosis >40%. In patients with stress-induced perfusion defects, the severity of stenosis was assessed using invasive coronary angiography including fractional flow reserve assessment. The CT findings were correlated with both classical and more recently developed parameters of atherosclerosis. According to the combined CT examination (CTA and stress CT perfusion), 36% of patients exhibited significant coronary stenosis. Stress-induced hypoperfusion was observed in 95.7% of severe stenotic lesions. After adjustment for confounders, the level of high-sensitivity troponin I was associated with severe coronary stenosis (OR 1.260 [95% CI 1.054 to 1.505]). Other biochemical parameters did not correlate with coronary stenosis. The annual mortality rate was 4%. The results of the present study confirm a significant diagnostic contribution of a complex cardiac CT examination in patients scheduled for major vascular surgery. A high prevalence of asymptomatic coronary heart disease was observed in this particular patient group. High-sensitivity measurements of troponin I correlated with the extent of the coronary stenosis.

  14. Left anterior descending coronary artery blood flow and left ventricular unloading during extracorporeal membrane oxygenation support in a swine model of acute cardiogenic shock.

    Science.gov (United States)

    Brehm, Christoph; Schubert, Sarah; Carney, Elizabeth; Ghodsizad, Ali; Koerner, Michael; McCoach, Robert; El-Banayosy, Aly

    2015-02-01

    The impact of extracorporeal membrane oxygenation (ECMO) support on coronary blood flow and left ventricular unloading is still debated. This study aimed to further characterize the influence of ECMO on coronary artery blood flow and its ability to unload the left ventricle in a short-term model of acute cardiogenic shock. Seven anesthetized pigs were intubated and then underwent median sternotomy and cannulation for venoarterial (VA) ECMO. Flow in the left anterior descending (LAD) artery, left atrial pressure (LAP), left ventricular end-diastolic pressure (LVEDP), and mean arterial pressure (MAP) were measured before and after esmolol-induced cardiac dysfunction and after initiating VA-ECMO support. Induction of acute cardiogenic shock was associated with short-term increases in LAP from 8 ± 4 mm Hg to 18 ± 14 mm Hg (P = 0.9) and LVEDP from 5 ± 2 mm Hg to 13 ± 17 mm Hg (P = 0.9), and a decrease in MAP from 63 ± 16 mm Hg to 50 ± 24 mm Hg (P = 0.3). With VA-ECMO support, blood flow in the LAD increased from 28 ± 25 mL/min during acute unsupported cardiogenic shock to 67 ± 50 mL/min (P = 0.003), and LAP and LVEDP decreased to 8 + 5 mm Hg (P = 0.7) and 5 ± 3 mm Hg (P = 0.5), respectively. In this swine model of acute cardiogenic shock, VA-ECMO improved coronary blood flow and provided some degree of left ventricular unloading for the short duration of the study.

  15. Effect of loading-dose ticagrelor on coronary blood flow, left ventricular remodeling and myocardial enzyme spectrum in patients with acute myocardial infarction after interventional therapy

    Institute of Scientific and Technical Information of China (English)

    Xiao-Rui Xie; Pu Yang

    2016-01-01

    Objective:To study the effect of loading-dose ticagrelor on coronary blood flow, left ventricular remodeling and myocardial enzyme spectrum in patients with acute myocardial infarction after interventional therapy.Methods: A total of 86 patients with acute myocardial infarction who received emergency PCI in our hospital between May 2013 and May 2016 were selected and randomly divided into two groups, ticagrelor group received perioperative ticagrelor therapy and clopidogrel group received perioperative clopidogrel therapy. After PCI, coronary blood flow reperfusion was evaluated, serum myocardial remodeling indexes and myocardial enzymes were determined, and cardiac color Doppler ultrasonography was conducted to determine the cardiac function indexes.Results:TIMI grading and TMPG grading of ticagrelor group after PCI were significantly higher than those of clopidogrel group; serum MMP9, BNP, CITP, PICP, PIIINP, CK, CK-MB, cTnI and cTnT content of ticagrelor group 24h after operation were significantly lower than those of clopidogrel group; LVEDD, LVSED and LVMI of ticagrelor group 2 weeks after operation were significantly lower than those of clopidogrel group while LVEF was significantly higher than that of clopidogrel group.Conclusion:Peri-PCI loading-dose ticagrelor can improve coronary blood perfusion and reduce ventricular remodeling and myocardial injury in patients with acute myocardial infarction.

  16. The Bolivar Channel Ecosystem of the Galapagos Marine Reserve: Energy flow structure and role of keystone groups

    Science.gov (United States)

    Ruiz, Diego J.; Wolff, Matthias

    2011-08-01

    The Bolivar Channel Ecosystem (BCE) is among the most productive zones in the Galapagos Marine Reserve (GMR). It is exposed to relatively cool, nutrient-rich waters of the Cromwell current, which are brought to the photic zone through topographic upwelling. The BCE is characterized by a heterogeneous rocky reef habitat covered by dense algae beds and inhabited by numerous invertebrate and fish species, which represent the food for higher predators including seals and sharks and exploited fish species. In addition, plankton and detritus based food chains channel large amounts of energy through the complex food web. Important emblematic species of the Galapagos archipelagos reside in this area such as the flightless cormorant, the Galapagos penguin and the marine iguanas. A trophic model of BCE was constructed for the habitats barracudas should be emphasized for their great contribution to the trophic flows and biomass of the system.

  17. Combining Coronary Angiography and Myocardial Perfusion by Computed Tomography in the Identification of Flow-Limiting Stenosis – The CORE320 study

    Science.gov (United States)

    Magalhães, Tiago A.; Kishi, Satoru; George, Richard; Arbab-Zadeh, Armin; Vavere, Andrea; Cox, Christopher; Matheson, Matthew B.; Miller, Julie; Brinker, Jeffrey; Di Carli, Marcelo; Rybicki, Frank J.; Rochitte, Carlos E.; Clouse, Melvin; Lima, João A.C.

    2015-01-01

    Background The combination of coronary computed tomography angiography (CTA) and myocardial CT perfusion (CTP) is gaining increasing acceptance, but a standardized approach to be implemented in the clinical setting is necessary. Objectives To investigate the accuracy of a combined coronary CTA and myocardial CTP comprehensive protocol compared to coronary CTA alone, using a combination of invasive coronary angiography (ICA) and Single-Photon Emission Computed Tomography (SPECT) as reference. Methods Three-hundred eighty-one patients included in CORE320 trial were analyzed in this study. Flow-limiting stenosis was defined as the presence of ≥50% stenosis by ICA with a related perfusion deficit by SPECT. The combined CTA+CTP definition of disease was the presence of a ≥50% stenosis with a related perfusion deficit. All data sets were analyzed by two experienced readers, aligning anatomical findings by CTA with perfusion deficits by CTP. Results Mean patient age was 62±6 years (66% male), 27% with prior history of myocardial infarction. In a per-patient analysis, sensitivity for CTA alone was 93% specificity was 54%, positive predictive value (PPV) was 55%; negative predictive value (NPV) 93% and overall accuracy was 69%. After combining CTA and CTP, sensitivity was 78%, specificity 73%, NPV 64%; PPV 0.85% and overall accuracy was 75%. In a per-vessel analysis, overall accuracy of CTA alone was 73%as compared to 79% for the combination of CTA and CTP (pcoronary CTA and myocardial CTP findings through a comprehensive protocol is feasible. While sensitivity is lower, specificity and overall accuracy are higher than assessment by coronary CTA when compared against a reference standard of stenosis with an associated perfusion deficit. PMID:25977111

  18. Corrected coronary opacification decrease from coronary computed tomography angiography: Validation with quantitative 13N-ammonia positron emission tomography.

    Science.gov (United States)

    Benz, Dominik C; Gräni, Christoph; Ferro, Paola; Neumeier, Luis; Messerli, Michael; Possner, Mathias; Clerc, Olivier F; Gebhard, Catherine; Gaemperli, Oliver; Pazhenkottil, Aju P; Kaufmann, Philipp A; Buechel, Ronny R

    2017-07-06

    To assess the functional relevance of a coronary artery stenosis, corrected coronary opacification (CCO) decrease derived from coronary computed tomography angiography (CCTA) has been proposed. The present study aims at validating CCO decrease with quantitative 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI). This retrospective study consists of 39 patients who underwent hybrid CCTA/PET-MPI. From CCTA, attenuation in the coronary lumen was measured before and after a stenosis and corrected to the aorta to calculate CCO and its decrease. Relative flow reserve (RFR) was calculated by dividing the stress myocardial blood flow (MBF) of a vessel territory subtended by a stenotic coronary by the stress MBF of the reference territories without stenoses. RFR was abnormal in 11 vessel territories (27%). CCO decrease yielded a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for prediction of an abnormal RFR of 73%, 70%, 88%, 47%, and 70%, respectively. CCTA-derived CCO decrease has moderate diagnostic accuracy to predict an abnormal RFR in PET-MPI. However, its high negative predictive value to rule out functional relevance of a given lesion may confer clinical implications in the diagnostic work-up of patients with a coronary stenosis.

  19. The deep hydrogeologic flow system underlying the Oak Ridge Reservation -- Assessing the potential for active groundwater flow and origin of the brine

    Energy Technology Data Exchange (ETDEWEB)

    Nativ, R. [Hebrew Univ. of Jerusalem (Israel). Dept. of Soil and Water Sciences; Halleran, A.; Hunley, A. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

    1997-08-01

    The deep hydrogeologic system underlying the Oak Ridge Reservation (ORR) contains contaminants such as radionuclides, heavy metals, nitrates, and organic compounds. The groundwater in the deep system is saline and has been considered to be stagnant in previous studies. This study was designed to address the following questions: is groundwater in the deep system stagnant; is contaminant migration controlled by diffusion only or is advection a viable mechanism; where are the potential outlet points? On the basis of existing and newly collected data, the nature of saline groundwater flow and potential discharge into shallow, freshwater systems was assessed. Data used for this purpose included (1) spatial and temporal pressures and hydraulic heads measured in the deep system, (2) hydraulic parameters of the formations in question, (3) spatial and temporal temperature variations at depth, and (4) spatial and temporal chemical and isotopic composition of the saline groundwater. The observations suggest that the saline water contained at depth is old but not isolated (in terms of recharge and discharge) from the overlying active, freshwater-bearing units. Influx of recent water does occur. Groundwater volumes involved in this flow are likely to be small. The origin of the saline groundwater was assessed by using existing and newly acquired chemical and isotopic data. The proposed model that best fits the data is modification of residual brine from which halite has been precipitated. Other models, such as ultrafiltration and halite dissolution, were also evaluated.

  20. The role of coronary microvascular dysfunction in the genesis of cardiovascular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Parodi, O.; Sambuceti, G. [CNR, Milan (Italy). Inst. of Clinical Physiology Section

    1996-03-01

    Positron emission tomography (PET) offers the unique capability of measuring specific flow (flow per unit of mass) in man by means of a regional, tridimensional, noninvasive approach. Using PET, myocardial perfusion abnormalities secondary to microvascular disorders have beeen investigated in arterial hypertension (AH), dilated and hypertrophic cardiomyopathy (CM), as well as in ischemic heart disease (CAD). In AH, regional perfusion at rest is within the normal range, while the coronary reserve and flow response to increase in metabolic demand are blunted. These flow abnormalities are independent of the degree of cardiac hypertrophy and the severity of AH; appropriate anti-ipertensive therapy is able to improve the perfusion abnormalities after long term treatment, independently of the effect on myocard ial hypertrophy. Both dilated and hypertrophic CM demonstrate abnormal vasodilaing capability, wich as bee schown to be presented in the subclinical form of dilated DM; the reduction of coronary reserve is not related to the presence and extent of the hemodynamic impairment in dilated CM, and involved also nonhypertropied myocardium in asymmetric hypertropic CM. These finding indicate a primary involvement of coronary microcirculation in non advanced forms of dilated and hypertrophic CM. Finally, in patients with CAD, myocardia teritories supplied by angiographically normal coronary arteries schow abnormal coronary reserve and flow during pacing, tachycardia, indicating that, even in absence of epicardial coronary artery obstruction, microcirculation is impaired in subject with coronary atherosclerosis. this abnormally can smooth perfusion differences, between control andd jeopardized regions. Accordingly, the absenca of a perfusion defect during stress might indicate the presence of either a non significant stenosis or a diffuse impairment in microcirculatory function. (Abstract Truncated)

  1. [Pregnancy and coronary artery dissection].

    Science.gov (United States)

    Martínez-Quintana, Efrén; Rodríguez-González, Fayna

    2015-01-01

    Acute myocardial infarction during pregnancy is associated with high maternal and fetal mortality. Coronary atherosclerosis is the most common cause due to an increase in the age of the patients and the association with cardiovascular risk factors such as smoking, hypertension, diabetes mellitus, preeclampsia, and the existence of family history of coronary disease. However, thrombosis, coronary dissection or coronary vasospasms are other causes that may justify it. We report the case of a 33 weeks pregnant first-time mother, without cardiovascular risk factors, who presented an acute coronary event in the context of atherosclerotic disease and coronary dissection after percutaneous coronary intervention. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  2. High gene flow in reef fishes and its implications for ad-hoc no-take marine reserves.

