Baroreflex and neurovascular responses to skeletal muscle mechanoreflex activation in humans: an exercise in integrative physiology.

Science.gov (United States)

Drew, Rachel C

2017-12-01

Cardiovascular adjustments to exercise resulting in increased blood pressure (BP) and heart rate (HR) occur in response to activation of several neural mechanisms: the exercise pressor reflex, central command, and the arterial baroreflex. Neural inputs from these feedback and feedforward mechanisms integrate in the cardiovascular control centers in the brain stem and modulate sympathetic and parasympathetic neural outflow, resulting in the increased BP and HR observed during exercise. Another specific consequence of the central neural integration of these inputs during exercise is increased sympathetic neural outflow directed to the kidneys, causing renal vasoconstriction, a key reflex mechanism involved in blood flow redistribution during increased skeletal muscle work. Studies in humans have shown that muscle mechanoreflex activation inhibits cardiac vagal outflow, decreasing the sensitivity of baroreflex control of HR. Metabolite sensitization of muscle mechanoreceptors can lead to reduced sensitivity of baroreflex control of HR, with thromboxane being one of the metabolites involved, via greater inhibition of cardiac vagal outflow without affecting baroreflex control of BP or baroreflex resetting. Muscle mechanoreflex activation appears to play a predominant role in causing renal vasoconstriction, both in isolation and in the presence of local metabolites. Limited investigations in older adults and patients with cardiovascular-related disease have provided some insight into how the influence of muscle mechanoreflex activation on baroreflex function and renal vasoconstriction is altered in these populations. However, future research is warranted to better elucidate the specific effect of muscle mechanoreflex activation on baroreflex and neurovascular responses with aging and cardiovascular-related disease. Copyright © 2017 the American Physiological Society.

Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans

NARCIS (Netherlands)

Silvani, A.; Calandra-Buonaura, G.; Johnson, B.D.; Helmond, N. van; Barletta, G.; Cecere, A.G.; Joyner, M.J.; Cortelli, P.

2017-01-01

The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological

Baroreflex sensitivity in the elderly : influence of age, breathing and spectral methods

NARCIS (Netherlands)

Gerritsen, J; TenVoorde, B J; Dekker, J M; Kostense, P J; Bouter, L M; Heethaar, R M

2000-01-01

Baroreflex sensitivity (BRS) has been proposed as a diagnostic parameter for neurological disorders and as a survival-prognosis parameter in diabetic and cardiac patients. Therefore reference values and the reproducibility of BRS were assessed, taking into account the possible influence of age,

The benefits of soluble non-bacterial fraction of kefir on blood pressure and cardiac hypertrophy in hypertensive rats are mediated by an increase in baroreflex sensitivity and decrease in angiotensin-converting enzyme activity.

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Brasil, Girlandia Alexandre; Silva-Cutini, Mirian de Almeida; Moraes, Flávia de Souza Andrade; Pereira, Thiago de Melo Costa; Vasquez, Elisardo Corral; Lenz, Dominik; Bissoli, Nazaré Souza; Endringer, Denise Coutinho; de Lima, Ewelyne Miranda; Biancardi, Vinícia Campana; Maia, June Ferreira; de Andrade, Tadeu Uggere

We aimed to evaluate whether long-term treatment with the soluble non-bacterial fraction of kefir affects mean arterial pressure (MAP) and cardiac hypertrophy through the modulation of baroreflex sensitivity, ACE activity, and the inflammatory-to-anti-inflammatory cytokine ratio in spontaneously hypertensive rats (SHRs). SHRs were treated with the soluble non-bacterial kefir fraction (SHR-kefir) or with kefir vehicle (SHR-soluble fraction of milk). Normotensive control Wistar Kyoto animals received the soluble fraction of milk. All treatments were administered by gavage (0.3 mL/100g/body weight), once daily for eight weeks. At the end, after basal MAP and Heart Rate (HT) measurement, barorreflex sensitivity was evaluated through in bolus administrations of sodium nitroprusside and phenylephrine (AP 50 [arterial pressure 50%], the lower plateau, and HR range were measured). ACE activity and cytokines (TNF-α and IL-10) were evaluated by ELISA. Cardiac hypertrophy was analysed morphometrically. Compared to SHR control, SHR-kefir exhibited a significant decrease in both MAP (SHR: 184 ± 5; SHR-Kefir: 142 ± 8 mmHg), and HR (SHR: 360 ± 10; SHR-kefir: 310 ± 14 bpm). The non-bacterial fraction of kefir also reduced cardiac hypertrophy, TNF-α-to-IL10 ratio, and ACE activity in SHRs. SHR-kefir baroreflex sensitivity, resulted in a partial but significant recovery of baroreflex gain, as demonstrated by improvements in AP 50 , the lower plateau, and HR range. In summary, our results indicate that long-term administration of the non-bacterial fraction of kefir promotes a significant decrease in both MAP and HR, by improving baroreflex, and reduces cardiac hypertrophy in SHRs, likely via ACE inhibition, and reduction of the TNF-α-to-IL10 ratio. Copyright © 2018 Elsevier Inc. All rights reserved.

Assessment of baroreflex sensitivity from spontaneous oscillations of blood pressure and heart rate: proven clinical value?

International Nuclear Information System (INIS)

Pinna, Gian Domenico; Maestri, Roberto; La Rovere, Maria Teresa

2015-01-01

The baroreceptor-heart rate reflex (baroreflex sensitivity, BRS) is a key mechanism contributing to the neural regulation of the cardiovascular system. Several methods have been proposed so far to assess BRS by analyzing the spontaneous beat-to-beat fluctuations of arterial blood pressure and heart rate. These methods are inherently simple, non-invasive and low-cost. This study is an attempt to address the question of whether spontaneous baroreflex methods have proven to be of value in the clinical setting. In the first part of this article, we critically review most representative clinical studies using spontaneous BRS techniques either for risk stratification or treatment evaluation, these being major issues in the clinical management of the patients. In the second part, we address two important aspects of spontaneous BRS measurements: measurability and reliability. Estimation of BRS in the studies selected for the review was performed according to the sequence, transfer function, alpha-index and phase-rectified signal averaging method. Arterial blood pressure was recorded non-invasively during supine, short-term (<30 min) laboratory recordings. The conclusion from this review is that spontaneous BRS techniques have been shown to be of great value in clinical practice but further work is needed to confirm the validity of previous findings and to widen the field of clinical applications. Measurability and reliability can be a major issue in the measurement of spontaneous BRS, particularly in some patient populations like post-myocardial infarction and heart failure patents. Main causes of poor measurability are: non-sinus rhythm, a high rate of ectopic beats and the need for recorded time series of RR interval and arterial blood pressure to satisfy the constraints of the different BRS estimation algorithms. As for reliability, within-subject variability is rather high in the measurements of spontaneous BRS and, therefore, should be carefully taken into account

Reduced Baroreflex Sensitivity in Cluster Headache Patients

DEFF Research Database (Denmark)

Barloese, Mads C J; Mehlsen, Jesper; Brinth, Louise

2015-01-01

by baroreflex sensitivity (BRS) in CH patients. METHODS: Twenty-six active CH patients and an equal number of age-, sex-, and BMI-matched controls underwent head-up tilt table test and BRS was determined by the sequence method. RESULTS: Compared with controls, patients exhibited a blunted reactivity of RR...... patients who had not (n = 13, 16.0 ms/mmHg, P = .1523). In the tilted position, the drop in SBP at the carotid sinuses was higher in patients who had recently suffered an attack. Despite this, they exhibited a less marked shortening of RR intervals when compared with patients who had been attack free...... of the autonomic nervous system or in the central relay of impulses from the baroreceptors....

Targeted deletion of neurokinin-1 receptor expressing nucleus tractus solitarii neurons precludes somatosensory depression of arterial baroreceptor-heart rate reflex.

Science.gov (United States)

Potts, J T; Fong, A Y; Anguelov, P I; Lee, S; McGovern, D; Grias, I

2007-03-30

Neurokinin-1 receptor (NK1-R) expressing neurons are densely distributed throughout the nucleus tractus solitarii (NTS). However, their fundamental role in arterial baroreflex function remains debated. Previously, our group has shown that activation of contraction-sensitive somatic afferents evoke substance P (SP) release in the NTS and resets the arterial baroreflex via activation of a GABAergic NTS circuit. Based on these findings, we hypothesized that modulation of arterial baroreflex function by somatic afferents is mediated by NK1-R dependent inhibition of barosensitive NTS circuits. In the present study, SP-conjugated saporin toxin (SP-SAP) was used to ablate NK1-R expressing NTS neurons. Contraction-sensitive somatic afferents were activated by electrically-evoked muscle contraction and the arterial baroreceptor-heart rate reflex was assessed by constructing reflex curves using a decerebrate, arterially-perfused preparation. Baseline baroreflex sensitivity was significantly attenuated in SP-SAP-treated rats compared with control rats receiving either unconjugated SAP or vehicle. Muscle contraction significantly attenuated baroslope in SAP and vehicle-treated animals and shifted the baroreflex curves to higher systemic pressure. In contrast, somatic afferent stimulation failed to alter baroslope or shift the baroreflex curves in SP-SAP-treated animals. Moreover, when reflex sensitivity was partially restored in SP-SAP animals, somatic stimulation failed to attenuate baroreflex bradycardia. In contrast, SP-SAP and somatic stimulation failed to blunt the reflex bradycardia evoked by the peripheral chemoreflex. Immunohistochemistry revealed that pretreatment with SP-SAP significantly reduced the number of NK1-R expressing neurons in the caudal NTS, while sparing NK1-R expressing neurons rostral to the injection site. This was accompanied by a significant reduction in the number of glutamic acid decarboxylase (GAD67) expressing neurons at equivalent levels of the

Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae.

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Zena, Lucas A; Dantonio, Valter; Gargaglioni, Luciane H; Andrade, Denis V; Abe, Augusto S; Bícego, Kênia C

2016-03-01

Baroreflex regulation of blood pressure is important for maintaining appropriate tissue perfusion. Although temperature affects heart rate (fH) reflex regulation in some reptiles and toads, no data are available on the influence of temperature-independent metabolic states on baroreflex. The South American tegu lizard Salvator merianae exhibits a clear seasonal cycle of activity decreasing fH along with winter metabolic downregulation, independent of body temperature. Through pharmacological interventions (phenylephrine and sodium nitroprusside), the baroreflex control of fH was studied at ∼ 25 °C in spring-summer- and winter-acclimated tegus. In winter lizards, resting and minimum fH were lower than in spring-summer animals (respectively, 13.3 ± 0.82 versus 10.3 ± 0.81 and 11.2 ± 0.65 versus 7.97 ± 0.88 beats min(-1)), while no acclimation differences occurred in resting blood pressure (5.14 ± 0.38 versus 5.06 ± 0.56 kPa), baroreflex gain (94.3 ± 10.7 versus 138.7 ± 30.3% kPa(-1)) or rate-pressure product (an index of myocardial activity). Vagal tone exceeded the sympathetic tone of fH, especially in the winter group. Therefore, despite the lower fH, winter acclimation does not diminish the fH baroreflex responses or rate-pressure product, possibly because of increased stroke volume that may arise because of heart hypertrophy. Independent of acclimation, fH responded more to hypotension than to hypertension. This should imply that tegus, which have no pressure separation within the single heart ventricle, must have other protection mechanisms against pulmonary hypertension or oedema, presumably through lymphatic drainage and/or vagal vasoconstriction of pulmonary artery. Such a predominant fH reflex response to hypotension, previously observed in anurans, crocodilians and mammals, may be a common feature of tetrapods. © 2016. Published by The Company of Biologists Ltd.

Tonic aortic depressor nerve stimulation does not impede baroreflex dynamic characteristics concomitantly mediated by the stimulated nerve.

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Kawada, Toru; Turner, Michael J; Shimizu, Shuji; Kamiya, Atsunori; Shishido, Toshiaki; Sugimachi, Masaru

2018-03-01

Although electrical activation of the carotid sinus baroreflex (baroreflex activation therapy) is being explored as a device therapy for resistant hypertension, possible effects on baroreflex dynamic characteristics of interaction between electrical stimulation and pressure inputs are not fully elucidated. To examine whether the electrical stimulation of the baroreceptor afferent nerve impedes normal short-term arterial pressure (AP) regulation mediated by the stimulated nerve, we electrically stimulated the right aortic depressor nerve (ADN) while estimating the baroreflex dynamic characteristics by imposing pressure inputs to the isolated baroreceptor region of the right ADN in nine anesthetized rats. A Gaussian white noise signal with a mean of 120 mmHg and standard deviation of 20 mmHg was used for the pressure perturbation. A tonic ADN stimulation (2 or 5 Hz, 10 V, 0.1-ms pulse width) decreased mean sympathetic nerve activity (367.0 ± 70.9 vs. 247.3 ± 47.2 arbitrary units, P ADN stimulation did not affect the slope of dynamic gain in the neural arc transfer function from pressure perturbation to sympathetic nerve activity (16.9 ± 1.0 vs. 14.7 ± 1.6 dB/decade, not significant). These results indicate that electrical stimulation of the baroreceptor afferent nerve does not significantly impede the dynamic characteristics of the arterial baroreflex concomitantly mediated by the stimulated nerve. Short-term AP regulation by the arterial baroreflex may be preserved during the baroreflex activation therapy.

Optimal Testing Intervals in the Squatting Test to Determine Baroreflex Sensitivity

OpenAIRE

Ishitsuka, S.; Kusuyama, N.; Tanaka, M.

2014-01-01

The recently introduced “squatting test” (ST) utilizes a simple postural change to perturb the blood pressure and to assess baroreflex sensitivity (BRS). In our study, we estimated the reproducibility of and the optimal testing interval between the STs in healthy volunteers. Thirty-four subjects free of cardiovascular disorders and taking no medication were instructed to perform the repeated ST at 30-sec, 1-min, and 3-min intervals in duplicate in a random sequence, while the systolic blood p...

Baroreflex failure: a neglected type of secondary hypertension

NARCIS (Netherlands)

Timmers, H. J. L. M.; Wieling, W.; Karemaker, J. M.; Lenders, J. W. M.

2004-01-01

The arterial baroreflex buffers abrupt transients of blood pressure and prevents pressure from rising or falling excessively. In experimental animals, baroreceptor denervation results in temporary or permanent increases in blood pressure level and variability, depending on the extent of denervation.

Baroreflex failure: a neglected type of secondary hypertension.

NARCIS (Netherlands)

Timmers, H.J.L.M.; Wieling, W.; Karemaker, J.M.; Lenders, J.W.M.

2004-01-01

The arterial baroreflex buffers abrupt transients of blood pressure and prevents pressure from rising or falling excessively. In experimental animals, baroreceptor denervation results in temporary or permanent increases in blood pressure level and variability, depending on the extent of denervation.

Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans

OpenAIRE

Silvani, Alessandro; Calandra-Buonaura, Giovanna; Johnson, Blair D.; van Helmond, Noud; Barletta, Giorgio; Cecere, Anna G.; Joyner, Michael J.; Cortelli, Pietro

2017-01-01

The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological mechanisms that mediate the coupling between HP and SAP in response to different postures, we analyzed the cross-correlation functions between low-frequency HP and SAP fluctuations and estimated cBR...

Resting spontaneous baroreflex sensitivity and cardiac autonomic control in anabolic androgenic steroid users

OpenAIRE

Santos, Marcelo R. dos; Sayegh, Ana L.C.; Armani, Rafael; Costa-Hong, Valéria; Souza, Francis R. de; Toschi-Dias, Edgar; Bortolotto, Luiz A.; Yonamine, Mauricio; Negrão, Carlos E.; Alves, Maria-Janieire N.N.

2018-01-01

OBJECTIVES: Misuse of anabolic androgenic steroids in athletes is a strategy used to enhance strength and skeletal muscle hypertrophy. However, its abuse leads to an imbalance in muscle sympathetic nerve activity, increased vascular resistance, and increased blood pressure. However, the mechanisms underlying these alterations are still unknown. Therefore, we tested whether anabolic androgenic steroids could impair resting baroreflex sensitivity and cardiac sympathovagal control. In addition, ...

A single inhalation exposure to acrolein desensitizes baroreflex responsiveness in Wistar-Kyoto and Spontaneously Hypertensive rats.

Science.gov (United States)

Arterial baroreflex is one of the body's homeostatic mechanisms that regulate blood pressure (BP) by changing heart rate (HR) and vasoconstriction. Increases in BP reflexively cause HR to decrease, whereas decreases in BP depress the baroreflex and cause HR to rise. As such, baro...

Endogenous leptin contributes to baroreflex suppression within the solitary tract nucleus of aged rats

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Arnold, Amy C.

2014-01-01

The decline in cardiovagal baroreflex function that occurs with aging is accompanied by an increase in circulating leptin levels. Our previous studies showed that exogenous leptin impairs the baroreflex sensitivity for control of heart rate in younger rats, but the contribution of this hormone to baroreflex dysfunction during aging is unknown. Thus we assessed the effect of bilateral leptin microinjection (500 fmol/60 nl) within the solitary tract nucleus (NTS) on the baroreflex sensitivity in older (66 ± 2 wk of age) urethane/chloralose anesthetized Sprague-Dawley rats with elevated circulating leptin levels. In contrast to the 63% reduction observed in younger rats, leptin did not alter the baroreflex sensitivity for bradycardia evoked by phenylephrine in older rats (0.76 ± 0.19 baseline vs. 0.71 ± 0.15 ms/mmHg after leptin; P = 0.806). We hypothesized that this loss of sensitivity reflected endogenous suppression of the baroreflex by elevated leptin, rather than cardiovascular resistance to the peptide. Indeed, NTS administration of a leptin receptor antagonist (75 pmol/120 nl) improved the baroreflex sensitivity for bradycardia in older rats (0.73 ± 0.13 baseline vs. 1.19 ± 0.26 at 10 min vs. 1.87 ± 0.32 at 60 min vs. 1.22 ± 0.54 ms/mmHg at 120 min; P = 0.002), with no effect in younger rats. There was no effect of the leptin antagonist on the baroreflex sensitivity for tachycardia, responses to cardiac vagal chemosensitive fiber activation, or resting hemodynamics in older rats. These findings suggest that the actions of endogenous leptin within the NTS, either produced locally or derived from the circulation, contribute to baroreflex suppression during aging. PMID:25260611

Carotid baroreflex function at the onset of cycling in men

DEFF Research Database (Denmark)

Barbosa, Thales C; Vianna, Lauro C; Hashimoto, Takeshi

2016-01-01

moderate-intensity exercise (P mediated by an increase in the total vascular conductance. These findings evidence altered carotid baroreflex function during the first 35 s of cycling compared with rest, with attenuated bradycardic......Arterial baroreflex function is important for blood pressure control during exercise, but its contribution to cardiovascular adjustments at the onset of cycling exercise remains unclear. Fifteen healthy male subjects (24 ± 1 yr) performed 45-s trials of low- and moderate-intensity cycling...... during moderate-intensity exercise, compared with the response at rest (P

Baroreflex deficiency induces additional impairment of vagal tone, diastolic function and calcium handling proteins after myocardial infarction

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Mostarda, Cristiano; Rodrigues, Bruno; Medeiros, Alessandra; Moreira, Edson D; Moraes-Silva, Ivana C; Brum, Patricia C; Angelis, Katia De; Irigoyen, Maria-Cláudia

2014-01-01

Baroreflex dysfunction has been considered an important mortality predictor after myocardial infarction (MI). However, the impact of baroreflex deficiency prior to MI on tonic autonomic control and cardiac function, and on the profile of proteins associated with intracellular calcium handling has not yet been studied. The aim of the present study was to analyze how the impairment of baroreflex induced by sinoaortic denervation (SAD) prior to MI in rats affects the tonic autonomic control, ventricular function and cardiomyocyte calcium handling proteins. After 15 days of following or SAD surgery, rats underwent MI. Echocardiographic, hemodynamic, autonomic and molecular evaluations were performed 90 days after MI. Baroreflex impairment led to additional damage on: left ventricular remodeling, diastolic function, vagal tonus and intrinsic heart rate after MI. The loss of vagal component of the arterial baroreflex and vagal tonus were correlated with changes in the cardiac proteins involved in intracellular calcium homeostasis. Furthermore, additional increase in sodium calcium exchanger expression levels was associated with impaired diastolic function in experimental animals. Our findings strongly suggest that previous arterial baroreflex deficiency may induce additional impairment of vagal tonus, which was associated with calcium handling proteins abnormalities, probably triggering ventricular diastolic dysfunction after MI in rats. PMID:24936224

Influence of a multideficient diet from northeastern Brazil on resting blood pressure and baroreflex sensitivity in conscious, freely moving rats

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F.M.F. Monteiro

2001-02-01

Full Text Available The "regional basic diet" or RBD is a multideficient diet (providing 8% protein which is known to produce dietary deficiencies in some populations in northeastern Brazil. The present study investigated the effects of RBD-induced malnutrition on resting blood pressure and baroreflex sensitivity in conscious rats. Malnourished rats were obtained by feeding dams the RBD during mating and pregnancy (RBD-1 group or during nursing and a 10-day period after weaning (RBD-2 group. At 90 days of age, only RBD-2 rats weighed significantly (P<0.001 less than control rats born to dams fed a standard commercial diet (23% protein during pregnancy and nursing. Baseline mean arterial pressure and heart rate of both RBD-1 and RBD-2 rats were comparable to those of controls. The slopes for both reflex bradycardia and tachycardia (bpm/mmHg induced by intravenous phenylephrine and sodium nitroprusside, respectively, were unchanged in either RBD-1 (-2.08 ± 0.11 and -3.10 ± 0.43, respectively or RBD-2 (-2.32 ± 0.30 and -3.73 ± 0.53, respectively rats, when compared to controls (-2.09 ± 0.10 and -3.17 ± 0.33, respectively. This study shows that, after a prolonged period of nutritional recovery, the patterns of resting blood pressure and baroreflex sensitivity of both pre- and postnatally malnourished rats were similar to those of controls. The decreased body weight and the tendency to increased reflex tachycardia in RBD-2 rats may suggest that this type of maternal malnutrition during lactation is more critical than during pregnancy.

RESTING SYMPATHETIC BAROREFLEX SENSITIVITY IN SUBJECTS WITH LOW AND HIGH TOLERANCE TO CENTRAL HYPOVOLEMIA INDUCED BY LOWER BODY NEGATIVE PRESSURE

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Carmen eHinojosa-Laborde

2014-06-01

Full Text Available Central hypovolemia elicited by orthostasis or hemorrhage triggers sympathetically-mediated baroreflex responses to maintain organ perfusion; these reflexes are less sensitive in patients with orthostatic intolerance, and during conditions of severe blood loss, may result in cardiovascular collapse (decompensatory or circulatory shock. The ability to tolerate central hypovolemia is variable and physiological factors contributing to tolerance are emerging. We tested the hypothesis that resting muscle sympathetic nerve activity (MSNA and sympathetic baroreflex sensitivity (BRS are attenuated in male and female subjects who have low tolerance (LT to central hypovolemia induced by lower body negative pressure (LBNP. MSNA and diastolic arterial pressure (DAP were recorded in 47 human subjects who subsequently underwent LBNP to tolerance (onset of presyncopal symptoms. LT subjects experienced presyncopal symptoms prior to completing LBNP of -60 mm Hg, and subjects with high tolerance (HT experienced presyncopal symptoms after completing LBNP after -60 mmHg. Contrary to our hypothesis, resting MSNA burst incidence was not different between LT and HT subjects, and was not related to time to presyncope. BRS was assessed as the slope of the relationship between spontaneous fluctuations in DAP and MSNA during 5 min of supine rest. MSNA burst incidence/DAP correlations were greater than or equal to 0.5 in 37 subjects (LT: n= 9; HT: n=28, and BRS was not different between LT and HT (-1.8 ± 0.3 vs. -2.2 ± 0.2 bursts•(100 beats-1•mmHg-1, p=0.29. We conclude that tolerance to central hypovolemia is not related to either resting MSNA or sympathetic BRS.

Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight

NARCIS (Netherlands)

Di Rienzo, Marco; Castiglioni, Paolo; Iellamo, Ferdinando; Volterrani, Maurizio; Pagani, Massimo; Mancia, Giuseppe; Karemaker, John M.; Parati, Gianfranco

2008-01-01

Di Rienzo M, Castiglioni P, Iellamo F, Volterrani M, Pagani M, Mancia G, Karemaker JM, Parati G. Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight. J Appl Physiol 105: 1569-1575, 2008. First published August 28, 2008;

Gender Differences in Baroreflex Sensitivity after Bed Rest

Science.gov (United States)

Arzeno, Natalia M.; Stenger, M. B.; Ribeiro, L. C.; Lee, S. M.; Platts, S. H.

2009-01-01

Two potential contributing factors to post-spaceflight orthostatic intolerance are decreases in baroreflex sensitivity (BRS) and sympathetic nervous system response. The purpose of this study was to examine the shape of the BRS curve and sympathetic response to a wide range of blood pressures (BP) before and during 6 head-down bed rest (BR). METHODS: Normal volunteers were tested one day before BR (20M, 1 0F) and near BR days 30 (20M, 10F), 60 (16M, 8F), and 90 (1 0M, 5F). BP was pharmacologically manipulated by 10-min infusions of phenylephrine (PE) and sodium nitroprusside (SNP) at 3 increasing concentrations with a 20-min rest between PE and SNP. Electrocardiogram and continuous finger blood pressure were recorded. A blood sample was drawn at the end of each infusion to measure plasma norepinephrine levels. The spontaneous baroreflex slope (SBS), a measure of BRS, was calculated as the slope of a sequence of 3 or more beats in which the systolic BP (SBP) and following R-R interval (RR) both increased or decreased. The data included saturated responses at the upper but not the lower end of the BP range. Mean response curves were constructed using second-order mixed model analysis. Results are based on term significance in the models. RESULTS RR: RR was lower during BR than pre BR (pgenders were modeled by a linear response; compared to males, females had an attenuated (lower slope) RR response to changes in SBP (p=0.031). SBS: SBS vs SBP analysis showed a lower SBS during BR (pgender and BR. Not only do gender and BR baseline differences exist, but gender and BR also influence the slope and saturation of the BRS curves. Attenuated and saturating RR and SBS responses, as well as differences in baseline values, may contribute to the higher rates of orthostatic intolerance in women and after bed rest.

The Effect of Physical Resistance Training on Baroreflex Sensitivity of Hypertensive Rats

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Moisés Felipe Pereira Gomes

Full Text Available Abstract Background: Baroreceptors act as regulators of blood pressure (BP; however, its sensitivity is impaired in hypertensive patients. Among the recommendations for BP reduction, exercise training has become an important adjuvant therapy in this population. However, there are many doubts about the effects of resistance exercise training in this population. Objective: To evaluate the effect of resistance exercise training on BP and baroreceptor sensitivity in spontaneously hypertensive rats (SHR. Method: Rats SHR (n = 16 and Wistar (n = 16 at 8 weeks of age, at the beginning of the experiment, were randomly divided into 4 groups: sedentary control (CS, n = 8; trained control (CT, n = 8; sedentary SHR (HS, n = 8 and trained SHR (HT, n = 8. Resistance exercise training was performed in a stairmaster-type equipment (1.1 × 0.18 m, 2 cm between the steps, 80° incline with weights attached to their tails, (5 days/week, 8 weeks. Baroreceptor reflex control of heart rate (HR was tested by loading/unloading of baroreceptors with phenylephrine and sodium nitroprusside. Results: Resistance exercise training increased the soleus muscle mass in SHR when compared to HS (HS 0.027 ± 0.002 g/mm and HT 0.056 ± 0.003 g/mm. Resistance exercise training did not alter BP. On the other hand, in relation to baroreflex sensitivity, bradycardic response was improved in the TH group when compared to HS (HS -1.3 ± 0.1 bpm/mmHg and HT -2.6 ± 0.2 bpm/mmHg although tachycardia response was not altered by resistance exercise (CS -3.3 ± 0.2 bpm/mmHg, CT -3.3 ± 0.1 bpm/mmHg, HS -1.47 ± 0.06 bpm/mmHg and HT -1.6 ± 0.1 bpm/mmHg. Conclusion: Resistance exercise training was able to promote improvements on baroreflex sensitivity of SHR rats, through the improvement of bradycardic response, despite not having reduced BP.

Effects of heat stress on baroreflex function in humans

Science.gov (United States)

Crandall, Craig G.; Cui, Jian; Wilson, Thad E.

2003-01-01

INTRODUCTION: Heat stress significantly reduces orthostatic tolerance in humans. The mechanism(s) causing this response remain unknown. The purpose of this review article is to present data pertaining to the hypothesis that reduced orthostatic tolerance in heat stressed individuals is a result of heat stress induced alterations in baroflex function. METHODS: In both normothermic and heat stressed conditions baroreflex responsiveness was assessed via pharmacological and non-pharmacological methods. In addition, the effects of heat stress on post-synaptic vasoconstrictor responsiveness were assessed. RESULTS: Generally, whole body heating did not alter baroreflex sensitivity defined as the gain of the linear portion of the baroreflex curve around the operating point. However, whole body heating shifted the baroreflex curve to the prevailing (i.e. elevated) heart rate and muscle sympathetic nerve activity. Finally, the heat stress impaired vasoconstrictor responses to exogenous administration of adrenergic agonists. CONCLUSION: Current data do not support the hypothesis that reduced orthostatic tolerance associated with heat stress in humans is due to impaired baroreflex responsiveness. This phenomenon may be partially due to the effects of heat stress on reducing vasoconstrictor responsiveness.

Dynamic Aerobic Exercise Induces Baroreflex Improvement in Diabetic Rats

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Luciana Jorge

2012-01-01

Full Text Available The objective of the present study was to investigate the effects of an acute aerobic exercise on arterial pressure (AP, heart rate (HR, and baroreflex sensitivity (BRS in STZ-induced diabetic rats. Male Wistar rats were divided into control (n=8 and diabetic (n=8 groups. AP, HR, and BRS, which were measured by tachycardic and bradycardic (BR responses to AP changes, were evaluated at rest (R and postexercise session (PE on a treadmill. At rest, STZ diabetes induced AP and HR reductions, associated with BR impairment. Attenuation in resting diabetes-induced AP (R: 103±2 versus PE: 111±3 mmHg and HR (R: 290±7 versus PE: 328±10 bpm reductions and BR dysfunction (R: -0.70±0.06 versus PE: -1.21±0.09 bpm/mmHg was observed in the postexercise period. In conclusion, the hemodynamic and arterial baro-mediated control of circulation improvement in the postexercise period reinforces the role of exercise in the management of cardiovascular risk in diabetes.

Dynamic Aerobic Exercise Induces Baroreflex Improvement in Diabetic Rats

Science.gov (United States)

Jorge, Luciana; da Pureza, Demilto Y.; Dias, Danielle da Silva; Conti, Filipe Fernandes; Irigoyen, Maria-Cláudia; De Angelis, Kátia

2012-01-01

The objective of the present study was to investigate the effects of an acute aerobic exercise on arterial pressure (AP), heart rate (HR), and baroreflex sensitivity (BRS) in STZ-induced diabetic rats. Male Wistar rats were divided into control (n = 8) and diabetic (n = 8) groups. AP, HR, and BRS, which were measured by tachycardic and bradycardic (BR) responses to AP changes, were evaluated at rest (R) and postexercise session (PE) on a treadmill. At rest, STZ diabetes induced AP and HR reductions, associated with BR impairment. Attenuation in resting diabetes-induced AP (R: 103 ± 2 versus PE: 111 ± 3 mmHg) and HR (R: 290 ± 7 versus PE: 328 ± 10 bpm) reductions and BR dysfunction (R: −0.70 ± 0.06 versus PE: −1.21 ± 0.09 bpm/mmHg) was observed in the postexercise period. In conclusion, the hemodynamic and arterial baro-mediated control of circulation improvement in the postexercise period reinforces the role of exercise in the management of cardiovascular risk in diabetes. PMID:22203833

[Relationship between baroreflex function and training effects on altitude training].

Science.gov (United States)

Yanagida, Ryo; Ogawa, Yojiro; Mizuochi, Fumio; Suzuki, Tsukasa; Takahashi, Masanori; Iwasaki, Kenichi

2012-05-01

Altitude training is frequently used for athletes requiring competitive endurance in an attempt to improve their sea-level performance. However, there has been no study in which the mechanisms by which spontaneous arterial-cardiac baroreflex function changes was examined in responders or nonresponders of altitude training. The purpose of this study was to clarify the different effects of altitude training on baroreflex function between responders and nonresponders. Twelve university student cross-country skiers (6 men, 6 women; age, 19±1 years) participated in the altitude training in a camp for 3 weeks, which was carried out in accordance with the method of Living High-Training Low. Baroreflex function was estimated by transfer function analysis before and after the training. The responders of the training were 3 men and 2 women, and the nonresponders were 3 men and 4 women. In the responders, the transfer function gain in the high-frequency range significantly increased after the training (28.9→46.5 ms/mmHg p=0.021). On the other hand, no significant change in this index was observed in the nonresponders (25.9→21.2 ms/mmHg p=0.405). As indicated by the results of transfer function gain in the high-frequency range, the baroreflex function in the responders increased significantly after the altitude training, whereas no significant change was observed in the nonresponders.

Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans.

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Silvani, Alessandro; Calandra-Buonaura, Giovanna; Johnson, Blair D; van Helmond, Noud; Barletta, Giorgio; Cecere, Anna G; Joyner, Michael J; Cortelli, Pietro

2017-01-01

The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological mechanisms that mediate the coupling between HP and SAP in response to different postures, we analyzed the cross-correlation functions between low-frequency HP and SAP fluctuations and estimated cBRS with the sequence technique in healthy male subjects during passive head-up tilt test (HUTT, n = 58), during supine wakefulness, supine slow-wave sleep (SWS), and in the seated and active standing positions ( n = 8), and during progressive loss of 1 L blood ( n = 8) to decrease central venous pressure in the supine position. HUTT, SWS, the seated, and the standing positions, but not blood loss, entailed significant increases in the positive correlation between HP and the previous SAP values, which is the expected result of arterial baroreflex control, compared with baseline recordings in the supine position during wakefulness. These increases were mirrored by increases in the low-frequency variability of SAP in each condition but SWS. cBRS decreased significantly during HUTT, in the seated and standing positions, and after blood loss compared with baseline during wakefulness. These decreases were mirrored by decreases in the RMSSD index, which reflects cardiac vagal modulation. These results support the view that the cBRS decrease associated with the upright posture is a byproduct of decreased cardiac vagal modulation, triggered by the arterial baroreflex in response to central hypovolemia. Conversely, the greater baroreflex contribution to cardiac control associated with upright posture may be explained, at least in part, by enhanced fluctuations of SAP, which elicit a more effective entrainment of HP fluctuations by the arterial baroreflex. These SAP fluctuations may result

Protective effect of the daming capsule on impaired baroreflexes in STZ-induced diabetic rats with hyperlipoidemia

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Lu Guan-Yi

2010-12-01

Full Text Available Abstract Background The Daming capsule (DMC is a traditional Chinese medicine used to treat hyperlipoidemia. Both clinic trials and studies on animal models have demonstrated that DMC is beneficial against diabetic symptoms. Impairment of the baroreflex can cause life-threatening arrhythmias and sudden cardiac death in patients with diabetes mellitus (DM. This study was designed to elucidate the effects of DMC on baroreflexes in streptozocin (STZ-induced diabetic rats with hyperlipoidemia. Methods Wistar rats were randomly divided into three groups: untreated controls, rats pretreated STZ and high lipids (a diabetes model or DM rats, and DM rats treated with DMC. The baroreflex sensitivity was examined during intravenous injection of phenylephrine (PE or sodium nitroprusside (SNP and quantified by the change in heart rate over the change in mean arterial blood pressure (ΔHR/ΔMABP. Morphological remodeling of baroreceptors was analyzed by transmission electron microscopy (TEM. The mRNA levels and expression of GluR2 and a GABAA receptor subunit were measured by quantitative RT-PCR and Western blotting. Results Compared to untreated DM rats, DMC significantly elevated the ratio of ΔHR/ΔMABP by enhancing the compensatory reduction in HR (-ΔHR in response to PE-induced hypertension (+ΔMABP (P P P A receptor expression. Conclusion The Daming capsule partially reversed the parasympathetic baroreflex impairment observed in STZ-induced diabetic rats with hyperlipoidemia. Treatment with DMC also prevented the degeneration of neurons and myelinated axons in the brain stem NAm and reversed the down-regulation of GluR2 mRNA. Rescue of NAm function may contribute to the medicinal properties of DMC in diabetic rats.

First-order differential-delay equation for the baroreflex predicts the 0.4-Hz blood pressure rhythm in rats.

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Burgess, D E; Hundley, J C; Li, S G; Randall, D C; Brown, D R

1997-12-01

We have described a 0.4-Hz rhythm in renal sympathetic nerve activity (SNA) that is tightly coupled to 0.4-Hz oscillations in blood pressure in the unanesthetized rat. In previous work, the relationship between SNA and fluctuations in mean arterial blood pressure (MAP) was described by a set of two first-order differential equations. We have now modified our earlier model to test the feasibility that the 0.4-Hz rhythm can be explained by the baroreflex without requiring a neural oscillator. In this baroreflex model, a linear feedback term replaces the sympathetic drive to the cardiovascular system. The time delay in the feedback loop is set equal to the time delay on the efferent side, approximately 0.5 s (as determined in the initial model), plus a time delay of 0.2 s on the afferent side for a total time delay of approximately 0.7 s. A stability analysis of this new model yields feedback resonant frequencies close to 0.4 Hz. Because of the time delay in the feedback loop, the proportional gain may not exceed a value on the order of 10 to maintain stability. The addition of a derivative feedback term increases the system's stability for a positive range of derivative gains. We conclude that the known physiological time delay for the sympathetic portion of the baroreflex can account for the observed 0.4-Hz rhythm in rat MAP and that the sensitivity of the baroreceptors to the rate of change in blood pressure, as well as average blood pressure, would enhance the natural stability of the baroreflex.

The Brain Renin-Angiotensin System and Mitochondrial Function: Influence on Blood Pressure and Baroreflex in Transgenic Rat Strains

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Manisha Nautiyal

2013-01-01

Full Text Available Mitochondrial dysfunction is implicated in many cardiovascular diseases, including hypertension, and may be associated with an overactive renin-angiotensin system (RAS. Angiotensin (Ang II, a potent vasoconstrictor hormone of the RAS, also impairs baroreflex and mitochondrial function. Most deleterious cardiovascular actions of Ang II are thought to be mediated by NADPH-oxidase- (NOX- derived reactive oxygen species (ROS that may also stimulate mitochondrial oxidant release and alter redox-sensitive signaling pathways in the brain. Within the RAS, the actions of Ang II are counterbalanced by Ang-(1–7, a vasodilatory peptide known to mitigate against increased oxidant stress. A balance between Ang II and Ang-(1–7 within the brain dorsal medulla contributes to maintenance of normal blood pressure and proper functioning of the arterial baroreceptor reflex for control of heart rate. We propose that Ang-(1–7 may negatively regulate the redox signaling pathways activated by Ang II to maintain normal blood pressure, baroreflex, and mitochondrial function through attenuating ROS (NOX-generated and/or mitochondrial.

Determination of baroreflex sensitivity during the modified Oxford maneuver by trigonometric regressive spectral analysis.

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Julia Gasch

Full Text Available BACKGROUND: Differences in spontaneous and drug-induced baroreflex sensitivity (BRS have been attributed to its different operating ranges. The current study attempted to compare BRS estimates during cardiovascular steady-state and pharmacologically stimulation using an innovative algorithm for dynamic determination of baroreflex gain. METHODOLOGY/PRINCIPAL FINDINGS: Forty-five volunteers underwent the modified Oxford maneuver in supine and 60° tilted position with blood pressure and heart rate being continuously recorded. Drug-induced BRS-estimates were calculated from data obtained by bolus injections of nitroprusside and phenylephrine. Spontaneous indices were derived from data obtained during rest (stationary and under pharmacological stimulation (non-stationary using the algorithm of trigonometric regressive spectral analysis (TRS. Spontaneous and drug-induced BRS values were significantly correlated and display directionally similar changes under different situations. Using the Bland-Altman method, systematic differences between spontaneous and drug-induced estimates were found and revealed that the discrepancy can be as large as the gain itself. Fixed bias was not evident with ordinary least products regression. The correlation and agreement between the estimates increased significantly when BRS was calculated by TRS in non-stationary mode during the drug injection period. TRS-BRS significantly increased during phenylephrine and decreased under nitroprusside. CONCLUSIONS/SIGNIFICANCE: The TRS analysis provides a reliable, non-invasive assessment of human BRS not only under static steady state conditions, but also during pharmacological perturbation of the cardiovascular system.

Changes in plasma volume and baroreflex function following resistance exercise

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Ploutz, L. L.; Tatro, D. L.; Dudley, G. A.; Convertino, V. A.

1993-01-01

The dynamics of change in plasma volume (PV) and baroreflex responses have been reported over 24 h immediately following maximal cycle exercise. The purpose of this study was to determine if PV and baroreflex showed similar changes for 24 h after resistance exercise. Eight men were studied on 2 test days, 1 week apart. On 1 day, per cent change (% delta) in PV was estimated at 0,3, and 6 h after resistance exercise using haematocrit and haemoglobin. Baseline PV was measured 24 h after exercise using Evans blue dye. The carotid baroreceptor-cardiac reflex response was measured before, and 3, 6, 9, 12, and 24 h post-exercise. Each subject performed six sets of the bench press and leg press with 10 repetitions per set with a load that induced failure within each set. On a control day, the protocol was used without exercise. Plasma volume did not change during the control day. There was a 20% decrease in PV immediately post-exercise; the recovery of the PV was rapid and complete within 3 h. PV was 20% greater 24 h post-exercise than on the control day. There were no differences in any of the baroreflex measurements. Therefore, it is suggested that PV shifts may occur without altering baroreflex sensitivity.

Impaired baroreflex sensitivity, carotid stiffness, and exaggerated exercise blood pressure: a community-based analysis from the Paris Prospective Study III.

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Sharman, James E; Boutouyrie, Pierre; Perier, Marie-Cécile; Thomas, Frédérique; Guibout, Catherine; Khettab, Hakim; Pannier, Bruno; Laurent, Stéphane; Jouven, Xavier; Empana, Jean-Philippe

2018-02-14

People with exaggerated exercise blood pressure (BP) have adverse cardiovascular outcomes. Mechanisms are unknown but could be explained through impaired neural baroreflex sensitivity (BRS) and/or large artery stiffness. This study aimed to determine the associations of carotid BRS and carotid stiffness with exaggerated exercise BP. Blood pressure was recorded at rest and following an exercise step-test among 8976 adults aged 50 to 75 years from the Paris Prospective Study III. Resting carotid BRS (low frequency gain, from carotid distension rate, and heart rate) and stiffness were measured by high-precision echotracking. A systolic BP threshold of ≥ 150 mmHg defined exaggerated exercise BP and ≥140/90 mmHg defined resting hypertension (±antihypertensive treatment). Participants with exaggerated exercise BP had significantly lower BRS [median (Q1; Q3) 0.10 (0.06; 0.16) vs. 0.12 (0.08; 0.19) (ms2/mm) 2×108; P < 0.001] but higher stiffness [mean ± standard deviation (SD); 7.34 ± 1.37 vs. 6.76 ± 1.25 m/s; P < 0.001) compared to those with non-exaggerated exercise BP. However, only lower BRS (per 1SD decrement) was associated with exaggerated exercise BP among people without hypertension at rest {specifically among those with optimal BP; odds ratio (OR) 1.16 [95% confidence intervals (95% CI) 1.01; 1.33], P = 0.04 and high-normal BP; OR, 1.19 (95% CI 1.07; 1.32), P = 0.001} after adjustment for age, sex, body mass index, smoking, alcohol, total cholesterol, high-density lipoprotein cholesterol, resting heart rate, and antihypertensive medications. Impaired BRS, but not carotid stiffness, is independently associated with exaggerated exercise BP even among those with well controlled resting BP. This indicates a potential pathway from depressed neural baroreflex function to abnormal exercise BP and clinical outcomes. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For

Strain differences in baroceptor reflex in adult Wistar Kyoto rats

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Vitor E. Valenti

2010-01-01

Full Text Available OBJECTIVES: A subset of normotensive Sprague-Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype. METHODS: Male Wistar Kyoto (WKY rats (16 weeks old were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP and heart rate (HR. Baroreflex gain was calculated as the ratio between change in HR and MAP variation (ΔHR/ΔMAP in response to a depressor dose of sodium nitroprusside (SNP, 50 µg/kg, i.v. and a pressor dose of phenylephrine (PE, 8 µg/kg, i.v.. Rats were divided into four groups: 1 low bradycardic baroreflex (LB, baroreflex gain (BG between -1 and -2 bpm/mmHg tested with PE; 2 high bradycardic baroreflex (HB, BG < -2 bpm/mmHg tested with PE; 3 low tachycardic baroreflex (LT, BG between -1 and -2 bpm/mmHg tested with SNP and; 4 high tachycardic baroreflex (HT, BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05. RESULTS: Approximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP. CONCLUSION: There is variability regarding baroreflex sensitivity among WKY rats from the same laboratory.

Interaction between graviception and carotid baroreflex function in humans during parabolic flight-induced microgravity.

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Ogoh, Shigehiko; Marais, Michaël; Lericollais, Romain; Denise, Pierre; Raven, Peter B; Normand, Hervé

2018-05-10

The aim of the present study was to assess carotid baroreflex (CBR) during acute changes in otolithic activity in humans. To address this question, we designed a set of experiments to identify the modulatory effects of microgravity on CBR function at a tilt angle of -2{degree sign}, which was identified to minimize changes in central blood volume during parabolic flight. During parabolic flight at 0g and 1g, CBR function curves were modelled from the heart rate (HR) and mean arterial pressure (MAP) responses to rapid pulse trains of neck pressure (NP) and neck suction (NS) ranging from +40 to -80 Torr; CBR control of HR (carotid-HR) and MAP (carotid-MAP) baroreflex function curves, respectively. The maximal gain (G max ) of both carotid-HR and carotid-MAP baroreflex function curves were augmented during microgravity compared to 1g (carotid-HR, -0.53 to -0.80 beats/min/mmHg, Pflight-induced acute change of otolithic activity may modify CBR function and identifies that the vestibular system contributes to blood pressure regulation under fluctuations in gravitational forces.

The Effect of Physical Resistance Training on Baroreflex Sensitivity of Hypertensive Rats.

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Gomes, Moisés Felipe Pereira; Borges, Mariana Eiras; Rossi, Vitor de Almeida; Moura, Elizabeth de Orleans C de; Medeiros, Alessandra

2017-01-01

Baroreceptors act as regulators of blood pressure (BP); however, its sensitivity is impaired in hypertensive patients. Among the recommendations for BP reduction, exercise training has become an important adjuvant therapy in this population. However, there are many doubts about the effects of resistance exercise training in this population. To evaluate the effect of resistance exercise training on BP and baroreceptor sensitivity in spontaneously hypertensive rats (SHR). Rats SHR (n = 16) and Wistar (n = 16) at 8 weeks of age, at the beginning of the experiment, were randomly divided into 4 groups: sedentary control (CS, n = 8); trained control (CT, n = 8); sedentary SHR (HS, n = 8) and trained SHR (HT, n = 8). Resistance exercise training was performed in a stairmaster-type equipment (1.1 × 0.18 m, 2 cm between the steps, 80° incline) with weights attached to their tails, (5 days/week, 8 weeks). Baroreceptor reflex control of heart rate (HR) was tested by loading/unloading of baroreceptors with phenylephrine and sodium nitroprusside. Resistance exercise training increased the soleus muscle mass in SHR when compared to HS (HS 0.027 ± 0.002 g/mm and HT 0.056 ± 0.003 g/mm). Resistance exercise training did not alter BP. On the other hand, in relation to baroreflex sensitivity, bradycardic response was improved in the TH group when compared to HS (HS -1.3 ± 0.1 bpm/mmHg and HT -2.6 ± 0.2 bpm/mmHg) although tachycardia response was not altered by resistance exercise (CS -3.3 ± 0.2 bpm/mmHg, CT -3.3 ± 0.1 bpm/mmHg, HS -1.47 ± 0.06 bpm/mmHg and HT -1.6 ± 0.1 bpm/mmHg). Resistance exercise training was able to promote improvements on baroreflex sensitivity of SHR rats, through the improvement of bradycardic response, despite not having reduced BP. Os barorreceptores atuam como reguladores da pressão arterial (PA); no entanto, sua sensibilidade encontra-se prejudicada em pacientes hipertensos. Dentre as recomendações para a redução da PA, o treinamento f

Modeling baroreflex regulation of heart rate during orthostatic stress

DEFF Research Database (Denmark)

Olufsen, Mette; Tran, Hien T.; Ottesen, Johnny T.

2006-01-01

. The model uses blood pressure measured in the finger as an input to model heart rate dynamics in response to changes in baroreceptor nerve firing rate, sympathetic and parasympathetic responses, vestibulo-sympathetic reflex, and concentrations of norepinephrine and acetylcholine. We formulate an inverse...... in healthy and hypertensive elderly people the hysteresis loop shifts to higher blood pressure values and its area is diminished. Finally, for hypertensive elderly people the hysteresis loop is generally not closed indicating that during postural change from sitting to standing, the blood pressure resettles......During orthostatic stress, arterial and cardiopulmonary baroreflexes play a key role in maintaining arterial pressure by regulating heart rate. This study, presents a mathematical model that can predict the dynamics of heart rate regulation in response to postural change from sitting to standing...

Coconut oil supplementation and physical exercise improves baroreflex sensitivity and oxidative stress in hypertensive rats.

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Alves, Naiane F B; Porpino, Suênia K P; Monteiro, Matheus M O; Gomes, Enéas R M; Braga, Valdir A

2015-04-01

The hypothesis that oral supplementation with virgin coconut oil (Cocos nucifera L.) and exercise training would improve impaired baroreflex sensitivity (BRS) and reduce oxidative stress in spontaneously hypertensive rats (SHR) was tested. Adult male SHR and Wistar Kyoto rats (WKY) were divided into 5 groups: WKY + saline (n = 8); SHR + saline (n = 8); SHR + coconut oil (2 mL·day(-1), n = 8); SHR + trained (n = 8); and SHR + trained + coconut oil (n = 8). Mean arterial pressure (MAP) was recorded and BRS was tested using phenylephrine (8 μg/kg, intravenous) and sodium nitroprusside (25 μg·kg(-1), intravenous). Oxidative stress was measured using dihydroethidium in heart and aorta. SHR + saline, SHR + coconut oil, and SHR + trained group showed higher MAP compared with WKY + saline (175 ± 6, 148 ± 6, 147 ± 7 vs. 113 ± 2 mm Hg; p coconut oil, SHR + trained group, and SHR + trained + coconut oil groups presented lower MAP compared with SHR + saline group (148 ± 6, 147 ± 7, 134 ± 8 vs. 175 ± 6 mm Hg; p Coconut oil combined with exercise training improved BRS in SHR compared with SHR + saline group (-2.47 ± 0.3 vs. -1.39 ± 0.09 beats·min(-1)·mm Hg(-1); p coconut oil group presented reduced oxidative stress compared with SHR + saline in heart (622 ± 16 vs. 774 ± 31 AU, p coconut oil reduced oxidative stress in SHR compared with SHR + saline group (454 ± 33 vs. 689 ± 29 AU, p coconut oil combined with exercise training improved impaired BRS and reduced oxidative stress in SHR.

Ovarian hormone deprivation reduces oxytocin expression in Paraventricular Nucleus preautonomic neurons and correlates with baroreflex impairment in rats

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Vitor Ulisses De Melo

2016-10-01

Full Text Available The prevalence of cardiovascular diseases including hypertension increases dramatically in women after menopause, however the mechanisms involved remain incompletely understood. Oxytocinergic (OTergic neurons are largely present within the paraventricular nucleus of the hypothalamus (PVN. Several studies have shown that OTergic drive from PVN to brainstem increases baroreflex sensitivity and improves autonomic control of the circulation. Since preautonomic PVN neurons express different types of estrogen receptors, we hypothesize that ovarian hormone deprivation causes baroreflex impairment, autonomic imbalance and hypertension by negatively impacting OTergic drive and oxytocin levels in pre-autonomic neurons. Here, we assessed oxytocin gene and protein expression (qPCR and immunohistochemistry within PVN subnuclei in sham-operated and ovariectomized Wistar rats. Conscious hemodynamic recordings were used to assess resting blood pressure and heart rate and the autonomic modulation of heart and vessels was estimated by power spectral analysis. We observed that the ovarian hormone deprivation in ovariectomized rats decreased baroreflex sensitivity, increased sympathetic and reduced vagal outflows to the heart and augmented the resting blood pressure. Of note, ovariectomized rats had reduced PVN oxytocin mRNA and protein expression in all pre-autonomic PVN subnuclei. Furthermore, reduced PVN oxytocin protein levels were positively correlated with decreased baroreflex sensitivity and negatively correlated with increased LF/HF ratio. These findings suggest that reduced oxytocin expression in OTergic neurons of the PVN contributes to the baroreflex dysfunction and autonomic dysregulation observed with ovarian hormone deprivation.

A method for assessment of the dynamic response of the arterial baroreflex

DEFF Research Database (Denmark)

Lund, Morten T; Salomonsson, Max; Jonassen, Thomas E N

2018-01-01

AIM: The baroreflex is a key mechanism in cardiovascular regulation and alterations in baroreceptor function are seen in many diseases, including heart failure, obesity and hypertension. We propose a new method for analyzing baroreceptor function from continuous blood pressure and heart rate...... in both health and disease. METHODS: 48-hour data series of blood pressure and heart rate were collected with telemetry. Sprague-Dawley rats on standard chow (n=11) served as controls, while rats on a high-fat, high-fructose diet (n=6) constituted the obese-hypertensive model. A third group of rats...

Baroreflex sensitivity in children and adolescents: physiology, hypertension, obesity, diabetes mellitus.

Science.gov (United States)

Honzíková, N; Závodná, E

2016-12-13

The increased prevalence of obesity in children and its complications have led to a greater interest in studying baroreflex sensitivity (BRS) in children. This review of BRS in children and adolescents includes subtopics on: 1. Resting values of BRS and their reproducibility, 2. Genetics of BRS, 3. The role of a primarily low BRS and obesity in the development of hypertension, and 4. Association of diabetes mellitus, BRS, and obesity. The conclusions specific to this age follow from this review: 1. The mean heart rate (HR) influences the measurement of BRS. Since the mean HR decreases during adolescence, HR should be taken into account. 2. A genetic dependency of BRS was found. 3. Low BRS values may precede pathological blood-pressure elevation in children with white-coat hypertension. We hypothesize that low BRS plays an active role in the emergence of hypertension in youth. A contribution of obesity to the development of hypertension was also found. We hypothesize that both factors, a primarily low BRS and obesity, are partially independent risk factors for hypertension in youths. 4. In diabetics, a low BRS compared to healthy children can be associated with insulin resistance. A reversibility of the BRS values could be possible after weight loss.

Baroreflex sensitivity during rest and executive functioning in attention-deficit/hyperactivity disorder. The TRAILS study

NARCIS (Netherlands)

Dietrich, A.; Althaus, M.; Hartman, C.A.; Buitelaar, J.K.; Minderaa, R.B.; van den Hoofdakker, B.J.; Hoekstra, P.J.

Children with attention-deficit/hyperactivity disorder (ADHD) often show executive function (EF) problems and neurophysiological hypoarousal. Baroreceptor activation, as part of the baroreflex short-term blood pressure regulatory mechanism, has been linked to cortical inhibition and attenuated

Baroreflex sensitivity during rest and executive functioning in attention-deficit/hyperactivity disorder. The TRAILS study.

NARCIS (Netherlands)

Dietrich, A.; Althaus, M.; Hartman, C.A.; Buitelaar, J.K.; Mindera, R.B.; Hoofdakker, B.J. van den; Hoekstra, P.J.

2012-01-01

Children with attention-deficit/hyperactivity disorder (ADHD) often show executive function (EF) problems and neurophysiological hypoarousal. Baroreceptor activation, as part of the baroreflex short-term blood pressure regulatory mechanism, has been linked to cortical inhibition and attenuated

Baroreflex Sensitivity and its Association with Arrhythmic Events in Chagas Disease

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Astrid Meireles Santos

2014-07-01

Full Text Available Background: Sudden death is the leading cause of death in Chagas disease (CD, even in patients with preserved ejection fraction (EF, suggesting that destabilizing factors of the arrhythmogenic substrate (autonomic modulation contribute to its occurrence. Objective: To determine baroreflex sensitivity (BRS in patients with undetermined CD (GI, arrhythmogenic CD with nonsustained ventricular tachycardia (NSVT (GII and CD with spontaneous sustained ventricular tachycardia (STV (GIII, to evaluate its association with the occurrence and complexity of arrhythmias. Method: Forty-two patients with CD underwent ECG and continuous and noninvasive BP monitoring (TASK force monitor. The following were determined: BRS (phenylephrine method; heart rate variability (HRV on 24-h Holter; and EF (echocardiogram. Results: GIII had lower BRS (6.09 ms/mm Hg as compared to GII (11.84 and GI (15.23. The difference was significant between GI and GIII (p = 0.01. Correlating BRS with the density of ventricular extrasystoles (VE, low VE density ( 10/h had preserved BRS (p = 0.003. Patients with depressed BRS had higher VE density (p = 0.01, regardless of the EF. The BRS was the only variable related to the occurrence of SVT (p = 0.028. Conclusion: The BRS is preserved in undetermined CD. The BRS impairment increases as disease progresses, being more severe in patients with more complex ventricular arrhythmias. The degree of autonomic dysfunction did not correlate with EF, but with the density and complexity of ventricular arrhythmias.

Baroreflex Responses to Acute Changes in Blood Volume in Humans

Science.gov (United States)

Thompson, Cynthia A.; Tatro, Dana L.; Ludwig, David A.; Convertino, Victor A.

1990-01-01

To test the hypothesis that acute changes in plasma volume affect the stimulus-response relations of high- and low- pressure baroreflexes, eight men (27-44 yr old) underwent measurements for carotid-cardiac and cardiopulmonary baro-reflex responses under the following three volemic conditions: hypovolemic, normovolemic, and hypervolemic. The stimulus- response relation of the carotid-cardiac response curve was generated using a neck cuff device, which delivered pressure changes between +40 and -65 mmHg in continuous steps of 15 mmHg. The stimulus-response relationship, of the cardio-pulmonary baroreflex were studied by measurements of Forearm Vascular Resistance (FVR) and Peripheral Venous Pressure (PVP) during low levels of lower body negative pressure (O to -20 mmHg). The results indicate greater demand for vasoconstriction for equal reductions in venous pressure during progressive hypovolemia; this condition may compromise the capacity to provide adequate peripheral resistance during severe orthostatic stress. Fluid loading before reentry after spaceflight may act to restore vasoconstrictive capacity of the cardiopulmonary baroreflex but may not be an effective countermeasure against potential post- flight impairment of the carotid-cardiac baroreflex.