    Science.gov (United States)

    Matias, Ambrocio Melvin A; Anticamara, Jonathan A; Quilang, Jonas P

    2013-10-01

    Integration of genetic connectivity information in effective marine reserve (MR) design is important in sustaining marine biodiversity. Here, genetic connectivity based on mitochondrial DNA (mtDNA) of three reef fish species, namely Epinephelus merra (n = 67; 32 from Bolinao, 14 from Alaminos, and 21 from Masinloc), Parupeneus multifasciatus (n = 23; 12 from Bolinao and 11 from Masinloc), and Odonus niger (n = 35; 21 from Mabini and 14 from Tingloy), sampled across western Luzon, Philippines, was inferred by assessing their genetic diversity, population genetic structure, and historical demography. The results show high haplotype and nucleotide diversity in the three species. Tests for population structure indicate high gene flow and no spatial genetic structuring for the three species. Mismatch analyses suggest unimodal distribution for E. merra and P. multifasciatus, but bimodal distribution for O. niger. Even with differences in mismatch distributions, all the three species exhibit low raggedness index indicating demographic population expansion. The bimodal distribution of O. niger could be attributed to the mixing of two isolated populations. High gene flow between sampling locations implies genetic exchanges and connectivity between many small MRs and fishing grounds in western Luzon, Philippines, at a scale similar to our study. This research is among the first few to elucidate the high genetic connectivity of reef fish communities across the Philippines (here western Luzon), but it also calls for more support (i.e. government and academia) for genetic research that aims to (1) understand the maintenance of megadiversity of the country and (2) search for effective biodiversity conservation options for the coral reefs.

  3. Assessment of renal artery stenosis using both resting pressures ratio and fractional flow reserve: relationship to angiography and ultrasonography.

    Science.gov (United States)

    Kadziela, Jacek; Witkowski, Adam; Januszewicz, Andrzej; Cedro, Krzysztof; Michałowska, Ilona; Januszewicz, Magdalena; Kabat, Marek; Prejbisz, Aleksander; Kalińczuk, Lukasz; Zieleń, Piotr; Michel-Rowicka, Katarzyna; Warchoł, Ewa; Rużyłło, Witold

    2011-08-01

    BACKGROUND. Clinical benefit from renal artery revascularization remains controversial, probably because of inaccurate stenosis severity assessment. Objective. The aim of the study was to evaluate resting translesional pressures ratio and renal fractional flow reserve (rFFR) in relation to angiography and Doppler duplex ultrasonography in patients with at least moderate renal artery stenosis (RAS). METHODS. 44 hypertensive patients (48% of males, mean age 65 years) with at least moderate RAS were investigated. Translesional systolic pressure gradient (TSPG), resting Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR - after intrarenal administration of papaverine - were evaluated. Quantitative angiographic analysis of stenosis severity was performed including minimal lumen diameter (MLD) and percent diameter stenosis (DS) assessment. Renal/aortic ratio (RAR), resistive index (RI) and deltaRI (side-to side difference) were obtained in Doppler-duplex ultrasonography. The predictive value of selected variables was calculated using receiver-operating characteristics curves. RESULTS. Mean Pd/Pa ratio was 0.86 ± 0.12 and decreased to 0.79 ± 0.13 after papaverine administration. Both Pd/Pa ratio and rFFR strongly correlated with TSPG (r = -0.92, p ratio and 0.80 for rFFR. CONCLUSIONS. Mean Pd/Pa ratio and rFFR strongly correlated with angiographic data and in less pronounced manner with ultrasound parameters reflecting intrarenal blood flow. The best accuracy cut-off points for severe RAS predicting were 0.93 and 0.80, respectively.

  4. Improvement in coronary haemodynamics after percutaneous coronary intervention: assessment using instantaneous wave-free ratio

    Science.gov (United States)

    Nijjer, Sukhjinder S; Sen, Sayan; Petraco, Ricardo; Sachdeva, Rajesh; Cuculi, Florim; Escaned, Javier; Broyd, Christopher; Foin, Nicolas; Hadjiloizou, Nearchos; Foale, Rodney A; Malik, Iqbal; Mikhail, Ghada W; Sethi, Amarjit S; Al-Bustami, Mahmud; Kaprielian, Raffi R; Khan, Masood A; Baker, Christopher S; Bellamy, Michael F; Hughes, Alun D; Mayet, Jamil; Kharbanda, Rajesh K; Di Mario, Carlo; Davies, Justin E

    2013-01-01

    Objective To determine whether the instantaneous wave-free ratio (iFR) can detect improvement in stenosis significance after percutaneous coronary intervention (PCI) and compare this with fractional flow reserve (FFR) and whole cycle Pd/Pa. Design A prospective observational study was undertaken in elective patients scheduled for PCI with FFR ≤0.80. Intracoronary pressures were measured at rest and during adenosine-mediated vasodilatation, before and after PCI. iFR, Pd/Pa and FFR values were calculated using the validated fully automated algorithms. Setting Coronary catheter laboratories in two UK centres and one in the USA. Patients 120 coronary stenoses in 112 patients were assessed. The mean age was 63±10 years, while 84% were male; 39% smokers; 33% with diabetes. Mean diameter stenosis was 68±16% by quantitative coronary angiography. Results Pre-PCI, mean FFR was 0.66±0.14, mean iFR was 0.75±0.21 and mean Pd/Pa 0.83±0.16. PCI increased all indices significantly (FFR 0.89±0.07, pcoronary haemodynamics elicited by PCI. FFR and iFR have a significantly larger dynamic range than resting Pd/Pa. iFR might be used to objectively document improvement in coronary haemodynamics following PCI in a similar manner to FFR. PMID:24047640

  5. Geometry-based pressure drop prediction in mildly diseased human coronary arteries

    NARCIS (Netherlands)

    J.T.C. Schrauwen (Jelle); J.J. Wentzel (Jolanda); A.F.W. van der Steen (Ton); F.J.H. Gijsen (Frank)

    2014-01-01

    textabstractPressure drop (△. p) estimations in human coronary arteries have several important applications, including determination of appropriate boundary conditions for CFD and estimation of fractional flow reserve (FFR). In this study a △. p prediction was made based on geometrical features deri

  6. Alterations of cerebral blood flow and cerebrovascular reserve in patients with chronic traumatic brain injury accompanying deteriorated intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Chun; Bom, Hee Seung [Chonnam National Univ. Hospital, Kwangju (Korea, Republic of)

    2000-06-01

    The purpose of this study was to evaluate alterations of regional cerbral blood flow (CBF) and cerebrovascular reserve (CVR), and correlation between these alternations and cognitive dysfunctin in patients with chronic traumatic brain injury (TBI) and normal brain MRI findings. Thirty TBI patients and 19 healthy volunteers underwent rest/acetazolaminde brain SPECT using Tc-99m HMPAO. Korean-Wechsler Adult Intelligence scale test was also performed in the patient group. Statistical analysis was performed with statistical parametric mapping software (SPM '97). CBF was diminished in the left hemisphere including Wernicke's area in all patients with lower verbal scale scores. In addition, a reduction in CBF in the right frontal, temporal and parietal cortices was related with depressed scores in information, digital span, arithmetic and similarities. In patients with lower performance scale scores, CBF was mainly diminished in the right hemisphere including superior temporal and supramarginal gyri, premotor, primary somatomotor and a part of prefrontal cortices, left frontal lobe and supramarginal gyrus. CVR was diminished in sixty-four Brodmann's areas compared to control. A reduction in CVR was demonstrated bilaterally in the frontal and temporal lobes in patients with lower scores in both verbal and performance tests, and in addition, both inferior parietal and occipital lobes in information subset. Alterations of CBF and CVR were demonstrated in the symptomatic TBI patients with normal MRI finding. These alterations were correlated with the change of intelligence, of which the complex functions are subserved by multiple interconnected cortical structures.

  7. Cerebral blood flow and cerebrovascular reserve capacity in patients with occlusion or severe stenosis of cerebral arterial trunk

    Energy Technology Data Exchange (ETDEWEB)

    Yoshinaga, Shinya; Tanaka, Akira; Nakayama, Yoshiya; Tomonaga, Masamichi [Fukuoka Univ., Chikushino (Japan). Chikushi Hospital

    1997-12-01

    The cerebral blood flow (CBF) and the cerebrovascular reserve capacity (CVRC) were sequentially measured using a xenon enhanced CT scan in patients with transient ischemic attack or minor stroke due to an occlusion or a severe stenosis of the cerebral arterial trunk. The patients consisted of twelve males and one female ranging from 37 to 71 years of age (53 years on average). The vascular lesion was located in the internal carotid artery (7 patients) and in the middle cerebral artery (6 patients). Eleven patients received antiplatelet drug therapy, while two other patients underwent STA-MCA anastomosis. The CBF measurements were initially done within one month after the attack and then from 6 to 24 months (12 months on average) after the first study. Only one of 13 patients demonstrated a reattack during the period of observation and the CVRC decreased to 0% from the 14% level observed prior to the reattack, although the CBF was preserved. In the other twelve patients without a reattack, the CVRC was found to improve to 29.4% from 9.9% with statistical significance, even though the CBF remained the same in the first study. This study suggests hemodynamic insult to be closely related to the decreased in the CVRC, while STA-MCA anastomosis does not for prevent hemodynamic reattack based on a decrease in the CVRC in the early stage. (author)

  8. Relief of compromised translocated right coronary artery blood flow by clockwise rotation of the heart in a Jatene procedure.

    Science.gov (United States)

    Kan, Chung-Dann; Roan, Jun-Neng; Wu, Jing-Ming; Yang, Yu-Jen

    2006-02-01

    A 1.9-kg premature boy with transposition of the great arteries, ventricular septal defect, and patent ductus arteriosus received a Jatene procedure at 16 days of age. His coronary artery pattern was type A. His arteries were harvested and translocated to appropriate holes in the sinus portion of his neoaorta. Partial obstruction due to torsion of the translocated right coronary artery was suspected, because the right ventricle turned pink in color to blue and bradycardia developed when cardiopulmonary bypass support was weaned. This was relieved by clockwise rotation of the heart, and the patient recovered well. Follow-up echocardiography 6 months later revealed good biventricular function.

  9. Prognostic Value of Gai's Plaque Score and Agatston Coronary Artery Calcium Score for Functionally Significant Coronary Artery Stenosis

    Institute of Scientific and Technical Information of China (English)

    Chuang Zhang; Shuang Yang; Lu-Yue Gai; Zhi-Qi Han; Qian Xin; Xiao-Bo Yang; Jun-Jie Yang

    2016-01-01

    Background:The prognostic values of the coronary computed tomography angiography (CCTA) score for predicting future cardiovascular events have been previously demonstrated in numerous studies.However,few studies have used the rich information available from CCTA to detect functionally significant coronary lesions.We sought to compare the prognostic values of Gai's plaque score and the coronary artery calcium score (CACS) of CCTA for predicting functionally significant coronary lesions,using fractional flow reserve (FFR) as the gold standard.Methods:We retrospectively analyzed 107 visually assessed significant coronary lesions in 88 patients (mean age,59.6 ± 10.2 years;76.14% of males) who underwent CCTA,invasive coronary angiography,and invasive FFR measurement.An FFR <0.80 indicated hemodynamically significant coronary stenosis.Lesions were divided into two groups using an FFR cutoff value of 0.80.We compared Gai's plaque scores and CACS between the two groups and evaluated the correlations of these scores with FFR.The statistical methods included unpaired t-test,Mann-Whitney U-test,and Spearman's correlation coefficients.Results:Coronary lesions with FFR <0.80 had higher Gai's scores than those with FFR ≥0.80.Gai's score had the strongest correlation with FFR (r =-0.48,P < 0.01) and had a greater area under the curve =0.72 (95% confidence interval:0.61-0.82;P < 0.01) than the CACS of whole arteries and a single artery.Conclusions:Both CACS in a single artery and Gai's plaque score demonstrated a good capacity to assess functionally significant coronary artery stenosis when compared to the gold standard FFR.However,Gai's plaque score was more predictive of FFR <0.80.Gai's score can be easily calculated in daily clinical practice and could be used when considering revascularization.

  10. Myocardial blood flow assessment with {sup 82}rubidium-PET imaging in patients with left bundle branch block

    Energy Technology Data Exchange (ETDEWEB)

    Falcao, Andrea; Chalela, William; Giorgi, Maria Clementina; Imada, Rodrigo; Soares Junior, Jose; Do Val, Renata; Oliveira, Marco Antonio; Izaki, Marisa; Kalil Filho, Roberto; Meneghetti, Jose C., E-mail: andrea.falcao@incor.usp.br [Universidade de Sao Paulo (InCor/USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Instituto do Coracao

    2015-11-15

    Objectives: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. Objective: we sought to investigate rubidium-82 ({sup 82}Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. Methods: thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress {sup 82}Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal {sup 82}Rb-positron emission tomography studies and without left bundle branch block (GII). Results: stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p>0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). Conclusion: the data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by {sup 82}Rb-positron emission tomography imaging may be useful in identifying coronary artery

  11. Comparison between positron emission tomography myocardial perfusion imaging and intracoronary Doppler flow velocity measurements at rest and during cold pressor testing in angiographically normal coronary arteries in patients with one-vessel coronary artery disease

    NARCIS (Netherlands)

    Meeder, JG; Blanksma, PK; Tan, ES; Pruim, J; vanderWall, EE; Vaalburg, W; Lie, KI

    1996-01-01

    With use of invasive methods, coronary endothelial function is generally studied by examining the response of epicardial coronary arteries to intracoronary administered acetylcholine or to cold presser testing. Because invasive methods have substantial inherent limitations, studies should attempt to

  12. Assessment of left and right ventricular diastolic and systolic functions using two-dimensional speckle-tracking echocardiography in patients with coronary slow-flow phenomenon.