Non-invasive baroreflex sensitivity assessment using wavelet transfer function-based time–frequency analysis

International Nuclear Information System (INIS)

Keissar, K; Gilad, O; Maestri, R; Pinna, G D; La Rovere, M T

2010-01-01

A novel approach for the estimation of baroreflex sensitivity (BRS) is introduced based on time–frequency analysis of the transfer function (TF). The TF method (TF-BRS) is a well-established non-invasive technique which assumes stationarity. This condition is difficult to meet, especially in cardiac patients. In this study, the classical TF was replaced with a wavelet transfer function (WTF) and the classical coherence was replaced with wavelet transform coherence (WTC), adding the time domain as an additional degree of freedom with dynamic error estimation. Error analysis and comparison between WTF-BRS and TF-BRS were performed using simulated signals with known transfer function and added noise. Similar comparisons were performed for ECG and blood pressure signals, in the supine position, of 19 normal subjects, 44 patients with a history of previous myocardial infarction (MI) and 45 patients with chronic heart failure. This yielded an excellent linear association (R > 0.94, p < 0.001) for time-averaged WTF-BRS, validating the new method as consistent with a known method. The additional advantage of dynamic analysis of coherence and TF estimates was illustrated in two physiological examples of supine rest and change of posture showing the evolution of BRS synchronized with its error estimations and sympathovagal balance

An Innovative Technique to Assess Spontaneous Baroreflex Sensitivity with Short Data Segments: Multiple Trigonometric Regressive Spectral Analysis.

Science.gov (United States)

Li, Kai; Rüdiger, Heinz; Haase, Rocco; Ziemssen, Tjalf

2018-01-01

Objective: As the multiple trigonometric regressive spectral (MTRS) analysis is extraordinary in its ability to analyze short local data segments down to 12 s, we wanted to evaluate the impact of the data segment settings by applying the technique of MTRS analysis for baroreflex sensitivity (BRS) estimation using a standardized data pool. Methods: Spectral and baroreflex analyses were performed on the EuroBaVar dataset (42 recordings, including lying and standing positions). For this analysis, the technique of MTRS was used. We used different global and local data segment lengths, and chose the global data segments from different positions. Three global data segments of 1 and 2 min and three local data segments of 12, 20, and 30 s were used in MTRS analysis for BRS. Results: All the BRS-values calculated on the three global data segments were highly correlated, both in the supine and standing positions; the different global data segments provided similar BRS estimations. When using different local data segments, all the BRS-values were also highly correlated. However, in the supine position, using short local data segments of 12 s overestimated BRS compared with those using 20 and 30 s. In the standing position, the BRS estimations using different local data segments were comparable. There was no proportional bias for the comparisons between different BRS estimations. Conclusion: We demonstrate that BRS estimation by the MTRS technique is stable when using different global data segments, and MTRS is extraordinary in its ability to evaluate BRS in even short local data segments (20 and 30 s). Because of the non-stationary character of most biosignals, the MTRS technique would be preferable for BRS analysis especially in conditions when only short stationary data segments are available or when dynamic changes of BRS should be monitored.

Four faces of baroreflex failure: hypertensive crisis, volatile hypertension, orthostatic tachycardia, and malignant vagotonia

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Ketch, Terry; Biaggioni, Italo; Robertson, RoseMarie; Robertson, David

2002-01-01

BACKGROUND: The baroreflex normally serves to buffer blood pressure against excessive rise or fall. Baroreflex failure occurs when afferent baroreceptive nerves or their central connections become impaired. In baroreflex failure, there is loss of buffering ability, and wide excursions of pressure and heart rate occur. Such excursions may derive from endogenous factors such as stress or drowsiness, which result in quite high and quite low pressures, respectively. They may also derive from exogenous factors such as drugs or environmental influences. METHODS AND RESULTS: Impairment of the baroreflex may produce an unusually broad spectrum of clinical presentations; with acute baroreflex failure, a hypertensive crisis is the most common presentation. Over succeeding days to weeks, or in the absence of an acute event, volatile hypertension with periods of hypotension occurs and may continue for many years, usually with some attenuation of pressor surges and greater prominence of depressor valleys during long-term follow-up. With incomplete loss of baroreflex afferents, a mild syndrome of orthostatic tachycardia or orthostatic intolerance may appear. Finally, if the baroreflex failure occurs without concomitant destruction of the parasympathetic efferent vagal fibers, a resting state may lead to malignant vagotonia with severe bradycardia and hypotension and episodes of sinus arrest. CONCLUSIONS: Although baroreflex failure is not the most common cause of the above conditions, correct differentiation from other cardiovascular disorders is important, because therapy of baroreflex failure requires specific strategies, which may lead to successful control.

Effects of Kefir on the Cardiac Autonomic Tones and Baroreflex Sensitivity in Spontaneously Hypertensive Rats.

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Klippel, Brunella F; Duemke, Licia B; Leal, Marcos A; Friques, Andreia G F; Dantas, Eduardo M; Dalvi, Rodolfo F; Gava, Agata L; Pereira, Thiago M C; Andrade, Tadeu U; Meyrelles, Silvana S; Campagnaro, Bianca P; Vasquez, Elisardo C

2016-01-01

It has been previously shown that the probiotic kefir (a symbiotic matrix containing acid bacteria and yeasts) attenuated the hypertension and the endothelial dysfunction in spontaneously hypertensive rats (SHR). In the present study, the effect of chronic administration of kefir on the cardiac autonomic control of heart rate (HR) and baroreflex sensitivity (BRS) in SHR was evaluated. SHR were treated with kefir (0.3 mL/100 g body weight) for 60 days and compared with non-treated SHR and with normotensive Wistar-Kyoto rats. Cardiac autonomic vagal (VT) and sympathetic (ST) tones were estimated through the blockade of the cardiac muscarinic receptors (methylatropine) and the blockade of β1-adrenoceptor (atenolol). The BRS was evaluated by the tachycardia and bradycardia responses to vasoactive drug-induced decreases and increases in arterial blood pressure (BP), respectively. Additionally, spontaneous BRS was estimated by autoregressive spectral analysis. Kefir-treated SHR exhibited significant attenuation of basal BP, HR, and cardiac hypertrophy compared to non-treated SHR (12, 13, and 21%, respectively). Cardiac VT and ST were significantly altered in the SHR (~40 and ~90 bpm) compared with Wistar rats (~120 and ~30 bpm) and were partially recovered in SHR-kefir (~90 and ~25 bpm). SHR exhibited an impaired bradycardic BRS (~50%) compared with Wistar rats, which was reduced to ~40% in the kefir-treated SHR and abolished by methylatropine in all groups. SHR also exhibited a significant impairment of the tachycardic BRS (~23%) compared with Wistar rats and this difference was reduced to 8% in the SHR-kefir. Under the action of atenolol the residual reflex tachycardia was smaller in SHR than in Wistar rats and kefir attenuated this abnormality. Spectral analysis revealed increased low frequency components of BP (~3.5-fold) and pulse interval (~2-fold) compared with Wistar rats and these differences were reduced by kefir-treatment to ~1.6- and ~1.5-fold, respectively

Effects of Kefir on the Cardiac Autonomic Tones and Baroreflex Sensitivity in Spontaneously Hypertensive Rats

Science.gov (United States)

Klippel, Brunella F.; Duemke, Licia B.; Leal, Marcos A.; Friques, Andreia G. F.; Dantas, Eduardo M.; Dalvi, Rodolfo F.; Gava, Agata L.; Pereira, Thiago M. C.; Andrade, Tadeu U.; Meyrelles, Silvana S.; Campagnaro, Bianca P.; Vasquez, Elisardo C.

2016-01-01

Aims: It has been previously shown that the probiotic kefir (a symbiotic matrix containing acid bacteria and yeasts) attenuated the hypertension and the endothelial dysfunction in spontaneously hypertensive rats (SHR). In the present study, the effect of chronic administration of kefir on the cardiac autonomic control of heart rate (HR) and baroreflex sensitivity (BRS) in SHR was evaluated. Methods: SHR were treated with kefir (0.3 mL/100 g body weight) for 60 days and compared with non-treated SHR and with normotensive Wistar-Kyoto rats. Cardiac autonomic vagal (VT) and sympathetic (ST) tones were estimated through the blockade of the cardiac muscarinic receptors (methylatropine) and the blockade of β1−adrenoceptor (atenolol). The BRS was evaluated by the tachycardia and bradycardia responses to vasoactive drug-induced decreases and increases in arterial blood pressure (BP), respectively. Additionally, spontaneous BRS was estimated by autoregressive spectral analysis. Results: Kefir-treated SHR exhibited significant attenuation of basal BP, HR, and cardiac hypertrophy compared to non-treated SHR (12, 13, and 21%, respectively). Cardiac VT and ST were significantly altered in the SHR (~40 and ~90 bpm) compared with Wistar rats (~120 and ~30 bpm) and were partially recovered in SHR-kefir (~90 and ~25 bpm). SHR exhibited an impaired bradycardic BRS (~50%) compared with Wistar rats, which was reduced to ~40% in the kefir-treated SHR and abolished by methylatropine in all groups. SHR also exhibited a significant impairment of the tachycardic BRS (~23%) compared with Wistar rats and this difference was reduced to 8% in the SHR-kefir. Under the action of atenolol the residual reflex tachycardia was smaller in SHR than in Wistar rats and kefir attenuated this abnormality. Spectral analysis revealed increased low frequency components of BP (~3.5-fold) and pulse interval (~2-fold) compared with Wistar rats and these differences were reduced by kefir-treatment to ~1

Changes of heart rate variability and baroreflex sensitivity in patients soon after orthotopic heart transplantation

Czech Academy of Sciences Publication Activity Database

Fráňa, P.; Kára, T.; Souček, M.; Halámek, Josef; Řiháček, I.; Orban, O.; Toman, J.; Bartosikova, L.; Nečas, J.; Dzurova, J.

2002-01-01

Roč. 20, č. 4 (2002), s. S293 ISSN 0263-6352. [Scientific meeting of the international society of hypertension - european meeting on hypertension. 23.06.2002-27.06.2002, Praha] R&D Projects: GA ČR GA102/00/1262; GA ČR GA102/02/1339 Institutional research plan: CEZ:AV0Z2065902 Keywords : baroreflex * heart transplantation * ANS Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Induction of hypertension blunts baroreflex inhibition of vasopressin neurons in the rat.

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Han, Su Young; Bouwer, Gregory T; Seymour, Alexander J; Korpal, Aaron K; Schwenke, Daryl O; Brown, Colin H

2015-11-01

Vasopressin secretion from the posterior pituitary gland is determined by action potential discharge of hypothalamic magnocellular neurosecretory cells. Vasopressin is a potent vasoconstrictor, but vasopressin levels are paradoxically elevated in some patients with established hypertension. To determine whether vasopressin neurons are excited in hypertension, extracellular single-unit recordings of vasopressin neurons from urethane-anaesthetized Cyp1a1-Ren2 rats with inducible angiotensin-dependent hypertension were made. The basal firing rate of vasopressin neurons was higher in hypertensive Cyp1a1-Ren2 rats than in non-hypertensive Cyp1a1-Ren2 rats. The increase in firing rate was specific to vasopressin neurons because oxytocin neuron firing rate was unaffected by the induction of hypertension. Intravenous injection of the α1-adrenoreceptor agonist, phenylephrine (2.5 μg/kg), transiently increased mean arterial blood pressure to cause a baroreflex-induced inhibition of heart rate and vasopressin neuron firing rate (by 52 ± 9%) in non-hypertensive rats. By contrast, intravenous phenylephrine did not inhibit vasopressin neurons in hypertensive rats, despite a similar increase in mean arterial blood pressure and inhibition of heart rate. Circulating angiotensin II can excite vasopressin neurons via activation of afferent inputs from the subfornical organ. However, the increase in vasopressin neuron firing rate and the loss of inhibition by intravenous phenylephrine were not blocked by intra-subfornical organ infusion of the angiotensin AT1 receptor antagonist, losartan. It can be concluded that increased vasopressin neuron activity at the onset of hypertension is driven, at least in part, by reduced baroreflex inhibition of vasopressin neurons and that this might exacerbate the increase in blood pressure at the onset of hypertension. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Anomalous baroreflex functionality inherent in floxed and Cre-Lox mice: an overlooked physiological phenotype.

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Tsai, Ching-Yi; Poon, Yan-Yuen; Chen, Chang-Han; Chan, Samuel H H

2017-10-01

The last two decades have seen the emergence of Cre-Lox recombination as one of the most powerful and versatile technologies for cell-specific genetic engineering of mammalian cells. Understandably, the primary concerns in the practice of Cre-Lox recombination are whether the predicted genome has been correctly modified and the targeted phenotypes expressed. Rarely are the physiological conditions of the animals routinely examined because the general assumption is that they are normal. Based on corroborative results from radiotelemetric recording, power spectral analysis, and magnetic resonance imaging/diffusion tensor imaging in brain-derived neurotrophic factor-floxed mice, the present study revealed that this assumption requires amendment. We found that despite comparable blood pressure and heart rate with C57BL/6 or Cre mice under the conscious state, floxed and Cre-Lox mice exhibited diminished baroreflex-mediated sympathetic vasomotor tone and cardiac vagal baroreflex. We further found that the capacity and plasticity of baroreflex of these two strains of mice under isoflurane anesthesia were retarded, as reflected by reduced connectivity between the nucleus tractus solitarii and rostral ventrolateral medulla or nucleus ambiguus. The identification of anomalous baroreflex functionality inherent in floxed and Cre-Lox mice points to the importance of incorporating physiological phenotypes into studies that engage gene manipulations such as Cre-Lox recombination. NEW & NOTEWORTHY We established that anomalous baroreflex functionality is inherent in floxed and Cre-Lox mice. These two mouse strains exhibited diminished baroreflex-mediated sympathetic vasomotor tone and cardiac vagal baroreflex under the conscious state, retarded capacity and plasticity of baroreflex under isoflurane anesthesia, and reduced connectivity between key nuclei in the baroreflex neural circuits. Copyright © 2017 the American Physiological Society.

Arg16Gly and Gln27Glu β2 adrenergic polymorphisms influence cardiac autonomic modulation and baroreflex sensitivity in healthy young Brazilians

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Atala, Magda M; Goulart, Alessandra; Guerra, Grazia M; Mostarda, Cristiano; Rodrigues, Bruno; Mello, Priscila R; Casarine, Dulce E; Irigoyen, Maria-Claudia; Pereira, Alexandre C; Consolim-Colombo, Fernanda M

2015-01-01

The association between functional β2 adrenergic receptor (β2-AR) polymorphisms and cardiac autonomic modulation is still unclear. Thus, two common polymorphisms in the β2-AR gene (Gln27Glu β2 and Arg16Gly β2) were studied to determine whether they might affect tonic and reflex cardiac sympathetic activity in healthy young subjects. A total of 213 healthy young white subjects of both genders (53% female), aged 18-30 years (23.5±3.4 y), had their continuous blood pressure curves noninvasively recorded by Finometer at baseline, and other hemodynamic parameters, as cardiac autonomic modulation, baroreflex sensitivity, and allele, genotype, and diplotype frequencies calculated. Associations were made between Arg16Gly β2 and Gln27Glu β2 polymorphisms and between β2-AR diplotypes and all variables. The heart rate was significantly lower (P<0.001) in the presence of homozygous Arg/Arg alleles (60.9±1.5 bpm) than in that of Arg/Gly heterozygotes (65.9±1.0 bpm) or Gly/Gly homozygotes (66.3±1.2 bpm). Homozygous carriers of Arg16 allele had an alpha index (19.2±1.3) significantly higher (P<0.001) than that of the subjects with the Gly allele Gly/Gly (14.5±0.7) or Arg/Gly (14.6±0.7). Furthermore, the recessive Glu27Glu and the heterozygous Gln27Glu genotypes had a higher percentage of low-frequency components (LF%) than the homozygous Gln27Gln (15.1% vs. 16.0% vs. 8.2%, P=0.03, respectively). In healthy young subjects, the presence of β2-AR Arg16 allele in a recessive model was associated with higher baroreflex sensitivity, and increased parasympathetic modulation in studied individuals. PMID:25755837

Effect of simvastatin in the autonomic system is dependent on the increased gain/sensitivity of the baroreceptors

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Moreira, Edson D; Mostarda, Cristiano T; Moraes-Silva, Ivana C; Ferreira, Janaina B; dos Santos, Fernando; Lacchini, Silvia; De Angelis, Kátia; Rodrigues, Bruno; Irigoyen, Maria Cláudia

2013-01-01

A number of mechanisms have been proposed to explain the pleiotropic effect of statin therapy to reduce sympathetic outflow in cardiovascular disease. We tested the hypothesis that statin treatment could improve baroreflex gain-sensitivity triggered by morphological adaptations in the mechanoreceptor site, thus reducing sympathetic activity, regardless of arterial pressure (AP) level reduction. Male spontaneously hypertensive rats (SHR) were divided into control (SHR, n = 8) and SHR-simvastatin (5 mg/kg/day, for 7 days) (SHR-S, n = 8). After treatment, AP, baroreflex sensitivity (BRS) in response to AP-induced changes, aortic depressor nerve activity, and spectral analyses of pulse interval (PI) and AP variabilities were performed. Internal and external carotids were prepared for morphoquantitative evaluation. Although AP was similar between groups, sympathetic modulation, represented by the low frequency band of PI (SHR: 6.84 ± 3.19 vs. SHR-S: 2.41 ± 0.96 msec2) and from systolic AP variability (SHR: 3.95 ± 0.36 vs. SHR-S: 2.86 ± 0.18 mmHg2), were reduced in treated animals. In parallel, simvastatin induced an increase of 26% and 21% in the number of elastic lamellae as well as a decrease of 9% and 25% in the carotid thickness in both, external and internal carotid, respectively. Moreover, improved baroreceptor function (SHR: 0.78 ± 0.03 vs. SHR-S: 1.06 ± 0.04% mv/mmHg) was observed in addition to a 115% increase in aortic depressor nerve activity in SHR-S rats. Therefore, our data suggest that the reduction of sympathetic outflow in hypertension by simvastatin treatment may be triggered by structural changes in the carotid arteries and increased BRS in response to an improvement of the baroreceptors discharge and consequently of the afferent pathway of the baroreflex arch. PMID:24303130

The estrogen-dependent baroreflex dysfunction caused by nicotine in female rats is mediated via NOS/HO inhibition: Role of sGC/PI3K/MAPK{sub ERK}

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Fouda, Mohamed A.; El-Gowelli, Hanan M.; El-Gowilly, Sahar M.; El-Mas, Mahmoud M., E-mail: mahelm@hotmail.com

2015-12-15

We have previously reported that estrogen (E2) exacerbates the depressant effect of chronic nicotine on arterial baroreceptor activity in female rats. Here, we tested the hypothesis that this nicotine effect is modulated by nitric oxide synthase (NOS) and/or heme oxygenase (HO) and their downstream soluble guanylate cyclase (sGC)/phosphatidylinositol 3-kinase (PI3K)/mitogen-activated protein kinases (MAPKs) signaling. We investigated the effects of (i) inhibition or facilitation of NOS or HO on the interaction of nicotine (2 mg/kg/day i.p., 2 weeks) with reflex bradycardic responses to phenylephrine in ovariectomized (OVX) rats treated with E2 or vehicle, and (ii) central pharmacologic inhibition of sGC, PI3K, or MAPKs on the interaction. The data showed that the attenuation by nicotine of reflex bradycardia in OVXE2 rats was abolished after treatment with hemin (HO inducer) or L-arginine (NOS substrate). The hemin or L-arginine effect disappeared after inhibition of NOS (Nω-Nitro-L-arginine methyl ester hydrochloride, L-NAME) and HO (zinc protoporphyrin IX, ZnPP), respectively, denoting the interaction between the two enzymatic pathways. E2-receptor blockade (ICI 182,780) reduced baroreflexes in OVXE2 rats but had no effect on baroreflex improvement induced by hemin or L-arginine. Moreover, baroreflex enhancement by hemin was eliminated following intracisternal (i.c.) administration of wortmannin, ODQ, or PD98059 (inhibitors of PI3K, sGC, and extracellular signal-regulated kinases, MAPK{sub ERK}, respectively). In contrast, the hemin effect was preserved after inhibition of MAPK{sub p38} (SB203580) or MAPK{sub JNK} (SP600125). Overall, NOS/HO interruption underlies baroreflex dysfunction caused by nicotine in female rats and the facilitation of NOS/HO-coupled sGC/PI3K/MAPK{sub ERK} signaling might rectify the nicotine effect. - Highlights: • Hemin or L-arginine blunts baroreflex dysfunction caused by nicotine in OVXE2 rats. • NO/CO crosstalk mediates

The degree of cardiac baroreflex involvement during active standing is associated with the quality of life in fibromyalgia patients.

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Antonio Roberto Zamunér

Full Text Available Fibromyalgia syndrome (FMS is a rheumatologic disorder characterized by chronic widespread pain, fatigue and other symptoms. Baroreflex dysfunction has been observed in women with FMS. However, it is unknown whether the limited involvement of the baroreflex control during an orthostatic stimulus has some impact on the quality of life of the FMS patient. Therefore, the aim of the study is evaluate the relationship between the quality of life of the FMS patient and indexes of the cardiovascular autonomic control as estimated from spontaneous fluctuations of heart period (HP and systolic arterial pressure (SAP. We enrolled 35 women with FMS (age: 48.8±8.9 years; body mass index: 29.3±4.3 Kg/m2. The electrocardiogram, non-invasive finger blood pressure and respiratory activity were continuously recorded during 15 minutes at rest in supine position (REST and in orthostatic position during active standing (STAND. Traditional cardiovascular autonomic control markers were assessed along with a Granger causality index assessing the strength of the causal relation from SAP to HP (CRSAP→HP and measuring the degree of involvement of the cardiac baroreflex. The impact of FMS on quality of life was quantified by the fibromyalgia impact questionnaire (FIQ and visual analog score for pain (VAS pain. No significant linear association was found between FIQ scores and the traditional cardiovascular indexes both at REST and during STAND (p>0.05. However, a negative relationship between CRSAP→HP during STAND and FIQ score was found (r = -0.56, p<0.01. Similar results were found with VAS pain. In conclusion, the lower the degree of cardiac baroreflex involvement during STAND in women with FMS, the higher the impact of FMS on the quality of life, thus suggesting that Granger causality analysis might be clinically helpful in assessing the state of the FMS patient.

Impaired baroreflex function in mice overexpressing alpha-synuclein

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Sheila eFleming

2013-07-01

Full Text Available Cardiovascular autonomic dysfunction, such as orthostatic hypotension consequent to baroreflex failure and cardiac sympathetic denervation, is frequently observed in the synucleinopathy Parkinson’s disease (PD. In the present study, the baroreceptor reflex was assessed in mice overexpressing human wildtype alpha-synuclein (Thy1-aSyn, a genetic mouse model of synucleinopathy. The beat-to-beat change in heart rate, computed from R-R interval, in relation to blood pressure was measured in anesthetized and conscious mice equipped with arterial blood pressure telemetry transducers during transient bouts of hypertension and hypotension. Compared to wildtype, tachycardia following nitroprusside-induced hypotension was significantly reduced in Thy1-aSyn mice. Thy1-aSyn mice also showed an abnormal cardiovascular response (i.e., diminished tachycardia to muscarinic blockade with atropine. We conclude that Thy1-aSyn mice have impaired basal and dynamic range of sympathetic and parasympathetic-mediated changes in heart rate and will be a useful model for long-term study of cardiovascular autonomic dysfunction associated with PD.

Spontaneous baroreflex sensitivity: toward an ideal index of cardiovascular risk in hypertension?

Science.gov (United States)

Lantelme, Pierre; Khettab, Fouad; Custaud, Marc-Antoine; Rial, Marie-Odile; Joanny, Christiane; Gharib, Claude; Milon, Hugues

2002-05-01

Estimating the risk entailed by classical risk factors like blood pressure (BP) or serum cholesterol may be difficult because of their variability and the often unknown duration of exposure. Having variables integrating the impact of those classical risk factors on the cardiovascular system would probably aid the prediction of cardiovascular events. The present study aimed at determining whether cardiac baroreflex sensitivity (BRS), correlates with several risk factors and thus is a good candidate for being such an integrative variable. As a comparison, left ventricular mass (LVM), pulse wave velocity (PWV), and creatinine were also tested for association with risk factors. A total of 302 subjects referred for hypertension, were considered. They had a 24-h BP recording and a determination of BRS by two different methods (sequence and alpha coefficient), in two different positions (lying and standing). They were also tested for the presence of left ventricular hypertrophy (LVH) (by echocardiography and electrocardiogram) and had a PWV measurement. Biological testing included serum lipids, blood glucose, creatinine, proteinuria and urinary excretion of microalbumin. There was a strong correlation between the two methods of BRS measurement in each position (P < 0.001). BRS determined by the sequence method in the lying position was correlated significantly and independently with age, 24-h systolic BP, heart rate, and serum cholesterol with P values < 0.001, < 0.001, < 0.01, and < 0.05, respectively. In an univariate analysis, BRS was also correlated with echocardiographic LVM index (r = -0.21, P < 0.05) and PWV (r = -0.27, P < 0.001), which possibly reflects its dependence on both vascular and cardiac damages. The present study supports the hypothesis that BRS could encompass the impact over time of several risk factors on the cardiovascular system. Thus, it may constitute a valuable parameter in assessing more precisely the risk of cardiovascular events.

Baroreflex Coupling Assessed by Cross-Compression Entropy

Directory of Open Access Journals (Sweden)

Andy Schumann

2017-05-01

Full Text Available Estimating interactions between physiological systems is an important challenge in modern biomedical research. Here, we explore a new concept for quantifying information common in two time series by cross-compressibility. Cross-compression entropy (CCE exploits the ZIP data compression algorithm extended to bivariate data analysis. First, time series are transformed into symbol vectors. Symbols of the target time series are coded by the symbols of the source series. Uncoupled and linearly coupled surrogates were derived from cardiovascular recordings of 36 healthy controls obtained during rest to demonstrate suitability of this method for assessing physiological coupling. CCE at rest was compared to that of isometric handgrip exercise. Finally, spontaneous baroreflex interaction assessed by CCEBRS was compared between 21 patients suffering from acute schizophrenia and 21 matched controls. The CCEBRS of original time series was significantly higher than in uncoupled surrogates in 89% of the subjects and higher than in linearly coupled surrogates in 47% of the subjects. Handgrip exercise led to sympathetic activation and vagal inhibition accompanied by reduced baroreflex sensitivity. CCEBRS decreased from 0.553 ± 0.030 at rest to 0.514 ± 0.035 during exercise (p < 0.001. In acute schizophrenia, heart rate, and blood pressure were elevated. Heart rate variability indicated a change of sympathovagal balance. The CCEBRS of patients with schizophrenia was reduced compared to healthy controls (0.546 ± 0.042 vs. 0.507 ± 0.046, p < 0.01 and revealed a decrease of blood pressure influence on heart rate in patients with schizophrenia. Our results indicate that CCE is suitable for the investigation of linear and non-linear coupling in cardiovascular time series. CCE can quantify causal interactions in short, noisy and non-stationary physiological time series.

Baroreflex dysfunction in sick newborns makes heart rate an unreliable surrogate for blood pressure changes.

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Govindan, Rathinaswamy B; Al-Shargabi, Tareq; Massaro, An N; Metzler, Marina; Andescavage, Nickie N; Joshi, Radhika; Dave, Rhiya; du Plessis, Adre

2016-06-01

Cerebral pressure passivity (CPP) in sick newborns can be detected by evaluating coupling between mean arterial pressure (MAP) and cerebral blood flow measured by near infra-red spectroscopy hemoglobin difference (HbD). However, continuous MAP monitoring requires invasive catheterization with its inherent risks. We tested whether heart rate (HR) could serve as a reliable surrogate for MAP in the detection of CPP in sick newborns. Continuous measurements of MAP, HR, and HbD were made and partitioned into 10-min epochs. Spectral coherence (COH) was computed between MAP and HbD (COHMAP-HbD) to detect CPP, between HR and HbD (COHHR-HbD) for comparison, and between MAP and HR (COHMAP-HR) to quantify baroreflex function (BRF). The agreement between COHMAP-HbD and COHHR-HbD was assessed using ROC analysis. We found poor agreement between COHMAP-HbD and COHHR-HbD in left hemisphere (area under the ROC curve (AUC) 0.68) and right hemisphere (AUC 0.71). Baroreflex failure (COHMAP-HR not significant) was present in 79% of epochs. Confining comparison to epochs with intact BRF showed an AUC of 0.85 for both hemispheres. In these sick newborns, HR was an unreliable surrogate for MAP required for the detection of CPP. This is likely due to the prevalence of BRF failure in these infants.

Physiological assessment of sensitivity of noninvasive testing for coronary artery disease

International Nuclear Information System (INIS)

Simonetti, I.; Rezai, K.; Rossen, J.D.; Winniford, M.D.; Talman, C.L.; Hollenberg, M.; Kirchner, P.T.; Marcus, M.L.

1991-01-01

The sensitivity of three noninvasive tests for coronary artery disease was assessed by means of quantitative indexes of disease severity in three different groups of patients. The overall population consisted of 110 subjects with limited coronary artery disease and no myocardial infarction. Planar dipyridamole- 201 Tl scintigraphy was evaluated in 31 patients, computer-assisted exercise treadmill in 28, and high-dose dipyridamole echocardiography testing in 51. Sensitivity was assessed by rigorous gold standards to define disease severity, such as measurement of minimum cross-sectional area and percent area of stenosis, by quantitative computerized coronary angiography (Brown/Dodge method). On the basis of the results of previous studies, the presence of physiologically significant coronary artery disease was indicated by a stenotic minimum cross-sectional area (MCSA) of less than 2.0 mm 2 or a greater than 75% area of stenosis. With MCSA as the gold standard, dipyridamole- 201 Tl scintigraphy, computerized exercise treadmill, and dipyridamole echocardiography testing showed sensitivities of 52%, 54%, and 61%, respectively, in the three different patient cohorts enrolled. With percent area of stenosis as the gold standard, the sensitivity figures obtained for dipyridamole- 201 Tl, computerized exercise treadmill, and dipyridamole echocardiography testing were 64%, 54%, and 69%, respectively. For each of the three tests, sensitivity increased with increasing lesion severity. Sensitivity was also better in patients with left anterior descending coronary (LAD) disease when compared with patients with left circumflex or right coronary artery disease. Results of these studies demonstrate that in patients with limited coronary artery disease none of the tests evaluated is definitely superior in sensitivity

Additive effects of heating and exercise on baroreflex control of heart rate in healthy males.

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Peçanha, Tiago; Forjaz, Cláudia L M; Low, David A

2017-12-01

This study assessed the additive effects of passive heating and exercise on cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV). Twelve healthy young men (25 ± 1 yr, 23.8 ± 0.5 kg/m 2 ) randomly underwent two experimental sessions: heat stress (HS; whole body heat stress using a tube-lined suit to increase core temperature by ~1°C) and normothermia (NT). Each session was composed of a preintervention rest (REST1); HS or NT interventions; postintervention rest (REST2); and 14 min of cycling exercise [7 min at 40%HR reserve (EX1) and 7 min at 60%HR reserve (EX2)]. Heart rate and finger blood pressure were continuously recorded. cBRS was assessed using the sequence (cBRS SEQ ) and transfer function (cBRS TF ) methods. HRV was assessed using the indexes standard deviation of RR intervals (SDNN) and root mean square of successive RR intervals (RMSSD). cBRS and HRV were not different between sessions during EX1 and EX2 (i.e., matched heart rate conditions: EX1 = 116 ± 3 vs. 114 ± 3 and EX2 = 143 ± 4 vs. 142 ± 3 beats/min but different workloads: EX1 = 50 ± 9 vs. 114 ± 8 and EX2 = 106 ± 10 vs. 165 ± 8 W; for HS and NT, respectively; P heat stress to exercise does not affect cBRS and HRV. Alternatively, in workload-matched conditions, the addition of heat to exercise results in reduced cBRS and HRV compared with exercise in normothermia. NEW & NOTEWORTHY The present study assessed cardiac baroreflex sensitivity during the combination of heat and exercise stresses. This is the first study to show that prior whole body passive heating reduces cardiac baroreflex sensitivity and autonomic modulation of heart rate during exercise. These findings contribute to the better understanding of the role of thermoregulation on cardiovascular regulation during exercise.

The degree of cardiac baroreflex involvement during active standing is associated with the quality of life in fibromyalgia patients.

Science.gov (United States)

Zamunér, Antonio Roberto; Porta, Alberto; Andrade, Carolina Pieroni; Forti, Meire; Marchi, Andrea; Furlan, Raffaello; Barbic, Franca; Catai, Aparecida Maria; Silva, Ester

2017-01-01

Fibromyalgia syndrome (FMS) is a rheumatologic disorder characterized by chronic widespread pain, fatigue and other symptoms. Baroreflex dysfunction has been observed in women with FMS. However, it is unknown whether the limited involvement of the baroreflex control during an orthostatic stimulus has some impact on the quality of life of the FMS patient. Therefore, the aim of the study is evaluate the relationship between the quality of life of the FMS patient and indexes of the cardiovascular autonomic control as estimated from spontaneous fluctuations of heart period (HP) and systolic arterial pressure (SAP). We enrolled 35 women with FMS (age: 48.8±8.9 years; body mass index: 29.3±4.3 Kg/m2). The electrocardiogram, non-invasive finger blood pressure and respiratory activity were continuously recorded during 15 minutes at rest in supine position (REST) and in orthostatic position during active standing (STAND). Traditional cardiovascular autonomic control markers were assessed along with a Granger causality index assessing the strength of the causal relation from SAP to HP (CRSAP→HP) and measuring the degree of involvement of the cardiac baroreflex. The impact of FMS on quality of life was quantified by the fibromyalgia impact questionnaire (FIQ) and visual analog score for pain (VAS pain). No significant linear association was found between FIQ scores and the traditional cardiovascular indexes both at REST and during STAND (p>0.05). However, a negative relationship between CRSAP→HP during STAND and FIQ score was found (r = -0.56, pquality of life, thus suggesting that Granger causality analysis might be clinically helpful in assessing the state of the FMS patient.

A computational analysis of the long-term regulation of arterial pressure.

Science.gov (United States)

Beard, Daniel A; Pettersen, Klas H; Carlson, Brian E; Omholt, Stig W; Bugenhagen, Scott M

2013-01-01

The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production-the acute pressure-diuresis and pressure-natriuresis curves-physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the "Guyton-Coleman model", no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. representing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex.

[Baroreflexes originated in vertebral artery zones upon peripheral vein tonus, systemic arterial blood pressure, and external respiration].

Science.gov (United States)

Agadzhanian, N A; Kupriianov, S V

2008-06-01

The investigation was intended to study the role ofbaroreceptors ofhemodynamically isolated zone of vertebral arteries in regulation of peripheral veins tonus, arterial pressure and external respiration. Pressure decrease in this vascular reflexogenic zone led to reflex responses of increase in femoral vein tonus, elevation of blood pressure level and stimulation of external respiration. The opposite reflex responses of cardio-respiratory functional system to initial pressure activation of vertebral arteries baroreceptors are observed. Basing on generalization of our own findings and similar physiological and morphological researches of other authors, it is established that afferentation from the vertebral artery zone is a reflexogenic factor of somatic muscles' veins tonus regulation. These reflexes of capacity vessels tonic activity changes are part of cardio-respiratory responses of maintaining the tissue gaseous exchange.

Cardiovascular regulation during body unweighting by lower body positive pressure.

Science.gov (United States)

Evans, Joyce M; Mohney, Lindsay; Wang, Siqi; Moore, Rachel K; Elayi, Samy-Claude; Stenger, Michael B; Moore, Fritz B; Knapp, Charles F

2013-11-01

We hypothesized that human cardiovascular responses to standing in reduced gravity environments, as on the Moon or Mars, could be modeled using a lower body positive pressure (LBPP) chamber. Heart rate, blood pressure, body segment fluid shifts, ECG, indexes of sympathetic, parasympathetic balance, and baroreflex control of the heart and periphery plus echocardiographic measures of cardiac function were recorded from seven men and seven women supine and standing at 100% (Earth), 40% (-Mars), and 20% (-Moon) bodyweights (BW). The fluid shifted from the chest was greater when standing at 100% BW than at 20% and 40% BW, while fluid pooled in the abdomen was similar at all BWs. Compared to moving from supine to standing at 100% BW, moving to 20% and 40% BW resulted in smaller decreases in stroke volume and pulse pressure, smaller increases in heart rate and smaller decreases in parasympathetic control of heart rate, baroreflex slope, numbers of blood pressure ramps, and much reduced indexes of sympathetic drive to the heart and periphery. However, peripheral vascular resistance, systolic pressure, and baroreflex effectiveness were elevated during 20% and 40% BW, compared to supine and standing at 100% BW. Standing at reduced bodyweight suppressed indexes of sympathetic control of heart rate and peripheral vasomotion. Regulatory responses indicated a combination of arterial and cardiopulmonary baroreflex control: mean heart rate, vasomotion, and baroreflex sensitivity appeared to be more under cardiopulmonary control while baroreflex effectiveness appeared to be driven more by the arterial baroreflex.

Efeitos da exposição à fumaça lateral do cigarro sobre o barorreflexo em ratos adultos Efectos de la exposición al humo lateral del cigarrillo sobre el barorreflejo en ratones adultos Sidestream cigarette smoke exposure effects on baroreflex in adult rats

Directory of Open Access Journals (Sweden)

Vitor E. Valenti

2011-02-01

�N: Nuestros datos sugieren que tres semanas de exposición a la HLC no son suficientes para causar daño significativo a los parámetros cardiovasculares y sensibilidad barorreflexa en ratones Wistar normotensos.BACKGROUND: It has been evidenced in the literature that exposure to cigarette smoke causes hypertension in rats; however, it has not been demonstrated if the baroreflex function is impaired before the animal becomes hypertensive. OBJECTIVE: We evaluated short-term effects of sidestream cigarette smoke (SSCS exposure on baroreflex function in Wistar normotensive rats. METHODS: Rats were exposed to SSCS during three weeks, 180 minutes, five days per week, at a concentration of monoxide carbon between 100-300 ppm. Mean arterial pressure (MAP and heart rate (HR were evaluated through cannulation of the femoral vein and artery. RESULTS: There was no significant difference between control and SSCS groups regarding basal mean arterial pressure and heart rate, sympathetic and parasympathetic components of the baroreflex function. CONCLUSION: Our data suggest that three weeks of exposure to SSCS is not enough to significantly impair cardiovascular parameters and baroreflex sensitivity in normotensive Wistar rats.

Baroreflex dysfunction and augmented sympathetic nerve responses during mental stress in veterans with post-traumatic stress disorder.

Science.gov (United States)

Park, Jeanie; Marvar, Paul J; Liao, Peizhou; Kankam, Melanie L; Norrholm, Seth D; Downey, Ryan M; McCullough, S Ashley; Le, Ngoc-Anh; Rothbaum, Barbara O

2017-07-15

Patients with post-traumatic stress disorder (PTSD) are at a significantly higher risk of developing hypertension and cardiovascular disease. The mechanisms underlying this increased risk are not known. Studies have suggested that PTSD patients have an overactive sympathetic nervous system (SNS) that could contribute to cardiovascular risk; however, sympathetic function has not previously been rigorously evaluated in PTSD patients. Using direct measurements of sympathetic nerve activity and pharmacological manipulation of blood pressure, we show that veterans with PTSD have augmented SNS and haemodynamic reactivity during both combat-related and non-combat related mental stress, impaired sympathetic and cardiovagal baroreflex sensitivity, and increased inflammation. Identifying the mechanisms contributing to increased cardiovascular (CV) risk in PTSD will pave the way for developing interventions to improve sympathetic function and reduce CV risk in these patients. Post-traumatic stress disorder (PTSD) is associated with increased cardiovascular (CV) risk. We tested the hypothesis that PTSD patients have augmented sympathetic nervous system (SNS) and haemodynamic reactivity during mental stress, as well as impaired arterial baroreflex sensitivity (BRS). Fourteen otherwise healthy Veterans with combat-related PTSD were compared with 14 matched Controls without PTSD.  Muscle sympathetic nerve activity (MSNA), continuous blood pressure (BP) and electrocardiography were measured at baseline, as well as during two types of mental stress:  combat-related mental stress using virtual reality combat exposure (VRCE) and non-combat related stress using mental arithmetic (MA). A cold pressor test (CPT) was administered for comparison. BRS was tested using pharmacological manipulation of BP via the Modified Oxford technique at rest and during VRCE. Blood samples were analysed for inflammatory biomarkers. Baseline characteristics, MSNA and haemodynamics were similar between

The influence of tobacco smoking on the relationship between pressure and flow in the middle cerebral artery in humans.

Science.gov (United States)

Peebles, Karen C; Horsman, Helen; Tzeng, Yu-Chieh

2013-01-01

Cigarette smoking is associated with an increased risk of stroke but the mechanism is unclear. The study examined whether acute and chronic cigarette smoking alters the dynamic relationship between blood pressure and cerebral blood flow. We hypothesised that acute and chronic smoking would result in a cerebral circulation that was less capable of buffering against dynamic fluctuations in blood pressure. Further, these changes would be accompanied by a reduction in baroreflex sensitivity, which is reduced after smoking (acute smoking). We recruited 17 non-smokers and 15 habitual smokers (13 ± 5 pack years). Continuous measurements of mean cerebral blood flow velocity (transcranial Doppler ultrasound), blood pressure (finger photoplethysmography) and heart rate enabled transfer function analysis of the dynamic relationship between pressure and flow (gain, normalised gain, phase and coherence) and baroreflex sensitivity during supine rest before and after smoking a single cigarette (acute smoking). There were no between-group differences in gain, phase or coherence before acute smoking. However, both groups showed a reduction in gain and coherence, associated with a reduction in baroreflex sensitivity, and increase in phase after acute smoking. Contrary to our hypothesis, these findings suggest that in the face of a reduction in baroreflex sensitivity acute smoking may potentially improve the ability of the cerebral circulation to buffer against changes in blood pressure. However, chronic smoking did not alter the dynamic relationship between blood pressure and cerebral blood flow velocity. These results have implications on understanding mechanisms for attenuating stroke risk.

Sensitivity of thallium scintigraphy in the detection of individual coronary artery disease

International Nuclear Information System (INIS)

Khan, A.; Rehman, A.; Wiqar, M.A.; Khan, Z.A.; Ahmad, S.A.

1988-01-01

In this study we randomly selected 45 patients whose coronary angiograms were abnormals i.e. showing triple, double and single vessel disease. Out of 80 patients who had undergone stress thallium imaging and coronary angiography during the one year. Majority of these patients were males and their ages ranged between 34-54 years. Fifteen patients had suffered inferior myocardial infraction and 5 had sustained anterior myocardial infraction in the fast. We analysed their coronary angiograms and compared them with the scintigraphic findings. It is concluded that although thallium scanning has high sensitivity for detection of coronary artery disease in general, it has only moderate sensitivity for detection of stenosis in individual coronary arteries. In this study thallium scan identified 75% of RCA lesions, 66% of LAD lesions and 38% circumflex lesions. Thallium scan sometimes fails to identify the less serve lesions in presence of more severe coronary lesions in the some patients. The sensitivity is much higher in single vessel coronary artery disease. (author)

Reduced baroreflex sensitivity and pulmonary dysfunction in alcoholic cirrhosis: effect of hyperoxia

DEFF Research Database (Denmark)

Møller, Søren; Iversen, Jens S; Krag, Aleksander

2010-01-01

matched controls underwent hemodynamic and pulmonary investigations. BRS was assessed by cross-spectral analysis of variabilities between blood pressure and heart rate time series. A 100% oxygen test was performed with the assessment of arterial oxygen tensions (Pa(O(2))) and alveolar-arterial oxygen...

Sensitivity of Hyperdense Basilar Artery Sign on Non-Enhanced Computed Tomography.

Directory of Open Access Journals (Sweden)

Marielle Ernst

Full Text Available The hyperdense basilar artery sign (HBAS is an indicator of vessel occlusion on non contrast-enhanced computer tomography (NECT in acute stroke patients. Since basilar artery occlusion (BAO is associated with a high mortality and morbidity, its early detection is of great clinical value. We sought to analyze the influence of density measurement as well as a normalized ratio of Hounsfield unit/hematocrit (HU/Hct ratio on the detection of BAO on NECT in patients with suspected BAO.102 patients with clinically suspected BAO were examined with NECT followed immediately by Multidetector computed tomography Angiography. Two observers independently analyzed the images regarding the presence or absence of HBAS on NECT and performed HU measurements in the basilar artery. Receiver operating characteristic curve analysis was performed to determine the optimal density threshold for BAO using attenuation measurements or HU/Hct ratio.Sensitivity of visual detection of the HBAS on NECT was relatively low 81% (95%-CI, 54-95% while specificity was high 91% (95%-CI, 82-96%. The highest sensitivity was achieved by the combination of visual assessment and additional quantitative attenuation measurements applying a cut-off value of 46.5 HU with 94% sensitivity and 81% specificity for BAO. A HU/Hct ratio >1.32 revealed sensitivity of 88% (95%-CI, 60-98% and specificity of 84% (95%-CI, 74-90%.In patients with clinically suspected acute BAO the combination of visual assessment and additional attenuation measurement with a cut-off value of 46.5 HU is a reliable approach with high sensitivity in the detection of BAO on NECT.

Assessing the strength of cardiac and sympathetic baroreflex controls via transfer entropy during orthostatic challenge

Science.gov (United States)

Porta, Alberto; Marchi, Andrea; Bari, Vlasta; De Maria, Beatrice; Esler, Murray; Lambert, Elisabeth; Baumert, Mathias

2017-05-01

The study assesses the strength of the causal relation along baroreflex (BR) in humans during an incremental postural challenge soliciting the BR. Both cardiac BR (cBR) and sympathetic BR (sBR) were characterized via BR sequence approaches from spontaneous fluctuations of heart period (HP), systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and muscle sympathetic nerve activity (MSNA). A model-based transfer entropy method was applied to quantify the strength of the coupling from SAP to HP and from DAP to MSNA. The confounding influences of respiration were accounted for. Twelve young healthy subjects (20-36 years, nine females) were sequentially tilted at 0°, 20°, 30° and 40°. We found that (i) the strength of the causal relation along the cBR increases with tilt table inclination, while that along the sBR is unrelated to it; (ii) the strength of the causal coupling is unrelated to the gain of the relation; (iii) transfer entropy indexes are significantly and positively associated with simplified causality indexes derived from BR sequence analysis. The study proves that causality indexes are complementary to traditional characterization of the BR and suggests that simple markers derived from BR sequence analysis might be fruitfully exploited to estimate causality along the BR. This article is part of the themed issue `Mathematical methods in medicine: neuroscience, cardiology and pathology'.

Bradykinin receptor blockade restores the baroreflex control of renal sympathetic nerve activity in cisplatin-induced renal failure rats.

Science.gov (United States)

Abdulla, M H; Duff, M; Swanton, H; Johns, E J

2016-11-01

This study investigated the effect of renal bradykinin B1 and B2 receptor blockade on the high- and low-pressure baroreceptor reflex regulation of renal sympathetic nerve activity (RSNA) in rats with cisplatin-induced renal failure. Cisplatin (5 mg/kg) or saline was given intraperitoneally 4 days prior to study. Following chloralose/urethane anaesthesia, rats were prepared for measurement of mean arterial pressure (MAP), heart rate and RSNA and received intrarenal infusions of either Lys-[des-Arg 9 , Leu 8 ]-bradykinin (LBK), a bradykinin B1 receptor blocker, or bradyzide (BZ), a bradykinin B2 receptor blocker. RSNA baroreflex gain curves and renal sympatho-inhibitory responses to volume expansion (VE) were obtained. In the control and renal failure groups, basal MAP (89 ± 3 vs. 80 ± 8 mmHg) and RSNA (2.0 ± 0.3 vs. 1.7 ± 0.6 μV.s) were similar but HR was lower in the latter group (331 ± 8 vs. 396 ± 9 beats/min). The baroreflex gain for RSNA in the renal failure rats was 39% (P renal failure rats. Intrarenal LBK infusion in the renal failure rats normalized the VE induced renal sympatho-inhibition whereas BZ only partially restored the response. These findings suggest that pro-inflammatory bradykinin acting at different receptors within the kidney generates afferent neural signals which impact differentially within the central nervous system on high- and low-pressure regulation of RSNA. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

A computational analysis of the long-term regulation of arterial pressure [v1; ref status: indexed, http://f1000r.es/1xq

Directory of Open Access Journals (Sweden)

Daniel A. Beard

2013-10-01

Full Text Available The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production—the acute pressure-diuresis and pressure-natriuresis curves—physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the “Guyton-Coleman model”, no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. capturing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex.

Physical exercise performance in temperate and warm environments is decreased by an impaired arterial baroreflex.

Directory of Open Access Journals (Sweden)

Washington Pires

Full Text Available The present study aimed to investigate whether running performance in different environments is dependent on intact arterial baroreceptor reflexes. We also assessed the exercise-induced cardiovascular and thermoregulatory responses in animals lacking arterial baroafferent signals. To accomplish these goals, male Wistar rats were subjected to sinoaortic denervation (SAD or sham surgery (SHAM and had a catheter implanted into the ascending aorta to record arterial pressure and a telemetry sensor implanted in the abdominal cavity to record core temperature. After recovering from these surgeries, the animals were subjected to constant- or incremental-speed exercises performed until the voluntary interruption of effort under temperate (25° C and warm (35° C conditions. During the constant-speed exercises, the running time until the rats were fatigued was shorter in SAD rats in both environments. Although the core temperature was not significantly different between the groups, tail skin temperature was higher in SAD rats under temperate conditions. The denervated rats also displayed exaggerated increases in blood pressure and double product compared with the SHAM rats; in particular, in the warm environment, these exaggerated cardiovascular responses in the SAD rats persisted until they were fatigued. These SAD-mediated changes occurred in parallel with increased variability in the very low and low components of the systolic arterial pressure power spectrum. The running performance was also affected by SAD during the incremental-speed exercises, with the maximal speed attained being decreased by approximately 20% in both environments. Furthermore, at the maximal power output tolerated during the incremental exercises, the mean arterial pressure, heart rate and double product were exaggerated in the SAD relative to SHAM rats. In conclusion, the chronic absence of the arterial baroafferents accelerates exercise fatigue in temperate and warm

The Neural Baroreflex Pathway in Subjects With Metabolic Syndrome

OpenAIRE

Zanoli, Luca; Empana, Jean-Philippe; Estrugo, Nicolas; Escriou, Guillaume; Ketthab, Hakim; Pruny, Jean-Francois; Castellino, Pietro; Laude, Dominique; Thomas, Frederique; Pannier, Bruno; Jouven, Xavier; Boutouyrie, Pierre; Laurent, Stephane

2016-01-01

Abstract The mechanisms that link metabolic syndrome (MetS) to increased cardiovascular risk are incompletely understood. We examined whether MetS is associated with the neural baroreflex pathway (NBP) and whether any such associations are independent of blood pressure values. This study involved the cross-sectional analysis of data on 2835 subjects aged 50 to 75 years from the Paris Prospective Study 3. The prevalence of MetS was defined according to the American Heart Association/National H...

Renal sympathetic denervation in uncontrolled arterial hypertension after successful repair for aortic coarctation.

Science.gov (United States)

Lurz, Philipp; Okon, Thomas; Riede, Thomas; Wagner, Robert; Schuler, Gerhard; Daehnert, Ingo; Desch, Steffen

2016-01-01

Uncontrolled arterial hypertension is a frequent problem after successful repair of CoA and has been attributed to increased central sympathetic drive as well as a blunted baroreceptor reflex. RSD is a promising therapy to reduce central sympathetic drive and improve baroreflex sensitivity. 8 patients (age: 27±6 years) with previous surgical and/or percutaneous repair of CoA, absence of any relevant restenosis (invasive gradient across the site of previous treatment 3±4 mmHg) and resistant arterial hypertension (daytime SBP≥140 mmHg on 24 hour ambulatory blood pressure measurements [ABPM] in spite of the concurrent use of 3 antihypertensive agents of different classes or intolerance to BP medications) were included. Bilateral RSD was performed using the Symplicity Flex™ catheter (Medtronic, MN, USA). RSD was successful in all patients with no procedural complications and no evidence for renal artery stenosis 6 months post procedure. From baseline to 6 month follow-up, RSD was followed by a significant reduction in average daytime systolic BP (150.4±7.8 to 143.1±8.0 mmHg; p=0.0117) as well as systolic BP throughout 24 h (146.8±7.3 vs. 140.5±7.8, p=0.04). The BP reductions observed in these patients justify engaging in a larger clinical trial on the efficacy of RSD in this specific type of secondary hypertension and bares the hope that RSD might extend the currently very limited armory against arterial hypertension in young adults with previous repair of CoA. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sex-specific genetic determinants for arterial stiffness in Dahl salt-sensitive hypertensive rats.

Science.gov (United States)

Decano, Julius L; Pasion, Khristine A; Black, Nicole; Giordano, Nicholas J; Herrera, Victoria L; Ruiz-Opazo, Nelson

2016-01-11

Arterial stiffness is an independent predictor of cardiovascular outcomes in hypertensive patients including myocardial infarction, fatal stroke, cerebral micro-bleeds which predicts cerebral hemorrhage in hypertensive patients, as well as progression to hypertension in non-hypertensive subjects. The association between arterial stiffness and various cardiovascular outcomes (coronary heart disease, stroke) remains after adjusting for age, sex, blood pressure, body mass index and other known predictors of cardiovascular disease, suggesting that arterial stiffness, measured via carotid-femoral pulse wave velocity, has a better predictive value than each of these factors. Recent evidence shows that arterial stiffening precedes the onset of high blood pressure; however their molecular genetic relationship (s) and sex-specific determinants remain uncertain. We investigated whether distinct or shared genetic determinants might underlie susceptibility to arterial stiffening in male and female Dahl salt-sensitive rats. Thus, we performed a genome-wide scan for quantitative trait loci (QTLs) affecting arterial stiffness in six-week old F2 (Dahl S x R)-intercross male and female rats characterized for abdominal aortic pulse wave velocity and aortic strain by high-resolution ultrasonography. We detected five highly significant QTLs affecting aortic stiffness: two interacting QTLs (AS-m1 on chromosome 4 and AS-m2 on chromosome16, LOD 8.8) in males and two distinct interacting QTLs (AS-f1 on chromosome 9 and AS-f2 on chromosome11, LOD 8.9) in females affecting pulse wave velocity. One QTL (AS-1 on chromosome 3, LOD 4.3) was found to influence aortic strain in a sex-independent manner. None of these arterial stiffness QTLs co-localized with previously reported blood pressure QTLs detected in equivalent genetic intercrosses. These data reveal sex-specific genetic determinants for aortic pulse wave velocity and suggest distinct polygenic susceptibility for arterial stiffness and

Teaching baroreflex physiology to medical students

DEFF Research Database (Denmark)

Berg, Ronan M G; Plovsing, Ronni R.; Damgaard, Morten

2012-01-01

quizzes individually and in groups with conventional teaching on the immediate learning during a laboratory exercise. We implemented two quizzes in a mandatory 4-h laboratory exercise on baroreflex physiology. A total of 155 second-year medical students were randomized to solve quizzes individually...... (intervention group I, n = 57), in groups of three to four students (intervention group II, n = 56), or not to perform any quizzes (control; intervention group III, n = 42). After the laboratory exercise, all students completed an individual test, which encompassed two recall questions, two intermediate...... questions, and two integrated questions. The integrated questions were of moderate and advanced difficulty, respectively. Finally, students completed an evaluation form. Intervention group I reached the highest total test scores and proved best at answering the integrated question of advanced difficulty...

Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

International Nuclear Information System (INIS)

Borelli, Flavio Antonio de Oliveira; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R.

2013-01-01

Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m 2 . Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction

Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

Energy Technology Data Exchange (ETDEWEB)

Borelli, Flavio Antonio de Oliveira, E-mail: fborelli@cardiol.br; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R. [Instituto Dante Pazzanese de Cardiologia, São Paulo, SP (Brazil)

2013-11-15

Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m{sup 2}. Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction.

Orthostatic blood pressure control before and after spaceflight, determined by time-domain baroreflex method

NARCIS (Netherlands)

Gisolf, J.; Immink, R. V.; van Lieshout, J. J.; Stok, W. J.; Karemaker, J. M.

2005-01-01

Reduction in plasma volume is a major contributor to orthostatic tachycardia and hypotension after spaceflight. We set out to determine time- and frequency-domain baroreflex (BRS) function during preflight baseline and venous occlusion and postflight orthostatic stress, testing the hypothesis that a

Stress-sensitive arterial hypertension, haemodynamic changes and brain metabolites in hypertensive ISIAH rats: MRI investigation.

Science.gov (United States)

Seryapina, A A; Shevelev, O B; Moshkin, M P; Markel, A L; Akulov, A E

2017-05-01

What is the central question of this study? Stress-sensitive arterial hypertension is considered to be controlled by changes in central and peripheral sympathetic regulating mechanisms, which eventually result in haemodynamic alterations and blood pressure elevation. Therefore, study of the early stages of development of hypertension is of particular interest, because it helps in understanding the aetiology of the disease. What is the main finding and its importance? Non-invasive in vivo investigation in ISIAH rats demonstrated that establishment of sustainable stress-sensitive hypertension is accompanied by a decrease in prefrontal cortex activity and mobilization of hypothalamic processes, with considerable correlations between haemodynamic parameters and individual metabolite ratios. The study of early development of arterial hypertension in association with emotional stress is of great importance for better understanding of the aetiology and pathogenesis of the hypertensive disease. Magnetic resonance imaging (MRI) was applied to evaluate the changes in haemodynamics and brain metabolites in 1- and 3-month-old inherited stress-induced arterial hypertension (ISIAH) rats (10 male rats) with stress-sensitive arterial hypertension and in control normotensive Wistar Albino Glaxo (WAG) rats (eight male rats). In the 3-month-old ISIAH rats, the age-dependent increase in blood pressure was associated with increased blood flow through the renal arteries and decreased blood flow in the lower part of the abdominal aorta. The renal vascular resistance in the ISIAH rats decreased during ageing, although at both ages it remained higher than the renal vascular resistance in WAG rats. An integral metabolome portrait demonstrated that development of hypertension in the ISIAH rats was associated with an attenuation of the excitatory and energetic activity in the prefrontal cortex, whereas in the WAG rats the opposite age-dependent changes were observed. In contrast, in the

Arterial Stiffness and Autonomic Modulation After Free-Weight Resistance Exercises in Resistance Trained Individuals.

Science.gov (United States)

Kingsley, J Derek; Mayo, Xián; Tai, Yu Lun; Fennell, Curtis

2016-12-01

Kingsley, JD, Mayo, X, Tai, YL, and Fennell, C. Arterial stiffness and autonomic modulation after free-weight resistance exercises in resistance trained individuals. J Strength Cond Res 30(12): 3373-3380, 2016-We investigated the effects of an acute bout of free-weight, whole-body resistance exercise consisting of the squat, bench press, and deadlift on arterial stiffness and cardiac autonomic modulation in 16 (aged 23 ± 3 years; mean ± SD) resistance-trained individuals. Arterial stiffness, autonomic modulation, and baroreflex sensitivity (BRS) were assessed at rest and after 3 sets of 10 repetitions at 75% 1-repetition maximum on each exercise with 2 minutes of rest between sets and exercises. Arterial stiffness was analyzed using carotid-femoral pulse wave velocity (cf-PWV). Linear heart rate variability (log transformed [ln] absolute and normalized units [nu] of low-frequency [LF] and high-frequency [HF] power) and nonlinear heart rate complexity (Sample Entropy [SampEn], Lempel-Ziv Entropy [LZEn]) were measured to determine autonomic modulation. BRS was measured by the sequence method. A 2 × 2 repeated measures analysis of variance (ANOVA) was used to analyze time (rest, recovery) across condition (acute resistance exercise, control). There were significant increases in cf-PWV (p = 0.05), heart rate (p = 0.0001), normalized LF (LFnu; p = 0.001), and the LF/HF ratio (p = 0.0001). Interactions were also noted for ln HF (p = 0.006), HFnu (p = 0.0001), SampEn (p = 0.001), LZEn (p = 0.005), and BRS (p = 0.0001) such that they significantly decreased during recovery from the resistance exercise compared with rest and the control. There was no effect on ln total power, or ln LF. These data suggest that a bout of resistance exercise using free-weights increases arterial stiffness and reduces vagal activity and BRS in comparison with a control session. Vagal tone may not be fully recovered up to 30 minutes after a resistance exercise bout.

Exercise thallium-201 myocardial imaging in left main coronary artery disease: sensitive but not specific

International Nuclear Information System (INIS)

Rehn, T.; Griffith, L.S.; Achuff, S.C.; Bailey, I.K.; Bulkley, B.H.; Burow, R.; Pitt, B.; Becker, L.C.

1981-01-01

To determine the usefulness of thallium-201 scintigraphy for identifying left main coronary artery disease, the results of scintigraphy at rest and during exercise were compared in 24 patients with 50 percent or greater narrowing of the left main coronary artery and 80 patients with 50 percent or greater narrowing of one or more of the major coronary arteries but without left main coronary involvement. By segmental analysis of the scintigrams, perfusion defects were assigned to the left anterior descending, left circumflex or right coronary artery, singly or in combination, and the pattern of simultaneous left anterior descending and circumflex arterial defects was used to identify left main coronary artery disease. Of the 24 patients with left main coronary artery disease, 22 (92 percent) had abnormal exercise scintigrams. Despite this high sensitivity, the pattern of perfusion defects was not specific; the ''left main pattern'' was found in 3 patients (13 percent) with left main coronary artery disease but also in 3 (33 percent) of 9 patients with combined left anterior descending and left circumflex arterial disease, 4 (19 percent) of 21 patients with three vessel disease and 3 (6 percent) of 50 patients with one or two vessel disease but excluding the group with left anterior descending plus left circumflex arterial disease. The pattern of perfusion defects in the patients with left main coronary artery disease was determined by the location and severity of narrowings in the coronary arteries downstream from the left main arterial lesion. Concomitant lesions in other arteries were found in all patients with left main coronary disease (one vessel in 1 patient, two vessels in 7 patients and three vessels in 16). For this reason, it is unlikely that even with improvements in radiopharmaceutical agents and imaging techniques, myocardial perfusion scintigraphy will be sufficiently specific for definitive identification of left main coronary artery disease

Antenatal hypoxia induces programming of reduced arterial blood pressure response in female rat offspring: role of ovarian function.

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DaLiao Xiao

Full Text Available In utero exposure to adverse environmental factors increases the risk of cardiovascular disease in adulthood. The present study tested the hypothesis that antenatal hypoxia causes a gender-dependent programming of altered arterial blood pressure response (BP in adult offspring. Time-dated pregnant rats were divided into normoxic and hypoxic (10.5% O2 from days 15 to 21 of gestation groups. The experiments were conducted in adult offspring. Antenatal hypoxia caused intrauterine growth restriction, and resulted in a gender-dependent increase Angiotensin II (Ang II-induced BP response in male offspring, but significant decrease in BP response in female offspring. The baroreflex sensitivity was not significantly altered. Consistent with the reduced blood pressure response, antenatal hypoxia significantly decreased Ang II-induced arterial vasoconstriction in female offspring. Ovariectomy had no significant effect in control animals, but significantly increased Ang II-induced maximal BP response in prenatally hypoxic animals and eliminated the difference of BP response between the two groups. Estrogen replacement in ovariectomized animals significantly decreased the BP response to angiotensin II I only in control, but not in hypoxic animals. The result suggests complex programming mechanisms of antenatal hypoxia in regulation of ovary function. Hypoxia-mediated ovary dysfunction results in the phenotype of reduced vascular contractility and BP response in female adult offspring.

Elastase-2, a Tissue Alternative Pathway for Angiotensin II Generation, Plays a Role in Circulatory Sympathovagal Balance in Mice.

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Becari, Christiane; Durand, Marina T; Guimaraes, Alessander O; Lataro, Renata M; Prado, Cibele M; de Oliveira, Mauro; Candido, Sarai C O; Pais, Paloma; Ribeiro, Mauricio S; Bader, Michael; Pesquero, Joao B; Salgado, Maria C O; Salgado, Helio C

2017-01-01

In vitro and ex vivo experiments indicate that elastase-2 (ELA-2), a chymotrypsin-serine protease elastase family member 2A, is an alternative pathway for angiotensin II (Ang II) generation. However, the role played by ELA-2 in vivo is unclear. We examined ELA-2 knockout (ELA-2KO) mice compared to wild-type (WT) mice and determined whether ELA-2 played a role in hemodynamics [arterial pressure (AP) and heart rate (HR)], cardiocirculatory sympathovagal balance and baroreflex sensitivity. The variability of systolic arterial pressure (SAP) and pulse interval (PI) for evaluating autonomic modulation was examined for time and frequency domains (spectral analysis), whereas a symbolic analysis was also used to evaluate PI variability. In addition, baroreflex sensitivity was examined using the sequence method. Cardiac function was evaluated echocardiographically under anesthesia. The AP was normal whereas the HR was reduced in ELA-2KO mice (425 ± 17 vs. 512 ± 13 bpm from WT). SAP variability and baroreflex sensitivity were similar in both strains. The LF power from the PI spectrum (33.6 ± 5 vs. 51.8 ± 4.8 nu from WT) and the LF/HF ratio (0.60 ± 0.1 vs. 1.45 ± 0.3 from WT) were reduced, whereas the HF power was increased (66.4 ± 5 vs. 48.2 ± 4.8 nu from WT) in ELA-2KO mice, indicating a shift toward parasympathetic modulation of HR. Echocardiographic examination showed normal fractional shortening and an ejection fraction in ELA-2KO mice; however, the cardiac output, stroke volume, and ventricular size were reduced. These findings provide the first evidence that ELA-2 acts on the sympathovagal balance of the heart, as expressed by the reduced sympathetic modulation of HR in ELA-2KO mice.

Adolescent vulnerability to cardiovascular consequences of chronic social stress: Immediate and long-term effects of social isolation during adolescence.

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Cruz, Fábio C; Duarte, Josiane O; Leão, Rodrigo M; Hummel, Luiz F V; Planeta, Cleopatra S; Crestani, Carlos C

2016-01-01

It has been demonstrated that disruption of social bonds and perceived isolation (loneliness) are associated with an increased risk of cardiovascular morbidity and mortality. Adolescence is proposed as a period of vulnerability to stress. Nevertheless, the impact of chronic social stress during this ontogenic period in cardiovascular function is poorly understood. Therefore, the purpose of this study was to compare the impact in cardiovascular function of social isolation for 3 weeks in adolescent and adult male rats. Also, the long-term effects of social isolation during adolescence were investigated longitudinally. Social isolation reduced body weight in adolescent, but not in adult animals. Disruption of social bonds during adolescence increased arterial pressure without affecting heart rate and pulse pressure (PP). Nevertheless, social isolation in adulthood reduced systolic arterial pressure and increased diastolic arterial pressure, which in turn decreased PP without affecting mean arterial pressure. Cardiovascular changes in adolescents, but not adults, were followed by facilitation of both baroreflex sensitivity and vascular reactivity to the vasodilator agent acetylcholine. Vascular responsiveness to either the vasodilator agent sodium nitroprusside or the vasoconstrictor agent phenylephrine was not affected by social isolation. Except for the changes in body weight and baroreflex sensitivity, all alterations evoked by social isolation during adolescence were reversed in adulthood after moving animals from isolated to collective housing. These findings suggest a vulnerability of adolescents to the effects of chronic social isolation in cardiovascular function. However, results indicate minimal cardiovascular consequences in adulthood of disruption of social bonds during adolescence. © 2015 Wiley Periodicals, Inc.

Autonomic modulation of arterial pressure and heart rate variability in hypertensive diabetic rats Modulação autonômica da pressão arterial e variabilidade da freqüência cardíaca em ratos hipertensos e diabéticos

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Vera de Moura Azevedo Farah

2007-01-01

Full Text Available OBJECTIVE: The aim of the present study was to evaluate the autonomic modulation of the cardiovascular system in streptozotocin (STZ-induced diabetic spontaneously hypertensive rats (SHR, evaluating baroreflex sensitivity and arterial pressure and heart rate variability. METHODS: Male SHR were divided in control (SHR and diabetic (SHR+DM, 5 days after STZ groups. Arterial pressure (AP and baroreflex sensitivity (evaluated by tachycardic and bradycardic responses to changes in AP were monitored. Autoregressive spectral estimation was performed for systolic AP (SAP and pulse interval (PI with oscillatory components quantified as low (LF:0.2-0.6Hz and high (HF:0.6-3.0Hz frequency ranges. RESULTS: Mean AP and heart rate in SHR+DM (131±3 mmHg and 276±6 bpm were lower than in SHR (160±7 mmHg and 330±8 bpm. Baroreflex bradycardia was lower in SHR+DM as compared to SHR (0.55±0.1 vs. 0.97±0.1 bpm/mmHg. Overall SAP variability in the time domain (standard deviation of beat-by-beat time series of SAP was lower in SHR+DM (3.1±0.2 mmHg than in SHR (5.7±0.6 mmHg. The standard deviation of the PI was similar between groups. Diabetes reduced the LF of SAP (3.3±0.8 vs. 28.7±7.6 mmHg2 in SHR, while HF of SAP were unchanged. The power of oscillatory components of PI did not differ between groups. CONCLUSIONS: These results show that the association of hypertension and diabetes causes an impairment of the peripheral cardiovascular sympathetic modulation that could be, at least in part, responsible for the reduction in AP levels. Moreover, this study demonstrates that diabetes might actually impair the reduced buffer function of the baroreceptors while reducing blood pressure.OBJETIVO: O objetivo do presente estudo foi investigar a modulação autonômica do sistema cardiovascular em ratos espontâneamente hipertensos (SHR e diabéticos por estreptozotocina (STZ, avaliando a sensibilidade do reflexo barorreceptor e a variabilidade da pressão arterial e da

Cardiac impairment evaluated by transesophageal echocardiography and invasive measurements in rats undergoing sinoaortic denervation.

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Raquel A Sirvente

Full Text Available BACKGROUND: Sympathetic hyperactivity may be related to left ventricular (LV dysfunction and baro- and chemoreflex impairment in hypertension. However, cardiac function, regarding the association of hypertension and baroreflex dysfunction, has not been previously evaluated by transesophageal echocardiography (TEE using intracardiac echocardiographic catheter. METHODS AND RESULTS: We evaluated exercise tests, baroreflex sensitivity and cardiovascular autonomic control, cardiac function, and biventricular invasive pressures in rats 10 weeks after sinoaortic denervation (SAD. The rats (n = 32 were divided into 4 groups: 16 Wistar (W with (n = 8 or without SAD (n = 8 and 16 spontaneously hypertensive rats (SHR with (n = 8 or without SAD (SHRSAD (n = 8. Blood pressure (BP and heart rate (HR did not change between the groups with or without SAD; however, compared to W, SHR groups had higher BP levels and BP variability was increased. Exercise testing showed that SHR had better functional capacity compared to SAD and SHRSAD. Echocardiography showed left ventricular (LV concentric hypertrophy; segmental systolic and diastolic biventricular dysfunction; indirect signals of pulmonary arterial hypertension, mostly evident in SHRSAD. The end-diastolic right ventricular (RV pressure increased in all groups compared to W, and the end-diastolic LV pressure increased in SHR and SHRSAD groups compared to W, and in SHRSAD compared to SAD. CONCLUSIONS: Our results suggest that baroreflex dysfunction impairs cardiac function, and increases pulmonary artery pressure, supporting a role for baroreflex dysfunction in the pathogenesis of hypertensive cardiac disease. Moreover, TEE is a useful and feasible noninvasive technique that allows the assessment of cardiac function, particularly RV indices in this model of cardiac disease.

Association between high-sensitive troponin I and coronary artery calcification in a Danish general population

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Olson, Fredrik; Engborg, Jonathan; Grønhøj, Mette H.

2016-01-01

BACKGROUND: High-sensitive troponin I (hs-TnI) is an individual predictor of future cardiovascular disease (CVD). However, the relationship between hs-TnI and coronary artery calcification (CAC) as determined by computed tomography (CT) has not previously been investigated in a general population...

Efficacy of double arterial phase dynamic magnetic resonance imaging with the sensitivity encoding technique versus dynamic multidetector-row helical computed tomography for detecting hypervascular hepatocellular carcinoma

International Nuclear Information System (INIS)

Kumano, Seishi; Okada, Masahiro; Murakami, Takamichi; Uemura, Masahiko; Haraikawa, Toyoaki; Hirata, Masaaki; Kikuchi, Keiichi; Mochizuki, Teruhito; Kim, Tonsok

2009-01-01

The aim of this study was to evaluate the efficacy of double arterial phase dynamic magnetic resonance imaging (MRI) with the sensitivity encoding technique (SENSE dynamic MRI) for detection of hypervascular hepatocellular carcinoma (HCC) in comparison with double arterial phase dynamic multidetector-row helical computed tomography (dynamic MDCT). A total of 28 patients with 66 hypervascular HCCs underwent both double arterial SENSE dynamic MRI and dynamic MDCT. The diagnosis of HCC was based on surgical resection (n=7), biopsy (n=10), or a combination of CT during arterial portography (CTAP), CT during hepatic arteriography (CTA), and/or the 6-month follow-up CT (n=49). Based on alternative-free response receiving operating characteristic (ROC) analysis, the diagnostic performance for detecting HCC was compared between double arterial phase SENSE dynamic MRI and double arterial phase dynamic MDCT. The mean sensitivity, positive predictive value, and mean A Z values for hypervascular HCCs were 72%, 80%, and 0.79, respectively, for SENSE dynamic MRI and 66%, 92%, and 0.78, respectively, for dynamic MDCT. The mean sensitivity for double arterial phase SENSE dynamic MRI was higher than that for double arterial phase dynamic MDCT, but the difference was not statistically significant. Double arterial phase SENSE dynamic MRI is as valuable as double arterial phase dynamic MDCT for detecting hypervascular HCCs. (author)

Dual-energy CT based vascular iodine analysis improves sensitivity for peripheral pulmonary artery thrombus detection: An experimental study in canines

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Tang, Chun Xiang [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu 210002 (China); Zhang, Long Jiang, E-mail: kevinzhlj@163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu 210002 (China); Han, Zong Hong; Zhou, Chang Sheng [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu 210002 (China); Krazinski, Aleksander W.; Silverman, Justin R. [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu 210002 (China); Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Lu, Guang Ming, E-mail: cjr.luguangming@vip.163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu 210002 (China)

2013-12-01

Purpose: To evaluate the performance of dual-energy CT (DECT) based vascular iodine analysis for the detection of acute peripheral pulmonary thrombus (PE) in a canine model with histopathological findings as the reference standard. Materials and methods: The study protocol was approved by our institutional animal committee. Thrombi (n = 12) or saline (n = 4) were intravenously injected via right femoral vein in sixteen dogs, respectively. CT pulmonary angiography (CTPA) in DECT mode was performed and conventional CTPA images and DECT based vascular iodine studies using Lung Vessels application were reconstructed. Two radiologists visually evaluated the number and location of PEs using conventional CTPA and DECT series on a per-animal and a per-clot basis. Detailed histopathological examination of lung specimens and catheter angiography served as reference standard. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of DECT and CTPA were calculated on a segmental and subsegmental or more distal pulmonary artery basis. Weighted κ values were computed to evaluate inter-modality and inter-reader agreement. Results: Thirteen dogs were enrolled for final image analysis (experimental group = 9, control group = 4). Histopathological results revealed 237 emboli in 45 lung lobes in 9 experimental dogs, 11 emboli in segmental pulmonary arteries, 49 in subsegmental pulmonary arteries, 177 in fifth-order or more distal pulmonary arteries. Overall sensitivity, specificity, accuracy, PPV, and NPV for CTPA plus DECT were 93.1%, 76.9%, 87.8%, 89.4%, and 84.2% for the detection of pulmonary emboli. With CTPA versus DECT, sensitivities, specificities, accuracies, PPVs, and NPVs are all 100% for the detection of pulmonary emboli on a segmental pulmonary artery basis, 88.9%, 100%, 96.0%, 100%, and 94.1% for CTPA and 90.4%, 93.0%, 92.0%, 88.7%, and 94.1% for DECT on a subsegmental pulmonary artery basis; 23.8%, 96.4%, 50.4%, 93

Appropriate control time constant in relation to characteristics of the baroreflex vascular system in 1/R control of the total artificial heart.

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Mizuta, Sora; Saito, Itsuro; Isoyama, Takashi; Hara, Shintaro; Yurimoto, Terumi; Li, Xinyang; Murakami, Haruka; Ono, Toshiya; Mabuchi, Kunihiko; Abe, Yusuke

2017-09-01

1/R control is a physiological control method of the total artificial heart (TAH) with which long-term survival was obtained with animal experiments. However, 1/R control occasionally diverged in the undulation pump TAH (UPTAH) animal experiment. To improve the control stability of the 1/R control, appropriate control time constant in relation to characteristics of the baroreflex vascular system was investigated with frequency analysis and numerical simulation. In the frequency analysis, data of five goats in which the UPTAH was implanted were analyzed with first Fourier transform technique to examine the vasomotion frequency. The numerical simulation was carried out repeatedly changing baroreflex parameters and control time constant using the elements-expanded Windkessel model. Results of the frequency analysis showed that the 1/R control tended to diverge when very low frequency band that was an indication of the vasomotion frequency was relative high. In numerical simulation, divergence of the 1/R control could be reproduced and the boundary curves between the divergence and convergence of the 1/R control varied depending on the control time constant. These results suggested that the 1/R control tended to be unstable when the TAH recipient had high reflex speed in the baroreflex vascular system. Therefore, the control time constant should be adjusted appropriately with the individual vasomotion frequency.

Hypoxia increases pulmonary arterial thromboxane receptor internalization independent of receptor sensitization.

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Fediuk, J; Sikarwar, A S; Lizotte, P P; Hinton, M; Nolette, N; Dakshinamurti, S

2015-02-01

Persistent Pulmonary Hypertension of the Newborn (PPHN) is characterized by sustained vasospasm and an increased thromboxane:prostacyclin ratio. Thromboxane (TP) receptors signal via Gαq to mobilize IP3 and Ca(2+), causing pulmonary arterial constriction. We have previously reported increased TP internalization in hypoxic pulmonary arterial (PA) myocytes. Serum-deprived PA myocytes were grown in normoxia (NM) or hypoxia (HM) for 72 h. TP localization was visualized in agonist-naïve and -challenged NM and HM by immunocytochemistry. Pathways for agonist-induced TP receptor internalization were determined by inhibiting caveolin- or clathrin-mediated endocytosis, and caveolar fractionation. Roles of actin and tubulin in TP receptor internalization were assessed using inhibitors of tubulin, actin-stabilizing or -destabilizing agents. PKA, PKC or GRK activation and inhibition were used to determine the kinase responsible for post-agonist receptor internalization. Agonist-naïve HM had decreased cell surface TP, and greater TP internalization after agonist challenge. TP protein did not sort with caveolin-rich fractions. Inhibition of clathrin prevented TP internalization. Both actin-stabilizing and -destabilizing agents prevented TP endocytosis in NM, while normalizing TP internalization in HM. Velocity of TP internalization was unaffected by PKA activity, but PKC activation normalized TP receptor internalization in HM. GRK inhibition had no effect. We conclude that in hypoxic myocytes, TP is internalized faster and to a greater extent than in normoxic controls. Internalization of the agonist-challenged TP requires clathrin, dynamic actin and is sensitive to PKC activity. TP receptor trafficking and signaling in hypoxia are pivotal to understanding increased vasoconstrictor sensitivity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Improvements in Heart Rate Variability, Baroreflex Sensitivity, and Sleep After Use of Closed-Loop Allostatic Neurotechnology by a Heterogeneous Cohort

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Hossam A. Shaltout

2018-04-01

Full Text Available BackgroundHeart rate variability (HRV is an indicator of dynamic adaptability of the autonomic nervous system. Few interventions target upstream, cerebral cortex components of the heart–brain system for autonomic management. We report changes in HRV and baroreflex sensitivity (BRS, associated with use of a noninvasive, closed-loop, allostatic, computer-guided, acoustic stimulation neurotechnology.MethodsOver 5 years, 220 subjects with heterogeneous neurological, cardiovascular, and psychophysiological conditions consecutively enrolled in a naturalistic, single-arm study exploring clinical effects associated with use of the neurotechnology. Of those, 202 completed the study protocol and 160 had recordings adequate to analyze HRV and BRS. Mean age was 44.0 (SD 19.4, with 130 women. Participants received a mean of 16.1 (5.2 sessions, over 24.2 days (23.3, with 9.5 (3.8 actual intervention days. Sessions included real-time analysis of brain electrical activity and software algorithm-guided translation of selected frequencies into patterns of acoustic stimulation (audible tones of variable pitch and timing, to facilitate auto-calibration of neural oscillations. Outcomes including 10-min supine, at-rest recordings of blood pressure and heart rate, and inventories for insomnia (ISI and depression (CES-D or BDI-II, were obtained at baseline and 15.3 (16.7 days after the last session.ResultsCompared to baseline, significant increases (all p < 0.001 were observed for measures of HRV across all participants including the mean percentage change for SDNN 24.2% (SE 0.04, and RMSSD, 42.2% (0.08, and BRS [Sequence Up, 55.5% (0.09, Sequence Down, 77.6% (0.23, and Sequence All, 53.7% (0.07]. Significant improvements were noted in SAP, MAP, and DAP, as well as natural log of HF, and total power. Self-reported ISI was reduced (ISI, −6.4 points, SD 5.6, p < 0.001. The proportion reporting clinically significant depressive symptoms reduced from 48

Chewing-induced hypertension in afferent baroreflex failure: a sympathetic response?

Science.gov (United States)

Fuente Mora, Cristina; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto; Kaufmann, Horacio

2015-11-01

What is the central question of this study? Our goal was to understand the autonomic responses to eating in patients with congenital afferent baroreflex failure, by documenting changes in blood pressure and heart rate with chewing, swallowing and stomach distension. What is the main finding and its importance? Patients born with lesions in the afferent baroreceptor pathways have an exaggerated pressor response to food intake. This appears to be a sympathetically mediated response, triggered by chewing, that occurs independently of swallowing or distension of the stomach. The chewing-induced pressor response may be useful as a counter-manoeuvre to prevent orthostatic hypotension in these patients. Familial dysautonomia (FD) is a rare genetic disease with extremely labile blood pressure resulting from baroreflex deafferentation. Patients have marked surges in sympathetic activity, frequently surrounding meals. We conducted an observational study to document the autonomic responses to eating in patients with FD and to determine whether sympathetic activation was caused by chewing, swallowing or stomach distension. Blood pressure and R-R intervals were measured continuously while chewing gum (n = 15), eating (n = 20) and distending the stomach by percutaneous endoscopic gastrostomy tube feeding (n = 9). Responses were compared with those of normal control subjects (n = 10) and of patients with efferent autonomic failure (n = 10) who have chronically impaired sympathetic outflow. In patients with FD, eating was associated with a marked but transient pressor response (P Chewing gum evoked a similar increase in blood pressure that was higher in patients with FD than in control subjects (P = 0.0001), but was absent in patients with autonomic failure. In patients with FD, distending the stomach by percutaneous endoscopic gastrostomy tube feeding failed to elicit a pressor response. The results provide indirect evidence that chewing triggers sympathetic

Usefulness of 3D-CE renal artery MRA using parallel imaging with array spatial sensitivity encoding technique (ASSET)

International Nuclear Information System (INIS)

Shibasaki, Toshiro; Seno Masafumi; Takoi, Kunihiro; Sato, Hirofumi; Hino, Tsuyoshi

2003-01-01

In this study of 3D contrast enhanced MR angiography of the renal artery using the array spatial sensitivity encoding technique (ASSET), the acquisition time per 1 phase shortened fairly. And using the technique of spectral inversion at lipids (SPECIAL) together with ASSET, the quality of image was improved by emphasizing the contrast. The timing of acquisition was determined by the test injection. We started acquiring the MR angiography 2 seconds after the arrival of maximum enhancement of the test injection at the upper abdominal aorta near the renal artery. As a result parenchymal enhancement was not visible and depiction of the segmental artery was possible in 14 (82%) of 17 patients. At the present time we consider it better not to use the Fractional number of excitation (NEX) together with ASSET, as it may cause various artifacts. (author)

βENaC is a molecular component of a VSMC mechanotransducer that contributes to renal blood flow regulation, protection from renal injury, and hypertension.

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Drummond, Heather A

2012-01-01

Pressure-induced constriction (also known as the "myogenic response") is an important mechano-dependent response in certain blood vessels. The response is mediated by vascular smooth muscle cells (VSMCs) and characterized by a pressure-induced vasoconstriction in small arteries and arterioles in the cerebral, mesenteric, cardiac, and renal beds. The myogenic response has two important roles; it is a mechanism of blood flow autoregulation and provides protection against systemic blood pressure-induced damage to delicate microvessels. However, the molecular mechanism(s) underlying initiation of myogenic response is unclear. Degenerin proteins have a strong evolutionary link to mechanotransduction in the nematode. Our laboratory has addressed the hypothesis that these proteins may also act as mechanosensors in certain mammalian tissues such as VSMCs and arterial baroreceptor neurons. This article discusses the importance of a specific degenerin protein, β Epithelial Na(+) Channel (βENaC) in pressure-induced vasoconstriction in renal vessels and arterial baroreflex function as determined in a mouse model of reduced βENaC (βENaC m/m). We propose that loss of baroreflex sensitivity (due to loss of baroreceptor βENaC) increases blood pressure variability, increasing the likelihood and magnitude of upward swings in systemic pressure. Furthermore, loss of the myogenic constrictor response (due to loss of VSMC βENaC) will permit those pressure swings to be transmitted to the microvasculature in βENaC m/m mice, thus increasing the susceptibility to renal injury and hypertension.

Cardiovascular, cerebrovascular, and respiratory changes induced by different types of music in musicians and non-musicians: the importance of silence.

Science.gov (United States)

Bernardi, L; Porta, C; Sleight, P

2006-04-01

To assess the potential clinical use, particularly in modulating stress, of changes in the cardiovascular and respiratory systems induced by music, specifically tempo, rhythm, melodic structure, pause, individual preference, habituation, order effect of presentation, and previous musical training. Measurement of cardiovascular and respiratory variables while patients listened to music. University research laboratory for the study of cardiorespiratory autonomic function. 12 practising musicians and 12 age matched controls. After a five minute baseline, presentation in random order of six different music styles (first for a two minute, then for a four minute track), with a randomly inserted two minute pause, in either sequence. Breathing rate, ventilation, carbon dioxide, RR interval, blood pressure, mid-cerebral artery flow velocity, and baroreflex. Ventilation, blood pressure, and heart rate increased and mid-cerebral artery flow velocity and baroreflex decreased with faster tempi and simpler rhythmic structures compared with baseline. No habituation effect was seen. The pause reduced heart rate, blood pressure, and minute ventilation, even below baseline. An order effect independent of style was evident for mid-cerebral artery flow velocity, indicating a progressive reduction with exposure to music, independent of style. Musicians had greater respiratory sensitivity to the music tempo than did non-musicians. Music induces an arousal effect, predominantly related to the tempo. Slow or meditative music can induce a relaxing effect; relaxation is particularly evident during a pause. Music, especially in trained subjects, may first concentrate attention during faster rhythms, then induce relaxation during pauses or slower rhythms.

Effect of angiotensin II-induced arterial hypertension on the voltage-dependent contractions of mouse arteries.

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Fransen, Paul; Van Hove, Cor E; Leloup, Arthur J A; Schrijvers, Dorien M; De Meyer, Guido R Y; De Keulenaer, Gilles W

2016-02-01

Arterial hypertension (AHT) affects the voltage dependency of L-type Ca(2+) channels in cardiomyocytes. We analyzed the effect of angiotensin II (AngII)-induced AHT on L-type Ca(2+) channel-mediated isometric contractions in conduit arteries. AHT was induced in C57Bl6 mice with AngII-filled osmotic mini-pumps (4 weeks). Normotensive mice treated with saline-filled osmotic mini-pumps were used for comparison. Voltage-dependent contractions mediated by L-type Ca(2+) channels were studied in vaso-reactive studies in vitro in isolated aortic and femoral arteries by using extracellular K(+) concentration-response (KDR) experiments. In aortic segments, AngII-induced AHT significantly sensitized isometric contractions induced by elevated extracellular K(+) and depolarization. This sensitization was partly prevented by normalizing blood pressure with hydralazine, suggesting that it was caused by AHT rather than by direct AngII effects on aortic smooth muscle cells. The EC50 for extracellular K(+) obtained in vitro correlated significantly with the rise in arterial blood pressure induced by AngII in vivo. The AHT-induced sensitization persisted when aortic segments were exposed to levcromakalim or to inhibitors of basal nitric oxide release. Consistent with these observations, AngII-treatment also sensitized the vaso-relaxing effects of the L-type Ca(2+) channel blocker diltiazem during K(+)-induced contractions. Unlike aorta, AngII-treatment desensitized the isometric contractions to depolarization in femoral arteries pointing to vascular bed specific responses of arteries to hypertension. AHT affects the voltage-dependent L-type Ca(2+) channel-mediated contraction of conduit arteries. This effect may contribute to the decreased vascular compliance in AHT and explain the efficacy of Ca(2+) channel blockers to reduce vascular stiffness and central blood pressure in AHT.

Sensitivity and accuracy of thallium-201 myocardial scintigraphy in the detection of coronary artery and myocardial disease

International Nuclear Information System (INIS)

Loesse, B.; Kroenert, H.; Rafflenbeul, D.; Feinendegen, L.E.; Loogen, F.; Duesseldorf Univ.

1979-01-01

169 patients (154 men, 15 women, mean age 49.5 years, range 27 to 64 years) were studied by means of 201-Thallium myocardial scintigraphy (201-Tl) and coronary angiography. According to the coronarangiogram, 130 patients had coronary artery disease (CAD): 53 a 1-vessel CAD, 29 a 2-vessel CAD, 48 a 3-vessel CAD. 39 patients had normal or less than 50% stenosed coronary arteries, but only 13 of these patients had also a normal ventriculogram, whereas 26 had an abnormal ventriculogram with local hypo-, a- or dyskinesia, diffuse hypokinesia, dilatation, or marked hypertrophy. The ramus interventicularis anterior (RIVA) was involved (stenosis of more than 50%) in 117 cases, the ramus circumflexus (R. circ.) in 70 cases, and the right coronary artery (RCA) in 67 cases. 201-Tl was abnormal in 98% of all 130 patients with CAD, in 100% of 93 patients with prior infarction, and in 95% of 37 patients without prior infarction. The sensitivity of the rest and/or exercise ECG in the same patients was only 79%, 88% and 57%, respectively. 201-Tl was abnormal in all 26 patients with a pathologic ventriculogram in spite of normal coronary arteries. 201-Tl and ECG were normal in only 9 of the 13 patients (=69%) with normal coronary arteries and normal ventriculogram. Myocardial biopsy, however, performed in 2 of the other 4 patients disclosed in part severe degenerative changes which can possibly explain the abnormal findings of 201-Tl and ECG. Significantly, i.e. more than 50% stenosed RIVA was correctly detected by 201-Tl in 98%, R. circ. in 71%, and RCA in 91% of the cases. The specificity of 201-Tl was limited by the great number of patients with a pathologic ventriculogram combined with normal coronary arteries. (orig.) [de

Demonstration of the dorsal pancreatic artery by CTA to facilitate superselective arterial infusion of stem cells into the pancreas

International Nuclear Information System (INIS)

Lin Yuning; Yang Xizhang; Chen Ziqian; Tan Jianming; Zhong Qun; Yang Li; Wu Zhixian

2012-01-01

Purpose: To investigate the diagnostic performance of 64-section CTA in the detection of dorsal pancreatic artery before interventional therapy for patients with diabetes. Materials and methods: The study was approved by the institutional ethics committee; written informed consent was obtained. Forty-two consecutive patients with diabetes received an experimental treatment of autologous bone marrow-derived stem cell transplantation by means of infusion into the dorsal pancreatic artery. All cases underwent abdominal CTA before angiography of pancreatic arteries in order to locate the origin and course of dorsal pancreatic artery. Angiography of coeliac artery, splenic artery, common hepatic artery and superior mesenteric artery were performed both in CTA and DSA. Superselective catheterization of dorsal pancreatic artery was carried out for the infusion of stem cell. Sensitivity, specificity and accuracy for the detection of dorsal pancreatic artery with CTA were calculated using DSA images as the reference standard. Results: Thirty-five and thirty-six dorsal pancreatic arteries were detected by CTA and DSA respectively. Dorsal pancreatic artery was not visualized in either CTA or DSA in 5 patients. The sensitivity, specificity and accuracy for CTA were 94.4%, 83.3% and 92.9%. Conclusion: 64-section CTA is accurate for the detection of dorsal pancreatic artery. It may be useful for the facilitation of superselective arterial infusion of stem cells to pancreas.

Autonomic and Renal Alterations in the Offspring of Sleep-Restricted Mothers During Late Pregnancy

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Joyce R.S. Raimundo

Full Text Available OBJECTIVES: Considering that changes in the maternal environment may result in changes in progeny, the aim of this study was to investigate the influence of sleep restriction during the last week of pregnancy on renal function and autonomic responses in male descendants at an adult age. METHODS: After confirmation of pregnancy, female Wistar rats were randomly assigned to either a control or a sleep restriction group. The sleep-restricted rats were subjected to sleep restriction using the multiple platforms method for over 20 hours per day between the 14th and 20th day of pregnancy. After delivery, the litters were limited to 6 offspring that were designated as offspring from control and offspring from sleep-restricted mothers. Indirect measurements of systolic blood pressure (BPi, renal plasma flow, glomerular filtration rate, glomerular area and number of glomeruli per field were evaluated at three months of age. Direct measurements of cardiovascular function (heart rate and mean arterial pressure, cardiac sympathetic tone, cardiac parasympathetic tone, and baroreflex sensitivity were evaluated at four months of age. RESULTS: The sleep-restricted offspring presented increases in BPi, glomerular filtration rate and glomerular area compared with the control offspring. The sleep-restricted offspring also showed higher basal heart rate, increased mean arterial pressure, increased sympathetic cardiac tone, decreased parasympathetic cardiac tone and reduced baroreflex sensitivity. CONCLUSIONS: Our data suggest that reductions in sleep during the last week of pregnancy lead to alterations in cardiovascular autonomic regulation and renal morpho-functional changes in offspring, triggering increases in blood pressure.

Coronary artery bypass grafts: assessment of graft patency and native coronary artery lesions using 16-slice MDCT

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Stauder, Norbert I.; Drosch, Tanja; Claussen, Claus D.; Kopp, Andreas F. [Eberhard-Karls-University, Department of Diagnostic Radiology, Tuebingen (Germany); Kuettner, Axel [Friedrich-Alexander-University, Department of Diagnostic Radiology, Erlangen (Germany); Schroeder, Stephen; Beck, Torsten [Eberhard-Karls-University, Department of Internal Medicine, Division Cardiology, Tuebingen (Germany); Stauder, Heidrun [Eberhard-Karls-University, Department of Thoracic and Cardiovascular Surgery, Tuebingen (Germany); Blumenstock, Gunnar [Eberhard-Karls-University, Department of Medical Information Processing, Tuebingen (Germany)

2006-11-15

The objective of this study was to evaluate the accuracy of electrocardiography (ECG)-gated 16-slice multidetector-row computed tomography (MDCT) in detection of stenosis of bypass grafts and native coronary arteries in patients who have undergone coronary artery bypass grafting (CABG). ECG-gated contrast-enhanced MDCT using 12 x 0.75-mm collimation was performed in 20 patients with recurrent angina 4.75 years after undergoing CABG. A total of 50 grafts, 16 arterial and 34 venous, were examined. All graft and coronary segments were evaluated for stenosis in comparison with conventional coronary angiography (CCA). Among the 80 arterial graft segments, 62 could be assessed (77.5%). Sensitivity, specificity, and positive and negative predictive values for stenosis were 96.2%, 97.2%, 96.2%, and 97.2%, respectively. In a total of 180 venous graft segments, 167 could be assessed. Sensitivity, specificity, and positive and negative predictive values for stenosis were 98.5%, 93.9%, 91.8%, and 98.9%, respectively. MDCT could assess 179 of 260 native coronary artery segments (68.8%).Sensitivity, specificity, and positive and negative predictive values for stenosis were 92.1%, 76.9%, 87.5%, and 84.7%, respectively. Sixteen-slice MDCT provides excellent image quality and diagnostic accuracy in detection of graft and coronary artery lesions in patients with suspected graft dysfunction. (orig.)

Characterisation of baroreflex sensitivity of recreational ultra-endurance athletes.

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Foulds, Heather J A; Cote, Anita T; Phillips, Aaron A; Charlesworth, Sarah A; Bredin, Shannon S D; Burr, Jamie F; Drury, Chipman Taylor; Ngai, Shirley; Fougere, Renee J; Ivey, Adam C; Warburton, Darren E R

2014-01-01

Altered autonomic function has been identified following ultra-endurance event participation among elite world-class athletes. Despite dramatic increases in recreational athlete participation in these ultra-endurance events, the physiological effects on these athletes are less known. This investigation sought to characterise changes in surrogate measures of autonomic function: heart rate variability (HRV), blood pressure variability (BPV) and baroreceptor sensitivity (BRS) following ultra-endurance race participation. Further, we sought to compare baseline measures among ultra-endurance athletes and recreationally active controls not participating in the ultra-endurance race. Recreational ultra-endurance athletes (n = 25, 44.6 ± 8.2 years, 8 females) and recreationally active age, sex and body mass index matched controls (n = 25) were evaluated. Measurements of HRV, BPV and BRS were collected pre- and post-race for recreational ultra-endurance athletes and at baseline, for recreationally active controls. Post-race, ultra-endurance athletes demonstrated significantly greater sympathetic modulation [low frequency (LF) power HRV: 50.3 ± 21.6 normalised units (n.u.) to 65.9 ± 20.4 n.u., p = 0.01] and significantly lower parasympathetic modulation [high frequency (HF) power HRV: 45.0 ± 22.4 n.u. to 23.9 ± 13.1 n.u., p HRV and BPV measures. Recreational ultra-endurance athletes experienced increased sympathetic tone and declines in BRS post-race, similar to previously reported elite world-class ultra-endurance athletes, though still within normal population ranges.

[Features of daily rhythm of arterial pressure in patients with primary arterial hypertension and neurogenic syncope conditions].

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Musaeva, Z A; Oknin, V Iu; Khapaev, B A; Fedotova, A V; Veĭn, A M

2002-01-01

A comparative analysis of parameters of systemic BP in patients with primary arterial hypotension (PAH) and in patients with neurogenic syncopes (NS) in the cycle sleep-awake. Blood pressure was investigated in 20 patients with PAH aged 16-44 years and 18 patients with NS aged 16-49 years. 24-h ambulatory monitoring of BP was made on the monitor ABPM-02/M (Meditech, Hungary). Rhythm indices of BP in NS patients corresponded to age normal criteria. 24-h arrhythmia of BP in PAH patients manifests with excessive drop of diastolic BP in sleep (55% patients were overdippers). PAH and NS patients differ maximally by hypotonic load in sleep: 1.0 +/- 0.7% in NS vs 15.4 +/- 3.2% in PAH. Hypotonia episodes in awake PAH patients were registered at each 4th-5th measurement of BP, in NS patients--at each 11th-13th. Heart rate in awake PAH patients is higher than in healthy subjects. Hypotonic load in sleep carries the highest differentially-diagnostic importance. This makes more perspective examinations of such patients in the cycle sleep-awake. The changes observed in PAH patients evidence for activation of cerebral sympathico-adrenal systems participating in baroreflex regulation.

Sensitivity and specificity of thallium-201 perfusion scintigrams under exercise in the diagnosis of coronary artery disease

International Nuclear Information System (INIS)

Verani, M.S.; Marcus, M.L.; Razzak, M.A.; Ehrhardt, J.C.

1978-01-01

The specificity and sensitivity of thallium-201 myocardial perfusion imaging (MPI), under exercise, in patients with suspected coronary-obstructive disease was compared with graded exercise ECG tests (GTX) in patients with angiographically normal (N = 34) and obstructed (N = 48) coronary arteries. Of the 34 patients with normal coronaries, only one had a perfusion defect on the MPI (specificity 97%). Of the 48 patients with coronary obstructive disease (>50% obstruction of at least one coronary vessel), MPI was positive in 38 (sensitivity 79%). In contrast, the GTX had a specificity of 62% and sensitivity of 88% if nondiagnostic GTX tests are excluded. When the MPI and the GTX were used in combination, however, the sensitivity of detecting patients with coronary obstructive disease was increased to 94% (p < 0.01). The MPI was particularly useful in the evaluation of the 26 patients with nondiagnostic GTX. In this group, 24 of the 26 patients were correctly identified by the MPI with respect to the presence or absence of coronary-obstructive disease. In the 14 patients with a history of classical angina but with normal coronaries, the MPI was negative in 13 and positive in one, thus suggesting that in the majority of these patients transient transmural myocardial ischemia probably does not occur during exercise. The presence or absence of angiographically demonstrable coronary collateral vessels did not seem to influence the exercise MPI in patients with coronary-obstructive disease. Thus, although the MPI does not correctly identify all patients with either coronary-obstructive disease or normal coronary arteries, it is helpful in patients who have a nondiagnostic GTX. Furthermore, when used in combination with the GTX, the MPI significantly increases the likelihood that significant coronary-obstructive disease is present when both tests are positive, and that coronary disease is absent when both tests are negative

Role of secretory phospholipase A(2) in rhythmic contraction of pulmonary arteries of rats with monocrotaline-induced pulmonary arterial hypertension.

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Tanabe, Yoshiyuki; Saito-Tanji, Maki; Morikawa, Yuki; Kamataki, Akihisa; Sawai, Takashi; Nakayama, Koichi

2012-01-01

Excessive stretching of the vascular wall in accordance with pulmonary arterial hypertension (PAH) induces a variety of pathogenic cellular events in the pulmonary arteries. We previously reported that indoxam, a selective inhibitor for secretory phospholipase A(2) (sPLA(2)), blocked the stretch-induced contraction of rabbit pulmonary arteries by inhibition of untransformed prostaglandin H(2) (PGH(2)) production. The present study was undertaken to investigate involvement of sPLA(2) and untransformed PGH(2) in the enhanced contractility of pulmonary arteries of experimental PAH in rats. Among all the known isoforms of sPLA(2), sPLA(2)-X transcript was most significantly augmented in the pulmonary arteries of rats with monocrotaline-induced pulmonary hypertension (MCT-PHR). The pulmonary arteries of MCT-PHR frequently showed two types of spontaneous contraction in response to stretch; 27% showed rhythmic contraction, which was sensitive to indoxam and SC-560 (selective COX-1 inhibitor), but less sensitive to NS-398 (selective COX-2 inhibitor); and 47% showed sustained incremental tension (tonic contraction), which was insensitive to indoxam and SC-560, but sensitive to NS-398 and was attenuated to 45% of the control. Only the rhythmically contracting pulmonary arteries of MCT-PHR produced a substantial amount of untransformed PGH(2), which was abolished by indoxam. These results suggest that sPLA(2)-mediated PGH(2) synthesis plays an important role in the rhythmic contraction of pulmonary arteries of MCT-PHR.

Thallium-201 myocardial perfusion imaging at rest and during exercise. Comparative sensitivity to electrocardiography in coronary artery disease

International Nuclear Information System (INIS)

Bailey, I.K.; Griffith, L.S.C.; Rouleau, J.; Strauss, H.W.; Pitt, B.

1977-01-01

The sensitivity of myocardial perfusion imaging (MPI) using thallium-201 injected both at rest and during peak exercise was compared to simultaneously recorded 12 lead electrocardiography (ECG) for the detection of transient ischemia in 20 normal subjects and 63 patients with coronary artery disease (CAD). No significant perfusion defects or ECG changes were seen on either the rest or exercise studies in any of the normal subjects. Fifty-six percent of patients with CAD developed new perfusion defects with exercise compared to 38 percent who developed ischemic ST-segment depression (P < 0.02). However, when chest pain and/or ST depression were considered indices of ischemia, the sensitivity of exercise testing and thallium-201 MPI was similar. The increased sensitivity of MPI compared to ST-segment depression on the ECG was due to patients with baseline ECG abnormalities and those who failed to achieve 85 percent of predicted maximum heart rate with exercise. Analysis of the exercise results according to the extent of coronary artery disease revealed a progressive increase in both positive ECGs and MPI with the number of vessels involved. In patients with single vessel disease the MPI was more sensitive than the ECG (P < 0.02). The combination of the rest and exercise ECG, MPI and chest pain during exercise failed to identify 11 percent of patients with CAD. Exercise thallium-201 MPI is a useful adjunct to conventional exercise testing particularly when evaluating patients with abnormal resting ECGs, those who develop ventricular conduction defects or arrhythmias during exercise, and those who fail to achieve their predicted heart rate because of fatigue or breathlessness

Arterial function of carotid and brachial arteries in postmenopausal vegetarians

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Su T

2011-08-01

Full Text Available Ta-Chen Su1, Pao-Ling Torng2, Jiann-Shing Jeng3, Ming-Fong Chen1, Chiau-Suong Liau1,41Division of Cardiology, Department of Internal Medicine, 2Department of Obstetrics and Gynecology, 3Department of Neurology, National Taiwan University Hospital, National Taiwan University College of Medicine, 4Cardiovascular Center, Taipei Buddist Tzu-Chi Hospital, Hsin-Dian, Taipei, TaiwanBackground: Vegetarianism is associated with a lower risk of cardiovascular disease. However, studies of arterial function in vegetarians are limited.Methods: This study investigated arterial function in vegetarianism by comparing 49 healthy postmenopausal vegetarians with 41 age-matched omnivores. The arterial function of the common carotid artery was assessed by carotid duplex, while the pulse dynamics method was used to measure brachial artery distensibility (BAD, compliance (BAC, and resistance (BAR. Fasting blood levels of glucose, lipids, lipoprotein (a, high-sensitivity C-reactive protein, homocysteine, and vitamin B12 were also measured.Results: Vegetarians had significantly lower serum cholesterol, high-density and low-density lipoprotein, and glucose compared with omnivores. They also had lower vitamin B12 but higher homocysteine levels. Serum levels of lipoprotein (a and high-sensitivity C-reactive protein were no different between the two groups. There were no significant differences in carotid beta stiffness index, BAC, and BAD between the two groups even after adjustment for associated covariates. However, BAR was significantly lower in vegetarians than in omnivores. Multiple linear regression analysis revealed that age and pulse pressure were two important determinants of carotid beta stiffness index and BAD. Vegetarianism is not associated with better arterial elasticity.Conclusion: Apparently healthy postmenopausal vegetarians are not significantly better in terms of carotid beta stiffness index, BAC, and BAD, but have significantly decreased BAR than

Preferential expression and function of voltage-gated, O2-sensitive K+ channels in resistance pulmonary arteries explains regional heterogeneity in hypoxic pulmonary vasoconstriction: ionic diversity in smooth muscle cells.

Science.gov (United States)

Archer, Stephen L; Wu, Xi-Chen; Thébaud, Bernard; Nsair, Ali; Bonnet, Sebastien; Tyrrell, Ben; McMurtry, M Sean; Hashimoto, Kyoko; Harry, Gwyneth; Michelakis, Evangelos D

2004-08-06

Hypoxic pulmonary vasoconstriction (HPV) is initiated by inhibition of O2-sensitive, voltage-gated (Kv) channels in pulmonary arterial smooth muscle cells (PASMCs). Kv inhibition depolarizes membrane potential (E(M)), thereby activating Ca2+ influx via voltage-gated Ca2+ channels. HPV is weak in extrapulmonary, conduit pulmonary arteries (PA) and strong in precapillary resistance arteries. We hypothesized that regional heterogeneity in HPV reflects a longitudinal gradient in the function/expression of PASMC O2-sensitive Kv channels. In adult male Sprague Dawley rats, constrictions to hypoxia, the Kv blocker 4-aminopyridine (4-AP), and correolide, a Kv1.x channel inhibitor, were endothelium-independent and greater in resistance versus conduit PAs. Moreover, HPV was dependent on Kv-inhibition, being completely inhibited by pretreatment with 4-AP. Kv1.2, 1.5, Kv2.1, Kv3.1b, Kv4.3, and Kv9.3. mRNA increased as arterial caliber decreased; however, only Kv1.5 protein expression was greater in resistance PAs. Resistance PASMCs had greater K+ current (I(K)) and a more hyperpolarized E(M) and were uniquely O2- and correolide-sensitive. The O2-sensitive current (active at -65 mV) was resistant to iberiotoxin, with minimal tityustoxin sensitivity. In resistance PASMCs, 4-AP and hypoxia inhibited I(K) 57% and 49%, respectively, versus 34% for correolide. Intracellular administration of anti-Kv1.5 antibodies inhibited correolide's effects. The hypoxia-sensitive, correolide-insensitive I(K) (15%) was conducted by Kv2.1. Anti-Kv1.5 and anti-Kv2.1 caused additive depolarization in resistance PASMCs (Kv1.5>Kv2.1) and inhibited hypoxic depolarization. Heterologously expressed human PASMC Kv1.5 generated an O2- and correolide-sensitive I(K) like that in resistance PASMCs. In conclusion, Kv1.5 and Kv2.1 account for virtually all the O2-sensitive current. HPV occurs in a Kv-enriched resistance zone because resistance PASMCs preferentially express O2-sensitive Kv-channels.

Effects of Some Indigenous Plants of North Karnataka (India) on Cardiovascular and Glucose Regulatory Systems in Alloxan-Induced Diabetic Rats.

Science.gov (United States)

Das, Kusal K; Chadchan, Kailash S; Reddy, R Chandramouli; Biradar, M S; Kanthe, Pallavi S; Patil, Bheemshetty S; Ambekar, Jeevan G; Bagoji, Ishwar B; Das, Swastika

2017-11-08

Kenaf (Hibiscus cannabinus Linn, Pundi), Chick pea (Cicer arietinum Linn, Chana) and Prickly lettuce (Lactuca scariola Linn, Hattaraki) leaves are a few of indigenous plants which are routinely consumed by the people of north Karnataka in the diet. Studies on these plants showed some potential anti-diabetic efficacies. To examine the effect of leaves extracts of Hibiscus cannabinus Linn, Cicer arietinum Linn and Lactuca scariola Linn on cardiovascular integrity, glucose homeostasis and oxygen sensing cell signaling mechanisms in alloxan induced diabetic rats. In vitro and in vivo tests on glucose regulatory systems and molecular markers such as - NOS3, HIF- 1α and VEGF were conducted in alloxan induced diabetic rats supplemented with all the three plant extracts. Electrophysiological analysis (HRV, LF: HF ratio, baroreflex sensitivity, BRS) and histopathogy of myocardial tissues and elastic artery were evaluated in diabetic rats treated with L. scariola linn. Out of these three plant extracts, Lactuca scariola Linn supplementation showed significant beneficial effects on glucose homeostasis and oxygen sensing cell signaling pathways in alloxaninduced diabetic rats. Furthermore, effects of sub chronic supplementation of Lactuca scariola Linn aqueous extracts showed significant improvement in sympatho-vagal balance in diabetic rats by increase of Heart Rate Variability (HRV) and regaining of Baroreflex Sensitivity (BRS). These results were also corroborated with myocardial and elastic artery histopathology of Lactuca scariola Linn supplemented diabetic rats. These findings indicate an adaptive pathway for glucose homeostasis, oxygen sensing cell signaling mechanisms and cardio protective actions in alloxan - induced diabetic rats supplemented with Lactuca scariola Linn extracts. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

High-NaCl diet impairs dynamic renal blood flow autoregulation in rats with adenine-induced chronic renal failure

DEFF Research Database (Denmark)

Saeed, Aso; DiBona, Gerald F; Grimberg, Elisabeth

2014-01-01

This study examined the effects of 2 wk of high-NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without...... arterial pressure variability (SAPV), and heart rate variability were assessed by spectral analytical techniques. Rats with ACRF showed marked reductions in glomerular filtration rate and renal blood flow (RBF), whereas mean arterial pressure and SAPV were significantly elevated. In addition, spontaneous...... adenine (controls). After 10 wk, rats were randomized to either remain on the same diet (0.6% NaCl) or to be switched to high 4% NaCl chow. Two weeks after randomization, renal clearance experiments were performed under isoflurane anesthesia and dynamic RBFA, baroreflex sensitivity (BRS), systolic...

A study of arteries of foot by flow sensitive dephasing prepared balanced steady-state free precession MR angiography in diabetes

International Nuclear Information System (INIS)

Zou Liqiu; Liu Xiaoyi; Liu Xin; Feng Fei; Qi Yulong; Liu Pengcheng

2011-01-01

Objective: To investigate balanced steady-state free precession with flow-sensitive dephasing magnetization preparation (FSD-bSSFP) in the assessment of arteries of foot in diabetic patients. Methods: The lower-extremity peripheral arteries of 43 diabetic patients were evaluated by FSD-bSSFP no contrast MRA and contrast-enhanced MRA (CE-MRA) in. Two experienced observers assessed the image quality, degree of venous contaminated and visibility of pedal artery branches by FSD-bSSFP and CE-MRA respectively in consensus. The signal intensity (SI), signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the source images of both groups were measured and Wilcoxon and t tests were performed. Results: The image score of FSD-bSSFP group was 2.7±1.1 and CE-MRA was 2.6±0.8, there was no statistical difference (Z= 0.134, P>0.05). The image score of demonstration of the pedal artery branches and degree of venous contamination on FSD-bSSFP were 3.2±0.9 and 1.8±0.4 respectively which were superior to that of CE-MRA (2.5±0.9 and 2.1±0.8 respectively). Significant statistical difference existed between the two groups in demonstration of pedal artery branches (Z=5.246, P 0.05). But CNR of CE-MRA was superior to that of FSD-bSSFP and significant statistical difference existed between these two methods (t=5.113, P<0.01). Conclusion: FSD-bSSFP without contrast could be used in the evaluation of foot arteries in patients of renal dysfunction and diabetes. (authors)

Arterial stiffness and cognitive impairment.

Science.gov (United States)

Li, Xiaoxuan; Lyu, Peiyuan; Ren, Yanyan; An, Jin; Dong, Yanhong

2017-09-15

damages the cerebral microcirculation, which causes various phenomena associated with cerebral small vessel diseases (CSVDs), such as white matter hyperintensities (WMHs), cerebral microbleeds (CMBs), and lacunar infarctions (LIs). The mechanisms underlying the relationship between arterial stiffness and cognitive impairment may also be associated with reductions in white matter and gray matter integrity, medial temporal lobe atrophy and Aβ protein deposition. Engaging in more frequent physical exercise; increasing flavonoid and long-chain n-3 polyunsaturated fatty acid consumption; increasing tea, nitrite, dietary calcium and vitamin D intake; losing weight and taking medications intended to improve insulin sensitivity; quitting smoking; and using antihypertensive drugs and statins are early interventions and lifestyle changes that may be effective in preventing arterial stiffness and thus preventing cognitive impairment. Arterial stiffness is a sensitive predictor of cognitive impairment, and arterial stiffness severity has the potential to serve as an indicator used to facilitate treatments designed to prevent or delay the onset and progression of dementia in elderly individuals. Early treatment of arterial stiffness is beneficial and recommended. Copyright © 2017 Elsevier B.V. All rights reserved.

Autonomic control of the heart is altered in Sprague-Dawley rats with spontaneous hydronephrosis

Science.gov (United States)

Arnold, Amy C.; Shaltout, Hossam A.; Gilliam-Davis, Shea; Kock, Nancy D.

2011-01-01

The renal medulla plays an important role in cardiovascular regulation, through interactions with the autonomic nervous system. Hydronephrosis is characterized by substantial loss of renal medullary tissue. However, whether alterations in autonomic control of the heart are observed in this condition is unknown. Thus we assessed resting hemodynamics and baroreflex sensitivity (BRS) for control of heart rate in urethane/chloralose-anesthetized Sprague-Dawley rats with normal or hydronephrotic kidneys. While resting arterial pressure was similar, heart rate was higher in rats with hydronephrosis (290 ± 12 normal vs. 344 ± 11 mild/moderate vs. 355 ± 13 beats/min severe; P hydronephrosis, with no differences in measures of indirect sympathetic activity among conditions. As a secondary aim, we investigated whether autonomic dysfunction in hydronephrosis is associated with activation of the renin-angiotensin system (RAS). There were no differences in circulating angiotensin peptides among conditions, suggesting that the impaired autonomic function in hydronephrosis is independent of peripheral RAS activation. A possible site for angiotensin II-mediated BRS impairment is the solitary tract nucleus (NTS). In normal and mild/moderate hydronephrotic rats, NTS administration of the angiotensin II type 1 receptor antagonist candesartan significantly improved the BRS, suggesting that angiotensin II provides tonic suppression to the baroreflex. In contrast, angiotensin II blockade produced no significant effect in severe hydronephrosis, indicating that at least within the NTS baroreflex suppression in these animals is independent of angiotensin II. PMID:21460193

Multislice CT Angiography in Renal Artery Stent Evaluation: Prospective Comparison with Intra-Arterial Digital Subtraction Angiography

International Nuclear Information System (INIS)

Raza, Syed A.; Chughtai, Aamer R.; Wahba, Mona; Cowling, Mark G.; Taube, David; Wright, Andrew R.