    Directory of Open Access Journals (Sweden)

    Yonghuai Wang

    Full Text Available Coronary slow-flow phenomenon (CSFP is an angiographic diagnosis characterised by a low rate of flow of contrast agent in the normal or near-normal epicardial coronary arteries. Many of the patients with CSFP may experience recurrent acute coronary syndromes. However, current clinical practice tends to underestimate the impact of CSFP due to the yet unknown effect on the cardiac function. This study was performed to evaluate left ventricular (LV and right ventricular (RV diastolic and systolic functions, using two-dimensional (2D longitudinal strain and strain rate, in patients with CSFP, and to determine the relationships between the thrombolysis in myocardial infarction (TIMI frame count (TFC and LV and RV diastolic and systolic functions.Sixty-three patients with CSFP and 45 age- and sex-matched controls without CSFP were enrolled in the study. Diagnosis of CSFP was made by TFC. LV and RV diastolic and systolic functions were assessed by 2D speckle-tracking echocardiography.LV peak early diastolic longitudinal strain rate (LSRe was lower in patients with CSFP than in controls (P = 0.01. LV peak systolic longitudinal strain (LS and LV peak systolic longitudinal strain rate (LSRs were lower in patients with CSFP than in controls (P = 0.004 and P = 0.03, respectively. There was no difference in LV ejection fraction. RV peak early diastolic longitudinal strain rate (RSRe was lower in patients with CSFP than in controls (P = 0.03. There were no differences in RV peak systolic longitudinal strain (RS, RV peak systolic longitudinal strain rate (RSRs, or RV fractional area change among the groups. The mean TFC correlated negatively with LSRe and RSRe in patients with CSFP (r = -0.26, P = 0.04 and r = -0.32, P = 0.01, respectively.LV diastolic and systolic functions were impaired in patients with CSFP. CSFP also affected RV diastolic function, but not RV systolic function.

  13. Maintenance of increased coronary blood flow in excess of demand by nisoldipine administered as an intravenous infusion

    NARCIS (Netherlands)

    A.L. Soward; P.J. de Feyter (Pim); P.G. Hugenholtz (Paul); P.W.J.C. Serruys (Patrick)

    1986-01-01

    textabstractSystemic and hemodynamic effects of nisoldipine, administered as a 4.5-micrograms/kg intravenous bolus over 3 minutes followed immediately by an infusion of 0.2 microgram/kg/min over 30 minutes, were studied in 13 patients undergoing diagnostic catheterization for suspected coronary arte

  14. Novel insights into the complexity of ischaemic heart disease derived from combined coronary pressure and flow velocity measurements

    NARCIS (Netherlands)

    van de Hoef, T.P.

    2015-01-01

    This thesis concerns the complexity of ischaemic heart disease, and the crucial role of the coronary microcirculation in its diagnosis and prognosis. After five decades of a stenosis-centered approach towards both its diagnosis and treatment, it is increasingly acknowledged that ischaemic heart

  15. Reduced 123I-BMIPP uptake implies decreased myocardial flow reserve in patients with chronic stable angina.

    Science.gov (United States)

    Kageyama, Hiroyuki; Morita, Koichi; Katoh, Chietsugu; Tsukamoto, Takahiro; Noriyasu, Kazuyuki; Mabuchi, Megumi; Naya, Masanao; Kawai, Yuko; Tamaki, Nagara

    2006-01-01

    Long-chain fatty acid (LCFA) is the main energy source for normal myocardium at rest, but in ischemic myocardium, the main energy substrate shifts from LCFA to glucose. 123I-BMIPP is a radiolabeled LCFA analog. In chronic stable angina without previous infarction, we suppose that reduced 123I-BMIPP uptake is related to the substrate shift in myocardium with decreased myocardial flow reserve (MFR). The purpose of this study was to relate 123I-BMIPP uptake to rest myocardial blood flow (MBF), hyperemic MBF, and MFR assessed with 15O-water positron emission tomography (PET). We enrolled 21 patients with chronic stable angina without previous infarction, all of whom underwent 123I-BMIPP single-photon emission computed tomography (SPECT) and 15O-water PET. The left ventricle was divided into 13 segments. In each segment, rest MBF and hyperemic MBF were measured by PET. 123I-BMIPP uptake was evaluated as follows: score 0=normal, 1=slightly decreased uptake, 2=moderately decreased uptake, 3=severely decreased uptake, and 4=complete defect. 123I-BMIPP uptake was compared with rest MBF, hyperemic MBF, and MFR. The numbers of segments with 123I-BMIPP scores 0, 1, 2, 3, and 4 were 178, 40, 25, 24, and 0, respectively. The rest MBFs for scores 0, 1, 2, and 3 were 0.93+/-0.25, 0.86+/-0.21, 0.97+/-0.30, and 0.99+/-0.37 ml/min/g, respectively. The hyperemic MBFs for scores 0, 1, 2, and 3 were 2.76+/-1.29, 1.84+/-0.74, 1.37+/-0.39, and 1.08+/-0.40 ml/min/g, respectively. The MFRs for scores 0, 1, 2, and 3 were 3.01+/-1.38, 2.20+/-0.95, 1.44+/-0.22, and 1.10+/-0.26, respectively. As 123I-BMIPP uptake declined, hyperemic MBF and MFR decreased. In chronic stable angina without previous infarction, reduced 123I-BMIPP uptake implies decreased MFR.

  16. Reduced {sup 123}I-BMIPP uptake implies decreased myocardial flow reserve in patients with chronic stable angina

    Energy Technology Data Exchange (ETDEWEB)

    Kageyama, Hiroyuki; Morita, Koichi; Katoh, Chietsugu; Mabuchi, Megumi; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Tsukamoto, Takahiro; Noriyasu, Kazuyuki; Naya, Masanao [Hokkaido University, Department of Cardiovascular Medicine, Sapporo (Japan); Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Kawai, Yuko [Hokko Memorial Hospital, Department of Cardiovascular Medicine, Sapporo (Japan)

    2006-01-01

    Long-chain fatty acid (LCFA) is the main energy source for normal myocardium at rest, but in ischemic myocardium, the main energy substrate shifts from LCFA to glucose. {sup 123}I-BMIPP is a radiolabeled LCFA analog. In chronic stable angina without previous infarction, we suppose that reduced {sup 123}I-BMIPP uptake is related to the substrate shift in myocardium with decreased myocardial flow reserve (MFR). The purpose of this study was to relate {sup 123}I-BMIPP uptake to rest myocardial blood flow (MBF), hyperemic MBF, and MFR assessed with {sup 15}O-water positron emission tomography (PET). We enrolled 21 patients with chronic stable angina without previous infarction, all of whom underwent {sup 123}I-BMIPP single-photon emission computed tomography (SPECT) and {sup 15}O-water PET. The left ventricle was divided into 13 segments. In each segment, rest MBF and hyperemic MBF were measured by PET. {sup 123}I-BMIPP uptake was evaluated as follows: score 0=normal, 1=slightly decreased uptake, 2=moderately decreased uptake, 3=severely decreased uptake, and 4=complete defect. {sup 123}I-BMIPP uptake was compared with rest MBF, hyperemic MBF, and MFR. The numbers of segments with {sup 123}I-BMIPP scores 0, 1, 2, 3, and 4 were 178, 40, 25, 24, and 0, respectively. The rest MBFs for scores 0, 1, 2, and 3 were 0.93{+-}0.25, 0.86{+-}0.21, 0.97{+-}0.30, and 0.99{+-}0.37 ml/min/g, respectively. The hyperemic MBFs for scores 0, 1, 2, and 3 were 2.76{+-}1.29, 1.84{+-}0.74, 1.37{+-}0.39, and 1.08{+-}0.40 ml/min/g, respectively. The MFRs for scores 0, 1, 2, and 3 were 3.01{+-}1.38, 2.20{+-}0.95, 1.44{+-}0.22, and 1.10{+-}0.26, respectively. As {sup 123}I-BMIPP uptake declined, hyperemic MBF and MFR decreased. In chronic stable angina without previous infarction, reduced {sup 123}I-BMIPP uptake implies decreased MFR. (orig.)

  17. Long-term outcome of FFR-guided PCI for stable coronary artery disease in daily clinical practice

    DEFF Research Database (Denmark)

    De Backer, Ole; Biasco, Luigi; Lønborg, Jacob

    2016-01-01

    AIMS: Our aim was to investigate the strength of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) for stable coronary artery disease (CAD) in daily practice. METHODS AND RESULTS: For this study, 3,512 patients with stable CAD and at least one 50-89% coronary stenosis...... were identified; those patients thought to require PCI (n=1,716) were selected. Of these, 962 (56%) were treated based on angiography (XA) alone, whereas 754 patients (44%) had an FFR-guided treatment. In the latter group, 321 patients (43%) were reallocated to another treatment, predominantly medical...

  18. Invasive Evaluation of Patients with Angina in the Absence of Obstructive Coronary Artery Disease

    Science.gov (United States)

    Lee, Bong-Ki; Lim, Hong-Seok; Fearon, William F.; Yong, Andy; Yamada, Ryotaro; Tanaka, Shigemitsu; Lee, David P.; Yeung, Alan C.; Tremmel, Jennifer A.

    2017-01-01

    Background More than 20% of patients presenting to the cardiac catheterization laboratory with angina have no angiographic evidence of coronary artery disease (CAD). Despite a “normal” angiogram, these patients often have persistent symptoms, recurrent hospitalizations, a poor functional status, and adverse cardiovascular outcomes, without a clear diagnosis. Methods and Results In 139 patients with angina in the absence of obstructive CAD (no diameter stenosis >50%), endothelial function was assessed, the index of microcirculatory resistance (IMR), coronary flow reserve (CFR), and fractional flow reserve (FFR) were measured, and intravascular ultrasound (IVUS) was performed. There were no complications. The average age was 54.0±11.4 years and 107 (77%) were women. All patients had at least some evidence of atherosclerosis based on IVUS examination of the LAD. Endothelial dysfunction (a decrease in luminal diameter of >20% after intracoronary acetylcholine) was present in 61 patients (44%). Microvascular impairment (an IMR ≥25) was present in 29 patients (21%). Seven patients (5%) had an FFR ≤0.80. A myocardial bridge was present in 70 patients (58%). Overall, only 32 patients (23%) had no coronary explanation for their angina, with normal endothelial function, normal coronary physiologic assessment, and no myocardial bridging. Conclusions The majority of patients with angina in the absence of obstructive CAD have occult coronary abnormalities. A comprehensive invasive assessment of these patients at the time of coronary angiography can be performed safely and provides important diagnostic information which may affect treatment and outcomes. PMID:25712205

  19. A randomized, single-center double-blinded trial on the effects of diltiazem sustained-release capsules in patients with coronary slow flow phenomenon at 6-month follow-up.

    Directory of Open Access Journals (Sweden)

    Lun Li

    Full Text Available OBJECTIVE: The aim of this study is to observe the chronic effects of diltiazem release capsules on patients with coronary slow flow (CSF phenomenon. METHODS: From 2004 to 2009, 80 consecutive patients with chest pain and normal coronary arteries evidenced by coronary angiography and CSF were included in this randomized, double-blind, placebo-controlled trial. CSF patterns were evaluated by the corrected TIMI frame count. Patients were randomly assigned at 1:1 ratio to diltiazem sustained-release capsules treatment group (Dil, 90 mg twice daily or placebo control group. Holter, liver and kidney function, treadmill exercise test, coronary angiography and left ventricular angiography were measured at baseline and after 6 months. The incidence of cardiovascular events (re-admission or progress in coronary heart disease, myocardial infarction, malignant arrhythmia or cardiac death was evaluated during the 6 months follow up. RESULTS: Thirty-nine patients in control and 40 patients in Dil group completed the 6 months follow-up. There was no medication induced drug withdraw during follow up. Left ventricular ejection fraction was similar between the 2 groups at baseline and during follow up. Heart rate was significantly lower in Dil group than in control group and there was no symptomatic bradycardia and II and III degree atrioventricular conduction block in both groups. Significant improvement was observed in the onset of chest pain, treadmill exercise test and coronary blood flow in Dil group while these parameters remained unchanged in control group at the end of 6 months follow up. The incidence of cardiovascular events was similar between the two groups. CONCLUSION: Diltiazem slow-release capsules improved coronary blood flow and alleviated angina in patients with CSF. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-TCC-11001864.

  20. Coronary microvascular function, insulin sensitivity and body composition in predicting exercise capacity in overweight patients with coronary artery disease

    DEFF Research Database (Denmark)

    Jürs, Anders; Pedersen, Lene Rørholm; Olsen, Rasmus Huan

    2015-01-01

    BACKGROUND: Coronary artery disease (CAD) has a negative impact on exercise capacity. The aim of this study was to determine how coronary microvascular function, glucose metabolism and body composition contribute to exercise capacity in overweight patients with CAD and without diabetes. METHODS......: Sixty-five non-diabetic, overweight patients with stable CAD, BMI 28-40 kg/m(2) and left ventricular ejection fraction (LVEF) above 35 % were recruited. A 3-hour oral glucose tolerance test was used to evaluate glucose metabolism. Peak aerobic exercise capacity (VO2peak) was assessed...... by a cardiopulmonary exercise test. Body composition was determined by whole body dual-energy X-ray absorptiometry scan and magnetic resonance imaging. Coronary flow reserve (CFR) assessed by transthoracic Doppler echocardiography was used as a measure of microvascular function. RESULTS: Median BMI was 31.3 and 72...