2004-01-01

Purpose: To assess the role of multislice computed tomography angiography (MCTA) in the evaluation of renal artery stents, using intra-arterial digital subtraction angiography (DSA) as the gold standard. Methods: Twenty consecutive patients (15 men, 5 women) with 23 renal artery stents prospectively underwent both MCTA and DSA. Axial images, multiplanar reconstructions and maximum intensity projection images were used for diagnosis. The MCTA and DSA images were each interpreted without reference to the result of the other investigation. Results:The three cases of restenosis on DSA were detected correctly by MCTA; in 19 cases where MCTA showed a fully patent stent, the DSA was also negative. Sensitivity and negative predictive value (NPV) of MCTA were therefore 100%. In four cases, MCTA showed apparently minimal disease which was not shown on DSA. These cases are taken as false positive giving a specificity of 80% and a positive predictive value of 43%. Conclusion: The high sensitivity and NPV suggest MCTA may be useful as a noninvasive screen for renal artery stentrestenosis. MCTA detected mild disease in a few patients which was not confirmed on angiography

[Twenty-four hour time and frequency domain variability of systolic blood pressure and heart rate in an experimental model of arterial hypertension plus obesity].

Science.gov (United States)

Pelat, M; Verwaerde, P; Lazartiques, E; Cabrol, P; Galitzky, J; Berlan, M; Montastruc, J L; Senard, J M

1998-08-01

Modifications of heart rate (HR) and systolic blood pressure (SBP) variabilities (V) have been reported in the human syndrome arterial hypertension plus insulin-resistance. The aim of this study was to characterize the 24 h SBPV and HRV in both time and frequency domains during weight increase in dogs fed ad libitum with a high fat diet. Implantable transmitter units for measurement of blood pressure and heart rate were surgically implanted in five beagle male dogs. BP and HR were continuously recorded using telemetric measurements during 24 hours, before and after 6 and 9 weeks of hypercaloric diet in quiet animals submitted to a 12h light-dark cycle. To study nychtemeral cycle of SBP and HR, two periods were chosen: day (from 6.00 h to 19.00 h) and night (from 23.00 h to 6.00 h). Spontaneous baroreflex efficiency was measured using the sequence method. Spectral variability of HR and SBP was analyzed using a fast Fourier transformation on 512 consecutive values and normalized units of low (LF: 50-150 mHz, reflecting sympathetic activity) and high (HF: respiratory rate +/- 50 mHz, reflecting parasympathetic activity) frequency bands were calculated. The energy of total spectrum (from 0.004 to 1 Hz) was also studied. Body weight (12.4 +/- 0.9 vs 14.9 +/- 0.9 kg, p vs 147 +/- 1 mmHg, p vs night: 71 +/- 1 bpm) but not after 9 weeks (day: 91 +/- 4 bpm ; night: 86 +/- 2 bpm). Concomitantly, the efficiency of spontaneous baroreflex decreased at 6 weeks (36 +/- 1 vs 42 +/- 2 mmHg/ms, p energy of HRV was found after 6 but not after 9 weeks. LF energy of SBPV was increased at 6 but not at 9 weeks (table). [table: see text] In conclusion, this study shows that an hyperlipidic and hypercaloric diet induces transient variations in autonomic nervous system activity which could be the physiopathological link between obesity, insulin-resistance and arterial hypertension.

Computerized analysis of coronary artery disease: Performance evaluation of segmentation and tracking of coronary arteries in CT angiograms

Energy Technology Data Exchange (ETDEWEB)

Zhou, Chuan, E-mail: chuan@umich.edu; Chan, Heang-Ping; Chughtai, Aamer; Kuriakose, Jean; Agarwal, Prachi; Kazerooni, Ella A.; Hadjiiski, Lubomir M.; Patel, Smita; Wei, Jun [Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2014-08-15

Purpose: The authors are developing a computer-aided detection system to assist radiologists in analysis of coronary artery disease in coronary CT angiograms (cCTA). This study evaluated the accuracy of the authors’ coronary artery segmentation and tracking method which are the essential steps to define the search space for the detection of atherosclerotic plaques. Methods: The heart region in cCTA is segmented and the vascular structures are enhanced using the authors’ multiscale coronary artery response (MSCAR) method that performed 3D multiscale filtering and analysis of the eigenvalues of Hessian matrices. Starting from seed points at the origins of the left and right coronary arteries, a 3D rolling balloon region growing (RBG) method that adapts to the local vessel size segmented and tracked each of the coronary arteries and identifies the branches along the tracked vessels. The branches are queued and subsequently tracked until the queue is exhausted. With Institutional Review Board approval, 62 cCTA were collected retrospectively from the authors’ patient files. Three experienced cardiothoracic radiologists manually tracked and marked center points of the coronary arteries as reference standard following the 17-segment model that includes clinically significant coronary arteries. Two radiologists visually examined the computer-segmented vessels and marked the mistakenly tracked veins and noisy structures as false positives (FPs). For the 62 cases, the radiologists marked a total of 10191 center points on 865 visible coronary artery segments. Results: The computer-segmented vessels overlapped with 83.6% (8520/10191) of the center points. Relative to the 865 radiologist-marked segments, the sensitivity reached 91.9% (795/865) if a true positive is defined as a computer-segmented vessel that overlapped with at least 10% of the reference center points marked on the segment. When the overlap threshold is increased to 50% and 100%, the sensitivities were 86

Diagnosis of renal artery stenosis : spiral CTA vs. IA-DSA

International Nuclear Information System (INIS)

Kim, Tae Sung; Chung, Jin Wook; Park, Jae Hyung; Kim, Seung Hyup; Yeon, Kyung Mo; Han, Man Chung

1996-01-01

To evaluate the accuracy of spiral CT angiography(CTA) in the demonstration of accessory or multiple renal arteries and renal artery stenosis. We prospectively performed CTA in 50 patients (24 males and 26 females) between nine and 77 years old (mean 39.3) in whom renovascular hypertension was suspected (n=32), or who were potential renal donors (n=18). Within two days of CTA, intraarterial digital subtraction angiography(IA-DSA) was performed. Both spiral CTA and IA-DSA images were blindly compared by two radiologists with respect to the number of accessory renal arteries and the location and severity of renal artery stenosis. The severity of renal arterial stenosis was graded with a five-point scale (grades 0-4). CTA demonstrated 26 of total 27 accessory renal arteries (detection rate=96.5%). For the diagnosis of grade 2-4 stenosis (≥50% stenosis) (n=40 of a total of 127 renal arteries), the sensitivity, specificity, and accuracy of CTA were 90%, 96.5%, and 94.5%, respectively. For the detection of grade 3-4 stenoses (≥75% stenosis) (n=33), the sensitivity, specificity, and accuracy of CTA were 87.9%, 98.9%, and 96.1%, respectively. For the detection of grade 3-4 stenoses in the main renal artery (n=27), the sensitivity, specificity, and accuracy of CTA were 96.3%, 100%, and 99.0%, respectively. Spiral CTA is a reliable and accurate screening modality for the evaluation of renal artery in patients suspected to be suffering from renovascular hypertension, or who are potential renal donors

Noncontrast MR angiography (MRA) of infragenual arteries using flow-sensitive dephasing (FSD)-prepared steady-state free precession (SSFP) at 3.0 Tesla: Comparison with contrast-enhanced MRA.

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Zhang, Nan; Fan, Zhaoyang; Luo, Nan; Bi, Xiaoming; Zhao, Yike; An, Jing; Liu, Jiayi; Chen, Zhong; Fan, Zhanming; Li, Debiao

2016-02-01

To evaluate the feasibility and diagnostic performance of flow-sensitive dephasing (FSD)-prepared steady-state free precession (SSFP) MR angiography (MRA) for imaging infragenual arteries at 3.0T, with contrast enhanced MR angiography (CE MRA) as reference. Twenty consecutive patients with suspicion of lower extremity arterial disease undergoing routine CE MRA were recruited. FSD MRA was performed at calf before CE MRA. Image quality and stenosis degree of infragenual arteries from both techniques were independently evaluated and compared. Six patients in this study underwent DSA examination. Three undiagnostic segments were excluded with severe venous contamination in CE MRA. A total of 197 calf arterial segments images were analyzed. No significant difference existed in the relative signal intensity (rSI) of arterial segments between FSD MRA and CE MRA techniques (0.92 ± 0.09 versus 0.93 ± 0.05; P = 0.207). However, the subjective image quality score was slightly higher in FSD MRA (3.66 ± 0.81 versus 3.49 ± 0.87; P = 0.050). With CE MRA images as reference standard, slight overestimation existed in FSD MRA (2.19 ± 1.24 versus 2.09 ± 1.18; P = 0.019), with total agreement of 84.3% on the basis of all arterial segments. The sensitivity, specificity, negative predictive value, and positive predictive value of FSD MRA was 96.4%, 93.0%, 98.5%, and 84.1%. No significant difference in the stenosis degree score was detected between MRA (FSD MRA and CE MRA) and DSA (P > 0.05). FSD MRA performed on at 3.0T without the use of contrast medium provides diagnostic images allowing for arterial stenosis assessment of calf arteries that was highly comparable with CE MRA. Moreover, venous contamination was less problematic with FSD MRA. © 2015 Wiley Periodicals, Inc.

Pressure drop and arterial compliance - Two arterial parameters in one measurement.

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Rotman, Oren M; Zaretsky, Uri; Shitzer, Avraham; Einav, Shmuel

2017-01-04

Coronary artery pressure-drop and distensibility (compliance) are two major, seemingly unrelated, parameters in the cardiovascular clinical setting, which are indicative of coronary arteries patency and atherosclerosis severity. While pressure drop is related to flow, and therefore serves as a functional indicator of a stenosis severity, the arterial distensibility is indicative of the arterial stiffness, and hence the arterial wall composition. In the present study, we hypothesized that local pressure drops are dependent on the arterial distensibility, and hence can provide information on both indices. The clinical significance is that a single measurement of pressure drop could potentially provide both functional and bio-mechanical metrics of lesions, and thus assist in real-time decision making prior to stenting. The goal of the current study was to set the basis for understanding this relationship, and define the accuracy and sensitivity required from the pressure measurement system. The investigation was performed using numerical fluid-structure interaction (FSI) simulations, validated experimentally using our high accuracy differential pressure measurement system. Simplified silicone mock coronary arteries with zero to intermediate size stenoses were used, and various combinations of arterial distensibility, diameter, and flow rate were simulated. Results of hyperemic flow cases were also compared to fractional flow reserve (FFR). The results indicate the potential clinical superiority of a high accuracy pressure drop-based parameter over FFR, by: (i) being more lesion-specific, (ii) the possibility to circumvent the FFR dependency on pharmacologically-induced hyperemia, and, (iii) by providing both functional and biomechanical lesion-specific information. Copyright © 2016 Elsevier Ltd. All rights reserved.

Predictive value of auscultation of femoropopliteal arteries.

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Kaufmann, Carla; Jacomella, Vincenzo; Kovacicova, Ludmila; Husmann, Marc; Clemens, Robert K; Thalhammer, Christopf; Amann-Vesti, Beatrice R

2013-03-05

Femoropopliteal bruits indicate flow turbulences and increased blood flow velocity, usually caused by an atherosclerotic plaque or stenosis. No data exist on the quality of bruits as a means for quantifying the degree of stenosis. We therefore conducted a prospective observational study to investigate the sensitivity and specificity of femoropopliteal auscultation, differentiated on the basis of bruit quality, to detect and quantify clinically relevant stenoses in patients with symptomatic and asymptomatic peripheral arterial disease (PAD). Patients with known chronic and stable PAD were recruited in the outpatient clinic. We included patients with known PAD and an ankle-brachial index (ABI) Auscultation was performed independently by three investigators with varied clinical experience after a 10-minute period of rest. Femoropopliteal lesions were classified as follows: normal vessel wall or slight wall thickening (auscultation were low in all vascular regions and did not differ between investigators. Sensitivity was low in most areas with an increase after exercise. The highest sensitivity in detecting relevant (>50%) stenosis was found in the common femoral artery (86%). Vascular auscultation is known to be of great use in routine clinical practice in recognising arterial abnormalities. Diagnosis of PAD is based on various diagnostic tools (pulse palpation, ABI measurement) and auscultation can localise relevant stenosis. However, auscultation alone is of limited sensitivity and specificity in grading stenosis in femoropopliteal arteries. Where PAD is clinically suspected further diagnostic tools, especially colour-coded duplex ultrasound, should be employed to quantify the underlying lesion.

Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

International Nuclear Information System (INIS)

Pedersen, Michael; Aarhus Univ.; Univ. Victor Segalen Bordeaux 2; Laustsen, Christoffer; Perot, Vincent; Grenier, Nicolas; Basseau, Fabrice; Moonen, Chrit

2010-01-01

Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2 * , and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2 * was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

Energy Technology Data Exchange (ETDEWEB)

Pedersen, Michael [Aarhus Univ. Hospital (Denmark). MR Research Centre; Aarhus Univ. (Denmark). Inst. of Experimental Clinical Medicine; Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231; Laustsen, Christoffer [Aarhus Univ. Hospital (Denmark). MR Research Centre; Perot, Vincent; Grenier, Nicolas [Hopital Pellegrin, CHU Bordeaux (France). Service d' Imagerie Diagnostique et Therapeutique de l' Adulte; Basseau, Fabrice; Moonen, Chrit [Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231

2010-07-01

Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2{sup *}, and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2{sup *} was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

Assessment of coronary artery disease with nicorandil stress magnetic resonance imaging

International Nuclear Information System (INIS)

Kawase, Yoshio; Nichimoto, Masaki; Hato, Katsunori; Okajima, Kazue; Yoshikawa, Junichi

2004-01-01

Although dipyridamole and adenosine have been used as vasodilator agents, we believe they are inadequate for vasodilator perfusion magnetic resonance imaging, due to adverse effects (flushing, warmth, headaches, and arrhythmia). Nicorandil, a potassium channel opener, has been reported to increase coronary blood flow and it was associated with fewer adverse effects than adenosine or dipiridamole. We set out to investigate whether the coronary artery stenosis could be assessed by nicorandil stress perfusion magnetic resonance imaging. First-pass contrast-enhanced magnetic resonance images of the left ventricle acquired from 50 patients at rest and during intravenous administration of nicorandil using multi-slice turbo field echo with multi shot echo-planar-imaging. Coronary angiography was performed within 1 week. There was no adverse effects during nicorandil stress in any patients. The overall sensitivity and specificity of magnetic resonance imaging in identifying patients with significant stenosis of at least one coronary artery were 93.9% (31 of 33 patients) and 94.1% (16 of 17 patients), respectively. The sensitivity of magnetic resonance imaging for detecting significant stenosis in the left anterior descending artery was 87.5%; the sensitivity in the left circumflex artery was 80%; the sensitivity in the right coronary artery was 92.3%. Similar sensitivities were observed for all 3 vascular regions, indicating that all myocardial segments were visualized with similar image quality. The present study shows that nicorandil stress perfusion magnetic resonance imaging is a safe, feasible technique for assessing coronary artery stenosis severity in a totally-noninvasive manner. (authors)

Renal artery stenosis: comparative assessment by unenhanced renal artery mra versus contrast-enhanced MRA

International Nuclear Information System (INIS)

Khoo, Michael M.Y.; Deeab, Dhafer; Gedroyc, Wladyslaw M.W.; Dick, Elizabeth A.; Duncan, Neil; Taube, David

2011-01-01

To evaluate steady-state free precession (SSFP) non-contrast-enhanced MR angiography (Unenhanced-MRA) versus conventional contrast-enhanced MR angiography (CE-MRA) in the detection of renal artery stenosis (RAS). Retrospective analysis of 70 consecutive patients referred for suspected RAS, examined by SSFP Unenhanced-MRA and CE-MRA. Image quality, quality of visible renal arterial segments, presence and grade of RAS were evaluated. The Unenhanced-MRA were compared against reference standard CE-MRA results. 149 renal arteries were assessed with 21 haemodynamically significant stenoses (≥50% stenosis) demonstrated by CE-MRA. Combined sensitivity and specificity for RAS detection by Unenhanced-MRA was 72.8% and 97.8% respectively. There is substantial correlation for RAS detection between Unenhanced-MRA and CE-MRA with kappa values of between 0.64 and 0.74. There was excellent inter-observer correlation for RAS on Unenhanced-MRA (kappa values 0.82-1.0). Our study has shown Unenhanced-MRA to be a viable alternative to CE-MRA, yielding images equal in quality without the requirement for gadolinium contrast agents. The sensitivity and specificity for the detection of haemodynamically significant stenoses are comparable to CE-MRA. Potentially, Unenhanced-MRA could be used as an initial investigation to avoid performing CE-MRA in patients with normal renal arteries, however we suggest that its real value will lie in being complementary to CE-MRA. (orig.)

Bidirectional interactions between the baroreceptor reflex and arousal: an update.

Science.gov (United States)

Silvani, Alessandro; Calandra-Buonaura, Giovanna; Benarroch, Eduardo E; Dampney, Roger A L; Cortelli, Pietro

2015-02-01

Studies involving genetic engineering on animal models and mathematical analysis of cardiovascular signals on humans are shedding new light on the interactions between the arterial baroreceptor reflex (baroreflex) and arousal. Baroreceptor stimulation, if very mild or performed under anaesthesia, may inhibit cortical arousal. However, substantial increases or decreases in baroreflex activation cause arousal in animal models and human subjects in physiological conditions. On the other hand, cardiovascular changes during autonomic arousals and between the states of wakefulness and sleep involve changes in the baroreflex set point and balance with central autonomic commands. Neural connectivity and functional data suggest that the nucleus of the solitary tract, adrenergic C1 neurons of the medulla, and the parabrachial nucleus of the pons mediate the bidirectional interactions between the baroreflex and arousal. These interactions may constitute a positive feedback loop that facilitates sharp and coordinated brain state and autonomic transitions upon arousal: upon arousal, central autonomic commands may increase blood pressure, thereby loading baroreceptors and further increasing arousal. Anomalies of this feedback loop may play a role in the pathophysiology of disease conditions associated with cardiovascular and sleep-wake cycle alterations. These conditions include: obstructive sleep apnoea syndrome, with its association with excessive daytime sleepiness and baroreflex impairment; and insomnia, with its association with autonomic hyperarousal and hypertension. When faced with disorders associated with cardiovascular and sleep-wake cycle alterations, clinical reasoning should entertain the possibility that both conditions are strongly influenced by anomalies of baroreflex function. Copyright © 2014 Elsevier B.V. All rights reserved.

Spiral CT angiography of renal arteries: comparison with angiography

International Nuclear Information System (INIS)

Wittenberg, G.; Kenn, W.; Tschammler, A.; Sandstede, J.; Hahn, D.

1999-01-01

A prospective study was carried out to determine the accuracy of spiral CT angiography (CTA) in the detection of renal artery stenosis (RAS). Eighty-two patients with arterial hypertension underwent CTA and digital subtraction angiography (DSA) to exclude RAS. For CTA a contrast medium bolus of 100-150 ml (flow rate 3 ml/s) was injected. A 24 or 40 s CTA was started at the origin of the superior mesenteric artery after a delay time determined by test bolus injection (collimation = 2 mm, pitch = 1/1.5). For stenosis detection transverse images supported by maximum intensity projections (MIP) or multiplanar reconstruction projections were used. Of 197 renal arteries examined (including 33 accessory arteries), 34 RAS were visualized using DSA. With CTA, one hemodynamic RAS was missed and one additional hemodynamic RAS was found. Sensitivity/specificity was calculated to be 94 %/98 %. For hemodynamically relevant RAS (> 50 %) the sensitivity/specificity was 96 %/99 %. CTA additionally depicted five adrenal masses. The high accuracy rate of RAS detection thus allows the use of CTA as a screening method in patients with arterial hypertension to exclude a renovascular cause. (orig.)

Autonomic and Vascular Control in Prehypertensive Subjects with a Family History of Arterial Hypertension

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Josária Ferraz Amaral

2018-02-01

Full Text Available Abstract Background: Individuals with a family history of systemic arterial hypertension (FHSAH and / or prehypertension have a higher risk of developing this pathology. Objective: To evaluate the autonomic and vascular functions of prehypertensive patients with FHSAH. Methods: Twenty-five young volunteers with FHSAH, 14 normotensive and 11 prehypertensive subjects were submitted to vascular function evaluation by forearm vascular conductance(VC during resting and reactive hyperemia (Hokanson® and cardiac and peripheral autonomic modulation, quantified, respectively, by spectral analysis of heart rate (ECG and systolic blood pressure (SBP (FinometerPRO®. The transfer function analysis was used to measure the gain and response time of baroreflex. The statistical significance adopted was p ≤ 0.05. Results: Pre-hypertensive individuals, in relation to normotensive individuals, have higher VC both at rest (3.48 ± 1.26 vs. 2.67 ± 0.72 units, p = 0.05 and peak reactive hyperemia (25, 02 ± 8.18 vs. 18.66 ± 6.07 units, p = 0.04. The indices of cardiac autonomic modulation were similar between the groups. However, in the peripheral autonomic modulation, greater variability was observed in prehypertensive patients compared to normotensive individuals (9.4 [4.9-12.7] vs. 18.3 [14.8-26.7] mmHg2; p < 0.01 and higher spectral components of very low (6.9 [2.0-11.1] vs. 13.5 [10.7-22.4] mmHg2, p = 0.01 and low frequencies (1.7 [1.0-3.0] vs. 3.0 [2.0-4.0] mmHg2, p = 0.04 of SBP. Additionally, we observed a lower gain of baroreflex control in prehypertensive patients compared to normotensive patients (12.16 ± 4.18 vs. 18.23 ± 7.11 ms/mmHg, p = 0.03, but similar delay time (-1.55 ± 0.66 vs. -1.58 ± 0.72 s, p = 0.90. Conclusion: Prehypertensive patients with FHSAH have autonomic dysfunction and increased vascular conductance when compared to normotensive patients with the same risk factor.

Correlation between obstructive coronary artery disease and electron beam tomography coronary artery calcium scan

International Nuclear Information System (INIS)

Lee, Sang Hoon; Hong, Yong Kook; Park, Sung Il; Lee, Hyang Mee; Choe, Kyu Ok

1998-01-01

To determine the correlation between obstructive coronary artery disease and electron beam tomography coronary artery calcium(EBT CAC) scan and to measure the difference in calcium score according to symptoms. Materials and Methods : Fifty-six patients underwent EBT CAC scanning and either coronary angiography or stress thallium 201 scanning or the treadmill test. When the results were positive, coronary artery obstructive disease(CAOD) was assumed to be present. The patients were divided into three groups : symptomatic CAOD,asymptomatic CAOD, and asymptomatic non- CAOD; those with a previous history of myocardial ischemia or who showed positive results in any of the three tests relating to typical symptoms of angina were assigned to the symptomatic group. Results : The number of cases assigned to group to group 1,2 and 3 was 19, 16 and 21, respectively; total CAC scores were 571 ± 751, 600 ± 726 293± 401, respectively. The difference in CAC score between asymptomatic CAOD and asymptomatic non- CAOD was not statistically significant(p=0.079) but in asymptomatic CAOD, the score tended to be higher. The CAC score was not different between symptomatic and asymptomatic CAOD(p>0.1). When the CAC threshold was 1, sensitivity was 89% and specificity was 14%;when the threshold was 200, sensitivity was 60% and specificity was 67%. Conclusion : When the EBT CAC score is high, further evaluation provides early evidence of coronary artery obstructive disease

The effects of postural changes of baroreflex gain in normal and hypertensive pregnancies.

Science.gov (United States)

Miyake, Yoshiaki; Ohnishi, Miyako; Fujii, T K; Yamamoto, Tatsuo; Yoneda, Chika; Takahashi, Sachie; Ichimaru, Yuhei

2002-01-01

In order to understand the changes of baroreflex gain due to postural changes in normal pregnancies, we measured percentage changes (% changes) in blood pressure (SBP, DBP), heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) as well as cardiac autonomic nervous function (HF as an index of parasympathetic and LF/HF as an index of sympathetic function) and compared these parameters in normal pregnancies with those found in hypertensive pregnancies, such as chronic hypertensive (CHP) and severe preeclamptic pregnancies (PE), in late pregnancy (after 32 wks). When the position was changed from supine to standing in normal and non-pregnant women, the % changes of HR, DBP, TPR and LF/HF were increased and SBP, SV, CO and HF were decreased. The % changes of these parameters, however, were gradually decreased as pregnancy progressed, especially after 20-24 wks of gestation. In hypertensive pregnancies, however, even in late pregnancy, the decreased SBP and increased TPR was still observed and the profound decrease of CO and SV and increase of TPR were characteristic in PE when compared to CHP.

Direct Doppler auscultation of the carotid arteries

International Nuclear Information System (INIS)

Nix, L.

1984-01-01

The results of the carotid Doppler examinations and contrast arteriograms are presented. The overall sensitivity of the carotid Doppler examinations in detecting severe stenosis or occlusion of the carotid artery was 92%. The Doppler studies correctly differentiated these two conditions in 84% of the diseased vessels. In carotid arteries with stenosis greater than or equal to 50%, the sensitivity of the Doppler examinations was 90%, and these studies suggested stenosis in all but two of the 36 abnormal examinations. In two patent carotids with greater than 90% stenosis, a signal could not be elicited, presumably because of the low blood flow through the severely stenotic segment

Biosensor cell assay for measuring real-time aldosterone-induced release of histamine from mesenteric arteries

DEFF Research Database (Denmark)

Dalgaard, Emil G; Andersen, Kenneth; Svenningsen, Per

2017-01-01

as a sensitive biosensor assay for histamine release from isolated mouse mesenteric arteries. Activation of the H1 receptor by histamine was measured as an increased number of intracellular Ca(2+) transient peaks using fluorescence imaging RESULTS: The developed biosensor was sensitive to histamine...... in physiological relevant concentrations and responded to substances released by the artery preparation. Aldosterone treatment of mesenteric arteries from wild type mice for 50 minutes resulted in an increased number of intracellular Ca(2+) transient peaks in the biosensor cells, which was significantly inhibited...... by the histamine H1 blocker pyrilamine. Mesenteric arteries from mast cell deficient SASH mice induced similar pyrilamine-sensitive Ca(2+) transient response in the biosensor cells. Mesenteric arteries from wild type and SASH mice expressed histamine decarboxylase mRNA, indicating that mast cells are not the only...

Transesophageal echocardiography in the assessment of coronary arteries

International Nuclear Information System (INIS)

Adamek-Kosmider, A.; Kasprzak, J.; Kosmider, M.; Krzeminska-Pakula, M.

1993-01-01

The study was undertaken to assess the usefulness of TEE for evaluation of morphology and flow in coronary arteries. TEE (2D, spectral and color Doppler imaging) and coronary angiography were performed in 75 patients - 41 with valvular heart disease and 34 with ischemic heart disease. Proximal coronary artery stenosis was detected by coronarography in 11 pts (9-left main coronary artery, 2-right coronary artery). TEE visualization of proximal coronary arteries was possible in all pts. Echocardiographic features of artery stenosis were: the narrowing of the vessel in 2D image (9 pts), high flow velocity spectral Doppler (4 pts, mean 135 cm/s vs 55 cm/s in normal arteries) and mosaic, turbulent flow in color Doppler (10 pts). Sensitivity and specificity of TEE for coronary artery stenosis detection was respectively 81%/98% for 2D imaging and 90%/100% for color Doppler. TEE is a new, noninvasive and safe method for the evaluation of proximal coronary arteries. Detection of LMCA stenosis prior to atheterization may enhance the safety of coronary angiography. (author)

Blood pressure responses to dietary sodium: Association with autonomic cardiovascular function in normotensive adults.

Science.gov (United States)

Matthews, Evan L; Brian, Michael S; Edwards, David G; Stocker, Sean D; Wenner, Megan M; Farquhar, William B

2017-12-01

Blood pressure responses to dietary sodium vary widely person-to-person. Salt sensitive rodent models display altered autonomic function, a trait thought to contribute to poor cardiovascular health. Thus, we hypothesized that increased salt sensitivity (SS) in normotensive humans would be associated with increased muscle sympathetic nerve activity (MSNA), decreased high frequency heart rate variability (HF-HRV), and decreased baroreflex sensitivity. Healthy normotensive men and women completed 1week of high (300mmol·day -1 ) and 1week of low (20mmol·day -1 ) dietary sodium (random order) with 24h mean arterial pressure (MAP) assessed on the last day of each diet to assess SS. Participants returned to the lab under habitual sodium conditions for testing. Forty-two participants are presented in this analysis, 19 of which successful MSNA recordings were obtained (n=42: age 39±2yrs., BMI 24.3±0.5kg·(m 2 ) -1 , MAP 83±1mmHg, habitual urine sodium 93±7mmol·24h -1 ; n=19: MSNA burst frequency 20±2 bursts·min -1 ). The variables of interest were linearly regressed over the magnitude of SS. Higher SS was associated with increased MSNA (burst frequency: r=0.469, p=0.041), decreased HF-HRV (r=-0.349, p=0.046), and increased LF/HF-HRV (r=0.363, p=0.034). SS was not associated with sympathetic or cardiac baroreflex sensitivity (p>0.05). Multiple regression analysis accounting for age found that age, not SS, independently predicted HF-HRV (age adjusted no longer significant; p=0.369) and LF/HF-HRV (age adjusted p=0.273). These data suggest that age-related salt sensitivity of blood pressure in response to dietary sodium is associated with altered resting autonomic cardiovascular function. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of coronary artery disease by post-mortem cardiac MR

International Nuclear Information System (INIS)

Ruder, Thomas D.; Bauer-Kreutz, Regula; Ampanozi, Garyfalia; Rosskopf, Andrea B.; Pilgrim, Thomas M.; Weber, Oliver M.; Thali, Michael J.; Hatch, Gary M.

2012-01-01

Objectives: Minimally invasive or virtual autopsies are being advocated as alternative to traditional autopsy, but have limited abilities to detect coronary artery disease. It was the objective of this study to assess if the occurrence of chemical shift artifacts (CSA) along the coronary arteries on non-contrast, post-mortem cardiac MR may be used to investigate coronary artery disease. Methods: We retrospectively compared autopsy and CT findings of 30 cases with significant (≥75%), insignificant (<75%), or absent coronary artery stenosis to post-mortem cardiac MR findings. The chi-square test was used to investigate if the occurrence of CSA depends on the presence or absence of stenosis. Sensitivity, specificity and predictive values were calculated for each finding. Results: CSA indicates the absence of (significant) stenosis (p < 0.001). The occurrence of paired dark bands in lieu of CSA on post-mortem cardiac MR suggests (significant) coronary arteries stenosis (p < 0.001). Both findings have a high specificity but low sensitivity. Conclusions: CSA is a marker of vessel patency. The presence of paired dark bands indicates stenosis. These criteria improve the ability of minimally invasive or virtual autopsy to detect coronary artery disease related deaths

Sex differences in flexibility-arterial stiffness relationship and its application for diagnosis of arterial stiffening: a cross-sectional observational study.

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Masato Nishiwaki

Full Text Available Arterial stiffness might be related to trunk flexibility in middle-aged and older participants, but it is also affected by age, sex, and blood pressure. This cross-sectional observational study investigated whether trunk flexibility is related to arterial stiffness after considering the major confounding factors of age, sex, and blood pressure. We further investigated whether a simple diagnostic test of flexibility could be helpful to screen for increased arterial stiffening.According to age and sex, we assigned 1150 adults (male, n = 536; female, n = 614; age, 18-89 y to groups with either high- or poor-flexibility based on the sit-and-reach test. Arterial stiffness was assessed by cardio-ankle vascular index.In all categories of men and in older women, arterial stiffness was higher in poor-flexibility than in high-flexibility (P<0.05. This difference remained significant after normalizing arterial stiffness for confounding factors such as blood pressure, but it was not found among young and middle-aged women. Stepwise multiple-regression analysis also supported the notion of the sex differences in flexibility-arterial stiffness relationship. Receiver operating characteristic curve analysis revealed that cut-off values for sit-and-reach among men and women were 33.2 (area under the curve [AUC], 0.711; 95% confidence interval [CI], 0.666-0.756; sensitivity, 61.7%; specificity, 69.7% and 39.2 (AUC, 0.639; 95% CI, 0.592-0.686; sensitivity, 61.1%; specificity, 62.0% cm, respectively.Our results indicate that flexibility-arterial stiffness relationship is not affected by BP, which is a major confounding factor. In addition, sex differences are observed in this relationship; poor trunk flexibility increases arterial stiffness in young, middle-aged, and older men, whereas the relationship in women is found only in the elderly. Also, the sit-and-reach test can offer a simple method of predicting arterial stiffness at home or elsewhere.

Extrahepatic Arteries Originating from Hepatic Arteries: Analysis Using CT During Hepatic Arteriography and Visualization on Digital Subtraction Angiography

International Nuclear Information System (INIS)

Ozaki, Kumi; Kobayashi, Satoshi; Matsui, Osamu; Minami, Tetsuya; Koda, Wataru; Gabata, Toshifumi

2017-01-01

PurposeTo investigate the prevalence and site of origin of extrahepatic arteries originating from hepatic arteries on early phase CT during hepatic arteriography (CTHA) was accessed. Visualization of these elements on digital subtraction hepatic angiography (DSHA) was assessed using CTHA images as a gold standard.Materials and MethodsA total of 943 patients (mean age 66.9 ± 10.3 years; male/female, 619/324) underwent CTHA and DSHA. The prevalence and site of origin of extrahepatic arteries were accessed using CTHA and visualized using DSHA.ResultsIn 924 (98.0%) patients, a total of 1555 extrahepatic branches, representing eight types, were found to originate from hepatic arteries on CTHA. CTHA indicated the following extrahepatic branch prevalence rates: right gastric artery, 890 (94.4%); falciform artery, 386 (40.9%); accessory left gastric artery, 161 (17.1%); left inferior phrenic artery (IPA), 43 (4.6%); posterior superior pancreaticoduodenal artery, 33 (3.5%); dorsal pancreatic artery, 26 (2.8%); duodenal artery, 12 (1.3%); and right IPA, 4 (0.4%). In addition, 383 patients (40.6%) had at least one undetectable branch on DSHA. The sensitivity, specificity, and accuracy of visualization on DSHA were as follows: RGA, 80.0, 86.8, and 80.4%; falciform artery, 53.9, 97.7, and 80.0%; accessory LGA, 64.6, 98.6, and 92.3%; left IPA, 76.7, 99.8, and 98.7%; PSPDA, 100, 99.7, and 99.9%; dorsal pancreatic artery, 57.7, 100, and 98.8%; duodenal artery, 8.3, 99.9, and 98.7%; and right IPA, 0, 100, and 99.6%, respectively.ConclusionExtrahepatic arteries originating from hepatic arteries were frequently identified on CTHA images. These arteries were frequently overlooked on DSHA.

Extrahepatic Arteries Originating from Hepatic Arteries: Analysis Using CT During Hepatic Arteriography and Visualization on Digital Subtraction Angiography

Energy Technology Data Exchange (ETDEWEB)

Ozaki, Kumi, E-mail: ozakik-rad@umin.org [Kanazawa University Graduate School of Medical Science, Department of Radiology (Japan); Kobayashi, Satoshi [Kanazawa University Graduate School of Medical Science, Department of Quantum Medicine Technology (Japan); Matsui, Osamu; Minami, Tetsuya; Koda, Wataru; Gabata, Toshifumi [Kanazawa University Graduate School of Medical Science, Department of Radiology (Japan)

2017-06-15

PurposeTo investigate the prevalence and site of origin of extrahepatic arteries originating from hepatic arteries on early phase CT during hepatic arteriography (CTHA) was accessed. Visualization of these elements on digital subtraction hepatic angiography (DSHA) was assessed using CTHA images as a gold standard.Materials and MethodsA total of 943 patients (mean age 66.9 ± 10.3 years; male/female, 619/324) underwent CTHA and DSHA. The prevalence and site of origin of extrahepatic arteries were accessed using CTHA and visualized using DSHA.ResultsIn 924 (98.0%) patients, a total of 1555 extrahepatic branches, representing eight types, were found to originate from hepatic arteries on CTHA. CTHA indicated the following extrahepatic branch prevalence rates: right gastric artery, 890 (94.4%); falciform artery, 386 (40.9%); accessory left gastric artery, 161 (17.1%); left inferior phrenic artery (IPA), 43 (4.6%); posterior superior pancreaticoduodenal artery, 33 (3.5%); dorsal pancreatic artery, 26 (2.8%); duodenal artery, 12 (1.3%); and right IPA, 4 (0.4%). In addition, 383 patients (40.6%) had at least one undetectable branch on DSHA. The sensitivity, specificity, and accuracy of visualization on DSHA were as follows: RGA, 80.0, 86.8, and 80.4%; falciform artery, 53.9, 97.7, and 80.0%; accessory LGA, 64.6, 98.6, and 92.3%; left IPA, 76.7, 99.8, and 98.7%; PSPDA, 100, 99.7, and 99.9%; dorsal pancreatic artery, 57.7, 100, and 98.8%; duodenal artery, 8.3, 99.9, and 98.7%; and right IPA, 0, 100, and 99.6%, respectively.ConclusionExtrahepatic arteries originating from hepatic arteries were frequently identified on CTHA images. These arteries were frequently overlooked on DSHA.

A quantitative method for studying human arterial baroreflexes

Science.gov (United States)

Eckberg, Dwain L.; Fritsch, Janice M.; Goble, Ross L.

1991-01-01

A new system is described that delivers precise, stereotyped pressure changes to the human neck and elicits neurally-mediated heart rate changes. The centerpiece of this system is a Silastic chamber that is strapped to the anterior neck. This chamber is connected to a stepping-motor-controlled bellows assembly. A strain-gauge transducer measures the intensity of pressure changes. The entire system is controlled by microprocessors, and both stimuli and responses are displayed on a digital oscilloscope. The end-product of this system is a reproducible baroreceptor stimulus-cardiac response relation that can be recorded rapidly and safely in astronauts in space.

Characteristics of arterial Na-K-ATPase in WKY and SHR

International Nuclear Information System (INIS)

Veit, E.I.; Cox, R.H.; Moisey, D.M.

1986-01-01

Segments of carotid and tail arteries and thoracic aorta from 12-week old male WKY and SHR were used to study Na-pump activity by 86 Rb-uptake method. Contiguous segments were used for the determination of cell Na content by ion substitution. The ouabain-dependence of maximum Na-pump activity was determined. The EC 50 value of ouabain (approximately 0.1 mM) was not significantly different for WKY and SHR arteries or at any of the three arterial sites. The maximum value of 86 Rb-uptake was significantly larger of all SHR arteries compared to WKY. No significant differences in ouabain-insensitive 86 Rb-uptake was found. No significant differences exist in estimates of cell Na in arteries from the two groups. Segments of arteries were stored in K-free PSS overnight at 2 0 C, and allowed to recover in normal PSS at 37 0 C for varying periods of time. Ouabain-sensitive 86 Rb-uptake and estimates of cell Na were determined during recovery from cold storage. There were no significant differences in the EC 50 value of Na, which produced a half-maximal ouabain-sensitive 86 Rb-uptake between WKY and SHR. The only difference observed in these studies was a larger turnover rate of the Na-pump in arteries from the SHR

Reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications

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Vilson Lacerda Brasileiro Junior

2014-02-01

Full Text Available Objective The present study evaluated the reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications. Materials and Methods Thirty-five patients under high-risk for development of carotid artery calcifications who had digital panoramic radiography were referred to undergo ultrasonography. Thus, 70 arteries were assessed by both methods. The main parameters utilized to evaluate the panoramic radiography reliability in the diagnosis of carotid artery calcifications were accuracy, sensitivity, specificity and positive predictive value of this method as compared with ultrasonography. Additionally, the McNemar's test was utilized to verify whether there was a statistically significant difference between digital panoramic radiography and ultrasonography. Results Ultrasonography demonstrated carotid artery calcifications in 17 (48.57% patients. Such individuals presented with a total of 29 (41.43% carotid arteries affected by calcification. Radiography was accurate in 71.43% (n = 50 of cases evaluated. The degree of sensitivity of this method was 37.93%, specificity of 95.12% and positive predictive value of 84.61%. A statistically significant difference (p < 0.001 was observed between the methods evaluated in their capacity to diagnose carotid artery calcifications. Conclusion Digital panoramic radiography should not be indicated as a method of choice in the investigation of carotid artery calcifications.

The effects of baroreflex activation therapy on blood pressure and sympathetic function in patients with refractory hypertension

DEFF Research Database (Denmark)

Gordin, Daniel; Fadl Elmula, Fadl Elmula M; Andersson, Bert

2017-01-01

). Results: The primary end point is the reduction in 24-hour systolic ABPM by BAT at 8 months, as compared to pharmacotherapy. Secondary and tertiary endpoints are effects of BAT on home and office blood pressures, measures of indices of cardiac and vascular structure and function during follow......Objective: To explore the effects of baroreflex activation therapy (BAT) on hypertension in patients with treatment resistant or refractory hypertension. Methods: This investigator-initiated randomized, double-blind, 1:1 parallel-design clinical trial will include 100 patients with refractory...... hypertension from 6 tertiary referral hypertension centers in the Nordic countries. A Barostim Neo System will be implanted and after 1 month patients will be randomized to either BAT for 16 months or continuous pharmacotherapy (BAT off) for 8 months followed by BAT for 8 months. A second randomization...

Stress scintigraphy using single-photon emission computed tomography in the evaluation of coronary artery disease

International Nuclear Information System (INIS)

Nohara, R.; Kambara, H.; Suzuki, Y.; Tamaki, S.; Kadota, K.; Kawai, C.; Tamaki, N.; Torizuka, K.

1984-01-01

Twenty-seven patients with angina pectoris, 24 with postmyocardial infarction angina and 7 with normal coronary arteries were examined by exercise thallium-201 emission computed tomography (SPECT) and planar scintigraphy. Exercise SPECT was compared with the reperfusion imaging obtained approximately 2 to 3 hours after exercise. The sensitivity and specificity of demonstrating involved coronary arteries by identifying the locations of myocardial perfusion defects were 96 and 87% for right coronary artery, 88 and 89% for left anterior descending artery (LAD) and 78 and 100% for left circumflex artery (LC). These figures are higher than those for planar scintigraphy (85 and 87% for right coronary artery, 73 and 89% for LAD and 39 and 100% for LC arteries). In patients with 3-vessel disease, sensitivity of SPECT (100, 88 and 75% for right coronary artery, LAD and LC, respectively) was higher than planar imaging (88, 63 and 31%, respectively), with a significant difference for LC (p less than 0.05). In 1, 2 and 0-vessel disease the sensitivity and specificity of the 2 techniques were comparable. Multivessel disease was more easily identified as multiple coronary involvement than planar imaging with a significant difference in 3-vessel disease (p less than 0.05). In conclusion, stress SPECT provides useful information for the identification of LC lesions in coronary heart disease, including 3-vessel involvement

Relative sensitivities of DCE-MRI pharmacokinetic parameters to arterial input function (AIF) scaling.

Science.gov (United States)

Li, Xin; Cai, Yu; Moloney, Brendan; Chen, Yiyi; Huang, Wei; Woods, Mark; Coakley, Fergus V; Rooney, William D; Garzotto, Mark G; Springer, Charles S

2016-08-01

Dynamic-Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) has been used widely for clinical applications. Pharmacokinetic modeling of DCE-MRI data that extracts quantitative contrast reagent/tissue-specific model parameters is the most investigated method. One of the primary challenges in pharmacokinetic analysis of DCE-MRI data is accurate and reliable measurement of the arterial input function (AIF), which is the driving force behind all pharmacokinetics. Because of effects such as inflow and partial volume averaging, AIF measured from individual arteries sometimes require amplitude scaling for better representation of the blood contrast reagent (CR) concentration time-courses. Empirical approaches like blinded AIF estimation or reference tissue AIF derivation can be useful and practical, especially when there is no clearly visible blood vessel within the imaging field-of-view (FOV). Similarly, these approaches generally also require magnitude scaling of the derived AIF time-courses. Since the AIF varies among individuals even with the same CR injection protocol and the perfect scaling factor for reconstructing the ground truth AIF often remains unknown, variations in estimated pharmacokinetic parameters due to varying AIF scaling factors are of special interest. In this work, using simulated and real prostate cancer DCE-MRI data, we examined parameter variations associated with AIF scaling. Our results show that, for both the fast-exchange-limit (FXL) Tofts model and the water exchange sensitized fast-exchange-regime (FXR) model, the commonly fitted CR transfer constant (K(trans)) and the extravascular, extracellular volume fraction (ve) scale nearly proportionally with the AIF, whereas the FXR-specific unidirectional cellular water efflux rate constant, kio, and the CR intravasation rate constant, kep, are both AIF scaling insensitive. This indicates that, for DCE-MRI of prostate cancer and possibly other cancers, kio and kep may be more suitable imaging

Comparison between angiographic and arterial duplex ultrasound assessment of tibial arteries in patients with peripheral arterial disease: on behalf of the Joint Endovascular and Non-Invasive Assessment of LImb Perfusion (JENALI) Group.

Science.gov (United States)

Mustapha, Jihad A; Saab, Fadi; Diaz-Sandoval, Larry; Karenko, Barbara; McGoff, Theresa; Heaney, Carmen; Sevensma, Matthew

2013-11-01

Endovascular treatment of peripheral arterial disease (PAD) involving the tibial arteries is becoming an increasingly important part of revascularization. The current anatomical description of vessel patency in tibial arteries does not contribute effectively to therapeutic strategies. The Joint Endovascular and Non-Invasive Assessment of Limb Perfusion (JENALI) score, is a novel scoring system developed to further assess patency of tibial arteries, via both angiography and arterial duplex ultrasonography. A comparison was made between the JENALI score obtained by ultrasound and by angiography. Angiography is currently considered the gold standard of tibial artery imaging. This prospective single-center study involved 49 patients undergoing peripheral angiography for evaluation of PAD, between November 2011 and November 2012. All patients underwent a detailed ultrasound assessment of the tibial arteries ± 7 days from diagnostic angiography. Eligible patients had a Rutherford score ≥ III or abnormal ankle-brachial index values. Angiography and ultrasound were evaluated in a blinded fashion. Average age of patients was 69.8 years. A total of 846 segments were assessed by both angiography and ultrasound. We found that 648 segments (76.6%) were deemed to be patent by angiography compared to 723 (85.5%) by ultrasound. Critical limb ischemia (CLI; Rutherford score ≥ 4) was described in 26 patients (53%). Average JENALI score for the right lower extremity was 7.0 by angiogram vs 7.7 by ultrasound. The average JENALI score of the left leg was 6.7 by angiogram vs 7.7 by ultrasound. A total of 94 lower extremities were assigned a JENALI score. Ultrasound was accurate in detecting tibial artery patency or occlusion in 80% of segments. The overall sensitivity/specificity of ultrasound detecting tibial artery patency was calculated at 93% and 40% (P<.05), respectively. Detection of patency via ultrasound was highest for the anterior tibial artery and the lowest for the

Arterial ammonia levels in the management of fulminant liver failure

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Curry S

2011-06-01

Full Text Available Previous studies have suggested that an arterial ammonia level greater than 150 mmol/L is highly sensitive for predicting subsequent development of cerebral edema in patients with fulminant liver failure. We performed a prospective cohort study to confirm this relationship. We enrolled 22 consecutive patients who presented to our transplant hepatology service with grade 3-4 encephalopathy associated with fulminant liver failure. All patients underwent placement of an intraparenchymal ICP monitor, and every 12 hourly arterial ammonia levels. The prevalence of intracranial hypertension (IHTN in our population was 95% (21/22 patients, with 82 discrete episodes recorded. The sensitivity of arterial ammonia levels to predict the onset of IHTN was 62% (95% CI: 40.8 to 79.3 at a cut point of 150 mmol/L. Arterial ammonia levels preceding the first intracranial hypertension event were less than 150 mmol/L in 8 of 21 patients (39%. Fifty nine of 82 episodes of IHTN (73% occurred when arterial ammonia levels were less than 150 mmol/L. We conclude that the arterial ammonia level is not useful in making decisions regarding management related to cerebral edema in patients with fulminant liver failure. In fact, since almost all our study patients with grade III or IV encephalopathy secondary to fulminant liver failure went on to develop intracranial hypertension, our study supports the contention that all such patients might benefit from ICP monitoring regardless of arterial ammonia levels.

Myogenic activation and calcium sensitivity of cannulated rat mesenteric small arteries

NARCIS (Netherlands)

VanBavel, E.; Wesselman, J. P.; Spaan, J. A.

1998-01-01

Pressure-induced activation of vascular smooth muscle may involve electromechanical as well as nonelectromechanical coupling mechanisms. We compared calcium-tone relations of cannulated rat mesenteric small arteries during pressure-induced activation, depolarization (16 to 46 mmol/L K+), and

Baroreflexes of the rat. IV. ADN-evoked responses at the NTS.

Science.gov (United States)

Tang, Xiaorui; Dworkin, Barry R

2007-12-01

In a long-term (7-21 days) neuromuscular blocked (NMB) rat preparation, using precise single-pulse aortic depressor nerve (ADN) stimulation and stable chronic evoked response (ER) recordings from the dorsal-medial solitary nucleus (dmNTS), two different response patterns were observed: continuous and discrete. For the continuous pattern, activity began approximately 3 ms after the stimulus and persisted for 45 ms; for the discrete pattern, two complexes were separated by a gap from approximately 17 to 25 ms. The early complex was probably transmitted via A-fibers: it had a low stimulus current threshold and an average conduction velocity (CV) of 0.58-5.5 m/s; the high threshold late (HTL) complex had a CV = 0.26-0.58 m/s. The average stimulus amplitude-ER magnitude transduction curves for the A and HTL complexes were sigmoidal. For individual rats, in the linear range, mean r2 = 0.96 +/- 0.03 for both complexes. The average stimulus amplitude vs. the systolic blood pressure change (delta sBP) transduction curve was also approximately linear; however, for individual rats, the relationship was not consistently reliable: mean r2 = 0.48 +/- 0.19. Approximately 90% of recording sites had respiratory, and 50% had cardiac synchronism. The NMB preparation is useful for studying central baroreflex mechanisms that operate on time scales of days or weeks, such as adaptation and other kinds of neural plasticity.

The value and limitation thallium scintigraphy in the detection of coronary artery disease

International Nuclear Information System (INIS)

Khan, A.; Rehman, A.; Amin, W.; Khan, Z.A.; Ahmed, S.A.

1986-01-01

In this study we randomly selected 45 patients whose coronary angiograms were abnormal i.e. showing triple, double and single vessel disease out of a pool of 80 patients who had undergone stress thallium imaging and coronary angiography during the one year. Majority of these patients were males, their ages ranged between 34-54 years. Resting ECG's were normal in 25 patients, 15 patients had suffered inferior myocardial infraction and 5 had sustained anterior myocardial infraction in the past. Coronary angiography revealed triple vessel disease in 20 patients, double vessel disease in 15, and single vessel coronary artery disease in 10. We analysed their coronary angiograms and compared them with the scintigraphic finding. It is concluded that although thallium scanning has high sensitivity for detection of coronary artery disease in general, it has only moderate sensitivity for detection of stenosis in individual coronary arteries. In this study thallium scan identified 75% of RCA lesions, 66% of LAD lesions and 38% of circumflex lesions. The sensitivity is much higher in single vessel coronary artery disease. (author)

Relationships between high-sensitive C-reactive protein and markers of arterial stiffness in hypertensive patients. Differences by sex

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Gomez-Marcos Manuel A

2012-06-01

Full Text Available Abstract Background The present study was designed to evaluate the relationship between high-sensitivity C-reactive protein (hs-CRP and arterial stiffness according to sex in patients with arterial hypertension. Methods A case-series study was carried out in 258 hypertensive patients without antecedents of cardiovascular disease or diabetes mellitus. Nephelometry was used to determine hs-CRP. Office or clinical and home blood pressures were measured with a validated OMRON model M10 sphygmomanometer. Ambulatory blood pressure monitoring was performed with the SpaceLabs 90207 system. Pulse wave velocity (PWV and central and peripheral augmentation index (AIx were measured with the SphygmoCor system, and a Sonosite Micromax ultrasound unit was used for automatic measurements of carotid intima-media thickness (IMT. Ambulatory arterial stiffness index and home arterial stiffness index were calculated as “1-slope” from the within-person regression analysis of diastolic-on-systolic ambulatory blood pressure. Results Central and peripheral AIx were greater in women than in men: 35.31 ± 9.95 vs 26.59 ± 11.45 and 102.06 ± 20.47 vs 85.97 ± 19.13, respectively. IMT was greater in men (0.73 ± 0.13 vs 0.69 ± 0.10. hs-CRP was positively correlated to IMT (r = 0.261, maximum (r = 0.290 and to peripheral AIx (r = 0.166 in men, and to PWV in both men (r = 0.280 and women (r = 0.250. In women, hs-CRP was negatively correlated to central AIx (r = −0.222. For each unit increase in hs-CRP, carotid IMT would increase 0.05 mm in men, and PWV would increase 0.07 m/sec in men and 0.08 m/sec in women, while central AIx would decrease 2.5 units in women. In the multiple linear regression analysis, hs-CRP explained 10.2% and 6.7% of PWV variability in women and men, respectively, 8.4% of carotid IMT variability in men, and 4.9% of central AIx variability in women. Conclusions After adjusting for age, other

Joint symbolic dynamics for the assessment of cardiovascular and cardiorespiratory interactions.

Science.gov (United States)

Baumert, Mathias; Javorka, Michal; Kabir, Muammar

2015-02-13

Beat-to-beat variations in heart period provide information on cardiovascular control and are closely linked to variations in arterial pressure and respiration. Joint symbolic analysis of heart period, systolic arterial pressure and respiration allows for a simple description of their shared short-term dynamics that are governed by cardiac baroreflex control and cardiorespiratory coupling. In this review, we discuss methodology and research applications. Studies suggest that analysis of joint symbolic dynamics provides a powerful tool for identifying physiological and pathophysiological changes in cardiovascular and cardiorespiratory control.

MR angiography of in situ and transplanted renal arteries

International Nuclear Information System (INIS)

Smith, H.J.; Bakke, S.J.

1993-01-01

Three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) was performed in 34 patients with suspected renal artery disease. In situ (i.e., nontransplanted) renal arteries were studied with MRA in 14 patients. Of these, 12 had conventional angiography for comparison. Twenty-four MRAs of transplanted renal arteries were obtained in 20 patients; 8 of these had angiography as well. Significant stenoses of in situ renal arteries were diagnosed with a sensitivity of 100% and a specificity of 95%. The stenoses were all proximal; 3D TOF MRA proved inadequate for depiction of peripheral renal arteries. MRA and angiography showed good agreement between findings in 7 of 8 patients with renal transplants. In one patient with a renal transplant, MRA showed a significant stenosis of the arterial anastomosis which appeared completely normal at i.a. DSA, indicating that findings at MRA still need to be confirmed by more established alternative methods. (orig.)

Prevention and treatment of complications for thyroid-arterial embolization

International Nuclear Information System (INIS)

Yang Jijin; Yuan Min; Tian Jianming; Chen Wei; Yang Chaoai; Hao Qiang; Zou Dajing; Wang Yongchun

2003-01-01

Objective: To investigate the complications of thyroid-arterial embolization and their prevention and treatment. Methods: 61 cases of thyroid disorders received the therapy of thyroid-arterial embolization were retrospectively studied. The complications of arterial embolization during or after the procedure were analyzed. How to prevent and deal with these complications were discussed. Results: Sensitivity to contrast media occurred in 1 case and surgical arterial injury in 2. After embolization thyroid storm occurred in 1 patient and all other complications including headache (23 cases), toothache (11 cases), neckache (13 cases), hoarseness (37 cases) were caused by non-target arterial embolization with the most serious one of cerebral infarction (1 case) and another eyelid ptosis (1 case). The cerebral infarct one was treated with some vasodilating drugs and anti-coagulant, all others were given anti-symptomatics or no special treatment. Conclusions: Proper treatment should be ready during thyroid arterial embolization and given in time with occurrence of complications

A vasoactive role for endogenous relaxin in mesenteric arteries of male mice.

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Chen Huei Leo

Full Text Available The peptide hormone relaxin has striking effects on the vascular system. Specifically, endogenous relaxin treatment reduces myogenic reactivity through nitric oxide (NO-mediated vasorelaxation and increases arterial compliance in small resistance arteries. However, less is known about the vascular roles of endogenous relaxin, particularly in males. Therefore, we used male wild-type (Rln+/+ and relaxin knockout (Rln-/- mice to test the hypothesis that passive wall properties and vascular reactivity in mesenteric arteries would be compromised in Rln-/- mice. Passive compliance was determined in arteries (n=8-9 mounted on a pressure myograph and in Ca2+-free Krebs containing 2 mM EGTA. Passive volume compliance was significantly (P=0.01 decreased in the mesenteric arteries of Rln-/- mice. Vascular reactivity was assessed using wire myography. In mesenteric arteries (n=5 of Rln-/- mice, there was a significant (P<0.03 increase in sensitivity to the vasoconstrictors phenylephrine and thromboxane-mimetic U41669. This enhanced responsiveness to vasoconstrictors was abolished by endothelial denudation, and attributed to impaired NO and prostanoid pathways in Rln-/- mice. Sensitivity to the endothelial agonist acetylcholine was significantly (n=7-9, P ≤ 0.03 decreased, and this was abolished in the presence of the cyclooxygenase inhibitor, indomethacin (2 µM. This indicates that prostanoid vasoconstrictor pathways were upregulated in the mesenteric arteries of Rln-/- mice. In summary, we demonstrate endothelial dysfunction and impaired arterial wall remodeling in male mice deficient in relaxin. Thus, our results highlight a role for endogenous relaxin in the maintenance of normal mesenteric artery structure and function in males.

Stress thallium-201 myocardial scintigraphy for the detection of individual coronary arterial lesions in patients with and without previous myocardial infarction

International Nuclear Information System (INIS)

Rigo, P.; Bailey, I.K.; Griffith, L.S.; Pitt, B.; Wagner, H.N. Jr.; Becker, L.C.

1981-01-01

The value of stress thallium-201 scintigraphy for detecting individual coronary arterial stenoses was analyzed in 141 patients with angiographically proved coronary artery disease, 101 with and 40 without a previous myocardial infarction. In patients without infarction, the sensitivity for detecting greater than 50 percent narrowing in the left anterior descending, the right and the left circumflex coronary artery was 66, 53 and 24 percent, respectively. In those with a previous infarction, the sensitivity for demonstrating disease in the artery corresponding to the site of infarction was 100 percent for the left anterior descending, 79 percent for the right and 63 percent for the left circumflex coronary artery. In patients with a prior anterior infarction, concomitant right or left circumflex coronary arterial lesions were detected in only 1 of 12 cases, whereas in those with previous inferior or inferolateral infarction, the sensitivity for left anterior descending coronary artery disease was 69 percent. Because of the reasonably high sensitivity for detecting left anterior descending arterial disease, irrespective of the presence and location of previous infarction, myocardial scintigraphy was useful in identifying multivessel disease in patients with a previous inferior infarction. However, because of its relative insensitivity for right or left circumflex coronary artery disease, scintigraphy proved to be a poor predictor of multivessel disease in patients with a prior anterior infarction and in patients without previous myocardial infarction

Contribution of reactive oxygen species to the pathogenesis of pulmonary arterial hypertension

Science.gov (United States)

Naik, Jay S.; Weise-Cross, Laura; Detweiler, Neil D.; Herbert, Lindsay M.; Yellowhair, Tracylyn R.; Resta, Thomas C.

2017-01-01

Pulmonary arterial hypertension is associated with a decreased antioxidant capacity. However, neither the contribution of reactive oxygen species to pulmonary vasoconstrictor sensitivity, nor the therapeutic efficacy of antioxidant strategies in this setting are known. We hypothesized that reactive oxygen species play a central role in mediating both vasoconstrictor and arterial remodeling components of severe pulmonary arterial hypertension. We examined the effect of the chemical antioxidant, TEMPOL, on right ventricular systolic pressure, vascular remodeling, and enhanced vasoconstrictor reactivity in both chronic hypoxia and hypoxia/SU5416 rat models of pulmonary hypertension. SU5416 is a vascular endothelial growth factor receptor antagonist and the combination of chronic hypoxia/SU5416 produces a model of severe pulmonary arterial hypertension with vascular plexiform lesions/fibrosis that is not present with chronic hypoxia alone. The major findings from this study are: 1) compared to hypoxia alone, hypoxia/SU5416 exposure caused more severe pulmonary hypertension, right ventricular hypertrophy, adventitial lesion formation, and greater vasoconstrictor sensitivity through a superoxide and Rho kinase-dependent Ca2+ sensitization mechanism. 2) Chronic hypoxia increased medial muscularization and superoxide levels, however there was no effect of SU5416 to augment these responses. 3) Treatment with TEMPOL decreased right ventricular systolic pressure in both hypoxia and hypoxia/SU5416 groups. 4) This effect of TEMPOL was associated with normalization of vasoconstrictor responses, but not arterial remodeling. Rather, medial hypertrophy and adventitial fibrotic lesion formation were more pronounced following chronic TEMPOL treatment in hypoxia/SU5416 rats. Our findings support a major role for reactive oxygen species in mediating enhanced vasoconstrictor reactivity and pulmonary hypertension in both chronic hypoxia and hypoxia/SU5416 rat models, despite a

Evaluation of coronary artery bypass grafts with magnetic resonance imaging

International Nuclear Information System (INIS)

Okamura, Yoshitaka; Yamada, Yasuyuki; Mochizuki, Yoshihiko; Iida, Hiroshi; Mori, Hideaki; Sugita, You-ichi; Shimada, Kou-ichirou

1997-01-01

Currently, the efficacy of magnetic resonance imaging (MRI) for evaluating coronary artery disease has been reported. In this study, we have evaluated the usefulness and the problems of MRI for evaluating the patency of coronary artery bypass grafts. Thirty-five patients who received coronary artery bypass grafting (CABG) were evaluated by using MRI for determining the graft patency compared with conventional coronary angiography. There were 30 men and 5 women. The mean age was 61.2 years (range 45 to 75). The 35 patients had a total of 92 grafts (28 internal thoracic artery, 7 gastroepiploic artery and 57 saphenous vein grafts). Magnetic resonance coronary angiogram (MRCA) was performed with SIGNA HORIZON 1.5 T (GE Inc.) by using 2D-FASTCARD sequence. All patients underwent imaging in the transverse and coronal planes, most had imaging in the sagittal plane, and a few had in the oblique plane. By using MRCA, 82 of 90 grafts were diagnosed correctly as patent, and 1 of 2 grafts were diagnosed correctly as occluded. Thirty-four of 40 LAD grafts (85%), 20 of 22 RCA grafts (91%) and 29 of 30 Cx grafts (97%) were correctly evaluated. The efficacy of MRCA for evaluating the patency of coronary artery bypass grafts was recognized. But the sternal wire (stainless steel) and hemoclip interfere with the interpretation and reduce the sensitivity. Higher sensitivity may be obtained by changing the material of the sternal wires and hemoclips at coronary surgery. (author)

[Arterial hypertension secondary to endocrine disorders].

Science.gov (United States)

Minder, Anna; Zulewski, Henryk

2015-06-01

Endocrine hypertension offers a potentially curative therapy if the underlying cause is identified and treated accordingly. In contrast to the high prevalence of arterial hypertension especially in the elderly, the classical endocrine causes remain a rare entity. Among patients with arterial hypertension the prevalence of Cushing's syndrome or pheochromocytoma is less than 1%. Primary hyperaldosteronism is more frequent with a reported prevalence of up to 9%. In order to avoid unnecessary, costly and potentially harmful evaluations and therapies due to the limited sensitivity and specificity of the critical endocrine tests it is mandatory to limit the exploration for endocrine causes to preselected patients with high pretest probability for an endocrine disorder. Younger age at manifestation of arterial hypertension or drug resistant hypertension together with other clinical signs of an endocrine disorder should raise the suspicion and prompt the appropriate evaluation.

Can baroreflex measurements with spontaneous sequence analysis be improved by also measuring breathing and by standardization of filtering strategies?

International Nuclear Information System (INIS)

Hollow, M R; Parkes, M J; Clutton-Brock, T H

2011-01-01

Baroreflex sensitivity (BRS) is known to be attenuated by inspiration and all the original BRS methodologies took this into account by measuring only in expiration. Spontaneous sequence analysis (SSA) is a non-invasive clinical tool widely used to estimate BRS in Man but does not take breathing into account. We have therefore modified it to test whether it too can detect inspiratory attenuation. Traditional SSA is also entangled with issues of distinguishing causal from random relationships between blood pressure and heart period and of the optimum choice of data filter settings. We have also tested whether the sequences our modified SSA rejects do behave as random relationships and show the limitations of the absence of filter standardization. SSA was performed on eupneic data from 1 h periods in 20 healthy subjects. Applying SSA traditionally produced a mean BRS of 23 ± 3 ms mmHg −1 . After modification to measure breathing, SSA detected significant inspiratory attenuation (11 ± 1 ms mmHg −1 ), and the mean expiratory BRS was significantly higher (26 ± 5 ms mmHg −1 ). Traditional SSA therefore underestimates BRS by an amount (3 ms mmHg −1 ) as big as the major physiological and clinical factors known to alter BRS. We show that the sequences rejected by SSA do behave like random associations between pressure and period. We also show the minimal effect of the r 2 filter and the biases that some pressure and heart period filters can introduce. We discuss whether SSA might be improved by standardization of filter settings and by also measuring breathing

Value of downstream circulation in renal artery stenosis with arterial hypertension: comparison between color Doppler flow and digital renal angiography in 123 patients

International Nuclear Information System (INIS)

Grataloup, C.; Challande, P.; Plainfosse, M.C.; Girerd, X.; Belattar, K.; Plouin, P.F.

1996-01-01

Digital renal angiography and color Doppler flow were compared for diagnosis of renal artery stenosis in 123 hypertensive patients with a prevalence of renal artery stenosis ≥75% of 21 %. Only color Doppler flow signs found downstream from the stenosis could be quantified. A rising time (RT) >0.07 s was the best marker for renal artery stenosis ≥ 75 % according to a receiver operating characteristic curve with a specificity of 97 %, a sensitivity of 88 %, a positive predictive value of 86 %, a negative predictive value of 98 % and an accuracy of 96 %. Digital renal angiography and color Doppler flow findings for renal artery lesions were classified into 4 degrees with agreement for 86 % of the kidneys. (authors). 13 refs., 5 figs., 8 tabs

Noninvasive detection and assessment of coronary artery disease by dipyridamloe thallium-201 imaging

International Nuclear Information System (INIS)

Jiang Maosong

1988-01-01

Dipyridamole (DP) thallium-201 perfusion scintigraphy was performed in 73 patients. IV DP (0.56 mg/kg) infused over 4 min. resulted in an increases in mean HR from 74 +- 12 bpm to a peak of 86 +- 12 bpm (p 201 Tl scintigraphy appears highly sensitive for the diagnosis of coronary artery highly sensitive for the diagnosis of coronary artery disease and provides a useful alternative test for patients who are unable to perform maximal exercise

Multislice CT imaging of anomalous coronary arteries

International Nuclear Information System (INIS)

Shi Heshui; Aschoff, Andrik J.; Brambs, Hans-Juergen; Hoffmann, Martin H.K.

2004-01-01

The purpose of the present study was to evaluate the role of 16 multislice computed tomography (MSCT) to identify the origin of anomalous coronary arteries and to confirm their anatomic course in relation to the great vessels. Accuracy of coronary artery disease (CAD) detection was a secondary aim and was tested with conventional angiograms (CA) serving as standard of reference. Two hundred and forty-two consecutive patients referred for noninvasive coronary CT imaging were reviewed for the study. Sixteen patients (6.6%) with anomalous coronary arteries were detected and included as the study group. MSCT and CA images were analyzed in a blinded fashion for accuracy of anomalous artery origin and path detection. Results were compared in a secondary consensus evaluation. Accuracy ratios to detect CAD with MSCT in all vessels were calculated. Coronary anomalies for all 16 patients were correctly displayed on MSCT. CA alone achieved correct identification of the abnormality in only 53% (P=0.016). Sensitivity and specificity of MSCT to detect significantly stenosed vessels was 90 and 92%. 16-MSCT is accurate to delineate abnormally branching coronary arteries and allows sufficiently accurate detection of obstructive coronary artery disease in distal branches. It should therefore be considered as a prime non-invasive imaging tool for suspected coronary anomalies. (orig.)

Abnormal splenic artery diameter/hepatic artery diameter ratio in cirrhosis-induced portal hypertension

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Zeng, Dao-Bing; Dai, Chuan-Zhou; Lu, Shi-Chun; He, Ning; Wang, Wei; Li, Hong-Jun

2013-01-01

AIM: To determine an optimal cutoff value for abnormal splenic artery diameter/proper hepatic artery diameter (S/P) ratio in cirrhosis-induced portal hypertension. METHODS: Patients with cirrhosis and portal hypertension (n = 770) and healthy volunteers (n = 31) underwent volumetric computed tomography three-dimensional vascular reconstruction to measure the internal diameters of the splenic artery and proper hepatic artery to calculate the S/P ratio. The cutoff value for abnormal S/P ratio was determined using receiver operating characteristic curve analysis, and the prevalence of abnormal S/P ratio and associations between abnormal S/P ratio and major complications of portal hypertension were studied using logistic regression. RESULTS: The receiver operating characteristic analysis showed that the cutoff points for abnormal splenic artery internal diameter and S/P ratio were > 5.19 mm and > 1.40, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value were 74.2%, 45.2%, 97.1%, and 6.6%, respectively. The prevalence of an abnormal S/P ratio in the patients with cirrhosis and portal hypertension was 83.4%. Patients with a higher S/P ratio had a lower risk of developing ascites [odds ratio (OR) = 0.708, 95%CI: 0.508-0.986, P = 0.041] and a higher risk of developing esophageal and gastric varices (OR = 1.483, 95%CI: 1.010-2.175, P = 0.044) and forming collateral circulation (OR = 1.518, 95%CI: 1.033-2.230, P = 0.034). After splenectomy, the portal venous pressure and maximum and mean portal venous flow velocities were reduced, while the flow rate and maximum and minimum flow velocities of the hepatic artery were increased (P portal hypertension, and it can be used as an important marker of splanchnic hemodynamic disturbances. PMID:23483462

Arm exercise-thallium imaging testing for the detection of coronary artery disease

International Nuclear Information System (INIS)

Balady, G.J.; Weiner, D.A.; Rothendler, J.A.; Ryan, T.J.

1987-01-01

Patients with lower limb impairment are often unable to undergo a standard bicycle or treadmill test for the evaluation of coronary artery disease. To establish an alternative method of testing, 50 subjects (aged 56 +/- 10 years) performed arm ergometry testing in conjunction with myocardial thallium scintigraphy. All underwent coronary angiography; significant coronary artery disease (greater than or equal to 70% stenosis) in at least one vessel was present in 41 (82%) of the 50 patients. Thallium scintigraphy was found to have an 83% sensitivity and 78% specificity for detecting coronary disease, compared with a sensitivity and specificity of 54% (p less than 0.01) and 67% (p = NS), respectively, for exercise electrocardiography. In the subgroup of 23 patients who had no prior myocardial infarction or left bundle branch block and were not taking digitalis, thallium scintigraphy had a sensitivity of 80% versus 50% for exercise electrocardiography. Scintigraphy yielded a sensitivity of 84, 74 and 90% for one, two and three vessel disease, respectively. Noninvasive arm ergometry exercise-thallium imaging testing appears to be reliable and useful and should be considered in the evaluation of coronary artery disease in patients with lower limb impairment

Detection of vessel wall calcifications in vertebral arteries using susceptibility weighted imaging

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Adams, Lisa C.; Boeker, Sarah M.; Bender, Yvonne Y.; Fallenberg, Eva M.; Wagner, Moritz; Hamm, Bernd; Makowski, Marcus R. [Department of Radiology, Charite, Berlin (Germany); Liebig, Thomas [Department of Neuroradiology, Charite, Berlin (Germany)

2017-09-15

Calcification of the brain supplying arteries has been linked to an increased risk for cerebrovascular disease. The purpose of this study was to test the potential of susceptibility weighted MR imaging (SWMR) for the detection of vertebral artery calcifications, based on CT as a reference standard. Four hundred seventy-four patients, who had received head CT and 1.5 T MR scans with SWMR, including the distal vertebral artery, between January 2014 and December 2016, were retrospectively evaluated and 389 patients were included. Sensitivity and specificity for the detection of focal calcifications and intra- and interobserver agreement were calculated for SWMR and standard MRI, using CT as a standard of reference. The diameter of vertebral artery calcifications was used to assess correlations between imaging modalities. Furthermore, the degree of vessel stenosis was determined in 30 patients, who had received an additional angiography. On CT scans, 40 patients showed a total of 52 vertebral artery calcifications. While SWMR reached a sensitivity of 94% (95% CI 84-99%) and a specificity of 97% (95% CI 94-98%), standard MRI yielded a sensitivity of 33% (95% CI 20-46%), and a specificity of 93% (95% CI 90-96%). Linear regression analysis of size measurements confirmed a close correlation between SWMR and CT measurements (R {sup 2} = 0.74, p < 0.001). Compared to standard MRI (ICC = 0.52; CI 0.45-0.59), SWMR showed a higher interobserver agreement for calcification measurements (ICC = 0.84; CI 0.81-0.87). For detection of distal vertebral artery calcifications, SWMR demonstrates a performance comparable to CT and considerably higher than conventional MRI. (orig.)

Associations of Baroreflex Sensitivity, Heart Rate Variability, and Initial Orthostatic Hypotension with Prenatal and Recent Postnatal Methylmercury Exposure in the Seychelles Child Development Study at Age 19 Years

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Daniel Périard

2015-03-01

Full Text Available Background: A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS. In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury. Methods: Subjects in the Seychelles Child Development Study (SCDS main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP monitoring (Finapres, Ohmeda was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects’ hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals; rMSSD (root mean of the squared sum of successive interval differences; LF/HF (low frequency/high frequency component ratio; ratio of the mean expiratory/inspiratory RR intervals (EI ratio; and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15. IOH was estimated by the deepest BP fall within the first 15 s after active standing up. Results: Prenatal MeHg exposures were similar in boys and girls (6.7 ± 4.3, 6.7 ± 3.8 ng/g but recent postnatal mercury levels were higher in males than females (11.2 ± 5.8 vs 7.9 ± 4.3 ng/g, p = 0.003. Markers of autonomic heart rate control were within the normal range (BRS: 24.8 ± 7 ms/mm Hg, PNN50: 24.9 ± 6.8%, rMSSD: 68 ± 22, LF/HF: 0.61 ± 0.28 in both sexes. After standing, 51.4% of subjects

Associations of baroreflex sensitivity, heart rate variability, and initial orthostatic hypotension with prenatal and recent postnatal methylmercury exposure in the Seychelles Child Development Study at age 19 years.

Science.gov (United States)

Périard, Daniel; Beqiraj, Bujar; Hayoz, Daniel; Viswanathan, Bharathi; Evans, Katie; Thurston, Sally W; Davidson, Philip W; Myers, Gary J; Bovet, Pascal

2015-03-23

A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV) related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS). In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH) in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury. Subjects in the Seychelles Child Development Study (SCDS) main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP) monitoring (Finapres, Ohmeda) was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects' hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals); rMSSD (root mean of the squared sum of successive interval differences); LF/HF (low frequency/high frequency component ratio); ratio of the mean expiratory/inspiratory RR intervals (EI ratio); and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15). IOH was estimated by the deepest BP fall within the first 15 s after active standing up. Prenatal MeHg exposures were similar in boys and girls (6.7±4.3, 6.7±3.8 ng/g) but recent postnatal mercury levels were higher in males than females (11.2±5.8 vs 7.9±4.3 ng/g, p=0.003). Markers of autonomic heart rate control were within the normal range (BRS: 24.8±7 ms/mm Hg, PNN50: 24.9±6.8%, rMSSD: 68±22, LF/HF: 0.61±0.28) in both sexes. After standing, 51.4% of subjects had a transient systolic BP drop>40 mm Hg, but only 5

Associations of Baroreflex Sensitivity, Heart Rate Variability, and Initial Orthostatic Hypotension with Prenatal and Recent Postnatal Methylmercury Exposure in the Seychelles Child Development Study at Age 19 Years

Science.gov (United States)

Périard, Daniel; Beqiraj, Bujar; Hayoz, Daniel; Viswanathan, Bharathi; Evans, Katie; Thurston, Sally W.; Davidson, Philip W.; Myers, Gary J.; Bovet, Pascal

2015-01-01

Background: A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV) related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS). In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH) in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury. Methods: Subjects in theSeychelles Child Development Study (SCDS) main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP) monitoring (Finapres, Ohmeda) was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects’ hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals); rMSSD (root mean of the squared sum of successive interval differences); LF/HF (low frequency/high frequency component ratio); ratio of the mean expiratory/inspiratory RR intervals (EI ratio); and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15). IOH was estimated by the deepest BP fall within the first 15 s after active standing up. Results: Prenatal MeHg exposures were similar in boys and girls (6.7 ± 4.3, 6.7 ± 3.8 ng/g) but recent postnatal mercury levels were higher in males than females (11.2 ± 5.8 vs 7.9 ± 4.3 ng/g, p = 0.003). Markers of autonomic heart rate control were within the normal range (BRS: 24.8 ± 7 ms/mm Hg, PNN50: 24.9 ± 6.8%, rMSSD: 68 ± 22, LF/HF: 0.61 ± 0.28) in both sexes. After standing, 51.4% of subjects had a

Impaired myogenic tone in mesenteric arteries from overweight rats

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Sweazea Karen L

2012-03-01

Full Text Available Abstract Background Rats fed high fat (HFD or high sucrose (HSD diets develop increased adiposity as well as impaired vasodilatory responsiveness stemming from oxidative stress. Moreover, HFD rats become hypertensive compared to either control (Chow or HSD fed rats, suggesting elevated vascular tone. We hypothesized that rats with increased adiposity and oxidative stress demonstrate augmented pressure-induced vasoconstriction (i.e. myogenic tone that could account for the hypertensive state. Methods Male Sprague-Dawley rats were fed Chow, HFD or HSD for 6 weeks. The effects of oxidative stress and endogenous nitric oxide on myogenic responses were examined in small mesenteric arteries by exposing the arteries to incremental intraluminal pressure steps in the presence of antioxidants or an inhibitor of nitric oxide synthase, LNNA (100 μM. Results Contrary to the hypothesis, rats fed either HSD or HFD had significantly impaired myogenic responses despite similar vascular morphology and passive diameter responses to increasing pressures. Vascular smooth muscle (VSM calcium levels were normal in HFD arteries suggesting that diminished calcium sensitivity was responsible for the impaired myogenic response. In contrast, VSM calcium levels were reduced in HSD arteries but were increased with pre-exposure of arteries to the antioxidants tiron (10 mM and catalase (1200 U/mL, also resulting in enhanced myogenic tone. These findings show that oxidative stress impairs myogenic tone in arteries from HSD rats by decreasing VSM calcium. Similarly, VSM calcium responses were increased in arteries from HFD rats following treatment with tiron and catalase, but this did not result in improved myogenic tone. Nitric oxide is involved in the impaired myogenic response in HFD, but not HSD, rats since inhibition with LNNA resulted in maximal myogenic responses at lower intraluminal pressures and VSM calcium levels, further implicating reduced calcium sensitivity in

Monosodium glutamate neonatal treatment induces cardiovascular autonomic function changes in rodents

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Signorá Peres Konrad

2012-10-01

Full Text Available OBJECTIVES: The aim of this study was to evaluate cardiovascular autonomic function in a rodent obesity model induced by monosodium glutamate injections during the first seven days of life. METHOD: The animals were assigned to control (control, n = 10 and monosodium glutamate (monosodium glutamate, n = 13 groups. Thirty-three weeks after birth, arterial and venous catheters were implanted for arterial pressure measurements, drug administration, and blood sampling. Baroreflex sensitivity was evaluated according to the tachycardic and bradycardic responses induced by sodium nitroprusside and phenylephrine infusion, respectively. Sympathetic and vagal effects were determined by administering methylatropine and propranolol. RESULTS: Body weight, Lee index, and epididymal white adipose tissue values were higher in the monosodium glutamate group in comparison to the control group. The monosodium glutamate-treated rats displayed insulin resistance, as shown by a reduced glucose/insulin index (-62.5%, an increased area under the curve of total insulin secretion during glucose overload (39.3%, and basal hyperinsulinemia. The mean arterial pressure values were higher in the monosodium glutamate rats, whereas heart rate variability (>7 times, bradycardic responses (>4 times, and vagal (~38% and sympathetic effects (~36% were reduced as compared to the control group. CONCLUSION: Our results suggest that obesity induced by neonatal monosodium glutamate treatment impairs cardiac autonomic function and most likely contributes to increased arterial pressure and insulin resistance.

Mesenteric artery contraction and relaxation studies using automated wire myography.

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Bridges, Lakeesha E; Williams, Cicely L; Pointer, Mildred A; Awumey, Emmanuel M

2011-09-22

Proximal resistance vessels, such as the mesenteric arteries, contribute substantially to the peripheral resistance. These small vessels of between 100-400 μm in diameter function primarily in directing blood flow to various organs according to the overall requirements of the body. The rat mesenteric artery has a diameter greater than 100 μm. The myography technique, first described by Mulvay and Halpern(1), was based on the method proposed by Bevan and Osher(2). The technique provides information about small vessels under isometric conditions, where substantial shortening of the muscle preparation is prevented. Since force production and sensitivity of vessels to different agonists is dependent on the extent of stretch, according to active tension-length relation, it is essential to conduct contraction studies under isometric conditions to prevent compliance of the mounting wires. Stainless steel wires are preferred to tungsten wires because of oxidation of the latter, which affects recorded responses(3).The technique allows for the comparison of agonist-induced contractions of mounted vessels to obtain evidence for normal function of vascular smooth muscle cell receptors. We have shown in several studies that isolated mesenteric arteries that are contracted with phenylyephrine relax upon addition of cumulative concentrations of extracellular calcium (Ca(2+)(e;)). The findings led us to conclude that perivascular sensory nerves, which express the G protein-coupled Ca(2+)-sensing receptor (CaR), mediate this vasorelaxation response. Using an automated wire myography method, we show here that mesenteric arteries from Wistar, Dahl salt-sensitive(DS) and Dahl salt-resistant (DR) rats respond differently to Ca(2+)(e;). Tissues from Wistar rats showed higher Ca(2+)-sensitivity compared to those from DR and DS. Reduced CaR expression in mesenteric arteries from DS rats correlates with reduced Ca(2+)(e;)-induced relaxation of isolated, pre-contracted arteries. The data

Time-resolved MR angiography of the renal artery: morphology and perfusion

International Nuclear Information System (INIS)

Krause, U.J.; Pabst, T.; Koestler, H.; Helbig, C.; Kenn, W.; Hahn, D.

2002-01-01

Purpose: To prove the hypothesis that renal artery stenosis and changes in renal perfusion can be detected with contrast-enhanced time-resolved MR angiography in a single examination. Material and Methods: In 71 patients, 137 renal arteries and 14 accessory renal arteries were studied. The examinations were performed on a 1.5 T system. A T 1 -weighted gradient echo sequence with a temporal resolution of 7 s was used. Single dose of contrast material (0.1 mmol/kg Gd-DTPA) was injected with a power injector with a flow rate of 2 ml/s. Criterion for the assessment of renal perfusion was the slope ratio of the signal intensity time curve in both kidneys. Results: Forty renal artery stenoses and one occlusion of a renal artery were detected. In 48 kidneys (35%) segmental arteries were evaluated. The accuracy of the slope ratio (limit value 0.75) concerning the detection of unilateral renal artery stenosis was 92.6% (sensitivity 75%, specificity 95.7%). Conclusion: Time-resolved MR angiography can detect changes in renal perfusion in patients with unilateral renal artery stenosis. (orig.) [de

High-NaCl diet impairs dynamic renal blood flow autoregulation in rats with adenine-induced chronic renal failure.

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Saeed, Aso; DiBona, Gerald F; Grimberg, Elisabeth; Nguy, Lisa; Mikkelsen, Minne Line Nedergaard; Marcussen, Niels; Guron, Gregor

2014-03-15

This study examined the effects of 2 wk of high-NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without adenine (controls). After 10 wk, rats were randomized to either remain on the same diet (0.6% NaCl) or to be switched to high 4% NaCl chow. Two weeks after randomization, renal clearance experiments were performed under isoflurane anesthesia and dynamic RBFA, baroreflex sensitivity (BRS), systolic arterial pressure variability (SAPV), and heart rate variability were assessed by spectral analytical techniques. Rats with ACRF showed marked reductions in glomerular filtration rate and renal blood flow (RBF), whereas mean arterial pressure and SAPV were significantly elevated. In addition, spontaneous BRS was reduced by ∼50% in ACRF animals. High-NaCl diet significantly increased transfer function fractional gain values between arterial pressure and RBF in the frequency range of the myogenic response (0.06-0.09 Hz) only in ACRF animals (0.3 ± 4.0 vs. -4.4 ± 3.8 dB; P renal failure by facilitating pressure transmission to the microvasculature.

Long-term monitoring of arterial pO2 in burned patients.

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Nilsson, E; Arnander, C

1984-02-01

Five patients, who were treated in a special ward for burns were followed by continuous intra-arterial pO2 monitoring for a total of 1612 h (range 13-604 h). The pao2 catheter electrodes used were surface-heparinized, and inserted either in the radial or the femoral artery. Some electrodes were accidentally withdrawn. Recalibration was performed for two of the 10 electrodes used. These electrodes presented a changed sensitivity after heavy stretching of the sensor during the nursing. The sensitivity of one of these electrodes was altered downwards and the other one upwards. After recalibration the pao2 electrodes presented accurate values for the rest of the monitoring period. Without compensation for drift, the pao2 electrode readout was compared to the results of traditional blood-gas analysis, which served as a reference. The regression function found was y = -0.62 + 1.04 chi (r = 0.93, SD = 1.40, n = 60). The blood flow velocity around some of the pao2 electrodes was studied by the pulsed Doppler technique. There was no influence of the surface-heparinized pao2 electrode on the femoral artery blood flow velocity as compared to the contralateral, non-catheterized femoral artery. The blood flow velocity proximal to a traditional radial artery catheter was compared to the flow velocity in the contralateral radial artery containing a surface-heparinized pao2 electrode. The surface-heparinized electrode did not decrease the mean flow velocity in contrast with the traditional radial artery catheter, which had to be withdrawn after 8 days because of clotting. The surface-heparinized catheter electrode was still monitoring pao2 accurately after 25 days in the artery, which was the longest period studied for a particular sensor.

Validation of a basic neurosonology laboratory for detecting cervical carotid artery stenosis.

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de la Cruz Cosme, C; Dawid Milner, M S; Ojeda Burgos, G; Gallardo Tur, A; Márquez Martínez, M; Segura, T

2017-03-24

Most of the cases of ischaemic stroke in our setting are of atherothrombotic origin. Detecting intracranial and cervical carotid artery stenosis in patients with ischaemic stroke is therefore essential. Ultrasonography has become the tool of choice for diagnosing carotid artery stenosis because it is both readily accessibility and reliable. However, use of this technique must be validated in each laboratory. The purpose of this study is to validate Doppler ultrasound in our laboratory as a means of detecting severe carotid artery stenosis. We conducted an observational descriptive study to evaluate diagnostic tests. The results from transcranial and cervical carotid Doppler ultrasound scans conducted by neurologists were compared to those from carotid duplex scans performed by radiologists in patients diagnosed with stroke. Arteriography was considered the gold standard (MR angiography, CT angiography, or conventional arteriography). Our sample included 228 patients. Transcranial and cervical carotid Doppler ultrasound showed a sensitivity of 95% and specificity of 100% for detection of carotid artery stenosis > 70%, whereas carotid duplex displayed a sensitivity of 87% and a specificity of 94%. Transcranial carotid Doppler ultrasound achieved a sensitivity of 78% and a specificity of 98% for detection of intracranial stenosis. Doppler ultrasound in our neurosonology laboratory was found to be a useful diagnostic tool for detecting cervical carotid artery stenosis and demonstrated superiority to carotid duplex despite the lack of B-mode. Furthermore, this technique was found to be useful for detecting intracranial stenosis. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Mechanisms of sympathetic activation and blood pressure elevation by intermittent hypoxia.

Science.gov (United States)

Prabhakar, Nanduri R; Kumar, Ganesh K

2010-11-30

Sleep disordered breathing with recurrent apneas is one of the most frequently encountered breathing disorder in adult humans and preterm infants. Recurrent apnea patients exhibit several co-morbidities including hypertension and persistent sympathetic activation. Intermittent hypoxia (IH) resulting from apneas appears to be the primary stimulus for evoking autonomic changes. The purpose of this article is to briefly review the effects of IH on chemo- and baro-reflexes and circulating vasoactive hormones and their contribution to sympathetic activation and blood pressures. Sleep apnea patients and IH-treated rodents exhibit exaggerated arterial chemo-reflex. Studies on rodent models demonstrated that IH leads to hyperactive carotid body response to hypoxia. On the other hand, baro-reflex function is attenuated in patients with sleep apnea and in IH-treated rodents. Circulating vasoactive hormone levels are elevated in sleep apnea patients and in rodent models of IH. Thus, persistent sympathetic activation and hypertension associated with sleep apneas seems to be due to a combination of altered chemo- and baro-reflexes resulting in sympathetic activation and action of elevated circulating levels of vasoactive hormones on vasculature. Copyright © 2010 Elsevier B.V. All rights reserved.

Ankle-brachial index as indicator of chronic arterial insufficiency of the lower extremities and renal artery stenosis CT/DS angiography

International Nuclear Information System (INIS)

Georgiev, A.; Chervenkov, L.; Karadon, S.

2015-01-01

Full text: The aim is to validate the measurements of ankle -brachial index (ABI), as part of routine examination algorithm in conducting CTA/DSA of the extremities in patients suffering from PAD. Correlations between ABI values and renal artery stenosis. The present study includes 200 patients (138 men and 62 women, aged between 60 and 75 years). 130 of them were examined by a computer- tomography angiography - 95 men and 32 women. 70 patients were examined by digital subtraction angiography - 50 men and 20 women. Measurements of ankle-brachial index (ABI) were performed on all patients by measuring the systolic blood pressure on both brachial arteries and determine the peak pressure in both aa. dorsalis pedis. Statistical data processing. There are no patients in the study with ABI values above 0.7 that have established renal artery stenosis. All patients with severe atherosclerotic changes have values of the ABI below 0.7, and those with the most severe changes below 0.5. This fully corresponds to global data showing that values below 0.9 ABI show mild engagement, below 0.7 average, and below 0.5 severe involvement. According to the results of this survey sensitivity of ABI for renal arteries below 0.7 equals 100% and its specificity = 67.5%. For values of ABI below 0.5: Sensitivity =100%; Specificity = 83.85%. By determining ABI values both symptomatic and asymptomatic form of a PAD can be diagnosed. the method is fast, non-invasive, inexpensive and applicable everywhere. No special preparation of the patient is needed. The method can be used not only to assess the degree of commitment of the vessels of the lower limbs, but also as an indicator for the state of renal arteries in those patients

Autonomic Predictors of Hospitalization Due to Heart Failure Decompensation in Patients with Left Ventricular Systolic Dysfunction.

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Ludmiła Daniłowicz-Szymanowicz

Full Text Available Autonomic nervous system balance can be significantly deteriorated during heart failure exacerbation. However, it is still unknown whether these changes are only the consequence of heart failure decompensation or can also predict development thereof. Objectives were to verify if simple, non-invasive autonomic parameters, such as baroreflex sensitivity and short-term heart rate variability can provide independent of other well-known clinical parameters information on the risk of heart failure decompensation in patients with left ventricular systolic dysfunction.In 142 stable patients with left ventricular ejection fraction ≤ 40%, baroreflex sensitivity and short-term heart rate variability, as well as other well-known clinical parameters, were analyzed. During 23 ± 9 months of follow-up 19 patients were hospitalized due to the heart failure decompensation (EVENT.Pre-specified cut-off values of baroreflex sensitivity (≤2.4 ms/mmHg and low frequency power index of heart rate variability (≤19 ms2 were significantly associated with the EVENTs (hazard ratio 4.43, 95% confidence interval [CI] 1.35-14.54 and 5.41, 95% CI 1.87-15.65 respectively. EVENTs were also associated with other parameters, such as left ventricular ejection fraction, NYHA class, diuretic use, renal function, brain natriuretic peptide and hemoglobin level, left atrial size, left and right ventricular heart failure signs. After adjusting baroreflex sensitivity and low frequency power index for each of the abovementioned parameters, autonomic parameters were still significant predictors of hospitalization due to the heart failure decompensation.Simple, noninvasive autonomic indices can be helpful in identifying individuals with increased risk of hospitalization due to the heart failure decompensation among clinically stable patients with left ventricular systolic dysfunction, even when adjusted for other well-known clinical parameters.

Accuracy of peripheral arterial tonometry in the diagnosis of obstructive sleep apnea

Directory of Open Access Journals (Sweden)

José Antonio Pinto

2015-10-01

Full Text Available ABSTRACT INTRODUCTION: The use of handheld devices that assess peripheral arterial tonometry has emerged as an auxiliary method for assessment and diagnosis of obstructive sleep apnea syndrome. OBJECTIVE: To evaluate the accuracy of peripheral arterial tonometry in the diagnosis of obstructive sleep apnea. METHODS: Contemporary cohort cross-sectional study. Thirty patients with suspected obstructive sleep apnea underwent peripheral arterial tonometry and assisted nocturnal polysomnography concomitantly. RESULTS: The mean apnea/hypopnea index by peripheral arterial tonometry was significantly higher than that by polysomnography (p < 0.001, but the values of both sleep studies were significantly correlated (r = 0.762. There was a high correlation between variables: minimum oxygen saturation (r = 0.842,p < 0.001, oxygen saturation < 90% (r = 0.799, p < 0.001, and mean heart rate (r = 0.951, p < 0.001. Sensitivity and specificity were 60% and 96.2% (AUC: 0.727;p = 0.113, respectively, when at a threshold value of 5 events/h. In severe cases (≥30 events/h, the result was a sensitivity of 77.8% and a specificity of 86.4% (AUC: 0.846, p = 0.003. CONCLUSION: Peripheral arterial tonometry is a useful portable device for the diagnosis of obstructive sleep apnea; its accuracy is higher in moderate and severe cases.

Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

International Nuclear Information System (INIS)

Kyriacou, P A; Shafqat, K; Pal, S K

2007-01-01

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO 2 ) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO 2 ) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO 2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse

Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

Science.gov (United States)

Kyriacou, P. A.; Shafqat, K.; Pal, S. K.

2007-10-01

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO2) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO2) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse

The Effects of Synthetic Cannabinoids on Alveolar-Arterial Oxygen Gradient

Directory of Open Access Journals (Sweden)

Egemen Kucuk

2016-09-01

Full Text Available Aim: Synthetic cannabinoids are chemicals that produce several marijuana-like effects in humans. Aim of this study is to investigate the effects of synthetic cannabinoids on to alveolar-arterial oxygen gradient. Material and Method: A total of 112 patients, who admitted directly to emergency clinic with synthetic cannabinoid usage, were determined between February 2014 and August 2014. Blood gases of 41 patients were determined as arterial blood gases on room air, and included in to study. Patients were evaluated according to age, sex, decade, partial pressure of arterial oxygen, partial pressure of arterial carbon dioxide, pH, bicarbonate, metabolic status, age consistent expected alveolar-arterial oxygen gradient and calculated alveolar-arterial oxygen gradient. Results: Synthetic cannabinoid using was higher in males, mean age of patients was 23.32±6.14 years. Number of patients in the third decade were significantly higher than the other decades. The calculated alveolar-arterial oxygen gradient value of patients was significantly higher than age consistent expected alveolar-arterial oxygen gradient value. Respiratory acidosis, was significantly higher than the other types of the metabolic disorders. The best cutoff point for calculated alveolar-arterial oxygen gradient was 12.70, with sensitivity of 90% and specifity of 85%. Area under curve was 0.70 for calculated alveolar-arterial oxygen gradient. Discussion: The value of alveolar-arterial oxygen gradient has been increased due to synthetic cannabinoid usage. This can be used as a supportive parameter in the diagnosis of synthetic cannabinoid usage.

[Burnout syndrome: a "true" cardiovascular risk factor].

Science.gov (United States)

Cursoux, Pauline; Lehucher-Michel, Marie-Pascale; Marchetti, Hélène; Chaumet, Guillaume; Delliaux, Stéphane

2012-11-01

The burnout syndrome is characterized by emotional exhaustion, depersonalization and reduced personal accomplishment in individuals professionally involved with others. The burnout syndrome is poorly recognized, particularly in France, as a distinct nosology from adaptation troubles, stress, depression, or anxiety. Several tools quantifying burnout and emotional exhaustion exist, the most spread is the questionnaire called Maslach Burnout Inventory. The burnout syndrome alters cardiovascular function and its neuroregulation by autonomic nervous system and is associated with: increased sympathetic tone to heart and vessels after mental stress, lowered physiological post-stress vagal rebound to heart, and lowered arterial baroreflex sensitivity. Job strain as burnout syndrome seems to be a real independent cardiovascular risk factor. Oppositely, training to manage emotions could increase vagal tone to heart and should be cardio-protective. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Non-invasive assessment of peripheral arterial disease: Automated ankle brachial index measurement and pulse volume analysis compared to duplex scan.

Science.gov (United States)

Lewis, Jane Ea; Williams, Paul; Davies, Jane H

2016-01-01

This cross-sectional study aimed to individually and cumulatively compare sensitivity and specificity of the (1) ankle brachial index and (2) pulse volume waveform analysis recorded by the same automated device, with the presence or absence of peripheral arterial disease being verified by ultrasound duplex scan. Patients (n=205) referred for lower limb arterial assessment underwent ankle brachial index measurement and pulse volume waveform recording using volume plethysmography, followed by ultrasound duplex scan. The presence of peripheral arterial disease was recorded if ankle brachial index 50% was evident with ultrasound duplex scan. Outcome measure was agreement between the measured ankle brachial index and interpretation of pulse volume waveform for peripheral arterial disease diagnosis, using ultrasound duplex scan as the reference standard. Sensitivity of ankle brachial index was 79%, specificity 91% and overall accuracy 88%. Pulse volume waveform sensitivity was 97%, specificity 81% and overall accuracy 85%. The combined sensitivity of ankle brachial index and pulse volume waveform was 100%, specificity 76% and overall accuracy 85%. Combining these two diagnostic modalities within one device provided a highly accurate method of ruling out peripheral arterial disease, which could be utilised in primary care to safely reduce unnecessary secondary care referrals.

Adenosine concentration in the porcine coronary artery wall and A2A receptor involvement in hypoxia-induced vasodilatation.

Science.gov (United States)

Frøbert, Ole; Haink, Gesine; Simonsen, Ulf; Gravholt, Claus H; Levin, Max; Deussen, Andreas

2006-01-15

We tested whether hypoxia-induced coronary artery dilatation could be mediated by an increase in adenosine concentration within the coronary artery wall or by an increase in adenosine sensitivity. Porcine left anterior descendent coronary arteries, precontracted with prostaglandin F(2alpha) (10(-5) M), were mounted in a pressure myograph and microdialysis catheters were inserted into the tunica media. Dialysate adenosine concentrations were analysed by HPLC. Glucose, lactate and pyruvate were measured by an automated spectrophotometric kinetic enzymatic analyser. The exchange fraction of [(14)C]adenosine over the microdialysis membrane increased from 0.32 +/- 0.02 to 0.46 +/- 0.02 (n = 4, P lactate/pyruvate ratio was significantly increased in hypoxic arteries but did not correlate with adenosine concentration. We conclude that hypoxia-induced coronary artery dilatation is not mediated by increased adenosine produced within the artery wall but might be facilitated by increased adenosine sensitivity at the A(2A) receptor level.

Toward the automatic detection of coronary artery calcification in non-contrast computed tomography data.

Science.gov (United States)

Brunner, Gerd; Chittajallu, Deepak R; Kurkure, Uday; Kakadiaris, Ioannis A

2010-10-01

Measurements related to coronary artery calcification (CAC) offer significant predictive value for coronary artery disease (CAD). In current medical practice CAC scoring is a labor-intensive task. The objective of this paper is the development and evaluation of a family of coronary artery region (CAR) models applied to the detection of CACs in coronary artery zones and sections. Thirty patients underwent non-contrast electron-beam computed tomography scanning. Coronary artery trajectory points as presented in the University of Houston heart-centered coordinate system were utilized to construct the CAR models which automatically detect coronary artery zones and sections. On a per-patient and per-zone basis the proposed CAR models detected CACs with a sensitivity, specificity and accuracy of 85.56 (± 15.80)%, 93.54 (± 1.98)%, and 85.27 (± 14.67)%, respectively while the corresponding values in the zones and segments based case were 77.94 (± 7.78)%, 96.57 (± 4.90)%, and 73.58 (± 8.96)%, respectively. The results of this study suggest that the family of CAR models provide an effective method to detect different regions of the coronaries. Further, the CAR classifiers are able to detect CACs with a mean sensitivity and specificity of 86.33 and 93.78%, respectively.

Value and limitations of segmental analysis of stress thallium myocardial imaging for localization of coronary artery disease

International Nuclear Information System (INIS)

Rigo, P.; Bailey, I.K.; Griffith, L.S.C.; Pitt, B.; Borow, R.D.; Wagner, H.N.; Becker, L.C.

1980-01-01

This study was done to determine the value of thallium-201 myocardial scintigraphic imaging (MSI) for identifying disease in the individual coronary arteries. Segmental analysis of rest and stress MSI was performed in 133 patients with ateriographically proved coronary artery disease (CAD). Certain scintigraphic segments were highly specific (97 to 100%) for the three major coronary arteries: anterior wall and septum for the left anterior descending (LAD) coronary artery; the inferior wall for the right coronary artery (RCA); and the proximal lateral wall for the circumflex (LCX) artery. Perfusion defects located in the anterolateral wall in the anterior view were highly specific for proximal disease in the LAD involving the major diagonal branches, but this was not true for septal defects. The apical segments were not specific for any of the three major vessels. Although MSI was abnormal in 89% of these patients with CAD, it was less sensitive for identifying individual vessel disease: 63% for LAD, 50% for RCA, and 21% for LCX disease (narrowings > = 50%). Sensitivity increased with the severity of stenosis, but even for 100% occlusions was only 87% for LAD, 58% for RCA and 38% for LCX. Sensitivity diminished as the number of vessels involved increased: with single-vessel disease, 80% of LAD, 54% of RAC and 33% of LCX lesions were detected, but in patients with triple-vessel disease, only 50% of LAD, 50% of RCA and 16% of LCX lesions were identified. Thus, although segmented analysis of MSI can identify disease in the individual coronary arteries with high specificity, only moderate sensitivity is achieved, reflecting the tendency of MSI to identify only the most severely ischemic area among several that may be present in a heart. Perfusion scintigrams display relative distributions rather than absolute values for myocardial blood flow

A Multiscale Closed-Loop Cardiovascular Model, with Applications to Heart Pacing and Hemorrhage

Science.gov (United States)

Canuto, Daniel; Eldredge, Jeff; Chong, Kwitae; Benharash, Peyman; Dutson, Erik

2017-11-01

A computational tool is developed for simulating the dynamic response of the human cardiovascular system to various stressors and injuries. The tool couples zero-dimensional models of the heart, pulmonary vasculature, and peripheral vasculature to one-dimensional models of the major systemic arteries. To simulate autonomic response, this multiscale circulatory model is integrated with a feedback model of the baroreflex, allowing control of heart rate, cardiac contractility, and peripheral impedance. The performance of the tool is demonstrated in two scenarios: increasing heart rate by stimulating the sympathetic nervous system, and an acute 10 percent hemorrhage from the left femoral artery.

The evaluation of atherosclerosis in coronary arteries with CT values

International Nuclear Information System (INIS)

Takemoto, Akiko

1990-01-01

In 50 patients with ischemic heart disease, X-ray computed tomography (CT) and coronary arteriography (CAG) were performed to compare CT values and CAG-proven stenosis in the left main trunk, left anterior descending, left circumflex, and right coronary artery. Luminal stenosis was graded as normal (no stenosis), minimal (between normal and significant), and significant (more than 50% in the left main trunk; more than 75% in the other arteries). CT values were significantly correlated with coronary artery stenosis; -5.4 in the normal group (71 arteries), +5.0 in the minimal group (63 arteries), and +31.8 in the significant group (51 arteries). In the normal group, CT values were independent of aging; -4.9 for patients younger than 50 years, -8.0 for those aged 50 to 59 years, and -0.4 for those more than 60 years. Increased CT values were associated with severer coronary artery disease shown on CAG. In determining significant coronary artery stenosis, CT values of more than 35 had a positive predictive value of 73.3%, a sensitivity of 43.1%, a specificity of 94.0%, an accuracy of 80.0%, and a likelihood ratio of 7.18. Measurement of CT values for the coronary arteries seems to be a noninvasive method for predicting significant stenosis. For patients younger than 60 years, high CT values even in a single artery seem to be associated with a high likelihood of significant stenosis and multivessel disease. (N.K.)

ARTERIAL REVASCULARIZATION WITH THE RIGHT GASTROEPIPLOIC ARTERY AND INTERNAL MAMMARY ARTERIES IN 300 PATIENTS

NARCIS (Netherlands)

GRANDJEAN, JG; BOONSTRA, PW; DENHEYER, P; EBELS, T; KIRKLIN, JW

From September 1989 to September 1992, the right gastroepiploic artery in combination with one or both internal mammary arteries was used as a graft in 300 patients who underwent coronary artery bypass grafting. The gastroepiploic artery was the primary choice in preference to the saphenous vein.

Abnormal norepinephrine clearance and adrenergic receptor sensitivity in idiopathic orthostatic intolerance

Science.gov (United States)

Jacob, G.; Shannon, J. R.; Costa, F.; Furlan, R.; Biaggioni, I.; Mosqueda-Garcia, R.; Robertson, R. M.; Robertson, D.

1999-01-01

BACKGROUND: Chronic orthostatic intolerance (OI) is characterized by symptoms of inadequate cerebral perfusion with standing, in the absence of significant orthostatic hypotension. A heart rate increase of >/=30 bpm is typical. Possible underlying pathophysiologies include hypovolemia, partial dysautonomia, or a primary hyperadrenergic state. We tested the hypothesis that patients with OI have functional abnormalities in autonomic neurons regulating cardiovascular responses. METHODS AND RESULTS: Thirteen patients with chronic OI and 10 control subjects underwent a battery of autonomic tests. Systemic norepinephrine (NE) kinetics were determined with the patients supine and standing before and after tyramine administration. In addition, baroreflex sensitivity, hemodynamic responses to bolus injections of adrenergic agonists, and intrinsic heart rate were determined. Resting supine NE spillover and clearance were similar in both groups. With standing, patients had a greater decrease in NE clearance than control subjects (55+/-5% versus 30+/-7%, Pheart rate 25 bpm was lower in patients than in control subjects (0.5+/-0.05 versus 1.0+/-0.1 microg, Pheart rate was similar in both groups. CONCLUSIONS: The decreased NE clearance with standing, resistance to the NE-releasing effect of tyramine, and increased sensitivity to adrenergic agonists demonstrate dramatically disordered sympathetic cardiovascular regulation in patients with chronic OI.

Accuracy of peripheral arterial tonometry in the diagnosis of obstructive sleep apnea.

Science.gov (United States)

Pinto, José Antonio; Godoy, Luciana Balester Mello de; Ribeiro, Renata Coutinho; Mizoguchi, Elcio Izumi; Hirsch, Lina Ana Medeiros; Gomes, Leonardo Marques

2015-01-01

The use of handheld devices that assess peripheral arterial tonometry has emerged as an auxiliary method for assessment and diagnosis of obstructive sleep apnea syndrome. To evaluate the accuracy of peripheral arterial tonometry in the diagnosis of obstructive sleep apnea. Contemporary cohort cross-sectional study. Thirty patients with suspected obstructive sleep apnea underwent peripheral arterial tonometry and assisted nocturnal polysomnography concomitantly. The mean apnea/hypopnea index by peripheral arterial tonometry was significantly higher than that by polysomnography (p<0.001), but the values of both sleep studies were significantly correlated (r=0.762). There was a high correlation between variables: minimum oxygen saturation (r=0.842, p<0.001), oxygen saturation<90% (r=0.799, p<0.001), and mean heart rate (r=0.951, p<0.001). Sensitivity and specificity were 60% and 96.2% (AUC: 0.727; p=0.113), respectively, when at a threshold value of 5 events/h. In severe cases (≥30 events/h), the result was a sensitivity of 77.8% and a specificity of 86.4% (AUC: 0.846, p=0.003). Peripheral arterial tonometry is a useful portable device for the diagnosis of obstructive sleep apnea; its accuracy is higher in moderate and severe cases. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

C-reactive protein predicts further ischemic events in first-ever transient ischemic attack or stroke patients with intracranial large-artery occlusive disease.

Science.gov (United States)

Arenillas, Juan F; Alvarez-Sabín, José; Molina, Carlos A; Chacón, Pilar; Montaner, Joan; Rovira, Alex; Ibarra, Bernardo; Quintana, Manuel

2003-10-01

The role of inflammation in intracranial large-artery occlusive disease is unclear. We sought to investigate the relationship between high-sensitivity C-reactive protein (CRP) levels and the risk of further ischemic events in first-ever transient ischemic attack (TIA) or stroke patients with intracranial large-artery occlusive disease. Of a total of 127 consecutive first-ever TIA or ischemic stroke patients with intracranial stenoses detected by transcranial Doppler ultrasonography, 71 fulfilled all inclusion criteria, which included angiographic confirmation. Serum high-sensitivity CRP level was determined a minimum of 3 months after the qualifying event. Patients were followed up during 1 year after blood sampling. Thirteen patients (18.3%) with intracranial large-artery occlusive disease experienced an end point event: 9 cerebral ischemic events, 7 of which were attributable to intracranial large-artery occlusive disease, and 4 myocardial infarctions. Patients in the highest quintile of high-sensitivity CRP level had a significantly higher adjusted odds ratio for new events compared with those in the first quintile (odds ratio, 8.66; 95% CI, 1.39 to 53.84; P=0.01). A high-sensitivity CRP level above the receiver operating characteristic curve cutoff value of 1.41 mg/dL emerged as an independent predictor of new end point events (hazard ratio, 7.14; 95% CI, 1.77 to 28.73; P=0.005) and of further intracranial large-artery occlusive disease-related ischemic events (hazard ratio, 30.67; 95% CI, 3.6 to 255.5; P=0.0015), after adjustment for age, sex, and risk factors. Kaplan-Meier curves showed that a significantly lower proportion of patients with a high-sensitivity CRP >1.41 mg/dL remained free of a new ischemic event (P<0.0001). High-sensitivity CRP serum level predicts further intracranial large-artery occlusive disease-related and any major ischemic events in patients with first-ever TIA or stroke with intracranial large-artery occlusive disease. These findings

Does training-induced orthostatic hypotension result from reduced carotid baroreflex responsiveness?

Science.gov (United States)

Pawelczyk, James A.; Raven, Peter B.

1994-01-01

As manned space travel has steadily increased in duration and sophistication, the answer to a simple, relevant question remains elusive. Does endurance exercise training - high intensity rhythmic activity, performed regularly for extended periods of time - alter the disposition to, or severity of, postflight orthostatic hypotension? Research results continue to provide different views; however, data are difficult to compare because of the following factors that vary between investigations: the type of orthostatic stress imposed (+Gz, lower body negative pressure (LBNP), head-up tilt); pretest perturbations used (exercise, heat exposure, head-down tilting, bed rest, water immersion, hypohydration, pharmacologically-induced diuresis); the length of the training program used in longitudinal investigations (days versus weeks versus months); the criteria used to define fitness; and the criteria used to define orthostatic tolerance. Generally, research results indicate that individuals engaged in aerobic exercise activities for a period of years have been reported to have reduced orthostatic tolerance compared to untrained control subjects, while the results of shorter term longitudinal studies remain equivocal. Such conclusions suggest that chronic athletic training programs reduce orthostatic tolerance, whereas relatively brief (days to weeks) training programs do not affect orthostatic tolerance to any significant degree (increase or decrease). A primary objective was established to identify the alterations in blood pressure control that contribute to training-induced orthostatic hypotension (TIOH). Although any aspect of blood pressure regulation is suspect, current research has been focused on the baroreceptor system. Reductions in carotid baroreflex responsiveness have been documented in exercise-trained rabbits, reportedly due to an inhibitory influence from cardiac afferent, presumably vagal, nerve fibers that is abolished with intrapericardiac denervation. The

Visualization of the coronary arteries. 6

International Nuclear Information System (INIS)

Koch, M.; Von Schulthess, G.K.

1991-01-01

Since MRI is very sensitive to motion, flow and perfusion, in addition to its ability to depict detailed morphology, it has many excellent advantages as a tool for studying vascular structures. These include its noninvasive nature, excellent and to a large degree user adjustable contrast between flowing blood and cardiovascular structures, and the ability to produce direct images in any plane. The coronary arteries can be identified in their proximal parts when imaging is done using sections perpendicular to the aortic root, more distally located portions are detected inconsistently and should not be confounded with cardiac veins. With gradient-echo imaging and MR angiograpic (MRA) methods the coronaries can be visualized well, because their is a positive, rather than a negative vascular contrast as found in spin-echo (SE) images. With regard to coronary artery imaging, to date MRA does not challenge the primary role of conventional coronary angiography. Conventional angiograms have superior spatial resolution and are less sensitive to degradation by flow disturbances. Current MRA is a purely experimental procedure and MRI of the coronary vessels is a research endeavour. (author). 32 refs.; 7 figs

Cardiorespiratory interactions to external stimuli.

Science.gov (United States)

Bernardi, L; Porta, C; Spicuzza, L; Sleight, P

2005-09-01

Respiration is a powerful modulator of heart rate variability, and of baro- or chemo-reflex sensitivity. This occurs via a mechanical effect of breathing that synchronizes all cardiovascular variables at the respiratory rhythm, particularly when this occurs at a particular slow rate coincident with the Mayer waves in arterial pressure (approximately 6 cycles/min). Recitation of the rosary prayer (or of most mantras), induces a marked enhancement of these slow rhythms, whereas random verbalization or random breathing does not. This phenomenon in turn increases baroreflex sensitivity and reduces chemoreflex sensitivity, leading to increases in parasympathetic and reductions in sympathetic activity. The opposite can be seen during either verbalization or mental stress tests. Qualitatively similar effects can be obtained even by passive listening to more or less rhythmic auditory stimuli, such as music, and the speed of the rhythm (rather than the style) appears to be one of the main determinants of the cardiovascular and respiratory responses. These findings have clinical relevance. Appropriate modulation of breathing, can improve/restore autonomic control of cardiovascular and respiratory systems in relevant diseases such as hypertension and heart failure, and might therefore help improving exercise tolerance, quality of life, and ultimately, survival.

Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

Energy Technology Data Exchange (ETDEWEB)

Kyriacou, P A [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Shafqat, K [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Pal, S K [St Andrew' s Centre for Plastic Surgery and Burns, Broomfield Hospital, Chelmsford, CM1 7ET (United Kingdom)

2007-10-15

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO{sub 2}) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO{sub 2}) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO{sub 2} sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures

Sensing of Blood Pressure Increase by Transient Receptor Potential Vanilloid 1 Receptors on Baroreceptors

OpenAIRE

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N.; Pan, Hui-Lin

2009-01-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling...

Autonomic dysfunction with early respiratory syncytial virus-related infection.

Science.gov (United States)

Stock, Claire; Teyssier, Georges; Pichot, Vincent; Goffaux, Philippe; Barthelemy, Jean-Claude; Patural, Hugues

2010-08-25

Apparent life-threatening events (ALTE) and/or prolonged apnoea have been well-documented during respiratory syncytial virus (RSV) infection in infants less than 2 months of age but fundamental mechanisms remain unclear. The possibility of a central origin for the development of severe cardiac and respiratory events encouraged us, to explore the autonomic nervous system (ANS) profile of infected infants, since ANS activity may contribute to the constellation of symptoms observed during severe forms of RSV bronchiolitis. Eight infants (2 preterm and 6 full-term) less than 2 months of age and presenting with severe and apnoeic forms of RSV infection were evaluated using non-invasive electrophysiological monitoring obtained simultaneously for approximately 2 consecutive hours, including a quiet sleep period. Eight control subjects, paired for gestational and postnatal age, were also evaluated. ANS status was monitored using electrocardiogram recordings and quantified through a frequency-domain analysis of heart rate variability (HRV). This included sympathetic (VLF and LF) and parasympathetic (HF) indices as well as a measure of baroreflex sensitivity (BRS) obtained using non-invasive continuous arterial pressure. Regardless of gestational and postnatal age, heart rate variability components (Ptot, VLF, LF, and HF) and baroreflex components (alpha LF, alpha HF and sBR) were found to be significantly lower in the RSV-infected group than in the control group (pimportance of maintaining prolonged cardiopulmonary monitoring. Copyright 2010 Elsevier B.V. All rights reserved.

Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis

International Nuclear Information System (INIS)

Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

2013-01-01

The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P=0.25) nor DSA (P=1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P=1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis.

Bilateral Internal Carotid Artery Occlusion, External Carotid Artery Stenosis, and Vertebral Artery Kinking: May It Be Asymptomatic?