  1. Impact of coronary tortuosity on coronary pressure: numerical simulation study.

    Directory of Open Access Journals (Sweden)

    Yang Li

    Full Text Available BACKGROUND: Coronary tortuosity (CT is a common coronary angiographic finding. Whether CT leads to an apparent reduction in coronary pressure distal to the tortuous segment of the coronary artery is still unknown. The purpose of this study is to determine the impact of CT on coronary pressure distribution by numerical simulation. METHODS: 21 idealized models were created to investigate the influence of coronary tortuosity angle (CTA and coronary tortuosity number (CTN on coronary pressure distribution. A 2D incompressible Newtonian flow was assumed and the computational simulation was performed using finite volume method. CTA of 30°, 60°, 90°, 120° and CTN of 0, 1, 2, 3, 4, 5 were discussed under both steady and pulsatile conditions, and the changes of outlet pressure and inlet velocity during the cardiac cycle were considered. RESULTS: Coronary pressure distribution was affected both by CTA and CTN. We found that the pressure drop between the start and the end of the CT segment decreased with CTA, and the length of the CT segment also declined with CTA. An increase in CTN resulted in an increase in the pressure drop. CONCLUSIONS: Compared to no-CT, CT can results in more decrease of coronary blood pressure in dependence on the severity of tortuosity and severe CT may cause myocardial ischemia.

  2. Preliminary investigation of groundwater flow and trichloroethene transport in the Surficial Aquifer System, Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota

    Science.gov (United States)

    King, Jeffrey N.; Davis, J. Hal

    2016-05-16

    Industrial practices at the Naval Industrial Reserve Ordnance Plant, in Fridley, Minnesota, caused soil and groundwater contamination. Some volatile organic compounds from the plant might have discharged to the Mississippi River, forced by the natural hydraulic gradient in the surficial aquifer system. The U.S. Environmental Protection Agency included the Naval Industrial Reserve Ordnance Plant on the Superfund National Priorities List in 1989.

  3. Application of cryopreserved vein grafts as a conduit between the coronary vein and liver graft to reconstruct portal flow in adult living liver transplantation.

    Science.gov (United States)

    Wu, Tsung-Han; Chou, Hong-Shiue; Pan, Kuang-Tse; Lee, Ching-Song; Wu, Ting-Jun; Chu, Sung-Yu; Chen, Miin-Fu; Lee, Wei-Chen

    2009-01-01

    Adult-to-adult living donor liver transplantation is an alternative to donation from a deceased individual, and can help relieve the shortage of liver donations available for adult patients in Asian countries. When transplant candidates have thrombosis and deterioration of the portal vein, living donor liver transplantation is relatively contraindicated because portal veins in the grafts are short and vein grafts may not be available to reconstruct the portal vein. From June 2003 to May 2007, 82 adult living donor liver transplantations were performed at Chang-Gung Memorial Hospital. Three patients had portal vein thrombosis and marked fibrosis of the portal vein and cryopreserved vein grafts were used to reconstruct portal flow from the engorged coronary vein to the graft portal vein. All vein grafts are patent and all patients have normal liver function at 21-36 months after transplantation. When cryopreserved vein grafts are available, adult living donor liver transplantation can be successfully performed in patients with marked deterioration of the portal vein. The short distance from the engorged coronary vein to the graft portal vein may decrease the incidence of re-thrombosis of the venous conduit.

  4. Coronary Arterioles in Type 2 Diabetic (db/db) Mice Undergo a Distinct Pattern of Remodeling Associated with Decreased Vessel Stiffness

    Science.gov (United States)

    Katz, Paige S.; Trask, Aaron J.; Souza-Smith, Flavia M.; Hutchinson, Kirk R.; Galantowicz, Maarten L.; Lord, Kevin C.; Stewart, James A.; Cismowski, Mary J.; Varner, Kurt J.; Lucchesi, Pamela A.

    2011-01-01

    Background Little is known about the impact of type 2 diabetes mellitus (DM) on coronary arteriole remodeling. The aim of this study was to determine the mechanisms that underlie coronary arteriole structural remodeling in type 2 diabetic (db/db) mice. Methods and Results Passive structural properties of septal coronary arterioles isolated from 12- and 16-wk-old diabetic db/db and control mice were assessed by pressure myography. Coronary arterioles from 12-wk-old db/db mice were structurally similar to age-matched controls. By 16-wks of age, coronary wall thickness was increased in db/db arterioles (p < 0.01), while luminal diameter was reduced (Control: 118±5μm; db/db: 102±4μm, p < 0.05), augmenting the wall-to-lumen ratio by 58% (Control: 5.9±0.6; db/db: 9.5±0.4, p < 0.001). Inward hypertrophic remodeling was accompanied by a 56% decrease in elastic modulus (p < 0.05, indicating decreased vessel coronary wall stiffness) and a ~30% reduction in coronary flow reserve in diabetic mice. Interestingly, aortic pulse wave velocity and femoral artery incremental modulus were increased (p < 0.05) in db/db mice, indicating macrovascular stiffness. Molecular tissue analysis revealed increased elastin-to-collagen ratio in diabetic coronaries when compared to control and a decrease in the same ratio in the diabetic aortas. Conclusions These data show that coronary arterioles isolated from type 2 diabetic mice undergo inward hypertrophic remodeling associated with decreased stiffness and increased elastin-to-collagen ratio which results in a decreased coronary flow reserve. This study suggests that coronary microvessels undergo a different pattern of remodeling from macrovessels in type 2 DM. PMID:21744279

  5. Manual thrombectomy efficiency in relationship to the area at risk in patients with myocardial infarction with TIMI 0-1 coronary flow: Insights from an all comers registry.

    Science.gov (United States)

    Luz, André; Silveira, Inês; Brochado, Bruno; Rodrigues, Patrícia; João Sousa, Maria; Santos, Raquel; Trêpa, Maria; Santos, Mário; Silveira, João; Torres, Severo; Leite-Moreira, Adelino F; Carvalho, Henrique

    2017-02-13

    To review the effectiveness of manual thrombectomy (MT) in a series of patients with ST-elevation myocardial infarction (STEMI) exclusively presenting with TIMI 0-1 flow undergoing percutaneous coronary intervention (PCI), in accordance to the angiographically estimated area at risk (AAR). Second, to assess major in-hospital clinical events, emphasizing neurological outcomes. The routine utilization of MT in STEMI is not recommended. However, in recent trials, a significant proportion of patients had neither large thrombus burden nor a totally occluded coronary segment, neutralizing the expected benefits of MT. In addition, the efficiency of MT to remove thrombus has rarely been addressed. Finally, MT diminished distal embolization, which has been related to mortality. In 850 consecutive STEMI-patients, MT was utilized in 525 (62%) and it was considered efficient (TIMI 2-3 flow after MT) in 445 (85%). We found a significant interaction between the AAR and the effectiveness of MT to reduce infarct size (P-interaction = 0.014). In patients having AAR ≥ 28% (n = 184), efficient MT conferred lesser infarct size compared to inefficient MT (Ln-transformed peak CK): 7.87 ± 0.86 versus 8.36 ± 0.41 IU/L, P = 0.005, with no impact for AAR <28%. Clinical outcomes including stroke between MT and PCI-only groups were not different. In comparison with the group where MT was inefficient, efficient MT may modestly reduce final infarct size without a significant clinical benefit. In comparison with PCI-only, no difference was found regarding stroke. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. Atrial supply-demand balance in healthy adult pigs: coronary blood flow, oxygen extraction, and lactate production during acute atrial fibrillation.

    Science.gov (United States)

    van Bragt, Kelly A; Nasrallah, Hussein M; Kuiper, Marion; Luiken, Joost J; Schotten, Ulrich; Verheule, Sander

    2014-01-01

    Little is known about how atrial oxygen supply responds to increased demand, and under which conditions it falls short (supply-demand mismatch). Here, we have investigated the vasodilator response, oxygen extraction, and lactate production of the left atrium (LA) and left ventricle (LV) in response to atrial pacing and atrial fibrillation (AF). Series A (n = 9 Dutch landrace pigs) was instrumented to measure LA and LV vascular conductance in branches of the circumflex artery. Coronary conductance reserve (CCR) was calculated as the ratio between conductance during adenosine infusion and baseline. Series B (n = 7) was instrumented with sampling catheters in LA and LV veins for determination of blood gases and lactate levels. LA CCR (1.76 ± 0.14) was significantly lower than LV CCR (3.16 ± 0.27, P = 0.002). However, basal oxygen extraction was lower in LA (27 ± 3%) than that in the LV (58 ± 6%, P = 0.0006), indicating a larger extraction reserve in the LA than that in the LV (4.68 ± 0.84 vs. 1.88 ± 0.26, P = 0.01). Atrial pacing caused an increase in LA conductance (Series A) and oxygen extraction (Series B). AF increased LA vascular conductance to 177 ± 14% at 1 min, 168 ± 14 at 5 min, and 164 ± 31% at 10 min of AF (P < 0.05 vs. baseline). Atrial oxygen extraction also increased from 26 ± 3% at baseline to 63 ± 5% (P < 0.01) at 5 min and 60 ± 11% (P < 0.01) at 10 min of AF. Arterio-venous lactate difference increased significantly (P = 0.02) during AF. In healthy pigs, the LA has a lower CCR, but a higher extraction reserve compared with the LV. Although both reserves were recruited during AF, atrial lactate production increased significantly.

  7. The conical stent in coronary artery improves hemodynamics compared with the traditional cylindrical stent.

    Science.gov (United States)

    Yu, Yi; Zhou, Yujie; Ma, Qian; Jia, Shuo; Wu, Sijing; Sun, Yan; Liu, Xiaoli; Zhao, Yingxin; Liu, Yuyang; Shi, Dongmei

    2017-01-15

    This study sought to explore the efficacy of the conical stent implantation in the coronary artery by comparing the effects of cylindrical and conical stents on wall shear stress (WSS) and velocity of flow and fractional flow reserve (FFR). The traditional cylindrical stent currently used in the percutaneous coronary intervention (PCI) has a consistent diameter, which does not match the physiological change of the coronary artery. On the contrary, as a new patent, the conical stent with tapering lumen is consistent with the physiological change of vascular diameter. However, the effect of the conical stent implantation on the coronary hemodynamics remains unclear. The coronary artery, artery stenosis and two stent models were established by Solidworks software. All models were imported into the computational fluid dynamics (CFD) software ANSYS ICEM-CFD to establish the fluid model. After the boundary conditions were set, CFD analysis was proceeded to compare the effects of two stent implantation on the change of WSS, velocity of flow and FFR. Hemodynamic indexes including FFR, blood flow velocity distribution (BVD) and WSS were improved by either the cylindrical or the conical stent implantation. However, after the conical stent implantation, the change of FFR seemed to be slower and more homogenous; the blood flow velocity was more appropriate without any obvious blood stagnation and direction changes; the WSS after the conical stent implantation was uniform from the proximal to distal side of the stent. Compared with the cylindrical stent, the conical stent implantation in the coronary artery can make the changes of vascular hemodynamic more closer to the physiological condition, which can reduce the incidence of intra-stent restenosis and thrombosis, thus making it more suitable for PCI therapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Impact of the Mobile Telecommunication Network’s Milk Flow Project on the Livelihoods of Pastoralists in Ladugga Grazing Reserve, Kaduna State, Nigeria

    Directory of Open Access Journals (Sweden)

    John Gambo Laah

    2013-12-01

    Full Text Available The paper aims at assessing the impact of Mobile Telecommunication Network (MTN Milk-Flow Project on the livelihoods of pastoralists in Ladugga Grazing Reserve in Kaduna State, Nigeria. A structured questionnaire was administered to 242 pastoralists in Ladugga. To complement the quantitative source of data, Focus Group Discussions (FGDs and in-depth interviews (IDIs were conducted to assess the benefits and impact of the Milk Flow Project. A total of four (4 FGD sand four (4 IDIs were held with Fulani pastoralists and stakeholders in Ladugga Grazing Reserve. The mean age for male respondents was 55 years while that of the females was 42 years. The result reveals that the milk-flow project has led to: formation and membership of cooperative societies; significant increase in milk production and consequently income; a reduction in morbidity and mortality rates of cows due to better health seeking behaviours; the development of pasture farms and an increase in school enrolment. The paper suggested the need to encourage more private sector participation in supporting pastoralists’ livelihoods within the grazing reserve systems.

  9. Integration of a capacitive pressure sensing system into the outer catheter wall for coronary artery FFR measurements

    Science.gov (United States)

    Stam, Frank; Kuisma, Heikki; Gao, Feng; Saarilahti, Jaakko; Gomes Martins, David; Kärkkäinen, Anu; Marrinan, Brendan; Pintal, Sebastian

    2017-05-01

    The deadliest disease in the world is coronary artery disease (CAD), which is related to a narrowing (stenosis) of blood vessels due to fatty deposits, plaque, on the arterial walls. The level of stenosis in the coronary arteries can be assessed by Fractional Flow Reserve (FFR) measurements. This involves determining the ratio between the maximum achievable blood flow in a diseased coronary artery and the theoretical maximum flow in a normal coronary artery. The blood flow is represented by a pressure drop, thus a pressure wire or pressure sensor integrated in a catheter can be used to calculate the ratio between the coronary pressure distal to the stenosis and the normal coronary pressure. A 2 Fr (0.67mm) outer diameter catheter was used, which required a high level of microelectronics miniaturisation to fit a pressure sensing system into the outer wall. The catheter has an eccentric guidewire lumen with a diameter of 0.43mm, which implies that the thickest catheter wall section provides less than 210 microns height for flex assembly integration consisting of two dies, a capacitive MEMS pressure sensor and an ASIC. In order to achieve this a very thin circuit flex was used, and the two chips were thinned down to 75 microns and flip chip mounted face down on the flex. Many challenges were involved in obtaining a flex layout that could wrap into a small tube without getting the dies damaged, while still maintaining enough flexibility for the catheter to navigate the arterial system.

  10. Coronary Anomaly and Coronary Artery Fistula as Cause of Angina Pectoris with Literature Review

    Science.gov (United States)

    Koneru, Jayanth; Samuel, Anish; Joshi, Meherwan; Hamden, Aiman; Shamoon, Fayez E.; Bikkina, Mahesh

    2011-01-01

    Coronary artery fistulas are rare anomalies of the coronary arteries that may sometimes cause symptoms by shunting blood flow away from the myocardial capillary network. We report the case of a 46-year old lady which shows the right coronary cusp giving rise to left main coronary artery called anomalous origin of a coronary artery (AOCA), and also a fistula between the left coronary artery and pulmonary artery. We describe our diagnostic approach and review the literature on the epidemiology, pathophysiology, the diagnostic modalities, and treatment options. PMID:22937462

  11. Coronary Anomaly and Coronary Artery Fistula as Cause of Angina Pectoris with Literature Review

    Directory of Open Access Journals (Sweden)

    Jayanth Koneru

    2011-01-01

    Full Text Available Coronary artery fistulas are rare anomalies of the coronary arteries that may sometimes cause symptoms by shunting blood flow away from the myocardial capillary network. We report the case of a 46-year old lady which shows the right coronary cusp giving rise to left main coronary artery called anomalous origin of a coronary artery (AOCA, and also a fistula between the left coronary artery and pulmonary artery. We describe our diagnostic approach and review the literature on the epidemiology, pathophysiology, the diagnostic modalities, and treatment options.

  12. [Ischemic burden vs. coronary artery morphology : What is crucial for the indication of revascularization?].

    Science.gov (United States)

    Heber, D; Hacker, M

    2016-08-01

    Ischemic heart disease still represents the leading cause of death in the western world despite a decrease of mortality in the last decade. For the diagnostics of coronary artery morphology, invasive coronary angiography represents the gold standard. Nevertheless, in recent years the importance of functional diagnostics of the coronary arteries has increased and various imaging procedures for the measurement of fractional flow reserve (FFR) during coronary angiography were established and recommended for ischemia testing in the actual guidelines on myocardial revascularization.Imaging modalities for diagnostics of the functional relevance of coronary artery disease include stress echocardiography, magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET). These procedures enable advanced risk stratification and therapy guiding in patients with suspected or known coronary artery disease. In future algorithms, hybrid imaging may facilitate the determination of anatomical and functional aspects after only one investigation.In the present article, the role of ischemia testing is compared with morphological methods for the diagnosis of coronary artery disease, individual risk stratification, and therapy guiding.

  13. Arterial pulse wave dynamics after percutaneous aortic valve replacement: fall in coronary diastolic suction with increasing heart rate as a basis for angina symptoms in aortic stenosis.

    Science.gov (United States)

    Davies, Justin E; Sen, Sayan; Broyd, Chris; Hadjiloizou, Nearchos; Baksi, John; Francis, Darrel P; Foale, Rodney A; Parker, Kim H; Hughes, Alun D; Chukwuemeka, Andrew; Casula, Roberto; Malik, Iqbal S; Mikhail, Ghada W; Mayet, Jamil

    2011-10-04

    Aortic stenosis causes angina despite unobstructed arteries. Measurement of conventional coronary hemodynamic parameters in patients undergoing valvular surgery has failed to explain these symptoms. With the advent of percutaneous aortic valve replacement (PAVR) and developments in coronary pulse wave analysis, it is now possible to instantaneously abolish the valvular stenosis and to measure the resulting changes in waves that direct coronary flow. Intracoronary pressure and flow velocity were measured immediately before and after PAVR in 11 patients with unobstructed coronary arteries. Using coronary pulse wave analysis, we calculated the intracoronary diastolic suction wave (the principal accelerator of coronary blood flow). To test physiological reserve to increased myocardial demand, we measured at resting heart rate and during pacing at 90 and 120 bpm. Before PAVR, the basal myocardial suction wave intensity was 1.9±0.3×10(-5) W · m(-2) · s(-2), and this increased in magnitude with increasing severity of aortic stenosis (r=0.59, P=0.05). This wave decreased markedly with increasing heart rate (β coefficient=-0.16×10(-4) W · m(-2) · s(-2); Pcoronary physiological reserve with increasing heart rate (β coefficient=0.9×10(-3) W · m(-2) · s(-2); P=0.014). In aortic stenosis, the coronary physiological reserve is impaired. Instead of increasing when heart rate rises, the coronary diastolic suction wave decreases. Immediately after PAVR, physiological reserve returns to a normal positive pattern. This may explain how aortic stenosis can induce anginal symptoms and their prompt relief after PAVR. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01118442.

  14. The influence of genotype on vascular endothelial growth factor and regulation of myocardial collateral blood flow in patients with acute and chronic coronary heart disease

    DEFF Research Database (Denmark)

    Ripa, R.S.; Jorgensen, E.; Baldazzi, F.;

    2009-01-01

    OBJECTIVE: To test the hypothesis that mutations in the vascular endothelial growth factor (VEGF) gene are associated with plasma concentration of VEGF and subsequently the ability to influence coronary collateral arteries in patients with coronary heart disease (CHD). METHODS: Blood samples from...... patients with chronic ischemic heart disease (n=53) and acute coronary syndrome (n=61) were analysed. Coronary collaterals were scored from diagnostic biplane coronary angiograms. RESULTS: The plasma concentration of VEGF was increased in patients with acute compared to chronic CHD (p=0.01). The genotype......-1154 and coronary collateral size (p=0.03) and a significant association between the VEGF plasma concentration and the collateral size (p=0.03). CONCLUSION: VEGF plasma concentration seems related to coronary collateral function in patients with CHD. The results did not support the hypothesis...

  15. Non-invasive assessment of coronary artery bypass grafts - an update; Koronare Bypassdiagnostik mit CT und MRT - eine Bestandsaufnahme

    Energy Technology Data Exchange (ETDEWEB)

    Kreitner, K.F.; Ehrhard, K.; Kunz, R.P.; Oberholzer, K.; Mildenberger, P.; Thelen, M. [Klinik und Poliklinik fuer Radiologie der Johannes Gutenberg-Univ. Mainz (Germany); Abegunewardene, N.; Horstick, G. [2. Medizinische Klinik und Poliklinik der Johannes Gutenberg-Univ. Mainz (Germany); Hake, U. [Klinik und Poliklinik fuer Herz-Thorax- und Gefaesschirurgie der Johannes Gutenberg-Univ. Mainz (Germany)

    2004-08-01

    The limited lifetime and the correlation between graft occlusion and recurring symptoms underline the need for repeated imaging of coronary artery bypass grafts. CT and MRI allow for noninvasive imaging of coronary bypasses with high accuracies concerning the patency of these vessels. Multidetector CT seem to be the CT technique of choice, especially after the introduction of 16 slice CT scanners for morphologic assessment of coronary artery bypass grafts. Compared with MRI, CT is a robust technique for assessment of cardiac anastomoses, native coronary arteries, anf for the detection of graft stenoses. MRI, however, is able to deliver functional information about the grafts and the recipient coronary arteries by determining the coronary flow reserve. Furthermore, it can be integrated in a multiparametric MR examination protocol. The follow-up of asymptomatic patients can primarily be done by these non-invasive techniques as nearly every third patient reveals an asymptomatic bypass occlusion 5 years after operation. Furthermore, patients with atypical complaints after the operation may undergo non-invasive imaging as long as documented patency of the bypass averts coronary angiography. Patients with recurrent angina pectoris and/or myocardial ischemia discovered by other cardiologic tests have to undergo coronary angiography. (orig.)

  16. Effects of DL-homocysteine thiolactone on cardiac contractility, coronary flow, and oxidative stress markers in the isolated rat heart: the role of different gasotransmitters.

    Science.gov (United States)

    Zivkovic, Vladimir; Jakovljevic, Vladimir; Pechanova, Olga; Srejovic, Ivan; Joksimovic, Jovana; Selakovic, Dragica; Barudzic, Nevena; Djuric, Dragan M

    2013-01-01

    Considering the adverse effects of DL-homocysteine thiolactone hydrochloride (DL-Hcy TLHC) on vascular function and the possible role of oxidative stress in these mechanisms, the aim of this study was to assess the influence of DL-Hcy TLHC alone and in combination with specific inhibitors of important gasotransmitters, such as L-NAME, DL-PAG, and PPR IX, on cardiac contractility, coronary flow, and oxidative stress markers in an isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique at a 70 cm H2O and administered 10  μM DL-Hcy TLHC alone or in combination with 30  μM L-NAME, 10  μM DL-PAG, or 10  μM PPR IX. The following parameters were measured: dp/dt max, dp/dt min, SLVP, DLVP, MBP, HR, and CF. Oxidative stress markers were measured spectrophotometrically in coronary effluent through TBARS, NO2, O2(-), and H2O2 concentrations. The administration of DL-Hcy TLHC alone decreased dp/dt max, SLVP, and CF but did not change any oxidative stress parameters. DL-Hcy TLHC with L-NAME decreased CF, O2(-), H2O2, and TBARS. The administration of DL-Hcy TLHC with DL-PAG significantly increased dp/dt max but decreased DLVP, CF, and TBARS. Administration of DL-Hcy TLHC with PPR IX caused a decrease in dp/dt max, SLVP, HR, CF, and TBARS.

  17. Effects of DL-Homocysteine Thiolactone on Cardiac Contractility, Coronary Flow, and Oxidative Stress Markers in the Isolated Rat Heart: The Role of Different Gasotransmitters

    Directory of Open Access Journals (Sweden)

    Vladimir Zivkovic

    2013-01-01

    Full Text Available Considering the adverse effects of DL-homocysteine thiolactone hydrochloride (DL-Hcy TLHC on vascular function and the possible role of oxidative stress in these mechanisms, the aim of this study was to assess the influence of DL-Hcy TLHC alone and in combination with specific inhibitors of important gasotransmitters, such as L-NAME, DL-PAG, and PPR IX, on cardiac contractility, coronary flow, and oxidative stress markers in an isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique at a 70 cm H2O and administered 10 μM DL-Hcy TLHC alone or in combination with 30 μM L-NAME, 10 μM DL-PAG, or 10 μM PPR IX. The following parameters were measured: dp/dt max, dp/dt min, SLVP, DLVP, MBP, HR, and CF. Oxidative stress markers were measured spectrophotometrically in coronary effluent through TBARS, NO2, O2-, and H2O2 concentrations. The administration of DL-Hcy TLHC alone decreased dp/dt max, SLVP, and CF but did not change any oxidative stress parameters. DL-Hcy TLHC with L-NAME decreased CF, O2-, H2O2, and TBARS. The administration of DL-Hcy TLHC with DL-PAG significantly increased dp/dt max but decreased DLVP, CF, and TBARS. Administration of DL-Hcy TLHC with PPR IX caused a decrease in dp/dt max, SLVP, HR, CF, and TBARS.

  18. Direct communication between the left circumflex and the right coronary arteries: a very rare coronary anomaly circulation.

    Science.gov (United States)

    Oliveira, Marcos Danillo Peixoto; Cavalcanti, Rafael R César; Kajita, Alexandre H; Miranda, Thais; Kajita, Luiz J; Horta, Pedro E; Ribeiro, Expedito E; Lemos, Pedro Alves

    2016-02-01

    Coronary artery anomalies (CAA) are congenital changes in their origin, course, and/or structure. Intercoronary communication (ICC) is a very rare subset with uni- or bidirectional blood flow between two or more coronary arteries. We present the case of a 58-year-old man with an acute coronary syndrome whose coronary angiography incidentally showed a surprising and very rare communication between the right coronary and left circumflex arteries.

  19. Endovascular Treatment of Right Coronary-to-Bronchial Anastomosis with Bronchopulmonary Shunt Presenting as Coronary Steal Syndrome: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Il Joong; Kim, Dong Hyun; Koh, Young Youp [Chosun University, College of Medicine, Gwangju (Korea, Republic of)

    2010-02-15

    The occurrence of an anastomosis between the coronary artery to the systemic artery is rare. However, the probability of hemodynamic changes sufficient to cause clinical symptoms is extremely low. Anastomosis of the coronary to bronchial artery can cause myocardial ischemia due to the decreased flow to the coronary arteries. The authors report a case of coronary to bronchial artery anastomosis presenting as coronary steal syndrome that was treated with transarterial microcoil embolization instead of surgical ligation.

  20. Woven coronary artery: a case report and review of literature.

    Science.gov (United States)

    Kursaklioglu, Hurkan; Iyisoy, Atila; Celik, Turgay

    2006-10-26

    Woven coronary artery is an extremely rare and clearly undefined coronary malformation. Up to now, very few cases have been reported. In this anomaly, epicardial coronary artery are branched into thin channels at any segment of the coronary artery and then these longitudinal twisted thin channels merge again as the main coronary lumen. This anomaly is regarded as a benign condition since there is completely normal blood flow after the distal segment of the abnormal coronary artery. In this case report, we present a 48-year-old male patient with a woven coronary artery anomaly in the circumflex artery and who had been followed up for 5 years.

  1. Influence of the amount of myocardium subtended to a coronary stenosis on the index of microcirculatory resistance. Implications for the invasive assessment of microcirculatory function in ischemic heart disease.