Science.gov (United States)

Fatic, Nikola; Jaffer, Usman; Ivana, Saicic; Gordana, Globarevic-Vukcevic; Markovic, Dragan; Kostic, Dusan; Davidovic, Lazar

2017-10-01

The clinical spectrum of internal carotid artery occlusion ranges from being a completely asymptomatic occlusion to a devastating stroke or death. The prevalence of asymptomatic internal carotid artery occlusion is unknown, particularly for bilateral occlusion. The distal branches of the external carotid artery anastomose with distal branches of the internal carotid artery provide important sources of collateral circulation to the brain. Stenosis of the external carotid artery with ipsilateral/bilateral internal occlusion may result in ischemic sequelae. Coiling or kinking of the vertebral artery is a rare morphological entity that is infrequently reported because it remains asymptomatic and has no clinical relevance. Currently, there is little evidence to support management strategies for this disease entity and no official recommendations for asymptomatic bilateral carotid artery occlusion. We present a case of a 62-year-old female with asymptomatic bilateral internal carotid artery occlusion, bilateral external carotid artery stenoses, and bilateral kinking of the vertebral artery at the V2 segment, who has been successfully managed conservatively for over 5 years. An individualized approach to management of patients with bilateral internal carotid artery occlusion, especially in combination with external carotid artery stenosis and elongation malformations of the vertebral artery is key to a successful strategy. Copyright © 2017 Elsevier Inc. All rights reserved.

Dose-dependent headache response and dilatation of limb and extracranial arteries after three doses of 5-isosorbide-mononitrate

DEFF Research Database (Denmark)

Iversen, Helle Klingenberg; Nielsen, T H; Garre, K

1992-01-01

of the temporal artery, but not for the radial artery. It is concluded that headache after 5-ISMN is caused by arterial dilatation or by mechanisms responsible for the arterial dilatation. Ultrasound monitoring of arterial diameters is an important and sensitive tool in the evaluation of nitrates and other...... and placebo on separate days. The diameters of the radial and superficial temporal arteries were repeatedly measured with high frequency ultrasound and pain was scored using a 10 point verbal scale. A clear dose-relationship was found for plasma concentrations and headache, and for changes in the diameter...

Superselective intra-arterial infusion via the superficial temporal artery and occipital artery for gingival carcinoma of the mandible. Simultaneous catheter placement to the maxillary artery and facial artery

International Nuclear Information System (INIS)

Iwai, Toshinori; Mitsudo, Kenji; Fukui, Takafumi

2009-01-01

Superselective intra-arterial infusion via the superficial temporal artery (STA) has become useful for oral cancer. Approaching via the occipital artery (OA) enables superselective intra-arterial infusion when catheter placement via the STA is impossible. Therefore, simultaneous catheter placement via the STA and OA is possible. We report a surgical method of simultaneous catheter placement via the STA and OA to achieve retrograde superselective intra-arterial infusion for gingival carcinoma of the mandible. Preoperatively, three-dimensional computed tomography angiography was performed to identify the route of the external carotid artery and branches such as the STA, OA, maxillary artery, and facial artery (FA). Thirteen patients with mandibular gingival cancer underwent catheter placement via the STA and OA under local anesthesia. Catheter placement via the STA and OA was superselectively successful in all the patients. The mean operating time was 150.8 min. Catheter placed to the FA via the OA was dislocated during the treatment in one patient, and so the catheter was replaced. This method is useful to enable superselective intra-arterial chemotherapy to the whole gingival carcinoma of the mandible from the start of treatment compared with approaching via the STA. (author)

Effect of maternal nutrient restriction and melatonin supplementation from mid to late gestation on vascular reactivity of maternal and fetal placental arteries.

Science.gov (United States)

Shukla, P; Lemley, C O; Dubey, N; Meyer, A M; O'Rourke, S T; Vonnahme, K A

2014-07-01

Maternal nutrient restriction and decreased scotophase concentrations of melatonin have been associated with severely compromised pregnancies. We hypothesized that melatonin supplementation in a compromised pregnancy enhances the bradykinin (BK)-induced relaxations of placental arteries thereby ensuring sufficient umbilical blood flow to the developing fetus. Pregnant ewes (n = 31) were fed an adequate (ADQ) or nutrient restricted (RES) diet supplemented with 5 mg of melatonin (MEL) or without melatonin (CON) from day 50 to 130 of gestation. On day 130 of gestation, the maternal (caruncular; CAR) and fetal (cotyledonary; COT) placental arteries were suspended in organ chambers for isometric tension recording. There were no treatment or dietary effects on CAR arteries for any vasoactive agent. However, in COT arteries, MEL ewes were more sensitive (P melatonin by nutritional level interaction (P melatonin by nutritional interaction (P = 0.04) for responsiveness to norepinephrine. The sensitivity of the COT arteries to norepinephrine in CON-RES ewes was decreased compared to CON-ADQ. Melatonin supplementation, regardless of maternal dietary intake, resulted in COT arteries having similar responsiveness to CON-RES ewes. An increase in placental vessel sensitivity to bradykinin-induced relaxation may contribute to melatonin-induced increases in umbilical artery blood flow. Copyright © 2014 Elsevier Ltd. All rights reserved.

Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

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Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

2014-02-15

Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

Pre-operative high sensitive C-reactive protein predicts cardiovascular events after coronary artery bypass grafting surgery: A prospective observational study

Directory of Open Access Journals (Sweden)

Balciunas Mindaugas

2009-01-01

Full Text Available C-reactive protein is a powerful independent predictor of cardiovascular events in patients with coronary artery disease. The relation between C-reactive protein (CRP concentration and in-hospital outcome, after coronary artery bypass grafting (CABG, has not yet been established. The study aims to evaluate the predictive value of pre-operative CRP for in-hospital cardiovascular events after CABG surgery. High-sensitivity CRP (hs-CRP levels were measured pre-operatively on the day of surgery in 66 patients scheduled for elective on pump CABG surgery. Post-operative cardiovascular events such as death from cardiovascular causes, ischemic stroke, myocardial damage, myocardial infarction and low output heart failure were recorded. During the first 30 days after surgery, 54 patients were free from observed events and 14 developed the following cardiovascular events: 10 (15% had myocardial damage, four (6% had low output heart failure and two (3% suffered stroke. No patients died during the follow-up period. Serum concentration of hs-CRP ≥ 3.3 mg/l (cut-off point obtained by ROC analysis was related to higher risk of post-operative cardiovascular events (36% vs 6%, P = 0.01, myocardial damage (24% vs 6%, P = 0.04 and low output heart failure (12% vs 0%, P = 0.04. Multivariate logistic regression analysis showed that hs-CRP ≥ 3.3 mg/l ( P = 0.002, O.R.: 19.3 (95% confidence interval (CI 2.9-128.0, intra-operative transfusion of red blood cells ( P = 0.04, O.R.: 9.9 (95% C.I. 1.1-85.5 and absence of diuretics in daily antihypertensive treatment ( P = 0.02, O.R.: 15.1 (95% C.I. 1.4-160.6 were independent predictors of combined cardiovascular event. Patients having hs-CRP value greater or equal to 3.3 mg/l pre-operatively have an increased risk of post-operative cardiovascular events after on pump coronary artery bypass grafting surgery.

Retinal artery occlusion during carotid artery stenting with distal embolic protection device.

Science.gov (United States)

Kohara, Kotaro; Ishikawa, Tatsuya; Kobayashi, Tomonori; Kawamata, Takakazu

2018-01-01

Retinal artery occlusion associated with carotid artery stenosis is well known. Although it can also occur at the time of carotid artery stenting, retinal artery occlusion via the collateral circulation of the external carotid artery is rare. We encountered two cases of retinal artery occlusion that were thought to be caused by an embolus from the external carotid artery during carotid artery stenting with a distal embolic protection device for the internal carotid artery. A 71-year-old man presented with central retinal artery occlusion after carotid artery stenting using the Carotid Guardwire PS and a 77-year-old man presented with branch retinal artery occlusion after carotid artery stenting using the FilterWire EZ. Because additional new cerebral ischaemic lesions were not detected in either case by postoperative diffusion-weighted magnetic resonance imaging, it was highly likely that the debris that caused retinal artery occlusion passed through not the internal carotid artery but collaterals to retinal arteries from the external carotid artery, which was not protected by a distal embolic protection device. It is suggested that a distal protection device for the internal carotid artery alone cannot prevent retinal artery embolisation during carotid artery stenting and protection of the external carotid artery is important to avoid retinal artery occlusion.

Favorable effects of insulin sensitizers pertinent to peripheral arterial disease in type 2 diabetes: results from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial.

Science.gov (United States)

Althouse, Andrew D; Abbott, J Dawn; Sutton-Tyrrell, Kim; Forker, Alan D; Lombardero, Manuel S; Buitrón, L Virginia; Pena-Sing, Ivan; Tardif, Jean-Claude; Brooks, Maria Mori

2013-10-01

The aim of this manuscript was to report the risk of incident peripheral arterial disease (PAD) in a large randomized clinical trial that enrolled participants with stable coronary artery disease and type 2 diabetes and compare the risk between assigned treatment arms. The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial randomly assigned participants to insulin sensitization (IS) therapy versus insulin-providing (IP) therapy for glycemic control. Results showed similar 5-year mortality in the two glycemic treatment arms. In secondary analyses reported here, we examine the effects of treatment assignment on the incidence of PAD. A total of 1,479 BARI 2D participants with normal ankle-brachial index (ABI) (0.91-1.30) were eligible for analysis. The following PAD-related outcomes are evaluated in this article: new low ABI≤0.9, a lower-extremity revascularization, lower-extremity amputation, and a composite of the three outcomes. During an average 4.6 years of follow-up, 303 participants experienced one or more of the outcomes listed above. Incidence of the composite outcome was significantly lower among participants assigned to IS therapy than those assigned to IP therapy (16.9 vs. 24.1%; Pdiabetes who are free from PAD, a glycemic control strategy of insulin sensitization may be the preferred therapeutic strategy to reduce the incidence of PAD and subsequent outcomes.

An effective fractal-tree closure model for simulating blood flow in large arterial networks.

Science.gov (United States)

Perdikaris, Paris; Grinberg, Leopold; Karniadakis, George Em

2015-06-01

The aim of the present work is to address the closure problem for hemodynamic simulations by developing a flexible and effective model that accurately distributes flow in the downstream vasculature and can stably provide a physiological pressure outflow boundary condition. To achieve this goal, we model blood flow in the sub-pixel vasculature by using a non-linear 1D model in self-similar networks of compliant arteries that mimic the structure and hierarchy of vessels in the meso-vascular regime (radii [Formula: see text]). We introduce a variable vessel length-to-radius ratio for small arteries and arterioles, while also addressing non-Newtonian blood rheology and arterial wall viscoelasticity effects in small arteries and arterioles. This methodology aims to overcome substantial cut-off radius sensitivities, typically arising in structured tree and linearized impedance models. The proposed model is not sensitive to outflow boundary conditions applied at the end points of the fractal network, and thus does not require calibration of resistance/capacitance parameters typically required for outflow conditions. The proposed model convergences to a periodic state in two cardiac cycles even when started from zero-flow initial conditions. The resulting fractal-trees typically consist of thousands to millions of arteries, posing the need for efficient parallel algorithms. To this end, we have scaled up a Discontinuous Galerkin solver that utilizes the MPI/OpenMP hybrid programming paradigm to thousands of computer cores, and can simulate blood flow in networks of millions of arterial segments at the rate of one cycle per 5 min. The proposed model has been extensively tested on a large and complex cranial network with 50 parent, patient-specific arteries and 21 outlets to which fractal trees where attached, resulting to a network of up to 4,392,484 vessels in total, and a detailed network of the arm with 276 parent arteries and 103 outlets (a total of 702,188 vessels

Systemic Arterial-to-Pulmonary Artery Shunt Utilization

African Journals Online (AJOL)

multiruka1

In certain circumstances, such as cyanotic neonates with tetralogy of Fallot (4) or cyanotic patients with. Tetralogy of Fallot and hypoplastic pulmonary arteries. (5), better outcomes are obtained if definitive surgery. (total correction or palliation) is preceded by creation of a systemic arterial-to-pulmonary artery shunt (SAPAS).

Effect of calcified plaques on estimation of arterial stenosis of lower extremity in diabetic foot patients using multislice computed tomography angiography

International Nuclear Information System (INIS)

Yu Xiaojing; Jin Yan; Wang Ge; Li Chunzhi; Zhang Yi; Ren Hua

2013-01-01

Objective: To investigate the impacts of calcified plaques on estimation of arterial stenosis of lower extremity in diabetic foot patients using 16 -slice computed tomography angiography (MSCTA). Materials and Methods: Thirty-five patients (representing 38 cases)underwent both MSCTA and digital subtraction angiography (DSA) examinations. The arteries of lower extremity were divided into 15 anatomic segments, and the degree of artery stenosis in each segment was classified as normal, mildly, moderately. severely or occluded. The extent of calcification in each segment was also assessed on cross -sectional image of MDCTA and was classified as absent, mildly, moderately, or severely. Using DSA as the standard reference, the sensitivity, specificity, accuracy, Youden index, positive predictive value and negative predictive value of MSCTA were calculated. Agreement between MSCTA and DSA was assessed by Cohen's kappa statistics. Results: In the noncalcified, mildly and moderately calcified segments of the artery above the knee, for the detection of segments that had more than mild stenosis, the sensitivity, specificity, accuracy. Youden index, positive predictive value and negative predictive value of MSCTA were 97.1%, 98.7%, 98.2%, 95.8%, 97.0% and 98.7%, respectively. In the severely calcified segments of the artery above the knee, for the detection of segments that had more than mild stenosis, the sensitivity, specificity, accuracy, Youden index, positive predictive value and negative predictive value of MSCTA were 96.3%, 93.8%, 94.7%, 90.1%, 89.7% and 97.8%, respectively. In the noncalcified, mildly and moderately calcified segments of the artery below the knee, for the detection of segments that had more than mild stenosis, the sensitivity, specificity, accuracy, Youden index, positive predictive value and negative predictive value of MSCTA were 95.1%, 93.2%, 94.1%, 88.3%, 93.4% and 94.9%, respectively. In the severely calcified segments of the artery below the

Modeling the Afferent Dynamics of the Baroreflex Control System

DEFF Research Database (Denmark)

Ottesen, Johnny T.; Mahdi, Adam; Sturdy, Jacob

2013-01-01

of mechanoreceptors located in the BR nerve-endings, and modulation of the action potential frequency. The three sub-systems are modeled individually following well-established biological principles. The first submodel, predicting arterial wall deformation, uses blood pressure as an input and outputs circumferential...... demonstrate that our preferred model can exhibit all known dynamics and that it is advantageous to combine qualitative and quantitative analysis methods....

Usefulness of lung and right ventricular thallium-201 uptake during single photon emission computed tomography in exercise testing of patients with coronary artery disease

International Nuclear Information System (INIS)

Matoh, Fumitaka; Tawarahara, Kei; Mikami, Naoshi

2005-01-01

Increased pulmonary or right ventricular 201 Tl uptake during the exercise test has been used as a marker of multivessel coronary artery disease. The most useful method for assessing the severity of coronary artery disease was evaluated among conventional evaluation of single photon emission computed tomography (SPECT), measurement of lung to heart uptake ratio (L/H), and right ventricular to left ventricular uptake ratio (RV/LV) on 201 Tl images during exercise testing. Regions-of-interest (4 x 4 pixels) were placed at the lung and the heart, and L/H was defined as mean lung uptake/mean heart uptake. Correspondingly, regions-of-interest (4 x 4 pixels) were placed at the RV and the LV, and RV/LV was defined as maximum RV uptake/maximum LV uptake. L/H and RV/LV on the initial image were analyzed in 216 patients (angiographically normal coronary arteries: 89, single-vessel disease: 82, multivessel disease: 45). The diagnostic value was evaluated using the receiver operating characteristic curve. All methods showed significantly higher values in patients with multivessel disease than in patients with no coronary artery disease or single-vessel disease. L/H was significantly higher in patients with prior myocardial infarction and RV/LV was significantly higher in patients without infarction. The sensitivity of only conventional SPECT evaluation for multivessel coronary artery disease was low (sensitivity 53%, specificity 94%). However, addition of evaluation of L/H and RV/LV to SPECT improved the sensitivity for multivessel coronary artery disease (sensitivity 93%, specificity 49%). The diagnostic sensitivity for multivessel coronary artery disease was improved by adding L/H and RV/LV to conventional evaluation of exercise 201 Tl SPECT. L/H and RV/LV during exercise 201 Tl imaging may provide additional information regarding the severity of coronary artery disease. (author)

MDCT Anatomic Assessment of Right Inferior Phrenic Artery Origin Related to Potential Supply to Hepatocellular Carcinoma and its Embolization

International Nuclear Information System (INIS)

Basile, Antonio; Tsetis, Dimitrios; Montineri, Arturo; Puleo, Stefano; Massa Saluzzo, Cesare; Runza, Giuseppe; Coppolino, Francesco; Ettorre, Giovanni Carlo; Patti, Maria Teresa

2008-01-01

Purpose. To prospectively assess the anatomic variation of the right inferior phrenic artery (RIPA) origin with multidetector computed tomography (MDCT) scans in relation to the technical and angiographic findings during transcatheter arterial embolization of hepatocellular carcinoma (HCC). Methods. Two hundred patients with hepatocellular carcinomas were examined with 16-section CT during the arterial phase. The anatomy of the inferior phrenic arteries was recorded, with particular reference to their origin. All patients with subcapsular HCC located at segments VII and VIII underwent arteriography of the RIPA with subsequent embolization if neoplastic supply was detected. Results. The RIPA origin was detected in all cases (sensitivity 100%), while the left inferior phrenic artery origin was detected in 187 cases (sensitivity 93.5%). RIPAs originated from the aorta (49%), celiac trunk (41%), right renal artery (5.5%), left gastric artery (4%), and proper hepatic artery (0.5%), with 13 types of combinations with the left IPA. Twenty-nine patients showed subcapsular HCCs in segments VII and VIII and all but one underwent RIPA selective angiography, followed by embolization in 7 cases. Conclusion. MDCT assesses well the anatomy of RIPAs, which is fundamental for planning subsequent cannulation and embolization of extrahepatic RIPA supply to HCC

Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis.

Science.gov (United States)

Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

2013-12-01

The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P = 0.25) nor DSA (P = 1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P = 1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

Spontaneous Arterial Dissection.

Science.gov (United States)

Brandt, Tobias; Caplan, Louis

2001-09-01

There is no controlled study for the best treatment or management of cervico-cerebral artery dissection (CAD). Rationale initial empiric treatment in acute CAD to prevent secondary embolism is partial thromboplastin time (PTT)-guided anticoagulation by intravenous heparin followed by anticoagulation with warfarin. Carotid surgery for treatment of CAD is not recommended anymore with the possible exception of persisting severe stenosis of the proximal internal carotid artery (ICA). There could be use of carotid angioplasty by balloon dilatation and stenting in selected cases of severe cerebral hemodynamic impairment by bilateral CAD. Duration of secondary prophylaxis by anticoagulation is best guided by Doppler sonography follow-up, and should be continued until normalization of blood flow or until at least 1 year after the vessel is occluded. There is no evidence that pseudoaneurysms increase the risk for embolic complication, and there is no evidence for surgery or continuation of anticoagulation in patients with pseudoaneurysms. Caution should be recommended for exercises that involve excessive head movements (eg, bungee jumping, trampoline jumping, and chiropractic maneuvers). The patient should be informed that recurrent rate is low in nonfamilial cases. Doppler sonography is a low-cost and high-sensitivity method for patients at risk.

Beneficial effects of prolonged blood pressure control after carotid artery stenting

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Chang A

2017-01-01

positive correlations between the mean or maximal SBP reductions 6 h post-CAS and SBP reductions 1 year post-CAS (β =0.20±0.07, P=0.0067 and β =0.47±0.10, P<0.0001, respectively. Conclusion: As compared to medical treatment alone, CAS may provide significant beneficial effect on long-term BP control 1 year post-CAS. Furthermore, SBP reductions 6 h post-CAS may predict the SBP reductions 1 year post-CAS. Keywords: carotid artery stenosis, hemodynamics, cerebral autoregulation, baroreflex, post-stenting hypotension, antihypertensive agents

GPER Mediates Functional Endothelial Aging in Renal Arteries.

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Meyer, Matthias R; Rosemann, Thomas; Barton, Matthias; Prossnitz, Eric R

2017-01-01

Aging is associated with impaired renal artery function, which is partly characterized by arterial stiffening and a reduced vasodilatory capacity due to excessive generation of reactive oxygen species by NADPH oxidases (Nox). The abundance and activity of Nox depends on basal activity of the heptahelical transmembrane receptor GPER; however, whether GPER contributes to age-dependent functional changes in renal arteries is unknown. This study investigated the effect of aging and Nox activity on renal artery tone in wild-type and GPER-deficient (Gper-/-) mice (4 and 24 months old). In wild-type mice, aging markedly impaired endothelium-dependent, nitric oxide (NO)-mediated relaxations to acetylcholine, which were largely preserved in renal arteries of aged Gper-/- mice. The Nox inhibitor gp91ds-tat abolished this difference by greatly enhancing relaxations in wild-type mice, while having no effect in Gper-/- mice. Contractions to angiotensin II and phenylephrine in wild-type mice were partly sensitive to gp91ds-tat but unaffected by aging. Again, deletion of GPER abolished effects of Nox inhibition on contractile responses. In conclusion, basal activity of GPER is required for the age-dependent impairment of endothelium-dependent, NO-mediated relaxation in the renal artery. Restoration of relaxation by a Nox inhibitor in aged wild-type but not Gper-/- mice strongly supports a role for Nox-derived reactive oxygen species as the underlying cause. Pharmacological blockers of GPER signaling may thus be suitable to inhibit functional endothelial aging of renal arteries by reducing Nox-derived oxidative stress and, possibly, the associated age-dependent deterioration of kidney function. © 2017 S. Karger AG, Basel.

Testicular artery arising from an aberrant right renal artery | Suluba ...

African Journals Online (AJOL)

This case report we discovered the rare variation of the origin of the right testicular artery arising from the right aberrant renal artery with double renal artery irrigating both left and right kidneys. These variations in the testicular arteries and renal arteries have implication to surgical procedures such as orchidopexy repair for ...

Sensitivity of hippuran renography in experimental renovascular hypertension

International Nuclear Information System (INIS)

Jonker, G.J.; Zeeuw, D. de; Huisman, R.M.; Beekhuis, H.; Piers, D.A.

1988-01-01

The aim of this research project was to examine the influence of angiotensin converting enzyme inhibitors on the sensitivity of hippuran renography in case of renovascular hypertension. Dogs are used for the experiments. A new constrictor device has been used for external induction of renal artery stenosis in the dogs. After ACE-inhibition a sensitivity of 100% has been found for small stenosis. Without ACE-inhibition the sensitivity was 50%. 6 refs.; 6 figs

The peripheral artery questionnaire: a new disease-specific health status measure for patients with peripheral arterial disease.

Science.gov (United States)

Spertus, John; Jones, Philip; Poler, Sherri; Rocha-Singh, Krishna

2004-02-01

The most common indication for treating patients with peripheral arterial disease is to improve their health status: their symptoms, function, and quality of life. Quantifying health status requires a valid, reproducible, and sensitive disease-specific measure. The Peripheral Artery Questionnaire (PAQ) is a 20-item questionnaire developed to meet this need by quantifying patients' physical limitations, symptoms, social function, treatment satisfaction, and quality of life. Psychometric and clinical properties of the PAQ were evaluated in a prospective cohort study of 44 patients undergoing elective percutaneous peripheral revascularization. To establish reproducibility, 2 assessments were performed 2 weeks apart and before revascularization. The change in scores before and 6 weeks after revascularization were used to determine the instruments' responsiveness and were compared with the Short Form-36 and the Walking Impairment Questionnaire. A series of cross-sectional analyses were performed to establish the construct validity of the PAQ. The 7 domains of the PAQ were internally reliable, with Cronbach alpha = 0.80 to 0.94. The test-retest reliability analyses revealed insignificant mean changes of 0.6 to 2.3 points (P = not significant for all). Conversely, the change after revascularization ranged from 13.7 to 41.9 points (P PAQ to clinical improvement. The PAQ Summary Scale was the most sensitive of all scales tested. Construct validity was established by demonstrating correlations with other measures of patient health status. The PAQ is a valid, reliable, and responsive disease-specific measure for patients with peripheral arterial disease. It may prove to be a useful end point in clinical trials and a potential aid in disease management.

Quantitative thallium-201 single-photon emission computed tomography during maximal pharmacologic coronary vasodilation with adenosine for assessing coronary artery disease

International Nuclear Information System (INIS)

Nishimura, S.; Mahmarian, J.J.; Boyce, T.M.; Verani, M.S.

1991-01-01

The diagnostic value of maximal pharmacologic coronary vasodilation with intravenously administered adenosine in conjunction with thallium-201 single-photon emission computed tomography (SPECT) for detection of coronary artery disease was investigated in 101 consecutive patients who had concomitant coronary arteriography. Tomographic images were assessed visually and from computer-quantified polar maps of the thallium-201 distribution. Significant coronary artery disease, defined as greater than 50% luminal diameter stenosis, was present in 70 patients. The sensitivity for detecting patients with coronary artery disease using quantitative analysis was 87% in the total group, 82% in patients without myocardial infarction and 96% in those with prior myocardial infarction; the specificity was 90%. The sensitivity for diagnosing coronary artery disease in patients without infarction with single-, double-and triple-vessel disease was 76%, 86% and 90%, respectively. All individual stenoses were identified in 68% of patients with double-vessel disease and in 65% of those with triple-vessel disease. The extent of the perfusion defects, as quantified by polar maps, was directly related to the extent of coronary artery disease. In conclusion, quantitative thallium-201 SPECT during adenosine infusion has high sensitivity and specificity for diagnosing the presence of coronary artery disease, localizing the anatomic site of coronary stenosis and identifying the majority of affected vascular regions in patients with multivessel involvement

Pulmonary Arterial Hypertension and Neonatal Arterial Switch Surgery for Correction of Transposition of the Great Arteries.

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Domínguez Manzano, Paula; Mendoza Soto, Alberto; Román Barba, Violeta; Moreno Galdó, Antonio; Galindo Izquierdo, Alberto

2016-09-01

There are few reports of the appearance of pulmonary arterial hypertension following arterial switch surgery in the neonatal period to correct transposition of the great arteries. We assessed the frequency and clinical pattern of this complication in our series of patients. Our database was reviewed to select patients with transposition of the great arteries corrected by neonatal arterial switch at our hospital and who developed pulmonary hypertension over time. We identified 2 (1.3%) patients with transposition of the great arteries successfully repaired in the first week of life who later experienced pulmonary arterial hypertension. The first patient was a 7-year-old girl diagnosed with severe pulmonary hypertension at age 8 months who did not respond to medical treatment and required lung transplantation. The anatomic pathology findings were consistent with severe pulmonary arterial hypertension. The second patient was a 24-month-old boy diagnosed with severe pulmonary hypertension at age 13 months who did not respond to medical therapy. Pulmonary hypertension is a rare but very severe complication that should be investigated in all patients with transposition of the great arteries who have undergone neonatal arterial switch, in order to start early aggressive therapy for affected patients, given the poor therapeutic response and poor prognosis involved. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

The usefulness of planar thallium myocardial perfusion imaging in the diagnosis of coronary artery disease

International Nuclear Information System (INIS)

Johannesen, K.A.; Andersen, K.; Foelling, M.; Vik-Mo, H.

1991-01-01

Stress thallium scintigraphy was performed in 60 patients with chest pain of uncertain origin. Myocardial ischemia was identified in 91% og the 47 patients who had angiographically significant coronary artery stenosis. Sensitivity of thallium scintigraphy was highest in patients with stenosis in the left descending coronary artery (LAD); 91% of the patients had abnormal thallium as compared with 67% of the patients with normal LAD, but significant stenosis in the circumflex artery and/or the right coronary artery. Perfusion defects in the circumflex or right coronary artery regions were detected in only 50% of the patients with multiple vessel disease. The authors conclude that stress thallium scintigraphy is a useful diagnostic procedure in patients with chest pain of uncertain origin and identifies the patients to be selected for coronary artery angiography. 15 refs., 2 figs., 2 tabs

Facilitating coronary artery evaluation in MDCT using a 3D automatic vessel segmentation tool

International Nuclear Information System (INIS)

Fawad Khan, M.; Gurung, Jessen; Maataoui, Adel; Brehmer, Boris; Herzog, Christopher; Vogl, Thomas J.; Wesarg, Stefan; Dogan, Selami; Ackermann, Hanns; Assmus, Birgit

2006-01-01

The purpose of this study was to investigate a 3D coronary artery segmentation algorithm using 16-row MDCT data sets. Fifty patients underwent cardiac CT (Sensation 16, Siemens) and coronary angiography. Automatic and manual detection of coronary artery stenosis was performed. A 3D coronary artery segmentation algorithm (Fraunhofer Institute for Computer Graphics, Darmstadt) was used for automatic evaluation. All significant stenoses (>50%) in vessels >1.5 mm in diameter were protocoled. Each detection tool was used by one reader who was blinded to the results of the other detection method and the results of coronary angiography. Sensitivity and specificity were determined for automatic and manual detection as well as was the time for both CT-based evaluation methods. The overall sensitivity and specificity of the automatic and manual approach were 93.1 vs. 95.83% and 86.1 vs. 81.9%. The time required for automatic evaluation was significantly shorter than with the manual approach, i.e., 246.04±43.17 s for the automatic approach and 526.88±45.71 s for the manual approach (P<0.0001). In 94% of the coronary artery branches, automatic detection required less time than the manual approach. Automatic coronary vessel evaluation is feasible. It reduces the time required for cardiac CT evaluation with similar sensitivity and specificity as well as facilitates the evaluation of MDCT coronary angiography in a standardized fashion. (orig.)

Noncontrast magnetic resonance angiography of the hand: improved arterial conspicuity by multidirectional flow-sensitive dephasing magnetization preparation in 3D balanced steady-state free precession imaging.

Science.gov (United States)

Fan, Zhaoyang; Hodnett, Philip A; Davarpanah, Amir H; Scanlon, Timothy G; Sheehan, John J; Varga, John; Carr, James C; Li, Debiao

2011-08-01

: To develop a flow-sensitive dephasing (FSD) preparative scheme to facilitate multidirectional flow-signal suppression in 3-dimensional balanced steady-state free precession imaging and to validate the feasibility of the refined sequence for noncontrast magnetic resonance angiography (NC-MRA) of the hand. : A new FSD preparative scheme was developed that combines 2 conventional FSD modules. Studies using a flow phantom (gadolinium-doped water 15 cm/s) and the hands of 11 healthy volunteers (6 males and 5 females) were performed to compare the proposed FSD scheme with its conventional counterpart with respect to the signal suppression of multidirectional flow. In 9 of the 11 healthy subjects and 2 patients with suspected vasculitis and documented Raynaud phenomenon, respectively, 3-dimensional balanced steady-state free precession imaging coupled with the new FSD scheme was compared with spatial-resolution-matched (0.94 × 0.94 × 0.94 mm) contrast-enhanced magnetic resonance angiography (0.15 mmol/kg gadopentetate dimeglumine) in terms of overall image quality, venous contamination, motion degradation, and arterial conspicuity. : The proposed FSD scheme was able to suppress 2-dimensional flow signal in the flow phantom and hands and yielded significantly higher arterial conspicuity scores than the conventional scheme did on NC-MRA at the regions of common digitals and proper digitals. Compared with contrast-enhanced magnetic resonance angiography, the refined NC-MRA technique yielded comparable overall image quality and motion degradation, significantly less venous contamination, and significantly higher arterial conspicuity score at digital arteries. : The FSD-based NC-MRA technique is improved in the depiction of multidirectional flow by applying a 2-module FSD preparation, which enhances its potential to serve as an alternative magnetic resonance angiography technique for the assessment of hand vascular abnormalities.

Combination of serum angiopoietin-2 and uterine artery Doppler for prediction of preeclampsia.

Science.gov (United States)

Puttapitakpong, Ploynin; Phupong, Vorapong

2016-02-01

The aim of this study was to determine the predictive value of the combination of serum angiopoietin-2 (Ang-2) levels and uterine artery Doppler for the detection of preeclampsia in women at 16-18 weeks of gestation and to identify other pregnancy complications that could be predicted with these combined tests. Maternal serum Ang-2 levels were measured, and uterine artery Doppler was performed in 400 pregnant women. The main outcome was preeclampsia. The predictive values of this combination were calculated. Twenty-five women (6.3%) developed preeclampsia. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of uterine artery Doppler combined with serum Ang-2 levels for the prediction of preeclampsia were 24.0%, 94.4%, 22.2% and 94.9%, respectively. For the prediction of early-onset preeclampsia, the sensitivity, specificity, PPV and NPV were 57.1%, 94.1%, 14.8% and 99.2%, respectively. Patients with abnormal uterine artery Doppler and abnormal serum Ang-2 levels (above 19.5 ng ml(-1)) were at higher risk for preterm delivery (relative risk=2.7, 95% confidence interval 1.2-5.8). Our findings revealed that the combination of uterine artery Doppler and serum Ang-2 levels at 16-18 weeks of gestation can be used to predict early-onset preeclampsia but not overall preeclampsia. Thus, this combination may be a useful early second trimester screening test for the prediction of early-onset preeclampsia.

Double profunda brachii artery

Directory of Open Access Journals (Sweden)

Gavishiddappa A Hadimani

2016-01-01

Full Text Available Brachial artery (BA is a continuation of the axillary artery at the lower border of teres major. In the cubital fossa, BA divides into radial artery and ulnar artery as terminal branches. Large branch given from the BA in the upper part is profunda brachii artery. In the present case, we noticed double profunda brachii that arises from the BA. They are profunda brachii artery 1 and profunda brachii artery 2. Profunda brachii artery 1 arises in the proximal part of the BA and profunda brachii artery 2 arises distal to the profunda brachii artery 1. Both the arteries run inferolaterally in the spiral groove along with radial nerve. Variations of profunda brachii artery are important during harvesting of the lateral arm flaps and may lead to inadvertent injury during percutaneous arterial catheterization or injection of drugs.

Uncertainty quantification and sensitivity analysis of an arterial wall mechanics model for evaluation of vascular drug therapies.

Science.gov (United States)

Heusinkveld, Maarten H G; Quicken, Sjeng; Holtackers, Robert J; Huberts, Wouter; Reesink, Koen D; Delhaas, Tammo; Spronck, Bart

2018-02-01

Quantification of the uncertainty in constitutive model predictions describing arterial wall mechanics is vital towards non-invasive assessment of vascular drug therapies. Therefore, we perform uncertainty quantification to determine uncertainty in mechanical characteristics describing the vessel wall response upon loading. Furthermore, a global variance-based sensitivity analysis is performed to pinpoint measurements that are most rewarding to be measured more precisely. We used previously published carotid diameter-pressure and intima-media thickness (IMT) data (measured in triplicate), and Holzapfel-Gasser-Ogden models. A virtual data set containing 5000 diastolic and systolic diameter-pressure points, and IMT values was generated by adding measurement error to the average of the measured data. The model was fitted to single-exponential curves calculated from the data, obtaining distributions of constitutive parameters and constituent load bearing parameters. Additionally, we (1) simulated vascular drug treatment to assess the relevance of model uncertainty and (2) evaluated how increasing the number of measurement repetitions influences model uncertainty. We found substantial uncertainty in constitutive parameters. Simulating vascular drug treatment predicted a 6% point reduction in collagen load bearing ([Formula: see text]), approximately 50% of its uncertainty. Sensitivity analysis indicated that the uncertainty in [Formula: see text] was primarily caused by noise in distension and IMT measurements. Spread in [Formula: see text] could be decreased by 50% when increasing the number of measurement repetitions from 3 to 10. Model uncertainty, notably that in [Formula: see text], could conceal effects of vascular drug therapy. However, this uncertainty could be reduced by increasing the number of measurement repetitions of distension and wall thickness measurements used for model parameterisation.

Aberrant overian artery originating from the Ilolumbar artery: A case report

Energy Technology Data Exchange (ETDEWEB)

Lee, Ji Eun; Lee, Jae Myeong [Dept. of Radiology, Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon (Korea, Republic of)

2016-05-15

Here, we report a case of a 30-year-old woman who presented with primary postpartum hemorrhage due to uterine atony. She received uterine artery embolization (UAE). During left internal iliac arteriography, an aberrant left ovarian artery originating from the left iliolumbar artery was visualized. The aberrant left ovarian artery was connected to the left uterine artery via prominent collateral vessels. It supplied a significant amount of blood to the fundus of the uterus. Bilateral hypertrophied uterine arteries were embolized very carefully so that the embolic material did not reflux into the aberrant left ovarian artery. After the procedure, her vaginal bleeding was successfully controlled. Accurate understanding of anatomical variations of the ovarian artery is essential to avoid failure in controlling postpartum hemorrhage with UAE.

Aberrant overian artery originating from the Ilolumbar artery: A case report

International Nuclear Information System (INIS)

Lee, Ji Eun; Lee, Jae Myeong

2016-01-01

Here, we report a case of a 30-year-old woman who presented with primary postpartum hemorrhage due to uterine atony. She received uterine artery embolization (UAE). During left internal iliac arteriography, an aberrant left ovarian artery originating from the left iliolumbar artery was visualized. The aberrant left ovarian artery was connected to the left uterine artery via prominent collateral vessels. It supplied a significant amount of blood to the fundus of the uterus. Bilateral hypertrophied uterine arteries were embolized very carefully so that the embolic material did not reflux into the aberrant left ovarian artery. After the procedure, her vaginal bleeding was successfully controlled. Accurate understanding of anatomical variations of the ovarian artery is essential to avoid failure in controlling postpartum hemorrhage with UAE

Transesophageal echocardiography in the assessment of coronary arteries; Echokardiografia przezprzelykowa w ocenie proksymalnych odcinkow naczyn wiencowych

Energy Technology Data Exchange (ETDEWEB)

Adamek-Kosmider, A.; Kasprzak, J.; Kosmider, M.; Krzeminska-Pakula, M. [Akademia Medyczna, Lodz (Poland)

1993-12-31

The study was undertaken to assess the usefulness of TEE for evaluation of morphology and flow in coronary arteries. TEE (2D, spectral and color Doppler imaging) and coronary angiography were performed in 75 patients - 41 with valvular heart disease and 34 with ischemic heart disease. Proximal coronary artery stenosis was detected by coronarography in 11 pts (9-left main coronary artery, 2-right coronary artery). TEE visualization of proximal coronary arteries was possible in all pts. Echocardiographic features of artery stenosis were: the narrowing of the vessel in 2D image (9 pts), high flow velocity spectral Doppler (4 pts, mean 135 cm/s vs 55 cm/s in normal arteries) and mosaic, turbulent flow in color Doppler (10 pts). Sensitivity and specificity of TEE for coronary artery stenosis detection was respectively 81%/98% for 2D imaging and 90%/100% for color Doppler. TEE is a new, noninvasive and safe method for the evaluation of proximal coronary arteries. Detection of LMCA stenosis prior to atheterization may enhance the safety of coronary angiography. (author) 21 refs, 8 figs

Cerebellar arteries originating from the internal carotid artery: angiographic evaluation and embryologic explanations

International Nuclear Information System (INIS)

Lee, Jae Young; Han, Moon Hee; Yu, In Gyu; Chang, Ki Hyun; Kim, Eui Jong; Kim, Dae Ho

1997-01-01

To find and describe the cerebellar arteries arising from the internal carotid artery, explain them embryologically, and evaluate their clinical implication. To determine the point in the internal carotid artery from which the cereballar artery arose anomalously, consecutive angiographic studies performed in the last three years were reviewed. The distribution of such anomalous cerebellar arteries, the point in the internal carotid artery from which the anomalous vessels originated, and associated findings were analyzed. Five anomalous origins of cerebellar arteries arising arising directly from the internal carotid artery were found in five patients. Three anterior inferior cerebellar arteries (AICA) and one common trunk of an AICA and a posterior inferior cerebellar artery (PICA) were found to originate from the internal carotid artery at a point close to the origin of the primitive trigeminal artery. A PICA arose from an artery presenting a course similar to the proatlantal intersegmental artery. Intracranial aneurysms in two patients, Moyamoya disease in one, and facial arteriovenous malformation in one. In our series, AICAs supplied from the arteries considered to be persistent trigeminal artery variants were the most common type. A correlation between type of anomalous cerebellar artery and type of carotid-vertebrobasilar anastomosis may exist. Cerebellar arteries originating anomalously from the internal carotid artery seem to occur as a result of the persistence of carotid-vertebrobasilar anastomoses associated with incomplete fusion of the longitudinal neural arteries. An understanding of these anomalous cerebellar arteries may help prevent accidents during therapeutic embolization and surgical treatment, as well as misinterpretation

Aberrant ovarian artery arising from the common Iliac artery: Case report

Energy Technology Data Exchange (ETDEWEB)

Kim, Won Kyung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Yang, Seung Boo; Lee, Jae Myeong [Dept. of Radiology, Soonchunhyang University Gumi Hospital, Soonchunhyang University College of Medicine, Gumi (Korea, Republic of); Goo, Dong Erk; Kim, Yong Jae; Chang, Yun Woo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

2013-01-15

A 46-year-old Vietnamese woman received embolization therapy in order to control postpartum hemorrhage. Angiography revealed an aberrant ovarian artery arising from the right common iliac artery. Superselective catheterization and subsequent embolization of the aberrant ovarian artery and bilateral uterine arteries were performed. Precise knowledge of the anatomic variations of the ovarian artery is important for successful embolization.

Aberrant ovarian artery arising from the common Iliac artery: Case report

International Nuclear Information System (INIS)

Kim, Won Kyung; Yang, Seung Boo; Lee, Jae Myeong; Goo, Dong Erk; Kim, Yong Jae; Chang, Yun Woo

2013-01-01

A 46-year-old Vietnamese woman received embolization therapy in order to control postpartum hemorrhage. Angiography revealed an aberrant ovarian artery arising from the right common iliac artery. Superselective catheterization and subsequent embolization of the aberrant ovarian artery and bilateral uterine arteries were performed. Precise knowledge of the anatomic variations of the ovarian artery is important for successful embolization.

Access to the ophthalmic artery by retrograde approach through the posterior communicating artery for intra-arterial chemotherapy of retinoblastoma

Energy Technology Data Exchange (ETDEWEB)

Pham, Chi-Tuan; Blanc, Raphael; Pistocchi, Silvia; Bartolini, Bruno; Piotin, Michel [Fondation Rothschild Hospital, Department of Interventional Neuroradiology, Paris (France); Lumbroso-Le Rouic, Livia [Institut Curie, Department of Ocular Oncology, Paris (France)

2012-08-15

Intra-arterial infusion of chemotherapy into the ophthalmic artery for treatment of retinoblastoma has been realized after catheterization of the internal carotid and temporary balloon occlusion beyond the orifice of the ophthalmic artery, or more recently after superselective canulation of the ophthalmic artery by a microcatheter. The superselective catheterization of the ophthalmic artery could be cumbersome because of the implantation of the ostium on the carotid siphon or because of the tortuosity of the carotid siphon. We report our experience of using a retrograde approach through the posterior communicating artery that allows a more direct angle of access to the origin of the ophthalmic artery. (orig.)

Altered Nocturnal Cardiovascular Control in Children With Sleep-Disordered Breathing.

Science.gov (United States)

El-Hamad, Fatima; Immanuel, Sarah; Liu, Xiao; Pamula, Yvonne; Kontos, Anna; Martin, James; Kennedy, Declan; Kohler, Mark; Porta, Alberto; Baumert, Mathias

2017-10-01

To assess cardiovascular control during sleep in children with sleep-disordered breathing (SDB) and the effect of adenotonsillectomy in comparison to healthy nonsnoring children. Cardiorespiratory signals obtained from overnight polysomnographic recordings of 28 children with SDB and 34 healthy nonsnoring children were analyzed. We employed an autoregressive closed-loop model with heart period (RR) and pulse transit time (PTT) as outputs and respiration as an external input to obtain estimates of respiratory gain and baroreflex gain. Mean and variability of PTT were increased in children with SDB across all stages of sleep. Low frequency power of RR and PTT were attenuated during non-rapid eye movement (REM) sleep. Baroreflex sensitivity was reduced in children with SDB in stage 2 sleep, while respiratory gain was increased in slow wave sleep. After adenotonsillectomy, these indices normalized in the SDB group attaining values comparable to those of healthy children. In children with mild-to-moderate SDB, vasomotor activity is increased and baroreflex sensitivity decreased during quiet, event-free non-REM sleep. Adenotonsillectomy appears to reverse this effect. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

The postprocessing techniques in renal artery reconstructions and clinical application with multidetector spiral CT angiography

International Nuclear Information System (INIS)

Yu Yuanxin; Liang Changhong; Zhang Zhonglin; Xie Shufei; Liu Yubao; Tang Xiangzhou

2005-01-01

Objective: To investigate the value and predominance for imaging postprocessing techniques of renal artery variation and lesions by multidetector spiral CT angiography. Methods: 51 patients with renal artery disease including 12 artery variation, 27 artery stenosis, 3 renal anenrysm, 3 thrombosis of renal artery and 3 dissecting aneurysm of renal artery by SSD, MIP and CPR were enrolled. The effectiveness of these imaging postprocessing methods was compared, 29 of them were confirmed by DSA and 3 by operation, others were checked by MRA and follow up. Results: All abnormalities and diseases were cleariy displayed. The specificity and sensitivity were 100% respectively. In the all imaging postprocessing techniques, MPR can clearly display the calcification of the arteries, stenosis, embolism, aneurysm but do not display the anatomy satisfactorily. MIP can not only clearly display the anatomy but display the different configurations. VR can display the artery figures but can not display the information of lumen of blood vessels. SSD can display the complex vessel anatomy but it was influenced by its threshold selection. CPR can spread and display directly the tortuous renal artery and measure the section area of stenosis. Conclusions: MSCTA is helpful to accurately display the renal artery variation and lesions. Both MIP and VR are the best choice to illustrate the renal artery abnormalities. And MPR and SSD are assistant in the diagnosis of' renal artery lesions. (authors)

Imaging anatomy of dorsal pancreatic artery in patients with diabetes: a comparative study between CTA and DSA

International Nuclear Information System (INIS)

Lin Yuning; Li Hui; Yang Xizhang; Chen Ziqian; Tan Jianming; Zhong Qun; Yang Li; Wu Zhixian; Li Huimin; Huang Yisheng

2011-01-01

Objective: To investigate the clinical value of 64-section CT angiography (CTA) in detecting the origin of dorsal pancreatic artery (DPA). Methods: Ninety-seven consecutive patients with diabetes received transcatheter infusion of autologous bone marrow-derived stem cell transplantation into DPA. Abdominal CTA was performed in 42 patients before angiography. Celiac trunk, splenic, common hepatic and superior mesenteric arteries were reconstructed in order to locate the origin and traveling course of DPA. A routine angiography of both celiac and superior mesenteric arteries was performed for the demonstration of DPA. Further angiography of splenic and gastroduodenal arteries was carried out if necessary. Taking DSA images as the reference standard, the sensitivity, specificity and accuracy of CTA for DPA detection were calculated. Results: DPA was the main supply artery of pancreas in 85.7% patients (36/42). CTA demonstrated the origin of DPA in 35 cases, although one of which was confirmed to be misjudged (false positive). In seven cases CTA could not demonstrate DPA, and DSA proved that 2 of them was misjudged (false negative). The sensitivity,specificity and accuracy of CTA for DPA detection were 94.4%, 83.3% and 92.9%, respectively. Conclusion: 64-section CTA can accurately detect the origin of main supply artery of pancreas, which is of great value in guiding the interventional procedure for pancreatic diseases. (authors)

Arterial scan versus radiographic angiography in detection of shallow arterial ulcers

International Nuclear Information System (INIS)

Pollak, E.W.; Webber, M.M.; Cragin, M.D.; Wolfman, E.F. Jr.

1977-01-01

A comparison of 99m-technetium albumin aggregated arterial scan and radiographic angiography for detection of shallow intimal carotid artery ulcerations was made in a series of 12 anesthetized dogs, having a total of 16 acute arterial ulcerations. Radiographic angiography showed positive findings related to presence of stenosis or mural thrombosis in 12 instances. Direct visualization of ulceration was only exceptionally encountered. Arterial scan detected 14 of 16 intimal ulcers. The radionuclide method was reliable even in absence of stenosis or when only minimal mural thrombosis was present. Moreover, autopsy scan of the isolated arterial segments detected all 16 intimal lesions. These results indicate that the arterial scan was a more reliable method for detection of shallow arterial ulcers in this experimental model than radiographic angiography, especially when arterial lumen stenosis or mural thrombosis was minimal or absent

Prediction of parent artery of anterior communicating artery aneurysm on CT angiography

International Nuclear Information System (INIS)

Chung, Jin Young; Han, Tae Il; Kim, Dae Hong; Han, Hyun Young; Kim, Hyun Jung; Song, Mun Kab

1999-01-01

To determine whether CT angiography can predict the parent artery of an anterior communicating aneurysm on the basis of characteristics of the aneurysm and precommunication anterior cerebral artery. Eighteen patients with anterior communication aneurysm were studied prospectively using CT angiography and conventional angiography. The parent artery of an aneurysm was predicted by evaluating aneurysm neck location, direction of aneurysm projection, and size of the precommunicating anterior cerebral artery, as seen on CT angiography. A somatom Plus-4 spiral CT scanner was used and shaded-surface display three-dimensional images were constructed. Aneurysm neck was located near the parent artery in 12 cases(66.7%), and aneurysm projection was against the parent artery in 11 cases(61.1%). The parent artery of the anterior cerebral artery was larger in 15 cases(83.3%), including ten cases of hypoplasia or agenesis of the contralateral anterior cerebral artery. In 17 of 18 aneurysms(94.4%) the parent artery seen on DSA was correctly predicted by CT angiography. The parent artery of an anterior communicating aneurysm can be predicted by evaluating aneurysm neck location, direction of aneurysm projection, and precommunicating anterior cerebral artery, as seen on CT angiography

[Stress and autonomic dysregulation in patients with fibromyalgia syndrome].

Science.gov (United States)

Friederich, H-C; Schellberg, D; Mueller, K; Bieber, C; Zipfel, S; Eich, W

2005-06-01

The aim of the present study was to evaluate to what extent the orthostatic dysregulation of FMS patients can be attributed primarily to reduced baroreceptor-mediated activation of the sympathetic nervous system and whether a hyporeactive sympathetic nervous system can also be confirmed for mental stress. A total of 28 patients with primary FMS were examined and compared with 15 healthy subjects. Diagnostic investigations of the autonomic nervous system were based on measuring HRV in frequency range and assessing spontaneous baroreflex sensitivity (sBRS) under mental stress and passive orthostatism. Both under orthostatic and mental stress FMS patients exhibited reduced activation of the sympathetic nervous system as measured by the spectral power of HRV in the low-frequency range and the mean arterial blood pressure or heart rate. The present study provided no indications for dysregulation of sBRS. The results obtained confirm the hypothesis of a hyporeactive stress system in FMS patients for both peripherally and centrally mediated stimulation of the sympathetic nervous system.

Timing of Incident Stroke Risk After Cervical Artery Dissection Presenting Without Ischemia.

Science.gov (United States)

Morris, Nicholas A; Merkler, Alexander E; Gialdini, Gino; Kamel, Hooman

2017-03-01

Cervical artery dissection is a common cause of stroke in young people. The temporal profile of stroke risk after cervical artery dissection presenting without ischemia remains uncertain. We performed a crossover cohort study using administrative claims data on all emergency department visits and acute care hospitalizations from 2005 to 2011 in CA, 2006 to 2013 in NY, and 2005 to 2013 in FL. Using previously validated International Classification of Diseases, Ninth Revision, Clinical Modification codes, we identified patients with a cervical artery dissection and no previous or concurrent stroke or transient ischemic attack diagnosis. We compared the risk of stroke in successive 2-week periods during the 12 weeks after dissection versus the corresponding 2-week period 1 year later. Absolute risk increases were calculated using McNemar test for matched data. In a sensitivity analysis, we limited our population to patients presenting with typical symptoms of cervical artery dissection. We identified 2791 patients with dissection without ischemia. The absolute increase in stroke risk was 1.25% (95% confidence interval, 0.84-1.67%) in the first 2 weeks after dissection compared with the same time period 1 year later. The absolute risk increase was 0.18% (95% confidence interval, 0.02-0.34%) during weeks 3 to 4 and was no longer significant during the remainder of the 12-week postdissection period. Our findings were similar in a sensitivity analysis identifying patients who presented with typical symptoms of acute dissection. The risk of stroke after cervical artery dissection unaccompanied by ischemia at time of diagnosis seems to be limited to the first 2 weeks. © 2017 American Heart Association, Inc.

Double profunda brachii artery

OpenAIRE

Gavishiddappa A Hadimani; Jyoti V Hadimani; Ishwar B Bagoji; Shardha Bai Rathod; Balappa M Bannur

2016-01-01

Brachial artery (BA) is a continuation of the axillary artery at the lower border of teres major. In the cubital fossa, BA divides into radial artery and ulnar artery as terminal branches. Large branch given from the BA in the upper part is profunda brachii artery. In the present case, we noticed double profunda brachii that arises from the BA. They are profunda brachii artery 1 and profunda brachii artery 2. Profunda brachii artery 1 arises in the proximal part of the BA and profunda brachii...

Anomalous external carotid artery-internal carotid artery anastomosis in two patients with proximal internal carotid arterial remnants

Energy Technology Data Exchange (ETDEWEB)

Kim, Chang Hun [Dept. of Neurology, Stroke Center, Myongji Hospital, Goyang (Korea, Republic of); Cho, Young Dae; Kang, Hyun Seung; Kim, Jeong Eun; Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jung, Seung Chai [Dept. of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Ahn, Jun Hyong [Dept. of Neurosurgery, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

2015-08-15

Two angiographic instances of anomalous external carotid artery (ECA) and internal carotid artery (ICA) anastomosis are described, each occurring at the C2-3 level and bearing remnants of proximal ICA. The ICA remnant of one patient (identifiable immediately upon bifurcation of the common carotid artery) was hypoplastic, and that of the other patient was an occluded arterial stump. These features are not typical of non-bifurcating ICA. The occipital artery originated from an anomalous connection in one instance and from the main trunk of the ECA (just past the ECA-ICA connection) in the other.

Baroreflexes of the rat. V. Tetanus-induced potentiation of ADN A-fiber responses at the NTS.

Science.gov (United States)

Tang, Xiaorui; Dworkin, Barry R

2007-12-01

In a long-term neuromuscular blocked (NMB) rat preparation, tetanic stimulation of the aortic depressor nerve (ADN) enhanced the A-fiber evoked responses (ERs) in the cardiovascular region, the nucleus of the solitary tract (dmNTS). The potentiation persisted for at least several hours and may be a mechanism for adaptive adjustment of the gain of the baroreflex, with functional implications for blood pressure regulation. Using a capacitance electrode, we selectively stimulated A-fibers and acquired a stable 10-h "A-fiber only" ER baseline at the dmNTS. Following baseline, an A+C-fiber activating tetanus was applied to the ADN. The tetanus consisted of 1,000 "high current" pulses (10 trains; 300 mus, 100 Hz, 1 s), with intertrain interval of 9 s. A 10-h A-fiber only posttetanic test phase repeated the stimulus pattern of the baseline. Fourteen tetanus experiments were done in 12 rats. Compared with the baseline before tetanus, the A-fiber ER magnitudes of posttetanus hours were larger [F(13, 247) = 3.407, P ADN A+C fiber-activating tetanus produced increases in the magnitude of the A-fiber ERs in the dmNTS that persisted for several hours. In an additional rat, application of an NMDA receptor antagonist, prior to the tetanus, blocked the potentiation effect. The stimulus protocols, magnitude and duration of the effect, and pharmacology resemble associative long-term potentiation (LTP).

N-terminal Pro-brain Natriuretic Peptide, High-sensitivity Troponin and Pulmonary Artery Clot Score as Predictors of Right Ventricular Dysfunction in Echocardiography.

Science.gov (United States)

Granér, Marit; Harjola, Veli-Pekka; Selander, Tuomas; Laiho, Mia K; Piilonen, Anneli; Raade, Merja; Mustonen, Pirjo

2016-06-01

We investigated the ability of cardiac biomarkers and total pulmonary artery (PA) clot score to predict right ventricular dysfunction (RVD) on admission and at seven-month follow-up in subjects with acute pulmonary embolism (APE). Sixty-three normotensive patients with APE were divided into two groups: patients with (n= 32, age 58±19 years) and without (n=31, age 55±16 years) echocardiographic RVD. Transthoracic echocardiography (TTE), N-terminal pro-brain natriuretic peptide (NT-proBNP), and high-sensitivity troponin T (hsTnT) were assessed upon arrival and repeated at seven months. Total PA clot score was determined on admission. The age- and sex dependent NT-proBNP on admission, on day 5, and at seven months exhibited the best sensitivity (admission 94%, day 5 100%, seven months 100%) and negative predictive value (NPV) (89%, 100%, 100%) for detecting RVD. Six patients (10%) had persistent RVD at seven months. Total PA clot score showed only low to moderate sensitivity (77%) and PPV (7%) for detection of RVD at seven months. Normal age- and sex dependent NT-proBNP on admission or measured five days later seems to be useful in exclusion of RVD at follow up. Total PA clot score shows only to be of modest benefit for predicting persistent RVD. Copyright © 2015 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.

Magnetic resonance imaging compared with echocardiography in the evaluation of pulmonary artery abnormalities in children with tetralogy of Fallot following palliative and corrective surgery

International Nuclear Information System (INIS)

Greenberg, S.B.; Crisci, K.L.; Koenig, P.; Robinson, B.; Anisman, P.; Russo, P.

1997-01-01

Background. Abnormalities of the pulmonary arteries following palliative or corrective surgery for tetralogy of Fallot (TOF) are common. Our purpose was to compare the usefulness of magnetic resonance imaging (MRI) and echocardiography in the post- operative evaluation of the pulmonary arteries in children with TOF. Objective. Our hypothesis was that MRI is more sensitive than echocardiography in the detection of branch pulmonary artery abnormalities in children with TOF. Materials and methods. Pulmonary artery MRI and echocardiography were performed in 20 children following palliative and/or corrective surgery for TOF. MRI and echocardiography were compared in their ability to detect abnormalities of the pulmonary arteries. Angiographic or surgical correlation was available in 15 children. A perfusion scan for confirmation of pulmonary artery patency was available in one additional child. Results. Abnormalities of the branch pulmonary arteries identified by MRI included: absence or occlusion (2), focal stenosis (15), hypoplasia (2), aneurysm (1), and non-confluence (1). Echocardiography could not adequately visualize the right and left branch pulmonary arteries in eight and ten children, respectively. Echocardiography missed stenosis in 13 branch pulmonary arteries, patency of hypoplastic pulmonary arteries in two children, non-confluence of the pulmonary arteries in one child, and a left pulmonary artery aneurysm in one child. Abnormalities identified by MRI were confirmed in 16 children by angiography, surgery or perfusion scan. Conclusion. MRI is more sensitive than echocardiography for the evaluation of branch pulmonary artery abnormalities in children following surgery for TOF. (orig.)