    Science.gov (United States)

    Echavarría-Pinto, Mauro; van de Hoef, Tim P; Nijjer, Sukhjinder; Gonzalo, Nieves; Nombela-Franco, Luis; Ibañez, Borja; Sen, Sayan; Petraco, Ricardo; Jimenez-Quevedo, Pilar; Nuñez-Gil, Ivan J; Cerrato, Enrico; Salinas, Pablo; Quirós, Alicia; Garcia-Garcia, Hector M; Fernandez-Ortiz, Antonio; Macaya, Carlos; Davies, Justin; Piek, Jan; Escaned, Javier

    2017-05-09

    The index of microcirculatory resistance (IMR) is growingly used to quantify microcirculatory function. However, in normal coronary arteries, resistance increases with the branching structure of the coronary tree, which suggest that IMR could be influenced by the amount of downstream myocardial mass (MM). We aimed to evaluate the influence of the amount of MM subtended to an intermediate stenosis on the IMR. IMR, fractional flow reserve and coronary flow reserve (CFR) were measured in 123 coronary arteries (102 patients) with intermediate stenosis. Jeopardized MM was estimated with the Myocardial Jeopardy Index (MJI). MM was inversely associated with IMR (R2=0.16, pcoronary stenosis is inversely associated with the IMR, while is not associated with the CFR.

  2. [Pediatric case of congenital coronary artery fistula; surgical result and late changes in coronary artery aneurysm].

    Science.gov (United States)

    Sugawara, Masaaki; Oguma, Fumiaki; Hirahara, Hiroyuki

    2014-07-01

    Congenital coronary artery fistula is an uncommon heart anomaly involving the coronary arteries. We report here a case of a 4-year-old boy who had a coronary fistula from the right coronary artery to the right ventricle, with a coronary aneurysm. He was asymptomatic, but the calculated ratio of pulmonary blood flow to systemic blood flow was shown to be high [pulmonary flow (Qp)/systemic flow(Qs)=1.78]. The coronary angiography showed that the right coronary artery was dilated beginning at the ostium and had an aneurysm at the acute marginal portion. A large spherical aneurysm approximately 20 mm in diameter was found to have been connected with coronary fistula opening into the right ventricle. Surgical repair by closure of the fistula under direct vision, partial resection and suture closure of the aneurysm was performed. Plication of the proximal portion of the right coronary artery was not performed, and the diffusely dilated artery was left untouched. After this operation, he recovered well under anticoagulant treatment with warfarin and aspirin. Postoperative angiography was performed 17 months after the surgery to evaluate morphological changes in the coronary artery. The angiography confirmed the closure of the fistula and the regression of coronary artery dilatation.

  3. Additional Value of Transluminal Attenuation Gradient in CT Angiography to Predict Hemodynamic Significance of Coronary Artery Stenosis

    Science.gov (United States)

    Stuijfzand, Wynand J.; Danad, Ibrahim; Raijmakers, Pieter G.; Marcu, C. Bogdan; Heymans, Martijn W.; van Kuijk, Cornelis C.; van Rossum, Albert C.; Nieman, Koen; Min, James K.; Leipsic, Jonathon; van Royen, Niels; Knaapen, Paul

    2015-01-01

    OBJECTIVES The current study evaluates the incremental value of transluminal attenuation gradient (TAG), TAG with corrected contrast opacification (CCO), and TAG with exclusion of calcified coronary segments (ExC) over coronary computed tomography angiogram (CTA) alone using fractional flow reserve (FFR) as the gold standard. BACKGROUND TAG is defined as the contrast opacification gradient along the length of a coronary artery on a coronary CTA. Preliminary data suggest that TAG provides additional functional information. Interpretation of TAG is hampered by multiple heartbeat acquisition algorithms and coronary calcifications. Two correction models have been proposed based on either dephasing of contrast delivery by relating coronary density to corresponding descending aortic opacification (TAG-CCO) or excluding calcified coronary segments (TAG-ExC). METHODS Eighty-five patients with intermediate probability of coronary artery disease were prospectively included. All patients underwent step-and-shoot 256-slice coronary CTA. TAG, TAG-CCO, and TAG-ExC analyses were performed followed by invasive coronary angiography in conjunction with FFR measurements of all major coronary branches. RESULTS Thirty-four patients (40%) were diagnosed with hemodynamically-significant coronary artery disease (i.e., FFR ≤0.80). On a per-vessel basis (n = 253), 59 lesions (23%) were graded as hemodynamically significant, and the diagnostic accuracy of coronary CTA (diameter stenosis ≥50%) was 95%, 75%, 98%, and 54% for sensitivity, specificity, negative predictive value, and positive predictive value, respectively. TAG and TAG-ExC did not discriminate between vessels with or without hemodynamically significant lesions (−13.5 ± 17.1 HU [Hounsfield units] × 10 mm−1 vs. −11.6 ± 13.3 HU × 10 mm−1, p = 0.36; and 13.1 ± 15.9 HU × 10 mm−1 vs. −11.4 ± 11.7 HU × 10 mm−1, p = 0.77, respectively). TAG-CCO was lower in vessels with a hemodynamically-significant lesion (−0

  4. Clinical risk factor analysis of slow coronary flow phenomenon%冠状动脉慢血流现象的临床影响因素分析

    Institute of Scientific and Technical Information of China (English)

    陈晖

    2015-01-01

    Objective To explore the risk factor of slow coronary flow (SCF) phenomenon. Methods 200 cases without obvious pathological changes of epicardial coronary artery by coronary angiography from January 2011 to June 2013 in our hospital were selected as the research object,the adjusted TIMI frame was more than 2 standard deviation of normal coronary flow velocity were defined as SCF.The comparison of age,gender,smoking history,body mass index(BMI),comor-bidities(including hypertension,diabetes,and hyperlipidemia),the level of and serum uric acid,C-reactive protein,platelet aggregation were analysed between the SCF group and the coronary artery normal group.The risk factor of SCF was analysed and observed by multiple regression analysis. Results BMI,the proportion of smoking history in the SCF group was higher than that in the coronary artery normal group,with significant difference (P<0.05).The level of serum uric acid,homocysteine,C reactive protein and platelet aggregation rate in the SCF group was higher than that in the normal group,with significant difference(P<0.05).Multivariate regression analysis showed that age,smoking,hyperlipidemia,serum uric acid,homocysteine,C reactive protein,platelet aggregation rate were the risk factors of SCF. Conclusion Age,smok-ing,high fat metabolism and inflammation status and high platelet aggregation are all risk factors of SCF phenomenon.%目的:探讨冠状动脉慢血流现象的相关影响因素。方法选取本院2011年1月~2013年6月冠状动脉造影显示心外膜主要冠状动脉无明显病变的200例患者作为研究对象,将校正的TIMI帧数大于正常冠状动脉血流速度2个标准差者定义为冠状动脉慢血流,分析冠状动脉慢血流组和冠状动脉正常组的年龄、性别、吸烟史、体重指数(BMI)、合并症(包括高血压、糖尿病和高脂血症)、以及血尿酸水平、同型半胱氨酸浓度、C反应蛋白水平、血小板聚集率等的差异,同时

  5. Prognostic value of dobutamine stress myocardial perfusion echocardiography in patients with known or suspected coronary artery disease and normal left ventricular function

    Science.gov (United States)

    Mattoso, Angele A. A.; Tsutsui, Jeane M.; Kowatsch, Ingrid; Cruz, Vitória Y. L.; Sbano, João C. N.; Ribeiro, Henrique B.; Kalil Filho, Roberto; Porter, Thomas R.; Mathias, Wilson

    2017-01-01

    Objective We sought to determine the prognostic value of qualitative and quantitative analysis obtained by real-time myocardial perfusion echocardiography (RTMPE) in patients with known or suspected coronary artery disease (CAD). Background Quantification of myocardial blood flow reserve (MBFR) in patients with CAD using RTMPE has been demonstrated to further improve accuracy over the analysis of wall motion (WM) and qualitative analysis of myocardial perfusion (QMP). Methods From March 2003 to December 2008, we prospectively studied 168 patients with normal left ventricular function (LVF) who underwent dobutamine stress RTMPE. The replenishment velocity reserve (β) and MBFR were derived from RTMPE. Acute coronary events were: cardiac death, myocardial infarction and unstable angina with need for urgent coronary revascularization. Results During a median follow-up of 34 months (5 days to 6.9 years), 17 acute coronary events occurred. Abnormal β reserve in ≥2 coronary territories was the only independent predictor of events hazard ratio (HR) = 21, 95% CI = 4.5–99; p<0.001). Both, abnormal β reserve and MBFR added significant incremental value in predicting events over qualitative analysis of WM and MP (χ2 = 6.6 and χ2 = 24.6, respectively; p = 0.001 and χ2 = 6.6 and χ2 = 15.5, respectively; p = 0.012, respectively). When coronary angiographic data was added to the multivariate analysis model, β reserve remained the only predictor of events with HR of 21.0 (95% CI = 4.5–99); p<0.001. Conclusion Quantitative dobutamine stress RTMPE provides incremental prognostic information over clinical variables, qualitative analysis of WM and MP, and coronary angiography in predicting acute coronary events. PMID:28234978

  6. Utility of pulmonary venous flow diastolic deceleration time in an adult patient undergoing surgical closure of atrial septal defect and coronary artery bypass grafting

    Directory of Open Access Journals (Sweden)

    Dharmesh R Agrawal

    2013-01-01

    Full Text Available Acute left ventricular (LV failure has been reported after surgical closure of atrial septal defect (ASD in adult patients. We report acute LV failure in a 56 year old gentleman following coronary artery bypass grafting (CABG and surgical closure of ASD. Transesophageal echocardiography examination of the patient following closure of ASD and CABG showed a residual ASD and a shunt (Qp :Qs = 1.5. The residual ASD was closed after re-institution of cardiopulmonary bypass (CPB under cardioplegic cardiac arrest. However, the patient did not tolerate closure of the residual ASD. The CPB was re-established and under cardioplegic cardiac arrest residual ASD was reopened to create a fenestration. This time patient was weaned easily from CPB. Postoperatively, 16 hours after extubation, patient became hemodynamically unstable, the patient was electively put on ventilator and intra-aortic balloon pump. Later the patient was weaned off successfully from ventilator. Retrospective analysis of pulmonary venous flow diastolic deceleration time (PVDT D recorded during prebypass period measured 102 msec suggestive of high left atrial pressure which indicate possibility of LV failure after ASD closure.

  7. Transient blood flow in elastic coronary arteries with varying degrees of stenosis and dilatations: CFD modelling and parametric study.

    Science.gov (United States)

    Wu, Jianhuang; Liu, Guiying; Huang, Wenhua; Ghista, Dhanjoo N; Wong, Kelvin K L

    2015-01-01

    In this paper, we have analysed pulsatile flow through partially occluded elastic arteries, to determine the haemodynamic parameters of wall shear stress (WSS), wall pressure gradient and pressure drops (ΔP), contributing to enhanced flow resistance and myocardial ischaemic regions which impair cardiac contractility and cause increased work load on the heart. In summary, it can be observed that stenoses in an artery significantly influence the haemodynamic parameters of wall shear stress and pressure drop in contrast to dilatations case. This deduces that stenosis plays a more critical role in plaque growth and vulnerability in contrast to dilatation, and should be the key element in cardiovascular pathology and diagnosis. Through quantitative analysis of WSS and ΔP, we have provided a clearer insight into the haemodynamics of atherosclerotic arteries. Determination of these parameters can be helpful to cardiologists, because it is directly implicated in the genesis and development of atherosclerosis.

  8. Microvascular Coronary Flow Comparison in Acute Myocardial Infarction Angioplasty treated with a mesh covered stent (MGUARD Stent) versus Bare Metal Stent

    Energy Technology Data Exchange (ETDEWEB)

    Lindefjeld, Dante S., E-mail: dslindef@puc.cl [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Guarda, Eduardo [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Méndez, Manuel [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Martínez, Alejandro [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Pérez, Osvaldo [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Hospital Dr. Sótero del Río, Santiago-Chile (Chile); Fajuri, Alejandro; Marchant, Eugenio [Hospital Clínico, Pontificia Universidad Católica de Chile (Chile); Aninat, Mauricio; Torres, Humberto [Hospital Dr. Gustavo Fricke, Viña del Mar-Chile (Chile); Dussaillant, Gastón [Hospital Clínico Universidad de Chile, Santiago-Chile (Chile)

    2013-01-15

    Background: Distal embolization of thrombus/platelet aggregates decreases myocardial reperfusion during primary percutaneous coronary intervention (PCI), and is associated with worse immediate and long-term prognosis of patients with ST-elevation myocardial infarction (STEMI). Objective: Assess the efficacy of a mesh covered stent (MGuard™ stent, MGS) in preventing distal embolization and microvascular reperfusion impairment during primary PCI, compared with a bare metal stent (BMS). Methods: Forty patients with STEMI referred for primary PCI were randomized for stenting the culprit lesion with the MGS (n = 20) or a BMS (n = 20). Blinded experts performed off-line measurements of angiographic epicardial and microvascular reperfusion criteria: TIMI flow grade, myocardial blush, corrected TIMI frame count (cTFC). Results: At baseline clinical, angiographic and procedural variables were not different between groups. Post PCI TIMI flow grade was similar in both groups. We observed better myocardial Blush grade in group MGS compared to BMS (median value 3.0 vs 2.5, 2p = 0.006) and cTFC (mean cTFC: MGS 19.65 ± 4.07 vs BMS 27.35 ± 7.15, 2p < 0.001, cTFC mean difference MGS-BMS: 7.7, CI 95%: 3.94 to 11.46). MGS stent group had a higher percentage of successful angioplasty (cTFC ≤ 23: MGS 85% vs BMS 30%, 2p < 0.001). We had two cases of acute stent thrombosis (one for each group) at 30 days follow up, but no clinical events at 6 months follow up. Conclusions: In this exploratory study, MGS significantly improved microvascular reperfusion criteria compared with a BMS in primary PCI. However its safety and impact on clinical outcomes should be verified in larger randomized clinical trials.

  9. Maximal blood flow acceleration analysis in the early diastolic phase for aortocoronary artery bypass grafts: a new transit-time flow measurement predictor of graft failure following coronary artery bypass grafting.

    Science.gov (United States)

    Handa, Takemi; Orihashi, Kazumasa; Nishimori, Hideaki; Yamamoto, Masaki

    2016-11-01

    Maximal graft flow acceleration (max df/dt) determined using transit-time flowmetry (TTFM) in the diastolic phase was assessed as a potential predictor of graft failure for aortocoronary artery (AC) bypass grafts in coronary artery bypass patients. Max df/dt was retrospectively measured in 114 aortocoronary artery bypass grafts. TTFM data were fitted to a 9-polynomial curve, which was derived from the first-derivative curve, to measure max df/dt (9-polynomial max df/dt). Abnormal TTFM was defined as a mean flow of 5 or a diastolic filling ratio of polynomial max df/dt was significantly lower in abnormal TTFM/failing by the CAG group compared with abnormal TTFM/patent by the CAG group (1.08 ± 0.89 vs. 2.05 ± 1.51 ml/s(2), respectively; P polynomial max df/dt in the early diastolic phase may be a promising predictor of future graft failure for AC bypass grafts, particularly in abnormal TTFM grafts.

  10. A simplified double-injection method to quantify cerebral blood flow and vascular reserve using iodine-123 IMP-SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Hiroshi; Nishizawa, Sadahiko; Shiozaki, Toshiki; Ueno, Makoto; Konishi, Junji [Kyoto Univ. (Japan). Graduate School of Medicine

    2002-04-01

    We developed and evaluated a simplified double-injection method for iodine-123 N-isopropyl-p-iodoamphetamine (IMP) to quantify regional cerebral blood flow (rCBF) twice in a single SPECT session. The method enabled rapid calculations of rCBF with five 10-minute SPECT scans, a fixed distribution volume (V{sub d}), and one-point arterial blood sampling to calibrate a standard input function (SIF). Sixty neurological patients were examined to measure rCBF twice in a single session of IMP-SPECT. Patients underwent frequent arterial blood sampling with two injections of IMP and acetazolamide challenge. We generated the SIF and determined the optimal V{sub d} and calibration time (t{sub cal}) for the SIF in 30 patients. Validities of the fixed t{sub cal} and V{sub d} were assessed in the remaining 30 patients. Simulation studies were also performed to evaluate the error sensitivity of the method. The optimal t{sub cal} and V{sub d} were 34 min and 30 ml/ml, respectively. The method was robust in rCBF calculation with noisy SPECT data and yielded rCBF with negligible bias and acceptable errors compared with those obtained by the double-injection method previously reported. The method can be applied to measure rCBF twice in a single SPECT session more easily and less invasively. (author)

  11. Non-invasive assessment of functionally relevant coronary artery stenoses with quantitative CT perfusion: preliminary clinical experiences

    Energy Technology Data Exchange (ETDEWEB)

    So, Aaron [Lawson Health Research Institute, Imaging Program, London, Ontario (Canada); Robarts Research Institute, Imaging Research Laboratories, London, Ontario (Canada); University of Western Ontario, Medical Biophysics, London, Ontario (Canada); Wisenberg, Gerald [Lawson Health Research Institute, Imaging Program, London, Ontario (Canada); University of Western Ontario, Medical Biophysics, London, Ontario (Canada); University of Western Ontario, Medical Imaging, London, Ontario (Canada); London Health Sciences Centre, Cardiology, London, Ontario (Canada); Islam, Ali; Amann, Justin; Romano, Walter [University of Western Ontario, Medical Imaging, London, Ontario (Canada); St. Joseph' s Health Care, Radiology, London, Ontario (Canada); Brown, James; Humen, Dennis; Jablonsky, George [London Health Sciences Centre, Cardiology, London, Ontario (Canada); Li, Jian-Ying; Hsieh, Jiang [GE Healthcare, CT Engineering, Waukesha, Wisconsin (United States); Lee, Ting-Yim [Lawson Health Research Institute, Imaging Program, London, Ontario (Canada); Robarts Research Institute, Imaging Research Laboratories, London, Ontario (Canada); University of Western Ontario, Medical Biophysics, London, Ontario (Canada); University of Western Ontario, Medical Imaging, London, Ontario (Canada)

    2012-01-15

    We developed a quantitative Dynamic Contrast-Enhanced CT (DCE-CT) technique for measuring Myocardial Perfusion Reserve (MPR) and Volume Reserve (MVR) and studied their relationship with coronary stenosis. Twenty-six patients with Coronary Artery Disease (CAD) were recruited. Degree of stenosis in each coronary artery was classified from catheter-based angiograms as Non-Stenosed (NS, angiographically normal or mildly irregular), Moderately Stenosed (MS, 50-80% reduction in luminal diameter), Severely Stenosed (SS, >80%) and SS with Collaterals (SSC). DCE-CT at rest and after dipyridamole infusion was performed using 64-slice CT. Mid-diastolic heart images were corrected for beam hardening and analyzed using proprietary software to calculate Myocardial Blood Flow (MBF, in mLmin{sup -1}100 g{sup -1}) and Blood Volume (MBV, in mL100 g{sup -1}) parametric maps. MPR and MVR in each coronary territory were calculated by dividing MBF and MBV after pharmacological stress by their respective baseline values. MPR and MVR in MS and SS territories were significantly lower than those of NS territories (p < 0.05 for all). Logistic regression analysis identified MPR MVR as the best predictor of {>=}50% coronary lesion than MPR or MVR alone. DCE-CT imaging with quantitative CT perfusion analysis could be useful for detecting coronary stenoses that are functionally significant. (orig.)

  12. Coronary artery fistula

    Science.gov (United States)

    Congenital heart defect - coronary artery fistula; Birth defect heart - coronary artery fistula ... A coronary artery fistula is often congenital, meaning that it is present at birth. It generally occurs when one of the coronary arteries ...

  13. Diagnostic ultrasound induced inertial cavitation to non-invasively restore coronary and microvascular flow in acute myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Feng Xie

    Full Text Available Ultrasound induced cavitation has been explored as a method of dissolving intravascular and microvascular thrombi in acute myocardial infarction. The purpose of this study was to determine the type of cavitation required for success, and whether longer pulse duration therapeutic impulses (sustaining the duration of cavitation could restore both microvascular and epicardial flow with this technique. Accordingly, in 36 hyperlipidemic atherosclerotic pigs, thrombotic occlusions were induced in the mid-left anterior descending artery. Pigs were then randomized to either a ½ dose tissue plasminogen activator (0.5 mg/kg alone; or same dose plasminogen activator and an intravenous microbubble infusion with either b guided high mechanical index short pulse (2.0 MI; 5 usec therapeutic ultrasound impulses; or c guided 1.0 mechanical index long pulse (20 usec impulses. Passive cavitation detectors indicated the high mechanical index impulses (both long and short pulse duration induced inertial cavitation within the microvasculature. Epicardial recanalization rates following randomized treatments were highest in pigs treated with the long pulse duration therapeutic impulses (83% versus 59% for short pulse, and 49% for tissue plasminogen activator alone; p<0.05. Even without epicardial recanalization, however, early microvascular recovery occurred with both short and long pulse therapeutic impulses (p<0.005 compared to tissue plasminogen activator alone, and wall thickening improved within the risk area only in pigs treated with ultrasound and microbubbles. We conclude that although short pulse duration guided therapeutic impulses from a diagnostic transducer transiently improve microvascular flow, long pulse duration therapeutic impulses produce sustained epicardial and microvascular re-flow in acute myocardial infarction.

  14. [Single coronary artery and right aortic arch].

    Science.gov (United States)

    Martínez-Quintana, Efrén; Rodríguez-González, Fayna

    2015-01-01

    Coronary anomalies are mostly asymptomatic and diagnosed incidentally during coronary angiography or echocardiography. However, they must be taken into account in the differential diagnosis of angina, dyspnea, syncope, acute myocardial infarction or sudden death in young patients. The case is presented of two rare anomalies, single coronary artery originating from right sinus of Valsalva and right aortic arch, in a 65 year-old patient with atherosclerotic coronary artery disease treated percutaneously. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  15. Impact of obesity and bariatric surgery on metabolism and coronary circulatory function.

    Science.gov (United States)

    Valenta, Ines; Dilsizian, Vasken; Quercioli, Alessandra; Jüngling, Freimut D; Ambrosio, Giuseppe; Wahl, Richard; Schindler, Thomas H

    2014-01-01

    Increases in intra-abdominal visceral adipose tissue have been widely appreciated as a risk factor for metabolic disorders such as dyslipidemia, hypertension, insulin resistance, and type 2 diabetes, whereas this is not the case for peripheral or subcutaneous obesity. While the underlying mechanisms that contribute to these differences in adipose tissue activity remain uncertain, increases in visceral fat commonly induce metabolic dysregulation, in part because of increased venous effluent of fatty acids and/or adipokines/cytokines to the liver. Increased body weight, paralleled by an increase in plasma markers of the insulin-resistance syndrome and chronic inflammation, is independently associated with coronary circulatory dysfunction. Recent data suggest that plasma proteins originating from the adipose tissue, such as endocannabinoids (EC), leptin, and adiponectin (termed adipocytes) play a central role in the regulation and control of coronary circulatory function in obesity. Positron emission tomography (PET) in concert with tracer kinetic modeling is a well established technique for quantifying regional myocardial blood flow at rest and in response to various forms of vasomotor stress. Myocardial flow reserve assessed by PET provides a noninvasive surrogate of coronary circulatory function. PET also enables the monitoring and characterization of coronary circulatory function in response to gastric bypass-induced weight loss in initially morbidly obese individuals, to medication and/or behavioral interventions related to weight, diet, and physical activity. Whether the observed improvement in coronary circulatory dysfunction via weight loss may translate to diminution in cardiovascular events awaits clinical confirmation.

  16. PLACENTAL GROWTH FACTOR AND CORONARY NEOANGIOGENESIS IN CORONARY HEART DISEASE

    Directory of Open Access Journals (Sweden)

    M. V. Tulikov

    2013-01-01

    Full Text Available Neoangiogenesis in coronary heart disease is a protective reaction aimed to improve ischemic myocardial perfusion, by increasing the number and size of arterial collaterals. Placental growth factor (PlGF is one of the key peptides regulating angiogenic processes in atherosclerosis. In particular, a number of investigators have shown that injection of recombinant PlGF into the system or regional blood flow can stimulate neoangiogenesis. On the other hand, there is evidence confirming the involvement of PlGF in the progression of atherosclerosis and in the development of acute coronary syndrome. In this connection, the problem of investigating the efficiency and safety of possible use of PlGF preparations, as well as its place in the diagnosis of coronary heart disease and acute coronary syndrome remains urgent

  17. Hemodynamics Simulation of Stenosed Coronary Bypass Graft

    Institute of Scientific and Technical Information of China (English)

    LIU You-jun; QIAO Aike; DU Jian-jun

    2005-01-01

    By means of FEM, the physiological blood flow in coronary bypass graft is simulated. The stenosis in coronary artery is involved in the graft model,and the deformation of graft end to allow the surgical suture with a smaller diameter coronary is taken into consideration. The flow pattern, secondary flow and wall shear stress in the vicinity of anastomosis are analyzed. It is shown that a zone of low wall stress and high wall stress gradient exists downstream the toe. The floor opposed to the anastomosis is an area of high wall stress and high wall stress gradient. Both the toe downstream and the anastomosis bottom floor are prone to intimal hyperplasia.

  18. Current Roles and Future Applications of Cardiac CT: Risk Stratification of Coronary Artery Disease

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yeonyee Elizabeth [Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam 463-707 (Korea, Republic of); Lim, Tae-Hwan [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736 (Korea, Republic of)

    2014-07-01

    Cardiac computed tomography (CT) has emerged as a noninvasive modality for the assessment of coronary artery disease (CAD), and has been rapidly integrated into clinical cares. CT has changed the traditional risk stratification based on clinical risk to image-based identification of patient risk. Cardiac CT, including coronary artery calcium score and coronary CT angiography, can provide prognostic information and is expected to improve risk stratification of CAD. Currently used conventional cardiac CT, provides accurate anatomic information but not functional significance of CAD, and it may not be sufficient to guide treatments such as revascularization. Recently, myocardial CT perfusion imaging, intracoronary luminal attenuation gradient, and CT-derived computed fractional flow reserve were developed to combine anatomical and functional data. Although at present, the diagnostic and prognostic value of these novel technologies needs to be evaluated further, it is expected that all-in-one cardiac CT can guide treatment and improve patient outcomes in the near future.