[Prognostic Doppler ultrasound examination of fetal arteries blood flow].

Science.gov (United States)

Sieroszewski, Piotr; Sabatowska, Małgorzata; Karowicz-Bilińska, Agata; Suzin, Jacek

2002-08-01

Early detection of fetal risk is one of the main issues in today obstetrics. Ultrasound diagnostics plays a significant role, as the introduction of Doppler imaging method in the evaluation of blood flow has enabled non-invasive assessment of uteroplacental circulation. Therefore, we have analysed foetal three arteries: umbilical artery, middle cerebral artery and renal artery after determining the normal range for the analysed parameters. 1. Comparison of the obtained blood flow indices (S/D, RI, PI) in the umbilical artery, middle cerebral artery and renal artery of foetuses from normal and complicated full-term pregnancies. 2. Determination of indices: umbilical-cerebral and renal-cerebral in normal and pathological pregnancy. 3. Evaluation of feasibility of the analysed flow parameters for the detection of intrauterine foetal hypoxia. We have examined 151 women, who were divided into control group--101 pregnant women with normal pregnancy and study group--50 pregnant women with complicated pregnancy. All pregnant women underwent ultrasound examination using the Hitachi EUB 515 C (Japan) scanner with 3.5 MHz convex probe, connected to the colour pulsed Doppler. The study consisted of the biometric measurements and evaluation of the spectrum of blood flow in the umbilical artery, middle cerebral artery and renal artery. We have determined following indices: a) systolic-diastolic ratio S/D, resistance index RI, pulsatility index PI, b) umbilical-cerebral ratio P/M. (PI ua/PI mca), renal--cerebral ratio N/M (PI ra/PI mca). Statistically significant difference was found between the study and control groups for all the flow indices assessed (S/D, RI, PI) for the middle cerebral artery, for the indices P/M and N/M. (p < 0.001) and pulsatility index in the renal artery (p < 0.01). Similar, although slightly smaller difference (p < 0.05) was seen for the values of flow parameters in the umbilical artery. 1) Evaluation of blood flow in the middle cerebral artery, and in

High sodium intake during postnatal phases induces an increase in arterial blood pressure in adult rats.

Science.gov (United States)

Moreira, M C S; da Silva, E F; Silveira, L L; de Paiva, Y B; de Castro, C H; Freiria-Oliveira, A H; Rosa, D A; Ferreira, P M; Xavier, C H; Colombari, E; Pedrino, Gustavo R

2014-12-28

Epigenetic studies suggest that diseases that develop in adulthood are related to certain conditions to which the individual is exposed during the initial stages of life. Experimental evidence has demonstrated that offspring born to mothers maintained on high-Na diets during pregnancy have higher mean arterial pressure (MAP) in adulthood. Although these studies have demonstrated the importance of prenatal phases to hypertension development, no evidence regarding the role of high Na intake during postnatal phases in the development of this pathology has been reported. Therefore, in the present study, the effects of Na overload during childhood on induced water and Na intakes and on cardiovascular parameters in adulthood were evaluated. Experiments were carried out in two groups of 21-d-old rats: experimental group, maintained on hypertonic saline (0.3 m-NaCl) solution and food for 60 d, and control group, maintained on tap water and food. Later, both groups were given water and food for 15 d (recovery period). After the recovery period, chronic cannulation of the right femoral artery was performed in unanaesthetised rats to record baseline MAP and heart rate (HR). The experimental group was found to have increased basal MAP (98.6 (sem 2.6) v. 118.3 (sem 2.7) mmHg, P< 0.05) and HR (365.4 (sem 12.2) v. 398.2 (sem 7.5) beats per min, P< 0.05). There was a decrease in the baroreflex index in the experimental group when compared with that in the control group. A water and Na intake test was performed using furosemide. Na depletion was found to induce an increase in Na intake in both the control and experimental groups (12.1 (sem 0.6) ml and 7.8 (sem 1.1), respectively, P< 0.05); however, this increase was of lower magnitude in the experimental group. These results demonstrate that postnatal Na overload alters behavioural and cardiovascular regulation in adulthood.

Mechanisms Involved in Thromboxane A2-induced Vasoconstriction of Rat Intracavernous Small Penile Arteries

DEFF Research Database (Denmark)

Grann, Martin; Comerma Steffensen, Simon Gabriel; Arcanjo, Daniel Dias Rufino

2015-01-01

relaxation in rat mesenteric arteries. Our findings suggest that U46619 contraction depends on Ca2+ influx through L-type and TRP channels, and ROCKdependent mechanisms in penile arteries. Inhibition of the ROCK pathway is a potential approach for the treatment of erectile dysfunction associated......Diabetes is associated with erectile dysfunction and with hypercontractility in erectile tissue and this is in part ascribed to increased formation of thromboxane. Rho kinase (ROCK) is a key regulator of calcium sensitization and contraction in vascular smooth muscle. This study investigated...... the role of calcium and ROCK in contraction evoked by activation of the thromboxane receptors. Rat intracavernous penile arteries were mounted for isometric tension and intracellular calcium ([Ca2+]i) recording and corpus cavernosum for measurements of MYPT1 phosphorylation. In penile arteries, U46619...

Association between internal carotid artery dissection and arterial tortuosity

International Nuclear Information System (INIS)

Saba, Luca; Piga, Mario; Argiolas, Giovanni Maria; Siotto, Paolo; Sumer, Suna; Wintermark, Max; Raz, Eytan; Sanfilippo, Roberto; Montisci, Roberto

2015-01-01

Carotid artery dissection is an important cause of ischemic stroke in all age groups, particularly in young patients. The purpose of this work was to assess whether there is an association between the presence of an internal carotid artery dissection (ICAD) and the arterial tortuosity. This study considered 124 patients (72 males and 52 females; median age 57 years) with CT/MR diagnosis of ICAD of the internal carotid artery were considered in this multi-centric retrospective study. The arterial tortuosity was evaluated and, when present, was categorized as elongation, kinking, or coiling. For each patient, both the right and left sides were considered for a total number of 248 arteries in order to have the same number of cases and controls. Fisher's exact test was applied to test the association between elongation, kinking, coiling, dissection, and the side affected by CAD. Fisher's exact test showed a statistically significant association between the ICAD and kinking (p = 0.0089) and coiling (p = 0.0251) whereas no statistically significant difference was found with arterial vessel elongation (p = 0.444). ICAD was more often seen on the left side compared to the right (p = 0.0001). These results were confirmed using both carotid arteries of the same patient as dependent parameter with p = 0.0012, 0.0129, and 0.3323 for kinking, coiling, and elongation, respectively. The presence of kinking and coiling is associated with ICAD. (orig.)

Association between internal carotid artery dissection and arterial tortuosity

Energy Technology Data Exchange (ETDEWEB)

Saba, Luca; Piga, Mario [Azienda Ospedaliero Universitaria (A.O.U.), Department of Radiology, Monserrato, Cagliari (Italy); Argiolas, Giovanni Maria; Siotto, Paolo [Azienda Ospedaliero Brotzu (A.O.B.), Department of Radiology, di Cagliari (Italy); Sumer, Suna; Wintermark, Max [Neuroradiology Division, Neuroradiology, UVA Department of Radiology, Charlottesville, VA (United States); Raz, Eytan [New York University School of Medicine, Department of Radiology, New York, NY (United States); Sapienza University of Rome, Department of Neurology and Psychiatry, Rome (Italy); Sanfilippo, Roberto; Montisci, Roberto [Azienda Ospedaliero Universitaria (A.O.U.), Department of Vascular Surgery, di Cagliari (Italy)

2014-10-18

Carotid artery dissection is an important cause of ischemic stroke in all age groups, particularly in young patients. The purpose of this work was to assess whether there is an association between the presence of an internal carotid artery dissection (ICAD) and the arterial tortuosity. This study considered 124 patients (72 males and 52 females; median age 57 years) with CT/MR diagnosis of ICAD of the internal carotid artery were considered in this multi-centric retrospective study. The arterial tortuosity was evaluated and, when present, was categorized as elongation, kinking, or coiling. For each patient, both the right and left sides were considered for a total number of 248 arteries in order to have the same number of cases and controls. Fisher's exact test was applied to test the association between elongation, kinking, coiling, dissection, and the side affected by CAD. Fisher's exact test showed a statistically significant association between the ICAD and kinking (p = 0.0089) and coiling (p = 0.0251) whereas no statistically significant difference was found with arterial vessel elongation (p = 0.444). ICAD was more often seen on the left side compared to the right (p = 0.0001). These results were confirmed using both carotid arteries of the same patient as dependent parameter with p = 0.0012, 0.0129, and 0.3323 for kinking, coiling, and elongation, respectively. The presence of kinking and coiling is associated with ICAD. (orig.)

Normal variation of hepatic artery

International Nuclear Information System (INIS)

Kim, Inn; Nam, Myung Hyun; Rhim, Hyun Chul; Koh, Byung Hee; Seo, Heung Suk; Kim, Soon Yong

1987-01-01

This study was an analyses of blood supply of the liver in 125 patients who received hepatic arteriography and abdominal aortography from Jan. 1984 to Dec. 1986 at the Department of Radiology of Hanyang University Hospital. A. Variations in extrahepatic arteries: 1. The normal extrahepatic artery pattern occurred in 106 of 125 cases (84.8%) ; Right hepatic and left hepatic arteries arising from the hepatic artery proper and hepatic artery proper arising from the common hepatic artery. 2. The most common type of variation of extrahepatic artery was replaced right hepatic artery from superior mesenteric artery: 6 of 125 cases (4.8%). B. Variations in intrahepatic arteries: 1. The normal intrahepatic artery pattern occurred in 83 of 125 cases (66.4%). Right hepatic and left hepatic arteries arising from the hepatic artery proper and middle hepatic artery arising from lower portion of the umbilical point of left hepatic artery. 2. The most common variation of intrahepatic arteries was middle hepatic artery. 3. Among the variation of middle hepatic artery; Right, middle and left hepatic arteries arising from the same location at the hepatic artery proper was the most common type; 17 of 125 cases (13.6%)

The value of coronary artery calcium score assessed by dual-source computed tomography coronary angiography for predicting presence and severity of coronary artery disease

International Nuclear Information System (INIS)

Almasi, Alireza; Pouraliakbar, Hamidreza; Sedghian, Ahmad; Karimi, Mohammad Ali; Firouzi, Ata; Tehrai, Mahmood

2014-01-01

Measuring coronary artery calcium score (CACS) using a dual-source CT scanner is recognized as a major indicator for assessing coronary artery disease. The present study aimed to validate the clinical significance of CACS in predicting coronary artery stenosis and its severity. This prospective study was conducted on 202 consecutive patients who underwent both conventional coronary angiography and dual-source (256-slice) computed tomography coronary angiography (CTA) for any reason in our cardiac imaging center from March to September 2013. CACS was measured by Agatston algorithm on non-enhanced CT. The severity of coronary artery disease was assessed by Gensini score on conventional angiography. There was a significant relationship between the number of diseased coronary vessels and mean calcium score, i.e. the mean calcium score was 202.25±450.06 in normal coronary status, 427.50±607.24 in single-vessel disease, 590.03±511.34 in two-vessel disease, and 953.35±1023.45 in three-vessel disease (p<0.001). There was a positive association between calcium score and Gensini score (r=0.636, p<0.001). In a linear regression model, calcium score was a strong determinant of the severity of coronary artery disease. Calcium scoring had an acceptable value for discriminating coronary disease from normal condition with optimal cutoff point of 350, yielding a sensitivity and specificity of 83% and 70%, respectively. Our study confirmed the strong relationship between the coronary artery calcium score and the presence and severity of stenosis in coronary arteries assessed by both the number of diseased coronary vessels and also by the Gnesini score

Massive cerebral arterial air embolism following arterial catheterization

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Yang, C.W. [Northwestem University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Yang, B.P. [Northwestern University Feinberg School of Medicine, Department of Neurological Surgery, Chicago, IL (United States)

2005-12-01

Microscopic cerebral arterial air embolism (CAAE) has been described in many patients undergoing cardiac surgery as well as other invasive diagnostic and therapeutic procedures. However, massive CAAE is rare. We report a 42-year-old woman who initially presented with thalamic and basal ganglia hemorrhages. Shortly after a radial arterial catheter was inserted, the patient suffered a generalized seizure and CT demonstrated intra-arterial air in bilateral cerebral hemispheres. (orig.)

Upper limb artery segmental occlusions due to chronic use of ergotamine combined with itraconazole, treated by thrombolysis

Directory of Open Access Journals (Sweden)

Nodari Franco

2011-08-01

Full Text Available Abstract Background The ergotamine tartrate associated with certain categories of drugs can lead to critical ischemia of the extremities. Discontinuation of taking ergotamine is usually sufficient for the total regression of ischemia, but in some cases it could be necessary thrombolytic and anticoagulant therapy to avoid amputation. Case report A woman of 62 years presented with a severe pain left forearm appeared 10 days ago, with a worsening trend. The same symptoms appeared after 5 days also in the right forearm. Physical examination showed the right arm slightly hypothermic, with radial reduced pulse in presence of reduced sensitivity. The left arm was frankly hypothermic, pulse less on radial and with an ulnar humeral reduced pulse, associated to a decreased sensitivity and motility. Clinical history shows a chronic headache for which the patient took a daily basis for years Cafergot suppository (equivalent to 3.2 mg of ergotamine. From about ten days had begun therapy with itraconazole for vaginal candidiasis. The Color-Doppler ultrasound shown arterial thrombosis of the upper limbs (humeral and radial bilateral, with minimal residual flow to the right and no signal on the humeral and radial left artery. Results Angiography revealed progressive reduction in size of the axillary artery and right humeral artery stenosis with right segmental occlusions and multiple hypertrophic collateral circulations at the elbow joint. At the level of the right forearm was recognizable only the radial artery, decreased in size. Does not recognize the ulnar, interosseous artery was thin. To the left showed progressive reduction in size of the distal subclavian and humeral artery, determined by multiple segmental steno-occlusion with collateral vessels serving only a thin hypotrophic interosseous artery. Arteriographic findings were compatible with systemic drug-induced disease. The immediate implementation of thrombolysis, continued for 26 hours, with

True pancreaticoduodenal artery aneurysms: A decision analysis

International Nuclear Information System (INIS)

Takao, Hidemasa; Nojo, Takeshi; Ohtomo, Kuni

2010-01-01

Purpose: True pancreaticoduodenal artery aneurysms are rare. No definitive study evaluating the natural history of these lesions or their preferred method of treatment has been published. The purpose of this study was to evaluate the outcome of preventive treatment of unruptured pancreaticoduodenal artery aneurysms using a Markov model. Materials and methods: With the use of a Markov model, we performed a decision analysis to evaluate the outcome of preventive treatment of unruptured pancreaticoduodenal artery aneurysms. The risk of rupture and the mortality of preventive treatment are unknown. Therefore, we performed sensitivity analysis using these parameters. Effectiveness was measured in life expectancy. Results: For 80-year-old patients, preventive treatment was dominated by no treatment if mortality rates of preventive treatment were greater than 1.4%, greater than 2.6%, greater than 3.8%, and greater than 4.8% at annual rupture rates of 1%, 2%, 3%, and 4%, respectively. For 50-year-old patients, preventive treatment was dominated by no treatment if mortality rates of preventive treatment were greater than 3.3%, greater than 5.9%, greater than 8.0%, and greater than 9.7% at annual rupture rates of 1%, 2%, 3%, and 4%, respectively. Conclusion: The effectiveness of preventive treatment of unruptured pancreaticoduodenal artery aneurysms depends on the aneurysm rupture rate, mortality rate of preventive treatment, and patient age. Taking into account the effects of these parameters is important in making treatment decisions.

Validation of subclavian duplex velocity criteria to grade severity of subclavian artery stenosis.

Science.gov (United States)

Mousa, Albeir Y; Morkous, Ramez; Broce, Mike; Yacoub, Michael; Sticco, Andrew; Viradia, Ravi; Bates, Mark C; AbuRahma, Ali F

2017-06-01

Validation of subclavian duplex ultrasound velocity criteria (SDUS VC) to grade the severity of subclavian artery stenosis has not been established or systematically studied. Currently, there is a paucity of published literature and lack of practitioner consensus for how subclavian duplex velocity findings should be interpreted in patients with subclavian artery stenosis. The objective of the present study was to validate SDUS measurements using subclavian conventional or computed tomography angiogram (subclavian angiogram [SA])-derived measurements. Secondary objectives included measuring the correlation between SDUS peak systolic velocities and SA measurements, and to determine the optimal cutoff value for predicting significant stenosis (>70%). This is a retrospective review of all patients with suspected subclavian artery stenosis and a convenience sample of carotid artery patients who underwent SDUS and SA from May 1999 to July 2013. SA reference vessel and intralesion minimal lumen diameters were measured and compared with SDUS velocities obtained within 3 months of the imaging study. Percent stenosis was calculated using the North American Symptomatic Carotid Endarterectomy Trial method for detecting stenosis in a sufficiently large cohort. Receiver operating characteristic curves was generated for SDUS VC to predict >70% stenosis. Velocity cutoff points were determined with equal weighting of sensitivity and specificity. We examined 268 arteries for 177 patients. The majority of the arteries were for female patients (52.5%) with a mean age of 66.7 ± 11.1 years. Twenty-three arteries had retrograde vertebral artery flow and excluded from further analysis. For the remaining 245 arteries, the average peak systolic velocity was 212.6 ± 110.7 cm/s, with a range of 45-626 cm/s. Average stenosis was 25.8% ± 28.2%, with a range of 0% to 100%. Following receiver operating characteristic analysis, we found a cutoff value of >240 cm/s to be most predictive

Orthostatic Intolerance Is Independent of the Degree of Autonomic Cardiovascular Adaptation after 60 Days of Head-Down Bed Rest

Science.gov (United States)

Aubert, André E.

2015-01-01

Spaceflight and head-down bed rest (HDBR) can induce the orthostatic intolerance (OI); the mechanisms remain to be clarified. The aim of this study was to determine whether or not OI after HDBR relates to the degree of autonomic cardiovascular adaptation. Fourteen volunteers were enrolled for 60 days of HDBR. A head-up tilt test (HUTT) was performed before and after HDBR. Our data revealed that, in all nonfainters, there was a progressive increase in heart rate over the course of HDBR, which remained higher until 12 days of recovery. The mean arterial pressure gradually increased until day 56 of HDBR and returned to baseline after 12 days of recovery. Respiratory sinus arrhythmia and baroreflex sensitivity decreased during HDBR and remained suppressed until 12 days of recovery. Low-frequency power of systolic arterial pressure increased during HDBR and remained elevated during recovery. Three subjects fainted during the HUTT after HDBR, in which systemic vascular resistance did not increase and remained lower until syncope. None of the circulatory patterns significantly differed between the fainters and the nonfainters at any time point. In conclusion, our data indicate that the impaired orthostatic tolerance after HDBR could not be distinguished by estimation of normal hemodynamic and/or neurocardiac data. PMID:26425559

Orthostatic Intolerance Is Independent of the Degree of Autonomic Cardiovascular Adaptation after 60 Days of Head-Down Bed Rest

Directory of Open Access Journals (Sweden)

Jiexin Liu

2015-01-01

Full Text Available Spaceflight and head-down bed rest (HDBR can induce the orthostatic intolerance (OI; the mechanisms remain to be clarified. The aim of this study was to determine whether or not OI after HDBR relates to the degree of autonomic cardiovascular adaptation. Fourteen volunteers were enrolled for 60 days of HDBR. A head-up tilt test (HUTT was performed before and after HDBR. Our data revealed that, in all nonfainters, there was a progressive increase in heart rate over the course of HDBR, which remained higher until 12 days of recovery. The mean arterial pressure gradually increased until day 56 of HDBR and returned to baseline after 12 days of recovery. Respiratory sinus arrhythmia and baroreflex sensitivity decreased during HDBR and remained suppressed until 12 days of recovery. Low-frequency power of systolic arterial pressure increased during HDBR and remained elevated during recovery. Three subjects fainted during the HUTT after HDBR, in which systemic vascular resistance did not increase and remained lower until syncope. None of the circulatory patterns significantly differed between the fainters and the nonfainters at any time point. In conclusion, our data indicate that the impaired orthostatic tolerance after HDBR could not be distinguished by estimation of normal hemodynamic and/or neurocardiac data.

Acute arterial occlusion - kidney

Science.gov (United States)

... main artery to the kidney is called the renal artery. Reduced blood flow through the renal artery can hurt kidney function. ... need include: Duplex Doppler ultrasound exam of the renal arteries to test blood flow MRI of the kidney arteries, which can show ...

Carotid artery surgery

Science.gov (United States)

Carotid endarterectomy; CAS surgery; Carotid artery stenosis - surgery; Endarterectomy - carotid artery ... through the catheter around the blocked area during surgery. Your carotid artery is opened. The surgeon removes ...

The Features of Extrahepatic Collateral Arteries Related to Hepatic Artery Occlusion and Benefits in the Trans arterial Management of Liver Tumors

International Nuclear Information System (INIS)

Yang, L.; Zhang, X.M.; Ren, Y.J.; Miao, N.D.; Huang, X.H.; Dong, G.L.

2013-01-01

To investigate the extrahepatic collateral arteries related to hepatic artery occlusion (HAO) and to determine its benefits in the trans arterial management of liver tumors. Methods and Findings. Eleven patients (7 hepatocellular carcinomas, 3 liver metastases, and 1 with hemangioma) with HAO confirmed with digital subtraction angiography (DSA) were admitted to our hospital. Of the 11 patients, 7 were men and 4 were women, with an average age of 41.5 ± 15.5 years (range: 29 to 70 years). DSA was performed to evaluate the collateral routes to the liver. In the 11 patients with HAO, DSA showed complete occlusion of the common hepatic artery in 9 patients and the proper hepatic artery (PHA) in 2 patients. Extrahepatic collateral arteries supplying the liver were readily evident. The collateral arteries originated from the superior mesenteric artery (SMA) in 8 patients, from the gastroduodenal artery in 2 patients, and from the left gastric artery (LGA) in 1 patient. Transcatheter treatment was successfully performed via the collateral artery in all patients except the one who had hemangioma. Conclusions. DSA is an effective method for detecting collateral circulation related to HAO and may provide information to guide transcatheter management decisions.

[Efferent innervation of the arteries of human leptomeninx in arterial hypertension].

Science.gov (United States)

Chertok, V M; Kotsiuba, A E; Babich, E V

2009-01-01

Structure of the efferent nerve plexuses (adrenergic, acetylcholinestherase- and cholinacetyltranspherase-positive, NO-dependent), was studied in the arteries of human leptomeninx with different diameters. Material was obtained from the corpses of the healthy people and of the patients with initial stages of arterial hypertension (AH). It was shown that the concentrations of cholinergic and adrenergic nerve fibers and varicosities in axon terminal part, innervating the arteries with the diameters ranging from 450 till 100 microm, were not significantly different. In these arteries, NO-ergic plexuses were also detected. In patients with AH, regardless the arterial diameters, the significant increase (up to 15-20%) of adrenergic nerve fiber and varicosity concentrations was found. The changes in cholinergic nerve fiber concentration were found to depend on the vessel diameter: the significant decrease of these parameter was observed only in arteries with the diameter of 100-200 microm. No significant changes in nerve plexus concentration was noticed in the arteries with greater or smaller diameter. In NO-ergic neural conductors, the enzyme activity decreased only in the large arteries, and remained almost unchanged in the small vascular branches. The changes in the vasomotor innervation described in AH, are interpreted as a vasomotor innervation dysfunction of the leptomeninx arteries that may result in the hemodynamic disturbances.

Feasibility study of the non-invasive estimation of the β+ arterial input function for human PET imaging

International Nuclear Information System (INIS)

Hubert, X.

2009-12-01

This work deals with the estimation of the concentration of molecules in arterial blood which are labelled with positron-emitting radioelements. This concentration is called 'β + arterial input function'. This concentration has to be estimated for a large number of pharmacokinetic analyses. Nowadays it is measured through series of arterial sampling, which is an accurate method but requiring a stringent protocol. Complications might occur during arterial blood sampling because this method is invasive (hematomas, nosocomial infections). The objective of this work is to overcome this risk through a non-invasive estimation of β + input function with an external detector and a collimator. This allows the reconstruction of blood vessels and thus the discrimination of arterial signal from signals in other tissues. Collimators in medical imaging are not adapted to estimate β + input function because their sensitivity is very low. During this work, they are replaced by coded-aperture collimators, originally developed for astronomy. New methods where coded apertures are used with statistical reconstruction algorithms are presented. Techniques for analytical ray-tracing and for the acceleration of reconstructions are proposed. A new method which decomposes reconstructions on temporal sets and on spatial sets is also developed to efficiently estimate arterial input function from series of temporal acquisitions. This work demonstrates that the trade-off between sensitivity and spatial resolution in PET can be improved thanks to coded aperture collimators and statistical reconstruction algorithm; it also provides new tools to implement such improvements. (author)

Aberrant Ovarian Collateral Originating from External Iliac Artery During Uterine Artery Embolization

Energy Technology Data Exchange (ETDEWEB)

Kwon, Joon Ho; Kim, Man Deuk, E-mail: mdkim@yuhs.ac; Lee, Kwang-hun; Lee, Myungsu; Lee, Mu Sook; Won, Jong Yun; Park, Sung Il; Lee, Do Yun [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Severance Hospital (Korea, Republic of)

2013-02-15

We report a case of a 35-year-old woman who underwent uterine artery embolization (UAE) for symptomatic multiple uterine fibroids with collateral aberrant right ovarian artery that originated from the right external iliac artery. We believe that this is the first reported case in the literature of this collateral uterine flow by the right ovarian artery originated from the right external iliac artery. We briefly present the details of the case and review the literature on variations of ovarian artery origin that might be encountered during UAE.

Aberrant Ovarian Collateral Originating from External Iliac Artery During Uterine Artery Embolization

International Nuclear Information System (INIS)

Kwon, Joon Ho; Kim, Man Deuk; Lee, Kwang-hun; Lee, Myungsu; Lee, Mu Sook; Won, Jong Yun; Park, Sung Il; Lee, Do Yun

2013-01-01

We report a case of a 35-year-old woman who underwent uterine artery embolization (UAE) for symptomatic multiple uterine fibroids with collateral aberrant right ovarian artery that originated from the right external iliac artery. We believe that this is the first reported case in the literature of this collateral uterine flow by the right ovarian artery originated from the right external iliac artery. We briefly present the details of the case and review the literature on variations of ovarian artery origin that might be encountered during UAE.

Magnetic resonance imaging compared with echocardiography in the evaluation of pulmonary artery abnormalities in children with tetralogy of Fallot following palliative and corrective surgery

Energy Technology Data Exchange (ETDEWEB)

Greenberg, S.B.; Crisci, K.L.; Koenig, P.; Robinson, B.; Anisman, P.; Russo, P. [St. Christopher`s Hospital for Children, Front Street at Erie Avenue, Philadelphia, PA 19134 (United States)

1997-12-01

Background. Abnormalities of the pulmonary arteries following palliative or corrective surgery for tetralogy of Fallot (TOF) are common. Our purpose was to compare the usefulness of magnetic resonance imaging (MRI) and echocardiography in the post- operative evaluation of the pulmonary arteries in children with TOF. Objective. Our hypothesis was that MRI is more sensitive than echocardiography in the detection of branch pulmonary artery abnormalities in children with TOF. Materials and methods. Pulmonary artery MRI and echocardiography were performed in 20 children following palliative and/or corrective surgery for TOF. MRI and echocardiography were compared in their ability to detect abnormalities of the pulmonary arteries. Angiographic or surgical correlation was available in 15 children. A perfusion scan for confirmation of pulmonary artery patency was available in one additional child. Results. Abnormalities of the branch pulmonary arteries identified by MRI included: absence or occlusion (2), focal stenosis (15), hypoplasia (2), aneurysm (1), and non-confluence (1). Echocardiography could not adequately visualize the right and left branch pulmonary arteries in eight and ten children, respectively. Echocardiography missed stenosis in 13 branch pulmonary arteries, patency of hypoplastic pulmonary arteries in two children, non-confluence of the pulmonary arteries in one child, and a left pulmonary artery aneurysm in one child. Abnormalities identified by MRI were confirmed in 16 children by angiography, surgery or perfusion scan. Conclusion. MRI is more sensitive than echocardiography for the evaluation of branch pulmonary artery abnormalities in children following surgery for TOF. (orig.) With 2 figs., 3 tabs., 11 refs.

Breath-hold two-dimensional MR angiography of coronary arteries. Comparison with conventional coronary angiography in ten cases

International Nuclear Information System (INIS)

Li Liwei; Zhang Wanshi; Liu Chaozhong; Lu Xiaoyan; Xu Jiaxing

1997-01-01

Purpose: To assess the diagnostic value of two-dimensional coronary magnetic resonance (MR) angiography in patients evaluated for ischemic heart disease. Materials and methods: Ten patients who underwent selective cardiac catheterization with coronary MR angiography were evaluated with two-dimensional coronary MR angiography. Coronary MR angiography was performed with breath-hold fat-suppressed ECG-gated Turbo-FLASH with K-space segmentation using a 1.5 T imager. Results: The left main coronary artery, proximal left anterior descending artery, circumflex artery and right coronary artery were demonstrated in all cases. Continuous segments (mean) of left anterior descending, circumflex and right coronary arteries visualized on MRA were 6.72 +- 3.16 cm, 3.67 +- 4.81 cm and 7.93 +- 3.12 cm respectively. The overall sensitivity for detection of hemodynamically significant coronary artery lesion (≥50%) was 62.5% respectively. Conclusion: Breath-hold two-dimensional coronary MR angiography was useful in showing relatively long segments of the main coronary arteries and also has potential in depicting hemodynamically significant coronary artery lesions

Hepatic falciform artery

International Nuclear Information System (INIS)

Jaques, Paul F.; Mauro, Matthew A.; Sandhu, Jeet

1997-01-01

The hepatic falciform artery is an occasional terminal branch of the left or middle hepatic artery, and may provide an uncommon but important collateral route when the principal visceral arteries are occluded

Feeding Arteries of Primary Tongue Cancers on Intra-arterial Infusion Chemotherapy

Energy Technology Data Exchange (ETDEWEB)

Kamitani, Takeshi, E-mail: kamitani@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan); Kawanami, Satoshi, E-mail: kawanami-01@mac.com [Kyushu University, Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences (Japan); Asayama, Yoshiki, E-mail: asayama@radiol.med.kyushu-u.ac.jp; Matsuo, Yoshio, E-mail: yymatsuo@radiol.med.kyushu-u.ac.jp; Yonezawa, Masato, E-mail: ymasato@radiol.med.kyushu-u.ac.jp; Yamasaki, Yuzo, E-mail: yyama@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan); Nagao, Michinobu, E-mail: minagao@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences (Japan); Yamanouchi, Torahiko, E-mail: tora0228@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan); Yabuuchi, Hidetake, E-mail: h-yabu@med.kyushu-u.ac.jp [Kyushu University, Department of Health Sciences, Graduate School of Medical Sciences (Japan); Nakamura, Katsumasa, E-mail: nakam@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan); Nakashima, Torahiko, E-mail: nakatora@qent.med.kyushu-u.ac.jp [Kyushu University, Department of Otorhinolaryngology, Graduate School of Medical Sciences (Japan); Honda, Hiroshi, E-mail: honda@radiol.med.kyushu-u.ac.jp [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences (Japan)

2016-02-15

PurposeTo evaluate the frequency and the predictive factor of each feeding artery on intra-arterial infusion chemotherapy (IAIC) in primary tongue cancer.Materials and MethodsWe retrospectively evaluated 20 patients who received IAIC for primary tongue cancer. The main and accompanying feeding arteries were identified on super-selective angiography of the branches of the external carotid artery. Tumor diameter, and extension to the contralateral side, tongue extrinsic muscles (TEMs), and lateral mesopharyngeal wall were determined based on magnetic resonance imaging or computed tomography findings.ResultsThe main feeding artery was the ipsilateral lingual artery (LA) in 15 of the 20 examined tumors and the contralateral LA in the other 5. Ten cancers had only one feeding artery, and multiple feeding arteries were detected in the remaining 10. Tumors >4 cm (n = 9), those with extension to the contralateral side (n = 13), and those with extension to TEMs (n = 15) were supplied by significantly larger numbers of feeding arteries compared to tumors without these features (P = 0.01, 0.049, and 0.02, respectively). The frequency of feeding from the contralateral LA was 64 % (9/14) and 17 % (1/6) in tumors with and without extension to the contralateral side, respectively. Feeding from a facial artery (FA) was not detected in tumors ≤4 cm, while 5 of the 9 (56 %) tumors >4 cm were supplied by a FA (P = 0.01).ConclusionA careful search for feeding arteries is required, especially in large tumors with extension to the contralateral side or to TEMs.

Feeding Arteries of Primary Tongue Cancers on Intra-arterial Infusion Chemotherapy.

Science.gov (United States)

Kamitani, Takeshi; Kawanami, Satoshi; Asayama, Yoshiki; Matsuo, Yoshio; Yonezawa, Masato; Yamasaki, Yuzo; Nagao, Michinobu; Yamanouchi, Torahiko; Yabuuchi, Hidetake; Nakamura, Katsumasa; Nakashima, Torahiko; Honda, Hiroshi

2016-02-01

To evaluate the frequency and the predictive factor of each feeding artery on intra-arterial infusion chemotherapy (IAIC) in primary tongue cancer. We retrospectively evaluated 20 patients who received IAIC for primary tongue cancer. The main and accompanying feeding arteries were identified on super-selective angiography of the branches of the external carotid artery. Tumor diameter, and extension to the contralateral side, tongue extrinsic muscles (TEMs), and lateral mesopharyngeal wall were determined based on magnetic resonance imaging or computed tomography findings. The main feeding artery was the ipsilateral lingual artery (LA) in 15 of the 20 examined tumors and the contralateral LA in the other 5. Ten cancers had only one feeding artery, and multiple feeding arteries were detected in the remaining 10. Tumors >4 cm (n = 9), those with extension to the contralateral side (n = 13), and those with extension to TEMs (n = 15) were supplied by significantly larger numbers of feeding arteries compared to tumors without these features (P = 0.01, 0.049, and 0.02, respectively). The frequency of feeding from the contralateral LA was 64 % (9/14) and 17 % (1/6) in tumors with and without extension to the contralateral side, respectively. Feeding from a facial artery (FA) was not detected in tumors ≤4 cm, while 5 of the 9 (56 %) tumors >4 cm were supplied by a FA (P = 0.01). A careful search for feeding arteries is required, especially in large tumors with extension to the contralateral side or to TEMs.

Exercise thallium-201 scintigraphy in the diagnosis and prognosis of coronary artery disease

International Nuclear Information System (INIS)

Kotler, T.S.; Diamond, G.A.

1990-01-01

The objective of this study is to determine the discriminant accuracy of exercise thallium-201 myocardial perfusion scintigraphy for the diagnosis and prognosis of patients with known or suspected coronary artery disease. This is a survey of the National Library of Medicine MEDLINE database. The key medical subject headings used were coronary disease, myocardial infarction, radionuclide imaging, and thallium. A total of 122 retrieved studies were considered relevant and were reviewed in depth. Only studies reporting both the sensitivity and specificity of thallium scintigraphy were analyzed. Discriminant accuracy for diagnosis and prognosis was summarized in terms of pooled sensitivity and specificity. Exercise thallium scintigraphy is useful in the noninvasive diagnosis of coronary artery disease, especially in patients with abnormal resting electrocardiograms, restricted exercise tolerance, and intermediate probability of having disease at the time of testing as well as of defining the prognosis of patients with known or suspected coronary artery disease, especially in those with previous myocardial infarction. Because of various shortcomings in the published record, however, the marginal discriminant accuracy and cost effectiveness of thallium scintigraphy compared with conventional clinical assessment and exercise electrocardiography remain controversial. 193 references

Association of pentraxin and high-sensitive C-reactive protein as inflammatory biomarkers in patients with chronic periodontitis and peripheral arterial disease.

Science.gov (United States)

Boyapati, Ramanarayana; Chinthalapani, Srikanth; Ramisetti, Arpita; Salavadhi, Shyam Sunder; Ramachandran, Radhika

2018-01-01

Inflammation is a common feature of both peripheral artery disease (PAD) and periodontal disease. The aim of this study is to evaluate the relationship between PAD and periodontal disease by examining the levels of inflammatory cytokines, pentraxin-3 (PTX-3), and high-sensitive C-reactive protein from serum. A total of 50 patients were included in this cross-sectional study. Patients were divided into two groups: those with PAD (test group) and those with the non-PAD group (control group) based on ankle-brachial index values. Periodontal examinations and biochemical analysis for PTX-3 and high-sensitive C-reactive protein were performed to compare the two groups. All the obtained data were sent for statistical analyses using SPSS version 18. In the clinical parameters, there is statistically significant difference present between plaque index, clinical attachment loss, and periodontal inflammatory surface area with higher mean values in patients with PAD having periodontitis. There is statistical significant ( P C-reactive protein (hs-CRP), and PTX-3. PTX-3 and acute-phase cytokine such as hs-CRP can be regarded as one of the best indicators to show the association between the PAD and periodontitis followed by hs-CRP, TC, very LDL (VLDL), and LDL. However, high-density lipoprotein (HDL) is a poor indicator for its association with chronic periodontitis and PAD.

Membrane depolarization-induced RhoA/Rho-associated kinase activation and sustained contraction of rat caudal arterial smooth muscle involves genistein-sensitive tyrosine phosphorylation

Science.gov (United States)

Mita, Mitsuo; Tanaka, Hitoshi; Yanagihara, Hayato; Nakagawa, Jun-ichi; Hishinuma, Shigeru; Sutherland, Cindy; Walsh, Michael P.; Shoji, Masaru

2013-01-01

Rho-associated kinase (ROK) activation plays an important role in K+-induced contraction of rat caudal arterial smooth muscle (Mita et al., Biochem J. 2002; 364: 431–40). The present study investigated a potential role for tyrosine kinase activity in K+-induced RhoA activation and contraction. The non-selective tyrosine kinase inhibitor genistein, but not the src family tyrosine kinase inhibitor PP2, inhibited K+-induced sustained contraction (IC50 = 11.3 ± 2.4 µM). Genistein (10 µM) inhibited the K+-induced increase in myosin light chain (LC20) phosphorylation without affecting the Ca2+ transient. The tyrosine phosphatase inhibitor vanadate induced contraction that was reversed by genistein (IC50 = 6.5 ± 2.3 µM) and the ROK inhibitor Y-27632 (IC50 = 0.27 ± 0.04 µM). Vanadate also increased LC20 phosphorylation in a genistein- and Y-27632-dependent manner. K+ stimulation induced translocation of RhoA to the membrane, which was inhibited by genistein. Phosphorylation of MYPT1 (myosin-targeting subunit of myosin light chain phosphatase) was significantly increased at Thr855 and Thr697 by K+ stimulation in a genistein- and Y-27632-sensitive manner. Finally, K+ stimulation induced genistein-sensitive tyrosine phosphorylation of proteins of ∼55, 70 and 113 kDa. We conclude that a genistein-sensitive tyrosine kinase, activated by the membrane depolarization-induced increase in [Ca2+]i, is involved in the RhoA/ROK activation and sustained contraction induced by K+. Ca2+ sensitization, myosin light chain phosphatase, RhoA, Rho-associated kinase, tyrosine kinase PMID:24133693

Calcium-sensitivity of smooth muscle contraction in the isolated ...

African Journals Online (AJOL)

sensitivity of smooth muscle contraction were studied in the isolated perfused rat tail artery, employing the activators noradrenaline (NA) (3ìM) sand potassium chloride (KC1) (100mM). Experiments were conduced in Ca2+ - buffered saline.

Comparison of digital subtraction angiography with gadolinium-enhanced magnetic resonance angiography in the diagnosis of renal artery stenosis

International Nuclear Information System (INIS)

Thornton, J.; O'Callaghan, J.; Varghese, J.C.; Lee, M.J.; Walshe, J.; O'Brien, E.

1999-01-01

Renal artery stenosis (RAS) is a treatable cause of hypertension and renal failure for which no ideal screening technique is currently available. We evaluated the use of dynamic gadolinium-enhanced magnetic resonance angiography (MRA) for the diagnosis of RAS. Sixty-two patients with secondary hypertension were enrolled in the study. All patients had conventional renal angiography and gadolinium enhanced MRA. The sequence used was a 3D FMP SPGR sequence with the following parameters (TR: 26 ms, TE: 6.9 ms, flip angle 40 , field of view 36 x 36 cm, matrix 246 x 256, 1 excitation). Gadolinium 0.3 mmol/kg was administered and 60 1.5-mm-thick partitions were obtained over a duration of 3.5 min. The MRA images were then compared with conventional digital subtraction angiography (DSA) images. Conventional DSA demonstrated 138 renal arteries, whereas gadolinium-enhanced MRA demonstrated 129 (93 %). Twenty-one renal artery stenoses and four occluded arteries were seen at conventional DSA. Gadolinium-enhanced MRA had a sensitivity of 88 %, specificity of 98 %, accuracy of 96 %, positive predictive value of 92 % and negative predictive value of 97 % when compared with conventional DSA. Gadolinium-enhanced MRA is an accurate technique for identifying patients with RAS. It is less sensitive in picking up accessory renal arteries. (orig.)

Recanalization of superficial femoral artery by retrograde approach via popliteal artery

International Nuclear Information System (INIS)

Kim, Jae Kyu; Kim, Hyung Kil; Yun, Ung; Seo, Jeong Jin; Kang, Heoung Keun

1995-01-01

To recanalize the occlusive lesion of superficial femoral artery at origin site by retrograde approach via popliteal artery. 15 patients, who were poor surgical candidates due to coronary artery disease and who had severe occlusive lesion of superficial femoral artery close to its origin with good distal runoffs to popliteal artery, were selected. Patients were all men and range of age were from 53 years to 66 years (mean age: 63 years). Range of lesion length were from 15 cm to 30 cm (mean length: 22.4 cm). Localization of popliteal artery was done with Doppler stethoscope or 'road-map' DSA. The method of recanalization were transluminal endarterectomy catheter (TEC), TEC and angioplasty, thrombolysoangioplasty (TLA). Retrograde puncture of popliteal artery was done in 15 patients successfully. TEC and PTA was performed in 9 patients, TEC only in 2 patients, and TLA and PTA in 2 patients. During the follow-up period of 5 months to 2 years reocclusion did not occur in 10 patients except for 1 patient with poor cardiac output in whom it occurred 1 day later. Remained 4 patients were lost in follow up. Any neurologic or vascular complication did not occur. Retrograde approach of superficial femoral artery via popliteal artery in patients with difficult vascular intervention by common method provides a useful, alternative recanalization method

Recanalization of superficial femoral artery by retrograde approach via popliteal artery

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Kyu; Kim, Hyung Kil; Yun, Ung; Seo, Jeong Jin; Kang, Heoung Keun [Chonnam University Medical School, Kwangju (Korea, Republic of)

1995-09-15

To recanalize the occlusive lesion of superficial femoral artery at origin site by retrograde approach via popliteal artery. 15 patients, who were poor surgical candidates due to coronary artery disease and who had severe occlusive lesion of superficial femoral artery close to its origin with good distal runoffs to popliteal artery, were selected. Patients were all men and range of age were from 53 years to 66 years (mean age: 63 years). Range of lesion length were from 15 cm to 30 cm (mean length: 22.4 cm). Localization of popliteal artery was done with Doppler stethoscope or 'road-map' DSA. The method of recanalization were transluminal endarterectomy catheter (TEC), TEC and angioplasty, thrombolysoangioplasty (TLA). Retrograde puncture of popliteal artery was done in 15 patients successfully. TEC and PTA was performed in 9 patients, TEC only in 2 patients, and TLA and PTA in 2 patients. During the follow-up period of 5 months to 2 years reocclusion did not occur in 10 patients except for 1 patient with poor cardiac output in whom it occurred 1 day later. Remained 4 patients were lost in follow up. Any neurologic or vascular complication did not occur. Retrograde approach of superficial femoral artery via popliteal artery in patients with difficult vascular intervention by common method provides a useful, alternative recanalization method.

One-hour protocol stress myocardial scintigraphy. Prospective study of diagnostic accuracy for the detection of coronary artery stenosis

International Nuclear Information System (INIS)

Matsuda, Junko; Miyamoto, Nobuhide; Onitsuka, Hisamitsu; Ikushima, Ippei; Unoki, Toshihide; Takenaga, Makoto; Koiwaya, Yasushi; Eto, Tanenao

1999-01-01

A one-hour protocol for stress myocardial scintigraphy using technetium-99m-tetrofosmin (Tc-tetrofosmin) was compared with coronary arteriography for the detection of coronary artery stenosis in 90 consecutive patients without prior myocardial infarction, revascularization procedure or vasospastic angina. Tc-tetrofosmin stress myocardial scintigraphy acquired a rest image 20 min after intravenous administration of Tc-tetrofosmin (185 MBq, 1/5 vial) using a three-head gamma camera collecting 20-sec views over 360 deg. The stress test using bicycle ergometer was performed and administration of Tc-tetrofosmin (740 MBq, 4/5 vial) was repeated at the peak stress point. The stress image was acquired 15 min after the second injection with 5-sec views over 360 deg. Coronary arteriography revealed the presence of significant coronary artery stenosis (>75%) in 56 vessels of 45 patients, including 35 patients with single-vessel disease, 5 with two-vessel disease, 2 with three-vessel disease, and 3 with left main trunk disease. The overall sensitivity and specificity for the detection of coronary artery disease by visual analysis were 91.1% and 77.8%, respectively, and by quantitative analyses (using bull's-eye method) were 95.6% and 91.1%, respectively. The individual stenotic vessel sensitivities in the right coronary artery, left anterior descending artery, and left circumflex artery were 84.6%, 90.9%, and 78.6%, respectively. The specificities were 97.3%, 95.9%, and 100.0%, respectively. These results suggest that stress myocardial scintigraphy using the present new protocol is a promising approach for the detection of coronary artery stenosis. (author)

Subarachnoid hemorrhage-induced upregulation of the 5-HT1B receptor in cerebral arteries in rats

DEFF Research Database (Denmark)

Hansen-Schwartz, Jacob; Hoel, Natalie Løvland; Xu, Cang-Bao

2003-01-01

experimental SAH. METHODS: Experimental SAH was induced in rats by using an autologous prechiasmatic injection of arterial blood. Two days later, the middle cerebral artery (MCA), posterior communicating artery (PCoA), and basilar artery (BA) were harvested and examined functionally with the aid of a sensitive...... RNA coding for the 5-HT1B receptor as determined by quantitative real-time PCR. In the PCoA no upregulation of the 5-HT1B receptor was observed. CONCLUSIONS: Changes in the receptor phenotype in favor of contractile receptors may well represent the end stage in a sequence of events leading from SAH...... to the actual development of cerebral vasospasm. Insight into the mechanism of upregulation may provide new targets for developing specific treatment against cerebral vasospasm....

Pulsatility of Lenticulostriate Arteries Assessed by 7 Tesla Flow MRI-Measurement, Reproducibility, and Applicability to Aging Effect.

Science.gov (United States)

Schnerr, Roald S; Jansen, Jacobus F A; Uludag, Kamil; Hofman, Paul A M; Wildberger, Joachim E; van Oostenbrugge, Robert J; Backes, Walter H

2017-01-01

Characterization of flow properties in cerebral arteries with 1.5 and 3 Tesla MRI is usually limited to large cerebral arteries and difficult to evaluate in the small perforating arteries due to insufficient spatial resolution. In this study, we assessed the feasibility to measure blood flow waveforms in the small lenticulostriate arteries with 7 Tesla velocity-sensitive MRI. The middle cerebral artery was included as reference. Imaging was performed in five young and five old healthy volunteers. Flow was calculated by integrating time-varying velocity values over the vascular cross-section. MRI acquisitions were performed twice in each subject to determine reproducibility. From the flow waveforms, the pulsatility index and damping factor were deduced. Reproducibility values, in terms of the intraclass correlation coefficients, were found to be good to excellent. Measured pulsatility index of the lenticulostriate arteries significantly increased and damping factor significantly decreased with age. In conclusion, we demonstrate that blood flow through the lenticostriate arteries can be precisely measured using 7 Tesla MRI and reveal effects of arterial stiffness due to aging. These findings hold promise to provide relevant insights into the pathologies involving perforating cerebral arteries.

Hepatic artery aneurysms (HAAs)

International Nuclear Information System (INIS)

Nosratini, H.

2004-01-01

The hepatic artery aneurysms are rare, especially in interahepatic branches, The frequency consists of 75-80% extrahepatic and 20-25% intrahepatic. Catheterization is achieved usually from common femoral artery, other methods implemented in the case of unsuccessful catheterization from femoral artery, are translumbar and brachial catheterization. The study consist of 565 patients that were referred to the angiography ward, During seven years of assessment, five cases of hepatic artery aneurysm were found; this is a rare condition reported in the English literature. In the literature as well as in this case report the hepatic artery aneurysms are rare. In reported series the extrahepatic artery aneurysms are found more often than in the intrahepatic artery aneurysm but in this case report intrahepatic artery aneurysms are more than extrahepatic one. (author)

Basilar artery angulation and vertigo due to the hemodynamic effect of dominant vertebral artery.

Science.gov (United States)

Cosar, Murat; Yaman, Mehmet; Eser, Olcay; Songur, Ahmet; Ozen, Oguz A

2008-01-01

Vertebral arteries form the basilar artery at the pontobulbar junction. The vertebral artery may have dominancy in one of them. The branches of basilar arteries supply blood for the vestibular nuclei and its connections. Vertigo is seen generally in the upper middle aged patients. Vertigo can be observed in dolichoectasia of basilar artery such as angulation and elongation, because of the diminished blood supply and changed hemodynamic factors of vestibular nuclei and its connections. We hypothesized that angulation or elongation of basilar artery can be estimated according to the unilateral vertebral artery dominant hypertensive patients. The basilar artery can angulate from the dominant side of vertebral artery to the recessive side. These angulation and elongation can effect the hemodynamic factors in absence of growing collateral arteries. So, the vertigo attacks may occur in these patients.

Middle cerebral artery thrombosis: acute blood-brain barrier consequences

Energy Technology Data Exchange (ETDEWEB)

Dietrich, W.D.; Prado, R.; Watson, B.D.; Nakayama, H.

1988-07-01

The effect of middle cerebral artery (MCA) thrombosis on the integrity of the blood-brain barrier (BBB) was studied in rats using horseradish peroxidase (HRP). Endothelial injury with subsequent platelet thrombosis was produced by means of a rose bengal-sensitized photochemical reaction, facilitated by irradiating the right proximal MCA segment with the focused beam of an argon laser. At 15 minutes following thrombosis formation, diffuse leakage of HRP was observed bilaterally within cortical and subcortical brain areas. Peroxidase extravasation was most dense within the territory of the occluded artery including neocortical areas and dorso-lateral striatum. Contralaterally, a similar distribution was observed but with less intense HRP leakage. Ultrastructural studies demonstrated an increase in permeability to HRP within arterioles, venules and capillaries. At these sites, the vascular endothelium contained HRP-filled pinocytotic vesicles and tubular profiles. Although less intense, bilateral HRP leakage was also observed following MCA stenosis or femoral artery occlusion. Endothelial-platelet interactions at the site of vascular injury may be responsible for releasing substances or neurohumoral factors which contribute to the acute opening of the BBB.

Endovascular rescue from arterial rupture and thrombosis during middle cerebral artery stenting

Energy Technology Data Exchange (ETDEWEB)

Ahn, J.Y.; Chung, Y.S. [Department of Neurosurgery, College of Medicine, Pundang CHA Hospital, 351 Yatap-ding, Pundang-gu, 463-712, Sungnam (Korea); Lee, B.H. [Department of Interventional Neuroradiology, College of Medicine, Pundang CHA Hospital, 351 Yatap-dong, Pundang-gu, 463-712, Sungnam (Korea); Kim, O.J. [Department of Emergency Medicine, College of Medicine, Pundang CHA Hospital, 351 Yatap-dong, Pundang-gu, 463-712, Sungnam (Korea)

2003-08-01

Intravascular stents are being used with increasing frequency in interventional neuroradiology. Iatrogenic arterial rupture is an uncommon but serious complication. We present a case of arterial rupture and subarachnoid haemorrhage during middle cerebral artery stenting, treated by emergency additional, overlapping stenting and balloon tamponade of the dissected vessel. Thrombotic occlusion of the artery was managed by intra-arterial abciximab. Normal vessel patency was re-established within 20 min and the patient recovered with no neurological deficit. (orig.)

Role of the autonomic nervous system and baroreflex in stress-evoked cardiovascular responses in rats.

Science.gov (United States)

Dos Reis, Daniel Gustavo; Fortaleza, Eduardo Albino Trindade; Tavares, Rodrigo Fiacadori; Corrêa, Fernando Morgan Aguiar

2014-07-01

Restraint stress (RS) is an experimental model to study stress-related cardiovascular responses, characterized by sustained pressor and tachycardiac responses. We used pharmacologic and surgical procedures to investigate the role played by sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS) in the mediation of stress-evoked cardiovascular responses. Ganglionic blockade with pentolinium significantly reduced RS-evoked pressor and tachycardiac responses. Intravenous treatment with homatropine methyl bromide did not affect the pressor response but increased tachycardia. Pretreatment with prazosin reduced the pressor and increased the tachycardiac response. Pretreatment with atenolol did not affect the pressor response but reduced tachycardia. The combined treatment with atenolol and prazosin reduced both pressor and tachycardiac responses. Adrenal demedullation reduced the pressor response without affecting tachycardia. Sinoaortic denervation increased pressor and tachycardiac responses. The results indicate that: (1) the RS-evoked cardiovascular response is mediated by the autonomic nervous system without an important involvement of humoral factors; (2) hypertension results primarily from sympathovascular and sympathoadrenal activation, without a significant involvement of the cardiac sympathetic component (CSNS); (3) the abrupt initial peak in the hypertensive response to restraint is sympathovascular-mediated, whereas the less intense but sustained hypertensive response observed throughout the remaining restraint session is mainly mediated by sympathoadrenal activation and epinephrine release; (4) tachycardia results from CSNS activation, and not from PSNS inhibition; (5) RS evokes simultaneous CSNS and PSNS activation, and heart rate changes are a vector of both influences; (6) the baroreflex is functional during restraint, and modulates both the vascular and cardiac responses to restraint.

Arterial stiffness

Directory of Open Access Journals (Sweden)

Ursula Quinn

2012-09-01

Full Text Available Measurements of biomechanical properties of arteries have become an important surrogate outcome used in epidemiological and interventional cardiovascular research. Structural and functional differences of vessels in the arterial tree result in a dampening of pulsatility and smoothing of blood flow as it progresses to capillary level. A loss of arterial elastic properties results a range of linked pathophysiological changes within the circulation including increased pulse pressure, left ventricular hypertrophy, subendocardial ischaemia, vessel endothelial dysfunction and cardiac fibrosis. With increased arterial stiffness, the microvasculature of brain and kidneys are exposed to wider pressure fluctuations and may lead to increased risk of stroke and renal failure. Stiffening of the aorta, as measured by the gold-standard technique of aortic Pulse Wave Velocity (aPWV, is independently associated with adverse cardiovascular outcomes across many different patient groups and in the general population. Therefore, use of aPWV has been proposed for early detection of vascular damage and individual cardiovascular risk evaluation and it seems certain that measurement of arterial stiffness will become increasingly important in future clinical care. In this review we will consider some of the pathophysiological processes that result from arterial stiffening, how it is measured and factors that may drive it as well as potential avenues for therapy. In the face of an ageing population where mortality from atheromatous cardiovascular disease is falling, pathology associated with arterial stiffening will assume ever greater importance. Therefore, understanding these concepts for all clinicians involved in care of patients with cardiovascular disease will become vital.

Anatomy of the arterial supply to the liver demonstrated by MRI

International Nuclear Information System (INIS)

Ward, J.; Guthrie, A.J.; Hughes, T.; Baudouin, C.J.; Pollard, S.; Robinson, P.J.

1997-01-01

The aim of this study was to establish the accuracy of dynamic contrast-enhanced magnetic resonance imaging (DCEMRI) in assessing the site of origin and the patency of the hepatic arteries. Sixty-one patients were examined with serial DCEMRI. MRI was performed at 1.0 T with a rapid multi-section breath-hold fast low-angle shot (FLASH) technique in the coronal oblique plane before and at 10, 40 and 70 s after a bolus of gadolinium-DTPA. The hepatic, left gastric, gastroduodenal, splenic and superior mesenteric arteries were examined. The main portal vein, its right and left intrahepatic divisions, and the splenic and superior mesenteric veins were also assessed. The common hepatic artery was occluded in one patient. The right hepatic artery was seen in 59 patients, left hepatic in 54, left gastric in 43, gastroduodenal in 54, splenic in 60 and superior mesenteric artery in 61. Results were concordant with surgery in 38 of 39 cases and with X-ray angiography in 21 of 22 cases. In the detection of aberrant vessels DCEMRI had a sensitivity of 89 %, a specificity of 100 % and an accuracy of 97 %. All five veins were occluded in 1 patient. The main portal vein was patent in 56 patients, occluded in 2 and narrowed in 2. Thirty-two patients had upper abdominal varices. It is concluded that DCEMRI with sequential imaging provides a non-invasive demonstration of hepatic arterial and venous structures. (orig.). With 6 figs., 1 tab

Correlation between total nitrite/nitrate concentrations and monoamine oxidase (types A and B) and semicarbazide-sensitive amine oxidase enzymatic activities in human mesenteric arteries from non-diabetic and type 2 diabetic patients

Energy Technology Data Exchange (ETDEWEB)

Nunes, S.F.; Figueiredo, I.V. [Laboratório de Farmacologia, Faculdade de Farmácia, Universidade de Coimbra, Coimbra (Portugal); Pereira, J.S. [Instituto Português de Oncologia de Coimbra, Coimbra (Portugal); Lopes, M.C.; Caramona, M.M. [Laboratório de Farmacologia, Faculdade de Farmácia, Universidade de Coimbra, Coimbra (Portugal)

2011-11-25

The aim of this study was to determine the correlation between total nitrite/nitrate concentrations (NOx) and the kinetic parameters of monoamine oxidase enzymes (MAO-A and MAO-B) and semicarbazide-sensitive amine oxidase (SSAO) in human mesenteric arteries. Arteries were from non-diabetic and type 2 diabetic patients with sigmoid or rectum carcinoma for whom surgery was the first option and who were not exposed to neo-adjuvant therapy. Segments of human inferior mesenteric arteries from non-diabetic (61.1 ± 8.9 years old, 7 males and 5 females, N = 12) and type 2 diabetic patients (65.8 ± 6.2 years old, 8 males and 4 females, N = 12) were used to determine NOx concentrations and the kinetic parameters of MAO-A, MAO-B and SSAO by the Griess reaction and by radiochemical assay, respectively. The NOx concentrations in arteries from diabetic patients did not differ significantly from those of the non-diabetic group (10.28 ± 4.61 vs 10.71 ± 4.32 nmol/mg protein, respectively). In the non-diabetic group, there was a positive correlation between NOx concentrations and MAO-B parameters: K{sub m} (r = 0.612, P = 0.034) and V{sub max} (r = 0.593, P = 0.042), and a negative correlation with the SSAO parameters: K{sub m} (r = -0.625, P = 0.029) and V{sub max} (r = -0.754, P = 0.005). However, in the diabetic group no correlation was found between NOx concentrations and the three kinetic parameters of the enzymes. These results suggest an important function of sympathetic nerves and vascular NOx concentrations in arteries of non-diabetic patients. Thus, these results confirm the importance of a balance between oxidants and antioxidants in the maintenance of vascular homeostasis to prevent oxidative stress.