  19. Invasive assessment of coronary microvascular dysfunction in hypertrophic cardiomyopathy: the index of microvascular resistance

    Energy Technology Data Exchange (ETDEWEB)

    Gutiérrez-Barrios, Alejandro, E-mail: aleklos@hotmail.com [Cardiology Department, Jerez Hospital, Jerez (Spain); Camacho-Jurado, Francisco [Cardiology Department, Punta Europa Hospital, Algeciras (Spain); Díaz-Retamino, Enrique; Gamaza-Chulián, Sergio; Agarrado-Luna, Antonio; Oneto-Otero, Jesús; Del Rio-Lechuga, Ana; Benezet-Mazuecos, Javier [Cardiology Department, Jerez Hospital, Jerez (Spain)

    2015-10-15

    Summary: We present a review of microvascular dysfunction in hypertrophic cardiomyopathy (HCM) and an interesting case of a symptomatic familial HCM patient with inducible ischemia by single photon emission computed tomography. Coronary angiography revealed normal epicardial arteries. Pressure wire measurements of fractional flow reserve (FFR), coronary flow reserve (CFR) and index of microvascular resistance (IMR) demonstrated a significant microcirculatory dysfunction. This is the first such case that documents this abnormality invasively using the IMR. The measurement of IMR, a novel marker of microcirculatory dysfunction, provides novel insights into the pathophysiology of this condition. - Highlights: • Microvascular dysfunction is a common feature in hypertrophic cardiomyopathy (HCM) and represents a strong predictor of unfavorable outcome and cardiovascular mortality. • The index of microvascular resistance (IMR) is a new method for invasively assessing the state of the coronary microcirculation using a single pressure-temperature sensor-tipped coronary wire. • However assessment of IMR in HCM has not been previously reported. We report a case in which microvascular dysfunction is assessed by IMR. This index may be useful in future researches of HCM.

  20. [Anatomy and physiology of the heart and coronary arteries].

    Science.gov (United States)

    Leclercq, Florence

    2015-03-01

    The myocardium assures the supply of oxygen to the body. The provision of oxygen to the myocardium by the coronary arteries is dependent on two key parameters: the coronary blood flow and the ability to extract oxygen from the arterial blood. Coronary artery disease is almost always the consequence of atherosclerosis and can lead to myocardial infarction.

  1. Non-invasive prediction of hemodynamically significant coronary artery stenoses by contrast density difference in coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Hell, Michaela M., E-mail: michaela.hell@uk-erlangen.de [Department of Cardiology, University of Erlangen (Germany); Dey, Damini [Department of Biomedical Sciences, Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Taper Building, Room A238, 8700 Beverly Boulevard, Los Angeles, CA 90048 (United States); Marwan, Mohamed; Achenbach, Stephan; Schmid, Jasmin; Schuhbaeck, Annika [Department of Cardiology, University of Erlangen (Germany)

    2015-08-15

    Highlights: • Overestimation of coronary lesions by coronary computed tomography angiography and subsequent unnecessary invasive coronary angiography and revascularization is a concern. • Differences in plaque characteristics and contrast density difference between hemodynamically significant and non-significant stenoses, as defined by invasive fractional flow reserve, were assessed. • At a threshold of ≥24%, contrast density difference predicted hemodynamically significant lesions with a specificity of 75%, sensitivity of 33%, PPV of 35% and NPV of 73%. • The determination of contrast density difference required less time than transluminal attenuation gradient measurement. - Abstract: Objectives: Coronary computed tomography angiography (CTA) allows the detection of obstructive coronary artery disease. However, its ability to predict the hemodynamic significance of stenoses is limited. We assessed differences in plaque characteristics and contrast density difference between hemodynamically significant and non-significant stenoses, as defined by invasive fractional flow reserve (FFR). Methods: Lesion characteristics of 59 consecutive patients (72 lesions) in whom invasive FFR was performed in at least one coronary artery with moderate to high-grade stenoses in coronary CTA were evaluated by two experienced readers. Coronary CTA data sets were acquired on a second-generation dual-source CT scanner using retrospectively ECG-gated spiral acquisition or prospectively ECG-triggered axial acquisition mode. Plaque volume and composition (non-calcified, calcified), remodeling index as well as contrast density difference (defined as the percentage decline in luminal CT attenuation/cross-sectional area over the lesion) were assessed using a semi-automatic software tool (Autoplaq). Additionally, the transluminal attenuation gradient (defined as the linear regression coefficient between intraluminal CT attenuation and length from the ostium) was determined

  2. Revascularização cirúrgica do miocárdio com enxerto composto de artérias torácica interna esquerda e radial: comparação do fluxo sangüíneo para artéria coronária esquerda com a técnica convencional Coronary artery bypass grafting with composite grafts: comparison of blood flow to the left coronary artery with the conventional technique

    Directory of Open Access Journals (Sweden)

    Josué V. Castro Neto

    2004-12-01

    when compared to the conventional alternative. We sought to compare the total blood flow to the left coronary branches that are revascularized with left internal thoracic (LITA and radial artery (RA grafts using composite and non-composite techniques. METHOD: A total of 42 patients were randomly assigned to three groups according to the CABG technique to be used: Group A or composite LITA-RA in a Y format (n=14; Group B or modified composite LITA-RA [intercoronary graft with RA and LITA to RA at the level of the left anterior descending artery (LAD, n=14]; and Group C or pedicled LITA to the LAD and aorto-coronary RA (n=14. The patients were submitted to postoperative blow flow velocity analysis using a 0.014 inch 12 MHz Doppler flowire. Coronary flow reserve (CFR was calculated by determining the average hyperemic peak velocity (APV after an injection of adenosine. RESULTS: Proximal LITA baseline APV was 28.4±4.8 cm/s in group A, 34.4±7.9 cm/s in group B (p=0.0384 x C and 25.8± 8.6 cm/s in group C. The CFR was 2.1 ± 0.4, 2±0.3 and 2±0.4 in groups A,B and C respectively (p=0.7208 A, B x C. The total Q to LCA branches was 110±30 in group A, 145±59 in B and 133±58 mL/min in C (p=0.3232 A, B x C. CONCLUSIONS: The LITA-RA composite graft maintains an adequate CFR and conveys similar blood flow to the left coronary artery branches when compared with conventional CABG technique.

  3. 伊伐布雷定和阿替洛尔保护大鼠心肌梗死后冠脉储备的比较研究%Comparative Study on Coronary Reserve between Ivabradine Therapy and Atenolol Therapy after Rat Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    张荣林; Robert J.Tomanek

    2011-01-01

    OBJECTIVE We compared the ivabradine and atenolol in preserving coronary reserve of infarcted rats. METHODS 12-month-old male Sprague-Dawley rats were randomly divided into 4 groups: sham group, MI group, MI +Iva group and MI +Ate group. Medical treatment was immediately begun following infarction and continued until the 28th day. Infarction area, heart rate and coronary reserve were compared among groups. RESULTS There were no statistical differences among the 3 infarcted groups with infarction size and baseline heart rate. Heart rates 28 d later were significantly lower in both MI + Ate group and MI + Iva group compared to MI group. However, there was no statistical difference between the two medicine treated groups. Compared with the sham group, the coronary reserve of both the free wall and the ventricular septum in the MI group were significantly lower, and the coronary reserve of the ventricular septum in the MI + Ate group was also significantly lower. The coronary reserve of both the free wall and the septum in the MI + Iva group were higher, compared with both the MI group and the MI + Ate group. CONCLUSION Iva preserves the coronary reserve of infarcted rats better than Ate treatment.%目的 比较伊伐布雷定(Iva)和阿替洛尔(Ate)治疗对大鼠心梗后冠脉储备的保护作用有无差异.方法 受试大鼠分为假手术(sham)组、心肌梗死(MI)组、MI+Iva组和MI+Ate组,药物治疗在诱导心肌梗死后开始,疗程28d.比较大鼠的心梗面积,以及治疗前后的心率、冠脉储备等情况.结果 三组心梗大鼠之间基础心率、梗死面积占心室面积的比例均无统计学差异;与MI组相比,术后第28天MI+Iva组和MI+Ate组的心率明显减慢;而MI+Iva组和Ml+Ate组相比,术后第28天的心率减慢程度没有统计学差异.与sham组相比,MI组无论游离壁还是室间隔的冠脉储备都显著降低,MI+Ate组室间隔的冠脉储备也显著降低.MI+Iva组无论游离壁还是室间隔的冠脉

  4. Effect of long-term alcohol habit on coronary morphology and blood flow in males%长期饮酒对男性冠状动脉内径及血流的影响

    Institute of Scientific and Technical Information of China (English)

    韩凯; 张海成; 肖世南; 董卫锋

    2013-01-01

    AIM: To investigate the angiographic characteristics of coronary artery in males with long-term alcohol habit. METHODS: Included in this study were males who underwent coronary angiography from July 2008 to July 2012 in our hospital and were found to have no coronary artery stenosis and no diseases that cause coronary artery ectasis. According to their alcohol consumption, subjects were divided into three groups: heavy alcohol consumption, light/moderate alcohol consumption, and no alcohol consumption. The results of coronary angiography were analyzed and compared. RESULTS: The coronary artery diameter in heavy alcohol consumption group was significantly wider than in the light/moderate alcohol group and no alcohol group ( P < 0. 05 ). In the heavy alcohol consumption group, the rate of coronary artery ecta-sias (18% ) was significantly higher than those in the light/moderate alcohol group (2% ) and no alcohol group (l%)(P<0. 05) and the rate of slow flow (29% ) was significantly higher than in the light/moderate alcohol group (4% ) and no alcohol group (3% ) (P <0. 05). CONCLUSION: Long-term heavy alcohol consumption can change the normal form of the coronary artery and increase the incidence of coronary artery dilatation and slow blood flow rate, thus affecting myocardial blood supply.%目的:初步探讨长期饮酒对男性冠状动脉内径及血流速度的影响.方法:选择2008年7月~2012年7月在我院行冠脉造影,无冠脉粥样硬化狭窄病变的所有男性为研究对象.根据既往是否饮酒及饮酒程度分为3组:重度饮酒组(38例)、轻中度饮酒组(84例)和不饮酒组(67例).对比分析各组冠状动脉造影结果.结果:重度饮酒组左主干、左前降支主支、回旋支主支、右冠状动脉主支内径均较轻中度饮酒组与不饮酒组显著增宽(均P<0.05);轻中度饮酒组与不饮酒组无统计学差异.重度饮酒组冠脉扩张病变率(18%)较轻中度饮酒组(2%)与不饮酒组(1

  5. Successful transradial removal of an inflated coronary stent dislodged from the right coronary ostium.

    Science.gov (United States)

    Porto, Italo; Larosa, Claudio; Rosa, Isabella; Burzotta, Francesco; Trani, Carlo

    2014-01-01

    We describe our solution to the unusual situation of an inflated, large coronary stent (3.5 mm diameter) which became dislodged from the ostium of the right coronary artery after deployment during a transradial procedure. We discussed tips for retrieval from the radial artery while preserving the access for completion of the procedure. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Coronary anomaly: the single coronary artery

    Institute of Scientific and Technical Information of China (English)

    QIN Xu-guang; XIONG Wei-guo; LU Chun-peng; GONG Cheng-jie; SHANG Li-hua

    2010-01-01

    @@ Single coronary artery (SCA), defined as an artery that arises from the arterial trunk and nourishes the entire myocardium, is rare. We report two cases of SCA, one is the right coronary artery (RCA) originating from the middle of left descending artery (LAD), and the other is the left main coronary artery (LMCA) arising from the proximal right coronary artery.

  7. Safety of guidewire-based measurement of fractional flow reserve and the index of microvascular resistance using intravenous adenosine in patients with acute or recent myocardial infarction

    Science.gov (United States)

    Ahmed, Nadeem; Layland, Jamie; Carrick, David; Petrie, Mark C.; McEntegart, Margaret; Eteiba, Hany; Hood, Stuart; Lindsay, Mitchell; Watkins, Stuart; Davie, Andrew; Mahrous, Ahmed; Carberry, Jaclyn; Teng, Vannesa; McConnachie, Alex; Curzen, Nick; Oldroyd, Keith G.; Berry, Colin

    2016-01-01

    Aims Coronary guidewire-based diagnostic assessments with hyperemia may cause iatrogenic complications. We assessed the safety of guidewire-based measurement of coronary physiology, using intravenous adenosine, in patients with an acute coronary syndrome. Methods We prospectively enrolled invasively managed STEMI and NSTEMI patients in two simultaneously conducted studies in 6 centers (NCT01764334; NCT02072850). All of the participants underwent a diagnostic coronary guidewire study using intravenous adenosine (140 μg/kg/min) infusion for 1–2 min. The patients were prospectively assessed for the occurrence of serious adverse events (SAEs) and symptoms and invasively measured hemodynamics were also recorded. Results 648 patients (n = 298 STEMI patients in 1 hospital; mean time to reperfusion 253 min; n = 350 NSTEMI in 6 hospitals; median time to angiography from index chest pain episode 3 (2, 5) days) were included between March 2011 and May 2013. Two NSTEMI patients (0.3% overall) experienced a coronary dissection related to the guidewire. No guidewire dissections occurred in the STEMI patients. Chest symptoms were reported in the majority (86%) of patient's symptoms during the adenosine infusion. No serious adverse events occurred during infusion of adenosine and all of the symptoms resolved after the infusion ceased. Conclusions In this multicenter analysis, guidewire-based measurement of FFR and IMR using intravenous adenosine was safe in patients following STEMI or NSTEMI. Self-limiting symptoms were common but not associated with serious adverse events. Finally, coronary dissection in STEMI and NSTEMI patients was noted to be a rare phenomenon. PMID:26418191

  8. Updates in management of coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dong Heon; Chae, Shung Chull [Kyungpook National University Medical School, Daegu (Korea, Republic of)

    2005-02-15

    Coronary artery disease (CAD) has been increasing during the last decade and is the one of major causes of death. The management of patients with coronary artery disease has evolved considerably. There are two main strategies in the management of CAD, complementary, not competitive, each other; the pharmacologic therapy to prevent and treat CAD and the percutaneous coronary intervention (PCI) to restore coronary flow. Antiplatelet drugs and cholesterol lowering drugs have central roles in pharmacotherapy. Drug eluting stent (DES) bring about revolutional changes in PCL in the management of patients with ST segment elevation acute myocardial infarction (AMI), there has been a debate on the better strategy for the restoration of