Percutaneous transluminal angioplasty (PTA) of supra-aortic arteries especially the internal carotid artery

Energy Technology Data Exchange (ETDEWEB)

Kachel, R.; Basche, S. (Medizinische Akademie, Erfurt (Germany, F.R.). Radiologische Klinik); Heerklotz, I.; Grossmann, K. (Medizinische Akademie, Erfurt (Germany, F.R.). Klinik fuer Innere Medizin); Endler, S. (Medizinische Akademie, Erfurt (Germany, F.R.). Klinik fuer Neurologie und Psychiatrie)

1991-06-01

We present our experience with 105 patients in whom percutaneous transluminal angioplasty was performed in 112 stenosed or occluded supra-aortic arteries. Symtoms of cerebrovascular and/or vertebrobasilar insufficiency were present in 104 of the 105 patients. The angioplasty was successful in 35 stenoses of the internal carotid artery, 2 stenoses of the common carotid artery, 1 stenosis of the external carotid artery, 15 stenoses of the vertebral artery, 3 stenoses of the innominate artery and 44 stenoses of the subclavian artery. There were only 4 minor-complications (2 haematomas, 1 transient ischemic attack, 1 small thrombus of the internal carotid artery which was detected by 111-indium platelet scintigraphy and treated by thrombendarterectomy before the appearance of neurological symptoms). All patients were symptom free after angioplasty. During the observations period of 3 to 109 months (average 58 months) there were only two cases with re-stenosis after subclavian angioplasty. The results of more than 700 personal and international published percutaneous transluminal angioplasties of supra-aortic arteries are presented. The results suggest that angioplasty of supra-aortic arteries is an effective method. On strict definition of the indications, the complication rate for angioplasty of the supra-aortic arteries is not likely to be higher than that for operative treatment. (orig.).

Long-term facial artery catheter implantation for serial arterial blood sampling and invasive arterial blood pressure measurement in horses.

Science.gov (United States)

Dias, Deborah Penteado Martins; Teixeira, Luisa Gouvêa; Canola, Paulo Aléscio; Albernaz, Raquel Mincarelli; Marques, José Antônio; Neto, José Corrêa de Lacerda

2012-06-01

The purpose of this investigation was to evaluate surgical catheter implantation in the facial artery of horses and the long-term maintenance of such arteries using heparin and ascorbic acid as filling solution. Nine horses were implanted with a polyurethane catheter. The catheters were flushed with a heparin/ascorbic acid solution every 8h and remained patent for 25 days. Arterial blood samples were collected twice a day, and one exercise test that included serial blood samples and arterial pressure recordings was performed on a treadmill. Polyurethane catheters surgically implanted in the facial artery can be kept patent by filling with a heparin/ascorbic acid solution and provide convenient invasive arterial access in horses which is suitable for use for serial blood sampling and blood pressure recordings, even during exercise on treadmill. Copyright © 2011 Elsevier Ltd. All rights reserved.

Congenital coronary artery fistula

International Nuclear Information System (INIS)

Oh, Yeon Hee; Kim, Hong; Zeon, Seoc Kil; Suh, Soo Jhi

1986-01-01

Congenital coronary artery fistula (CCAF) is communication of a coronary artery or its main branch with one of the atria or ventricles, the coronary sinus, the superior vena cava, or the pulmonary artery. In Korean peoples, only 4 cases of the CCAF were reported as rare as worldwide and authors want to report another case of CCAF, confirmed by operation. 10-year-old girl shows a fistula between sinus node artery of the right coronary artery and right atrium on root aortogram with left-to-right shunt and Qp/Qs=1.58, in which simple ligation of the sinus node artery from right coronary artery was performed. All of the 5 Korean CCAF (4 were previously reported and 1 of authors) were originated from right coronary artery, and of which 4 were opening into right ventricle and 1 of authors were into right atrium. Associated cardiac anomaly was noted in only 1 case as single coronary artery. Ages were from 9 months of age to 10 years old and no adult left case were found. 3 were female and 2 were male patients.

Arterial occlusion to treat basilar artery dissecting aneurysm

NARCIS (Netherlands)

Cui, Qing Ke; Liu, Wei Dong; Liu, Peng; Li, Xue Yuan; Zhang, Lian Qun; Ma, Long Jia; Ren, Yun Fei; Wu, Ya Ping; Wang, Zhi Gang

2015-01-01

Object: To explore the clinical feasibility of employing occlusion to treat basilar artery dissecting aneurysm. Methods: One patient, male and 46 years old, suffered transient numbness and weakness on the right limbs. Cerebral angiography indicated basilar artery dissecting aneurysm. The patient

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

International Nuclear Information System (INIS)

El-Mas, Mahmoud M.; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-01-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE 2 ) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS PE and BRS SNP ). Nicotine (100 μg/kg i.v.) reduced BRS SNP in OVX rats but not in proestrus or OVXE 2 rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS PE was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS SNP interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS SNP attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E 2 against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

Spiral CT angiography (SCTA) study of celiac artery and superior mesenteric artery

International Nuclear Information System (INIS)

Yuan Zhenguo; Zhou Cunsheng; Xu Zuodong; Shi Hao; Wang Tao

1999-01-01

Objective: To study the visualization capability and scanning technique of SCTA in celiac artery, superior mesenteric artery (SMA) and other branches. Methods: Thirty patients, with normal abdominal SCTA results, were given small injection test dose after plain scan. The abdominal aorta parallel to the body of pancreas was chosen as target vessel, the peak-time plus 2 seconds as the best delay scan time. Iodine contrast medium 90∼110 ml was injected into antecubital vein at the speed of 3.5 ml/s, then scan from cranial to caudal was performed. Pitch 1.0 and slice thickness 3.2 mm were selected as the scan parameters. Maximum intensity projection (MaxIP) was employed in all patients and shaded surface display (SSD) in 23 cases. Results: The display rate using MaxIP and SSD of celiac artery, splenic artery, common hepatic artery, proper hepatic artery and SMA were all 100%, the gastroduodenal artery 100% and 91%, the left gastric artery 83% and 87%, respectively. Conclusions: SCTA as a minimally invasive examination is a valuable method to detect and diagnose disease or variations of celiac artery, its branches and SMA. Spiral scanning technique and image processing have a decisive effect on the image quality

Psychophysiology of arterial baroreceptors and the etiology of hypertension

OpenAIRE

Rau, Harald; Elbert, Thomas

2001-01-01

Arterial baroreceptors are sensitive to blood pressure dependent blood vessel dilation. They play a key role in the short term regulation of blood pressure. Their impact on psychological and psychophysiological aspects is of increasing interest. The review focuses on experimental techniques for the controlled baroreceptor manipulation. Results from the application of these techniques show that baroreceptor activation influences the cardiovascular system as well as central nervous functioning:...

Arterial calcification: friend or foe?

Science.gov (United States)

Nicoll, Rachel; Henein, Michael Y

2013-07-31

There is a significant relationship between the presence, extent and progression of coronary artery calcification (CAC) and cardiovascular (CV) events and mortality in both CV and renal patients and CAC scoring can provide improved predictive ability over risk factor scoring alone. There is also a close relationship between CAC presence and atherosclerotic plaque burden, with angiography studies showing very high sensitivity but poor specificity of CAC score for predicting obstructive disease. Nevertheless, there are objections to CAC screening because of uncertainties and lack of studies showing improved outcome. Furthermore, histopathology studies indicate that heavily calcified plaque is unlikely to result in a CV event, while the vulnerable plaque tends to be uncalcified or 'mixed', suggesting that calcification may be protective. This scenario highlights a number of paradoxes, which may indicate that the association between CAC and CV events is spurious, following from the adoption of CAC as a surrogate for high plaque burden, which itself is a surrogate for the presence of vulnerable plaque. Since studies indicate that arterial calcification is a complex, organised and regulated process similar to bone formation, there is no particular reason why it should be a reliable indicator of either the plaque burden or the risk of a future CV event. We suggest that it is time to divorce arterial calcification from atherosclerosis and to view it as a distinct pathology in its own right, albeit one which frequently coexists with atherosclerosis and is related to it for reasons which are not yet fully understood. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Exposure to a high-fat diet alters leptin sensitivity and elevates renal sympathetic nerve activity and arterial pressure in rabbits.

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Prior, Larissa J; Eikelis, Nina; Armitage, James A; Davern, Pamela J; Burke, Sandra L; Montani, Jean-Pierre; Barzel, Benjamin; Head, Geoffrey A

2010-04-01

The activation of the sympathetic nervous system through the central actions of the adipokine leptin has been suggested as a major mechanism by which obesity contributes to the development of hypertension. However, direct evidence for elevated sympathetic activity in obesity has been limited to muscle. The present study examined the renal sympathetic nerve activity and cardiovascular effects of a high-fat diet (HFD), as well as the changes in the sensitivity to intracerebroventricular leptin. New Zealand white rabbits fed a 13.5% HFD for 4 weeks showed modest weight gain but a 2- to 3-fold greater accumulation of visceral fat compared with control rabbits. Mean arterial pressure, heart rate, and plasma norepinephrine concentration increased by 8%, 26%, and 87%, respectively (Pdiet rabbits and was correlated to plasma leptin (r=0.87; Pfat accumulation through consumption of a HFD leads to marked sympathetic activation, which is related to increased responsiveness to central sympathoexcitatory effects of leptin. The paradoxical reduction in hypothalamic neuronal activation by leptin suggests a marked "selective leptin resistance" in these animals.

Calculation of arterial wall temperature in atherosclerotic arteries: effect of pulsatile flow, arterial geometry, and plaque structure

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Kim Taehong

2007-03-01

Full Text Available Abstract Background This paper presents calculations of the temperature distribution in an atherosclerotic plaque experiencing an inflammatory process; it analyzes the presence of hot spots in the plaque region and their relationship to blood flow, arterial geometry, and inflammatory cell distribution. Determination of the plaque temperature has become an important topic because plaques showing a temperature inhomogeneity have a higher likelihood of rupture. As a result, monitoring plaque temperature and knowing the factors affecting it can help in the prevention of sudden rupture. Methods The transient temperature profile in inflamed atherosclerotic plaques is calculated by solving an energy equation and the Navier-Stokes equations in 2D idealized arterial models of a bending artery and an arterial bifurcation. For obtaining the numerical solution, the commercial package COMSOL 3.2 was used. The calculations correspond to a parametric study where arterial type and size, as well as plaque geometry and composition, are varied. These calculations are used to analyze the contribution of different factors affecting arterial wall temperature measurements. The main factors considered are the metabolic heat production of inflammatory cells, atherosclerotic plaque length lp, inflammatory cell layer length lmp, and inflammatory cell layer thickness dmp. Results The calculations indicate that the best location to perform the temperature measurement is at the back region of the plaque (0.5 ≤ l/lp ≤ 0.7. The location of the maximum temperature, or hot spot, at the plaque surface can move during the cardiac cycle depending on the arterial geometry and is a direct result of the blood flow pattern. For the bending artery, the hot spot moves 0.6 millimeters along the longitudinal direction; for the arterial bifurcation, the hot spot is concentrated at a single location due to the flow recirculation observed at both ends of the plaque. Focusing on the

Detection of coronary artery calcification by ultrafast CT and correlation with angiography

International Nuclear Information System (INIS)

Zhang Shaoxiong; Dai Ruping; Lu Bin

1997-01-01

To investigate the relationship between coronary calcification and significant coronary stenosis ninety patients including 81 men and 9 women were studied asithage ranging from 27∼72 years (mean, 58 years). All patients had both ultrafast CT (UFCT) examination and coronary angiography within one month. Single slice mode with ECG gating and thickness of 3 mm were used in UFCT scan. Selected coronary angiography was performed by the Judkins technique. Among 160 vessels in which coronary calcifications were identified, 74% had significant coronary stenosis (>50% stenosis), and 77% of 154 vessels with significant coronary stenosis had calcification demonstrable by UFCT. In the younger age group the sensitivity of calcification for evaluating stenosis of coronary artery was lower and the specificity was generally higher than those in the elderly group. UFCT is a promising procedure for detecting coronary arterial disease, since this examination has high sensitivity and specificity, easy to conduct, noninvasive, and widely applicable for screening a large population

Disconnection of pulmonary and systemic arterial stiffness in COPD

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Weir-McCall JR

2018-05-01

Full Text Available Jonathan R Weir-McCall,1 Patrick SK Liu-Shiu-Cheong,2 Allan D Struthers,1 Brian J Lipworth,2 J Graeme Houston1 1Division of Molecular and Clinical Medicine, Medical Research Institute, University of Dundee, Dundee, UK; 2Scottish Centre for Respiratory Research, Medical Research Institute, University of Dundee, Dundee, UK Background: Both pulmonary arterial stiffening and systemic arterial stiffening have been described in COPD. The aim of the current study was to assess pulse wave velocity (PWV within these two arterial beds to determine whether they are separate or linked processes. Materials and methods: In total, 58 participants with COPD and 21 healthy volunteers (HVs underwent cardiac magnetic resonance imaging (MRI and were tested with a panel of relevant biomarkers. Cardiac MRI was used to quantify ventricular mass, volumes, and pulmonary (pulse wave velocity [pPWV] and systemic pulse wave velocity [sPWV]. Results: Those with COPD had higher pPWV (COPD: 2.62 vs HV: 1.78 ms-1, p=0.006, higher right ventricular mass/volume ratio (RVMVR; COPD: 0.29 vs HV: 0.25 g/mL, p=0.012, higher left ventricular mass/volume ratio (LVMVR; COPD: 0.78 vs HV: 0.70 g/mL, p=0.009, and a trend toward a higher sPWV (COPD: 8.7 vs HV: 7.4 ms-1, p=0.06. Multiple biomarkers were elevated: interleukin-6 (COPD: 1.38 vs HV: 0.58 pg/mL, p=0.02, high-sensitivity C-reactive protein (COPD: 6.42 vs HV: 2.49 mg/L, p=0.002, surfactant protein D (COPD: 16.9 vs HV: 9.13 ng/mL, p=0.001, N-terminal pro-brain natriuretic peptide (COPD: 603 vs HV: 198 pg/mL, p=0.001, and high-sensitivity troponin I (COPD: 2.27 vs HV: 0.92 pg/mL, p<0.001. There was a significant relationship between sPWV and LVMVR (p=0.01 but not pPWV (p=0.97 nor between pPWV and RVMVR (p=0.27. Conclusion: Pulmonary arterial stiffening and systemic arterial stiffening appear to be disconnected and should therefore be considered independent processes in COPD. Further work is warranted to determine whether both these

Dynamic contrast-enhanced ultrasound and transient arterial occlusion for quantification of arterial perfusion reserve in peripheral arterial disease

International Nuclear Information System (INIS)

Amarteifio, E.; Wormsbecher, S.; Krix, M.; Demirel, S.; Braun, S.; Delorme, S.; Böckler, D.; Kauczor, H.-U.; Weber, M.-A.

2012-01-01

Objective: To quantify muscular micro-perfusion and arterial perfusion reserve in peripheral arterial disease (PAD) with dynamic contrast-enhanced ultrasound (CEUS) and transient arterial occlusion. Materials and methods: This study had local institutional review board approval and written informed consent was obtained from all subjects. We examined the dominant lower leg of 40 PAD Fontaine stage IIb patients (mean age, 65 years) and 40 healthy volunteers (mean age, 54 years) with CEUS (7 MHz; MI, 0.28) during continuous intravenous infusion of 4.8 mL microbubbles. Transient arterial occlusion at mid-thigh level simulated physical exercise. With time–CEUS–intensity curves obtained from regions of interest within calf muscles, we derived the maximum CEUS signal after occlusion (max) and its time (t max ), slope to maximum (m), vascular response after occlusion (AUC post ), and analysed accuracy, receiver operating characteristic (ROC) curves, and correlations with ankle-brachial index (ABI) and walking distance. Results: All parameters differed in PAD and volunteers (p max was delayed (31.2 ± 13.6 vs. 16.7 ± 8.5 s, p post as optimal parameter combination for diagnosing PAD and therefore impaired arterial perfusion reserve. Conclusions: Dynamic CEUS with transient arterial occlusion quantifies muscular micro-perfusion and arterial perfusion reserve. The technique is accurate to diagnose PAD.

Involvement of the dorsomedial hypothalamus and the nucleus tractus solitarii in chronic cardiovascular changes associated with anxiety in rats

NARCIS (Netherlands)

Sevoz-Couche, Caroline; Brouillard, Charly; Camus, Francoise; Laude, Dominique; De Boer, Sietse F.; Becker, Chrystel; Benoliel, Jean-Jacques

Key points center dot Anxiety disorders reduce both the heart rate variability (HRV) and the sensitivity of the cardiac baroreflex (BRS). This may lead to sudden cardiac death. center dot To elucidate the mechanisms underlying these alterations, male rats were subjected to social defeat sessions

Male-female differences in upregulation of vasoconstrictor responses in human cerebral arteries.

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Hilda Ahnstedt

Full Text Available BACKGROUND AND PURPOSE: Male-female differences may significantly impact stroke prevention and treatment in men and women, however underlying mechanisms for sexual dimorphism in stroke are not understood. We previously found in males that cerebral ischemia upregulates contractile receptors in cerebral arteries, which is associated with lower blood flow. The present study investigates if cerebral arteries from men and women differ in cerebrovascular receptor upregulation. EXPERIMENTAL APPROACH: Freshly obtained human cerebral arteries were placed in organ culture, an established model for studying receptor upregulation. 5-hydroxtryptamine type 1B (5-HT1B, angiotensin II type 1 (AT1 and endothelin-1 type A and B (ETA and ETB receptors were evaluated using wire myograph for contractile responses, real-time PCR for mRNA and immunohistochemistry for receptor expression. KEY RESULTS: Vascular sensitivity to angiotensin II and endothelin-1 was markedly lower in cultured cerebral arteries from women as compared to men. ETB receptor-mediated contraction occurred in male but not female arteries. Interestingly, there were similar upregulation in mRNA and expression of 5-HT1B, AT1, and ETB receptors and in local expression of Ang II after organ culture. CONCLUSIONS AND IMPLICATIONS: In spite of receptor upregulation after organ culture in both sexes, cerebral arteries from women were significantly less responsive to vasoconstrictors angiotensin II and endothelin-1 as compared to arteries from men. This suggests receptor coupling and/or signal transduction mechanisms involved in cerebrovascular contractility may be suppressed in females. This is the first study to demonstrate sex differences in the vascular function of human brain arteries.

Venous digital subtraction angiography for diagnosis of renal artery stenosis in arterial hypertony

International Nuclear Information System (INIS)

Schoerner, W.; Kempter, H.; Banzer, D.; Aviles, C.; Weiss, T.; Felix, R.

1984-01-01

Venous digital subtraction angiography was performed in 248 patients for the diagnosis of renal arterial stenosis. In 88% of the investigations the stenosis could be found. Comparison of digital angiography and conventional angiography was made for 57 renal arteries (25 investigations). In 52 renal arteries we found the same results with both methods, in 5 renal arteries we found the same results with both methods, in 5 renal arteries the digital angiography showed false positive results. The spatial resolution of digital subtraction angiography is sufficient for the correct diagnosis of significant renal arterial stenosis. With regard to the lower invasion of digital subtraction angiography compared to conventional angiography the first method should be used for clarification of renal arterial hypertension. (orig.)

NON-INVASIVE MONITORING OF FOETAL ANAEMIA IN KELL SENSITIZED PREGNANCY.

Science.gov (United States)

Memon, Zaibunnisa; Sheikh, Sana Sadiq

2015-01-01

We report a case of Kell sensitized pregnancy with good neonatal outcome. Anti-K antibodies were detected in maternal serum in early pregnancy as a part of routine antibody screening test. The middle cerebral artery doppler monitoring and serial titers were carried out to screen for foetal anaemia. Despite of rising antibody titers, serial middle cerebral artery doppler was normal and did not showed foetal anaemia. The pregnancy was carried out till term and patient delivered at 37 weeks of pregnancy with no evidence of foetal anaemia. This case underlines the need of general screening on rare antibodies in all pregnant women and that non-invasive monitoring of foetal anaemia can be done with anti-k titers and middle cerebral artery Doppler.

Resting early peak diastolic filling rate: a sensitive index of myocardial dysfunction in patients with coronary artery disease

International Nuclear Information System (INIS)

Polak, J.F.; Kemper, A.J.; Bianco, J.A.; Parisi, A.F.; Tow, D.E.

1982-01-01

Resting first-pass radionuclide angiocardiography (RNA) was used to derive left-ventricular (LV) peak diastolic filling rates (PFR) in normals (Group 1:N . 12) and in patients with coronary artery disease (CAD), both without (Group 2:N . 27) and with previous myocardial infarction (Group 3:N . 23). Resting peak filling rates were significantly depressed in both Group 2 (1.61 +/- 0.36; p less than 0.01) and Group 3 (1:35 +/- 0.26; p less than 0.001) patients when compared with Group 1, normals (2.14 +/- 0.63). Even though LV systolic function of Group 2 patients was normal and comparable to that in Group 1 (EF . 0.55 +/- 0.06 against EF 0.55 +/- 0.06 NS), diastolic dysfunction [PFR less than 1.61 end diastolic volume/sec (EDV/sec)] was present at rest in 14 of 27 (52%). Depressed PFR values was also seen in 20 of 23 Group 3 patients (87%). It appears that (a) resting PFR is a sensitive and easily obtainable parameter of the diastolic dysfunction associated with CAD; (b) abnormal PFR values are seen in almost all patients with previous myocardial damage, and (c) a significant proportion of CAD patients without any evidence of abnormal systolic function have depressed resting PFR of the LV

Myocardial perfusion SPECT in diabetic patients for detection of coronary artery disease

International Nuclear Information System (INIS)

Saeed, M.A.; Fatima, S.; Fatmi, S.; Kureshi, S.

2003-01-01

The aim of this study was to evaluate the efficacy of myocardial SPECT perfusion scan in the diagnosis of coronary artery disease in diabetic patients. A total number of thirty diabetic patients (21 males, 9 females) were included in the study. All the patients had strong risk-factors for coronary artery disease (strong family history, chronic smokers, hyperlipidemia, history of chest pain). All patients underwent coronary angiography and stress/rest myocardial perfusion SPECT scans with Tc-99m MIBI (two days protocol). Twenty two patients had significant coronary artery stenosis and 8 had normal coronary arteries. Myocardial perfusion scintigraphy (MPS) was positive in 19 subjects out of the 22 patients with significant stenosis (Sensitivity 86.4%) and negative (false negative) in only three. Out of 8 patients with normal angiography 7 had normal MPS (Specificity 87.5%) whereas only one patient revealed abnormality in the myocardial perfusion study. When compared with coronary angiography the positive predictive value and negative predictive value for Tc-99m MIBI myocardial perfusion scan was 86.4% and 87.5% respectively. In conclusion, Tc-99m MIBI myocardial perfusion scintigraphy is a useful screening modality for the detection of coronary artery disease in diabetic patients. (author)

Role of adenosine A2A receptor signaling in the nicotine-evoked attenuation of reflex cardiac sympathetic control

International Nuclear Information System (INIS)

El-Mas, Mahmoud M.; El-gowilly, Sahar M.; Fouda, Mohamed A.; Saad, Evan I.

2011-01-01

Baroreflex dysfunction contributes to increased cardiovascular risk in cigarette smokers. Given the importance of adenosinergic pathways in baroreflex control, the hypothesis was tested that defective central adenosinergic modulation of cardiac autonomic activity mediates the nicotine-baroreflex interaction. Baroreflex curves relating changes in heart rate (HR) to increases or decreases in blood pressure (BP) evoked by i.v. doses (1-16 μg/kg) of phenylephrine (PE) and sodium nitroprusside (SNP), respectively, were constructed in conscious rats; slopes of the curves were taken as measures of baroreflex sensitivity (BRS). Nicotine (25 and 100 μg/kg i.v.) dose-dependently reduced BRS SNP in contrast to no effect on BRS PE . BRS SNP was also attenuated after intracisternal (i.c.) administration of nicotine. Similar reductions in BRS SNP were observed in rats pretreated with atropine or propranolol. The combined treatment with nicotine and atropine produced additive inhibitory effects on BRS, an effect that was not demonstrated upon concurrent exposure to nicotine and propranolol. BRS SNP was reduced in preparations treated with i.c. 8-phenyltheophylline (8-PT, nonselective adenosine receptor antagonist), 8-(3-Chlorostyryl) caffeine (CSC, A 2A antagonist), or VUF5574 (A 3 antagonist). In contrast, BRS SNP was preserved after blockade of A 1 (DPCPX) or A 2B (alloxazine) receptors or inhibition of adenosine uptake by dipyridamole. CSC or 8-PT abrogated the BRS SNP depressant effect of nicotine whereas other adenosinergic antagonists were without effect. Together, nicotine preferentially impairs reflex tachycardia via disruption of adenosine A 2A receptor-mediated facilitation of reflex cardiac sympathoexcitation. Clinically, the attenuation by nicotine of compensatory sympathoexcitation may be detrimental in conditions such as hypothalamic defense response, posture changes, and ventricular rhythms. - Research highlights: → The role of central adenosinergic sites in

Improved noninvasive assessment of coronary artery disease by quantitative analysis of regional stress myocardial distribution and washout of thallium-201

International Nuclear Information System (INIS)

Maddahi, J.; Garcia, E.V.; Berman, D.S.; Waxman, A.; Swan, H.J.C.; Forrester, J.

1981-01-01

Visual interpretation of stress-redistribution thallium-201 ( 201 Tl) scintigrams is subject to observer variability and is suboptimal for evaluation of extent of coronary artery disease (CAD). An objective, computerized technique has been developed that quantitatively expresses the relative space-time myocardial distribution of 201 Tl. Multiple-view, maximum-count circumferential profiles for stress myocardial distribution of 201 Tl and segmental percent washout were analyzed in a pilot group of 31 normal subjects and 20 patients with CAD to develop quantitative criteria for abnormality. Subsequently, quantitative analysis was applied prospectively to a group of 22 normal subjects and 45 CAD patients and compared with visual interpretation of scintigrams for detection and evaluation of CAD. The sensitivity and specificity of the quantitative technique (93% and 91%, respectively) were not significantly different from those of the visual method (91% and 86%). The quantitative analysis significantly (p 201 Tl imaging over the visual method in the left anterior descending artery (from 56% to 80%), left circumflex artery (from 34% to 63%) and right coronary artery (from 65% to 94%) without significant loss of specificity. Using quantitative analysis, sensitivity for detection of deseased vessels did not diminish as the number of vessels involved increased, as it did with visual interpretations. In patients with one-vessel disease, 86% of the lesions were detected by both techniques; however, in patients with three-vessel disease, quantitative analysis detected 83% of the lesions, while the sensitivity was only 53% for the visual method. Seventy percent of the coronary arteries with moderate

Classification of hypervascular liver lesions based on hepatic artery and portal vein blood supply coefficients calculated from triphasic CT scans.

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Boas, F Edward; Kamaya, Aya; Do, Bao; Desser, Terry S; Beaulieu, Christopher F; Vasanawala, Shreyas S; Hwang, Gloria L; Sze, Daniel Y

2015-04-01

Perfusion CT of the liver typically involves scanning the liver at least 20 times, resulting in a large radiation dose. We developed and validated a simplified model of tumor blood supply that can be applied to standard triphasic scans and evaluated whether this can be used to distinguish benign and malignant liver lesions. Triphasic CTs of 46 malignant and 32 benign liver lesions were analyzed. For each phase, regions of interest were drawn in the arterially enhancing portion of each lesion, as well as the background liver, aorta, and portal vein. Hepatic artery and portal vein blood supply coefficients for each lesion were then calculated by expressing the enhancement curve of the lesion as a linear combination of the enhancement curves of the aorta and portal vein. Hepatocellular carcinoma (HCC) and hypervascular metastases, on average, both had increased hepatic artery coefficients compared to the background liver. Compared to HCC, benign lesions, on average, had either a greater hepatic artery coefficient (hemangioma) or a greater portal vein coefficient (focal nodular hyperplasia or transient hepatic attenuation difference). Hypervascularity with washout is a key diagnostic criterion for HCC, but it had a sensitivity of 72 % and specificity of 81 % for diagnosing malignancy in our diverse set of liver lesions. The sensitivity for malignancy was increased to 89 % by including enhancing lesions that were hypodense on all phases. The specificity for malignancy was increased to 97 % (p = 0.039) by also examining hepatic artery and portal vein blood supply coefficients, while maintaining a sensitivity of 76 %.

Noninvasive detection of coronary artery bypass graft patency by intravenous electron beam computed tomographic angiography.

Science.gov (United States)

Yamakami, Shoji; Toyama, Junji; Okamoto, Mitsuhiro; Matsushita, Toyoaki; Murakami, Yoshimasa; Ogata, Masaki; Ito, Shigenori; Fukutomi, Tatsuya; Okayama, Naotsuka; Itoh, Makoto

2003-11-01

This study evaluates the usefullness of intravenous electron beam computed tomographic angiography (EBA) for the detection of coronary artery bypass graft patency in 43 patients (33 men and 10 women, mean age, 65 years) who had coronary artery bypass graft surgery. EBA was performed a few days before selective bypass graft angiography (SGA). Forty axial cross-sections of angiographic images of the heart were acquired consecutively by an electrocardiographic trigger signal at 40% of the RR interval, which corresponds to the end-systolic phase. EBA data were reconstructed as a three-dimensional shaded surface display of the heart and bypass grafts. Detectability of the patency of bypass gratis was evaluated, taking selective angiographic images of the bypass grafts as a gold standard. One hundred and nine grafts (96%) out of 114 grafts were subjected to evaluation: 37 grafts were left internal mammary artery grafts (LIMA), 7 were right internal mammary artery grafts (RIMA), 6 were gastroepiploic artery grafts (GEA), 7 were free gastroepiploic artery grafts with venous drainage (free-GEA), 7 were radial artery grafts (RAG), and 45 were saphenous vein gratis (SVG). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBA were 98%, 100%, 100%, 91%, and 98%, respectively. EBA sampled at the end-systolic period was determined to be useful for the detection of coronary artery bypass graft patency and occlusion.

Spontaneous intracranial arterial dissection in the young: diagnosis by CT angiography

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Given Curtis A

2006-04-01

Full Text Available Abstract Background Spontaneous carotid artery dissections have been rarely reported in children. Diagnosis has traditionally been confirmed by catheter arteriography. More recently diagnosis has been made by magnetic resonance imaging and magnetic resonance angiography; however the sensitivity of these techniques has yet to be determined. The authors are unaware of reports of carotid dissection confirmed by dynamic computed tomography (computerized tomographic arteriography in the young. Case presentation We recently evaluated a fourteen year-old male following the development of transient neurologic symptoms. There was no antecedent illness or trauma. Dynamic computed tomography revealed an intracranial dissection involving the supraclinoid segment of the left internal carotid artery (confirmed by catheter arteriography. Studies for vasculitis, pro-thrombotic states, and defects of collagen were negative. Conclusion Spontaneous carotid artery dissection is a potential cause of transient neurological symptoms and ischemic stroke in the pediatric population. Dynamic computed tomography appears to be a reliable diagnostic tool which can lead to early diagnosis.

Imaging of Dual Ophthalmic Arteries: Identification of the Central Retinal Artery

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Louise Louw

2014-01-01

Full Text Available Identification of the origin of the central retinal artery (CRA is imperative in tailoring angiographic studies to resolve a given clinical problem. A case with dual ophthalmic arteries (OAs, characterized by different origins and distinct branching patterns, is documented for training purposes. Pre-clinical diagnosis of a 9-year-old child who presented with a sharp wire in the left-side eyeball was primarily corneal laceration. For imaging, a selected six-vessel angiographic study with the transfemoral approach was performed. Embolization was not required and the wire could be successfully removed. Right-side OA anatomy was normal, while left-side dual OAs with external carotid artery (ECA and internal carotid artery (ICA origins were seen. The case presented with a left-side meningo-ophthalmic artery (M-OA anomaly via the ECA, marked by a middle meningeal artery (MMA (origin: Maxillary artery; course: Through foramen spinosum with normal branches (i.e. anterior and posterior branches, and an OA variant (course: Through superior orbital fissure with a distinct orbital branching pattern. A smaller OA (origin: ICA; course: Through optic foramen with a distinct ocular branching pattern presented with the central retinal artery (CRA. The presence of the dual OAs and the M-OA anomaly can be explained by disturbed evolutionary changes of the primitive OA and stapedial artery during development. The surgical interventionist must be aware of dual OAs and M-OA anomalies with branching pattern variations on retinal supply, because of dangerous extracranial-intracranial anastomotic connections. It is of clinical significance that the origin of the CRA from the ICA or ECA must be determined to avoid complications to the vision.

Automated classification and quantitative analysis of arterial and venous vessels in fundus images

Science.gov (United States)

Alam, Minhaj; Son, Taeyoon; Toslak, Devrim; Lim, Jennifer I.; Yao, Xincheng

2018-02-01

It is known that retinopathies may affect arteries and veins differently. Therefore, reliable differentiation of arteries and veins is essential for computer-aided analysis of fundus images. The purpose of this study is to validate one automated method for robust classification of arteries and veins (A-V) in digital fundus images. We combine optical density ratio (ODR) analysis and blood vessel tracking algorithm to classify arteries and veins. A matched filtering method is used to enhance retinal blood vessels. Bottom hat filtering and global thresholding are used to segment the vessel and skeleton individual blood vessels. The vessel tracking algorithm is used to locate the optic disk and to identify source nodes of blood vessels in optic disk area. Each node can be identified as vein or artery using ODR information. Using the source nodes as starting point, the whole vessel trace is then tracked and classified as vein or artery using vessel curvature and angle information. 50 color fundus images from diabetic retinopathy patients were used to test the algorithm. Sensitivity, specificity, and accuracy metrics were measured to assess the validity of the proposed classification method compared to ground truths created by two independent observers. The algorithm demonstrated 97.52% accuracy in identifying blood vessels as vein or artery. A quantitative analysis upon A-V classification showed that average A-V ratio of width for NPDR subjects with hypertension decreased significantly (43.13%).

Relationship of daily arterial blood pressure monitoring readings and arterial stiffness profile in male patients with chronic obstructive pulmonary disease combined with arterial hypertension

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Karoli N.A.

2013-06-01

Full Text Available The aim of the study was to determine correlation between arterial blood pressure daily rhythm and daily profile of arterial stiffness in male patients with chronic obstructive pulmonary disease (COPD and arterial hypertension. Materials et methods: Prospective investigation comprised 45 male patients with COPD and arterial hypertension. Individuals of 40 years younger and 80 years elder, patients with diabetes, stroke, angina pectoris, or heart infarction, vascular diseases, and exacerbation of chronic disease, bronchial and pulmonary diseases of other etiology were excluded from the analyses. Comparison group included 47 patients with essential arterial hypertension and without chronic respiratory diseases closely similar on general parameters with patients from main clinical series. Twenty-four-hour arterial blood pressure monitoring (ABPM and daily arterial stiffness monitoring were performed using BPLab® MnSDP-2 apparatus (Petr Telegin, Russian Federation. Results: Patients with COPD combined with arterial hypertension with raised arterial stiffness measures prevail over individuals in essential hypertension group. There is pathological alteration of the ABPM circadian rhythm and raised «Pressure load» values in raised arterial stiffness group. Conclusion: We found ABPM raised parameters in patients with COPD and arterial hypertension. It confirms necessity of ABPM in daily arterial stiffness assessment in patients with COPD.

Comparison of stress-rest and rest-stress one day myocardial perfusion scintigraphies in detecting coronary artery diseases

International Nuclear Information System (INIS)

Bom, Hee Seung; Min, Jung Jun; Song, Ho Cheon; Kim, Ji Yeul

1997-01-01

It has been shown that both rest and stress myocardial perfusion imaging with technetium agents can be performed on the same day using two different doses injected within few hours. The purpose of this study was to compare the two protocols (stress-rest and rest-stress) in detecting coronary artery diseases. One hundred and sixty patients (101 males, 59 females, mean age 57±9 years) and 120 patients (79 males, 41 females, mean age 59±10 years) underwent stress-rest myocardial perfusion SPECT and rest-stress myocardial perfusion SPECT, respectively. All of them underwent both myocardial perfusion SPECT and coronary angiography within 1 month. A coronary stenosis was considered significant when it compromised the luminal diameter by ≥50%. The chi square test was used to compare differences in sensitivity, specificity and accuracy between the two groups. The overall sensitivity, specificity and accuracy of stress-rest protocol were 99%, 35% and 68%, respectively. Those of rest-stress protocol were 96%, 47% and 78%, respectively. There was no difference between the two protocols in identifying individual diseased coronary artery branches. Therefore, one day stress-rest and rest-stress myocardial SPECT using 99m Tc agents were comparable and were very sensitive tests in detecting coronary artery diseases

Pulmonary artery hypertension in chronic obstructive lung disease. The validity of morphometric tests in radiodiagnosis of the thorax

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Dinkel, E; Mundinger, A; Reinbold, W D; Wuertemberger, G

1989-06-01

Standard biplane chest X-rays were tested for the validity of morphometric criteria in the diagnosis of pulmonary artery hypertension. Twenty-seven patients suffering from chronic obstructive lung disease were examined and compared with a control group without cardiopulmonary disease. The diameter of the right and left pulmonary artery, pulmonary conus and the hilar-to-thoracic ratio were significantly increased in patients with chronic obstructive lung disease (p<0.0001). Measurement of the right pulmonary artery was 19.7+-3.9 mm compared to 13.6+-1.2 mm of the control group; mean hilar thoracic index was 0.35 compared to 0.31. Thus if the width of the descending branch of the right pulmonary artery was above 16 mm, pulmonary arterial hypertension was suggested, with a specificity of almost 100%, although the sensitivity of the diagnosis was only 59%. The mean pulmonary arterial pressure obtained by right heart catheterization correlated poorly with the morphometric criteria obtained. (orig.).

Neural set point for the control of arterial pressure: role of the nucleus tractus solitarius

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Valentinuzzi Max E

2010-01-01

Full Text Available Abstract Background Physiological experiments have shown that the mean arterial blood pressure (MAP can not be regulated after chemo and cardiopulmonary receptor denervation. Neuro-physiological information suggests that the nucleus tractus solitarius (NTS is the only structure that receives information from its rostral neural nuclei and from the cardiovascular receptors and projects to nuclei that regulate the circulatory variables. Methods From a control theory perspective, to answer if the cardiovascular regulation has a set point, we should find out whether in the cardiovascular control there is something equivalent to a comparator evaluating the error signal (between the rostral projections to the NTS and the feedback inputs. The NTS would function as a comparator if: a its lesion suppresses cardiovascular regulation; b the negative feedback loop still responds normally to perturbations (such as mechanical or electrical after cutting the rostral afferent fibers to the NTS; c perturbation of rostral neural structures (RNS to the NTS modifies the set point without changing the dynamics of the elicited response; and d cardiovascular responses to perturbations on neural structures within the negative feedback loop compensate for much faster than perturbations on the NTS rostral structures. Results From the control theory framework, experimental evidence found currently in the literature plus experimental results from our group was put together showing that the above-mentioned conditions (to show that the NTS functions as a comparator are satisfied. Conclusions Physiological experiments suggest that long-term blood pressure is regulated by the nervous system. The NTS functions as a comparator (evaluating the error signal between its RNS and the cardiovascular receptor afferents and projects to nuclei that regulate the circulatory variables. The mean arterial pressure (MAP is regulated by the feedback of chemo and cardiopulmonary receptors and

Clinical role of non-contrast magnetic resonance angiography for evaluation of renal artery stenosis

International Nuclear Information System (INIS)

Utsunomiya, Daisuke; Nomitsu, Yohei; Komeda, Yosuke; Okigawa, Takashi; Urata, Joji; Miyazaki, Mitsue; Yamashita, Yasuyuki

2008-01-01

The association between a gadolinium-based contrast material and nephrogenic systemic fibrosis has been discussed. The purpose of our study was to evaluate whether non-contrast enhanced magnetic resonance angiography (MRA) might provide sufficient information of renal artery stenosis. The non-contrast MRA of 26 patients with hypertension was retrospectively reviewed in the present study. The significant renal artery stenosis was visually evaluated by comparing non-contrast MRA with computed tomography or conventional angiographic finding. Difference of the intensities between the proximal and distal aorta was quantitatively evaluated. The sensitivity, specificity, positive predictive value and negative predictive value of non-contrast MRA in the evaluation of the renal artery stenosis was 78%, 91%, 64% and 96%, respectively. The distal abdominal aorta showed less signal intensity than the proximal aorta by 16.9±12.2%. Non-contrast MRA is a non-invasive and effective method that allows evaluation of the renal artery stenosis. (author)

3D-CT angiography. Intracranial arterial lesions

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Asato, Mikio; Tong, X.Q.; Tamura, Shozo [Miyazaki Medical Coll., Kiyotake (Japan)] [and others

1997-06-01

Since its introduction, three dimensional CT angiography (3D-CTA) on spiral (helical) CT has played an important role in clinical imaging. Initially it was reported to be useful in depicting aortic abnormalities, afterwards the merit in detecting intracranial aneurysm by 3D-CTA was also described. We have investigated the usefullness of 3D-CTA in detecting patients of intracranial aneurysm as well as arterio-venous malformation (AVM), Moyamoya disease and stenosis of middle cerebral artery, meanwhile the MR angiography (MRA) and digital subtraction angiography (DSA) examination of these patients were also studied as comparison to the 3D-CTA results. The sensitivity and specificity on investigating intracranial aneurysm were similar with other reports so far. 3D-CTA was possible to identify the feeding artery, nidus and draining vein of AVM, although DSA showed higher detectability. Occlusion of internal carotid artery and post-operative anastomosis in Moyamoya disease were all demonstrated by 3D-CTA, however the Moyamoya collaterals were shown better on MRA. 3D-CTA revealed the site of stenosis of middle cerebral artery in all of our cases, but in general maximum intensity projection (MIP) images can provide more exact information about the degree of stenosis. Five years has passed since the emergence of spiral CT and utilizing of 3D-CTA in clinical applications. With the development of hard and soft ware in the near future, it is possible to delineate more small vessels by 3D-CTA. We predict that 3D-CTA would be widely used for detecting vasculature of the whole body, and may take the place of conventional angiography in many cases. (author)

Potential Biomarkers of Insulin Resistance and Atherosclerosis in Type 2 Diabetes Mellitus Patients with Coronary Artery Disease

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Sharifah Intan Qhadijah Syed Ikmal

2013-01-01

Full Text Available Type 2 diabetes mellitus patients with coronary artery disease have become a major public health concern. The occurrence of insulin resistance accompanied with endothelial dysfunction worsens the state of atherosclerosis in type 2 diabetes mellitus patients. The combination of insulin resistance and endothelial dysfunction leads to coronary artery disease and ischemic heart disease complications. A recognized biological marker, high-sensitivity C-reactive protein, has been used widely to assess the progression of atherosclerosis and inflammation. Along with coronary arterial damage and inflammatory processes, high-sensitivity C-reactive protein is considered as an essential atherosclerosis marker in patients with cardiovascular disease, but not as an insulin resistance marker in type 2 diabetes mellitus patients. A new biological marker that can act as a reliable indicator of both the exact state of insulin resistance and atherosclerosis is required to facilitate optimal health management of diabetic patients. Malfunctioning of insulin mechanism and endothelial dysfunction leads to innate immune activation and released several biological markers into circulation. This review examines potential biological markers, YKL-40, alpha-hydroxybutyrate, soluble CD36, leptin, resistin, interleukin-18, retinol binding protein-4, and chemerin, as they may play significant roles in insulin resistance and atherosclerosis in type 2 diabetes mellitus patients with coronary artery disease.

An isolated left subclavian artery supplied by a collateral artery from the abdominal aorta

International Nuclear Information System (INIS)

Ming, Zhu; Qian, Wang

2009-01-01

An isolated left subclavian artery is a rare anomaly. We report a 9-month-old boy with an isolated left subclavian artery associated with tetralogy of Fallot and the right aortic arch. MRI and angiography show that the blood supply through the left subclavian artery was maintained by a large tortuous collateral artery from the abdominal aorta. This type of collateral artery structure is unique. (orig.)

An isolated left subclavian artery supplied by a collateral artery from the abdominal aorta

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Ming, Zhu; Qian, Wang [Shanghai Jiaotong University School of Medicine, Department of Radiology, Shanghai Children' s Medical Center, Shanghai (China)

2009-08-15

An isolated left subclavian artery is a rare anomaly. We report a 9-month-old boy with an isolated left subclavian artery associated with tetralogy of Fallot and the right aortic arch. MRI and angiography show that the blood supply through the left subclavian artery was maintained by a large tortuous collateral artery from the abdominal aorta. This type of collateral artery structure is unique. (orig.)

Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats

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Durand, M.T.; Mota, A.L. [Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Barale, A.R. [Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG (Brazil); Castania, J.A.; Fazan, R. Jr.; Salgado, H.C. [Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

2012-03-16

The time to reach the maximum response of arterial pressure, heart rate and vascular resistance (hindquarter and mesenteric) was measured in conscious male spontaneously hypertensive (SHR) and normotensive control rats (NCR; Wistar; 18-22 weeks) subjected to electrical stimulation of the aortic depressor nerve (ADN). The parameters of stimulation were 1 mA intensity and 2 ms pulse length applied for 5 s, using frequencies of 10, 30, and 90 Hz. The time to reach the hemodynamic responses at different frequencies of ADN stimulation was similar for SHR (N = 15) and NCR (N = 14); hypotension = NCR (4194 ± 336 to 3695 ± 463 ms) vs SHR (3475 ± 354 to 4494 ± 300 ms); bradycardia = NCR (1618 ± 152 to 1358 ± 185 ms) vs SHR (1911 ± 323 to 1852 ± 431 ms), and the fall in hindquarter vascular resistance = NCR (6054 ± 486 to 6550 ± 847 ms) vs SHR (4849 ± 918 to 4926 ± 646 ms); mesenteric = NCR (5574 ± 790 to 5752 ± 539 ms) vs SHR (5638 ± 648 to 6777 ± 624 ms). In addition, ADN stimulation produced baroreflex responses characterized by a faster cardiac effect followed by a vascular effect, which together contributed to the decrease in arterial pressure. Therefore, the results indicate that there is no alteration in the conduction of the electrical impulse after the site of baroreceptor mechanical transduction in the baroreflex pathway (central and/or efferent) in conscious SHR compared to NCR.

Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats

International Nuclear Information System (INIS)

Durand, M.T.; Mota, A.L.; Barale, A.R.; Castania, J.A.; Fazan, R. Jr.; Salgado, H.C.

2012-01-01

The time to reach the maximum response of arterial pressure, heart rate and vascular resistance (hindquarter and mesenteric) was measured in conscious male spontaneously hypertensive (SHR) and normotensive control rats (NCR; Wistar; 18-22 weeks) subjected to electrical stimulation of the aortic depressor nerve (ADN). The parameters of stimulation were 1 mA intensity and 2 ms pulse length applied for 5 s, using frequencies of 10, 30, and 90 Hz. The time to reach the hemodynamic responses at different frequencies of ADN stimulation was similar for SHR (N = 15) and NCR (N = 14); hypotension = NCR (4194 ± 336 to 3695 ± 463 ms) vs SHR (3475 ± 354 to 4494 ± 300 ms); bradycardia = NCR (1618 ± 152 to 1358 ± 185 ms) vs SHR (1911 ± 323 to 1852 ± 431 ms), and the fall in hindquarter vascular resistance = NCR (6054 ± 486 to 6550 ± 847 ms) vs SHR (4849 ± 918 to 4926 ± 646 ms); mesenteric = NCR (5574 ± 790 to 5752 ± 539 ms) vs SHR (5638 ± 648 to 6777 ± 624 ms). In addition, ADN stimulation produced baroreflex responses characterized by a faster cardiac effect followed by a vascular effect, which together contributed to the decrease in arterial pressure. Therefore, the results indicate that there is no alteration in the conduction of the electrical impulse after the site of baroreceptor mechanical transduction in the baroreflex pathway (central and/or efferent) in conscious SHR compared to NCR

Sidestream cigarette smoke effects on cardiovascular responses in conscious rats: involvement of oxidative stress in the fourth cerebral ventricle

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Valenti Vitor E

2012-03-01

Full Text Available Abstract Background Cigarette exposure increases brain oxidative stress. The literature showed that increased brain oxidative stress affects cardiovascular regulation. However, no previous study investigated the involvement of brain oxidative stress in animals exposed to cigarette and its relationship with cardiovascular regulation. We aimed to evaluate the effects of central catalase inhibition on baroreflex and cardiovascular responses in rats exposed to sidestream cigarette smoke (SSCS. Methods We evaluated males Wistar rats (320-370 g, which were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4th V. Femoral artery and vein were cannulated for mean arterial pressure (MAP and heart rate (HR measurement and drug infusion, respectively. Rats were exposed to SSCS during three weeks, 180 minutes, 5 days/week (CO: 100-300 ppm. Baroreflex was tested with a pressor dose of phenylephrine (PHE, 8 μg/kg, bolus to induce bradycardic reflex and a depressor dose of sodium nitroprusside (SNP, 50 μg/kg, bolus to induce tachycardic reflex. Cardiovascular responses were evaluated before, 5, 15, 30 and 60 minutes after 3-amino-1,2,4-triazole (ATZ, catalase inhibitor, 0.001 g/100 μL injection into the 4th V. Results Central catalase inhibition increased basal HR in the control group during the first 5 minutes. SSCS exposure increased basal HR and attenuated bradycardic peak during the first 15 minutes. Conclusion We suggest that SSCS exposure affects cardiovascular regulation through its influence on catalase activity.

Incremental value of contrast myocardial perfusion to detect intermediate versus severe coronary artery stenosis during stress-echocardiography

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Ugo Fabrizio

2010-05-01

Full Text Available Abstract Background We aimed to compare the incremental value of contrast myocardial perfusion imaging (MPI for the detection of intermediate versus severe coronary artery stenosis during dipyridamole-atropine echocardiography (DASE. Wall motion (WM assessment during stress-echocardiography demonstrates suboptimal sensitivity to detect coronary artery disease (CAD, particularly in patients with isolated intermediate (50%-70% coronary stenosis. Methods We performed DASE with MPI in 150 patients with a suspected chest pain syndrome who were given clinical indication to coronary angiography. Results and discussion When CAD was defined as the presence of a ≥50% stenosis, the addition of MPI increased sensitivity (+30% and decreased specificity (-14%, with a final increase in total diagnostic accuracy (+16%, p Conclusions The addition of MPI on top of WM analysis during DASE increases the diagnostic sensitivity to detect obstructive CAD, whatever its definition (≥50% or > 70% stenosis, but it is mainly driven by the sensitivity increase in the intermediate group (50%-70% stenosis. The total diagnostic accuracy increased only when defining CAD as ≥50% stenosis, since in patients with severe stenosis (> 70% the decrease in specificity is not counterbalanced by the minor sensitivity increase.

Acetylcholine produces contraction mediated by cyclooxigenase pathway in arterial vessels in the marine fish (Isacia conceptionis

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FA. Moraga

Full Text Available Preliminary studies showed that dorsal artery contraction mediated by acetylcholine (ACh is blocked with indomethacin in intertidal fish (G. laevifrons. Our objective was to characterize the cholinergic pathway in several artery vessels of the I. conceptionis. Afferent and efferent branchial, dorsal and mesenteric arteries were dissected of 6 juvenile specimens, isometric tension studies were done using doses response curves (DRC for Ach (10–13 to 10–3 M, and cholinergic pathways were obtained by blocking with atropine or indomethacin. CRC to ACh showed a pattern of high sensitivity only in efferente branchial artery and low sensibility in all vessels. Furthermore, these contractions were blocked in the presence of atropine and indomethacin in all vessels. Our results corroborate previous results observed in intertidal species that contraction induced by acetylcholine is mediated by receptors that activate a cyclooxygenase contraction pathway.

Accuracy of 3 T MR angiography in vertebral artery stenosis and coincidence with other cerebrovascular stenoses

International Nuclear Information System (INIS)

Choi, Hyun Seok; Kim, Dong Ik; Kim, Dong Joon; Kim, Jinna; Kim, Eun Soo; Lee, Seung-Koo

2010-01-01

Ostium of vertebral artery (VA) is a common site of pseudostenosis on contrast-enhanced MR angiography (CE-MRA). The purpose of this study was to determine the diagnostic accuracy of CE-MRA at 3 T in the evaluation of ostial stenosis of VA and to find associated coincidental stenoses using logistic regression analysis. One hundred and thirty-five VA ostial regions from 72 patients who received CE-MRA of neck vessels, intracranial time of flight (TOF) MRA, and digital subtraction angiography (DSA) were retrospectively reviewed. The sensitivity and specificity of the CE-MRA in detection of ostial stenosis were calculated with reference standard of DSA. Ostial stenosis on MRA was correlated with coincidental lesions in intracranial and cervical arteries by logistic regression analysis. The sensitivity and specificity of the CE-MRA were 100% and 80.4% for detection of significant stenosis. In case of significant stenoses, CE-MRA showed a tendency of overestimation with a false-positive rate of 52.5%. Logistic regression analysis showed that the stenoses of middle cerebral artery (MCA) on TOF MRA was associated with significant stenoses of VA ostia (OR = 5.84, 95% confidence intervals 1.41-24.17). CE-MRA is sensitive in detection of VA ostial stenosis although it has high false-positive rate. True positive ostial stenosis should be considered in cases of coincidental stenoses of MCA on TOF MRA. (orig.)

Diagnostic evaluation of uterine artery Doppler sonography for the prediction of adverse pregnancy outcomes

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Mojgan Barati

2014-01-01

Full Text Available Background : Increased impedance to flow in the uterine arteries assessed by value of the Doppler is associated with adverse pregnancy outcomes, especially pre-eclampsia. We investigated the predictive value of a uterine artery Doppler in the identification of adverse pregnancy outcomes such as ′pre-eclampsia′ and ′small fetus for gestational age′ (SGA. Materials and Methods: Three hundred and seventy-nine women, with singleton pregnancy, between 18 and 40 years of age, without risk factors, randomly underwent Doppler interrogation of the uterine arteries, between 16-22 weeks of gestation. Those who had a mean pulsatility index (PI of >1.45 were considered to have an abnormal result, and were evaluated and compared with those who had normal results for adverse pregnancy outcomes, including pre-eclampsia and small for gestational age. The relationship between the variables was assessed with the use of the chi-square test. Results : There were 17 cases (4.5% of abnormal uterine artery Doppler results and 15 of them (88.2% developed pre-eclampsia and four cases (23.5% had neonates small for gestational age. For predicting pre-eclampsia, the mean uterine artery PI had to be >1.45, had to have a specificity of 95.5% (95% CI, 70-92%, a sensitivity of 79% (95% CI, 43-82%, a negative predictive value (NPV of 98.9% (95% CI, 72-96%, and a positive predictive value (PPV of 88.2% (95% CI, 68-98%. In the case of ′small for gestational age′ it had to have a specificity of 96.5% (95% CI, 42-68%, a sensitivity of 57% (95% CI, 53-76%, an NPV of 99.2% (95% CI, 70-92%, and a PPV of 23.5% (95% CI, 30-72%. Conclusion : Uterine artery Doppler evaluation at 16-22 weeks of gestation might be an appropriate tool for identifying pregnancies that may be at an increased risk for development of pre-eclampsia and small fetus for gestational age.

Anomalous right coronary artery arising from the pulmonary artery and constrictive pericarditis: an unusual association

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Silvestre, Odilson Marcos; Adam, Eduardo Leal; de Melo, Dirceu Thiago Pessoa; Dias, Ricardo Ribeiro; Ramires, Felix J. A.; Mady, Charles

2013-01-01

ABSTRACT The association of anomalous right coronary artery originating from the pulmonary artery and constrictive pericarditis has never been showed in the literature. We present the first case of this unusual association in a patient with right heart failure. After diagnosis, the patient was referred to surgery and underwent phrenic-to-phrenic pericardiectomy; graft implant of right internal thoracic artery to right coronary artery; and ligation of the anomalous origin of the right coronary artery from the pulmonary artery. Such procedures solved the potential risk of sudden death related to anomalous right coronary artery originating from the pulmonary artery and alleviated the symptoms of heart failure caused by constrictive pericarditis. PMID:24136766

Development and psychometric evaluation of the arterial puncture self-efficacy scale.

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Hernández-Padilla, José Manuel; Granero-Molina, José; Márquez-Hernández, Verónica V; Suthers, Fiona; Fernández-Sola, Cayetano

2016-05-01

Arterial puncture for arterial blood gases (ABG) analysis can be a risky, painful, difficult-to-perform procedure that is often insufficiently practised and generates stress and discomfort amongst patients and healthcare professionals. Self-efficacy is a key component in the acquisition of procedural skills. Therefore, professionals' self-efficacy in arterial puncture should be measured before attempting the procedure on real patients. To develop and psychometrically assess a self-efficacy scale in arterial puncture. An observational cross-sectional design was used in this study. Faculty of Education Sciences, Nursing and Physiotherapy in a higher education institution in the south of Spain. A convenience sample of 342 nursing students entered and completed the study. All participants met the following inclusion criteria: (1) ≥18years old and (2) enrolled in a nursing degree programme during the 2014/2015 academic year. Participants were 74% female (n=254) and their age ranged from 18 to 50, with a mean age of 21.74years (SD=5.14). The Arterial Puncture Self-Efficacy Scale (APSES) was developed and psychometrically tested. Reliability and content validity were studied. Predictive validity and concurrent validity assessed criterion validity. In addition, principal component analysis and known-group analysis evaluated construct validity. Principal component analysis revealed the two-subscale structure of the final 22-item version of the Arterial Puncture Self-Efficacy Scale (APSES). A total Cronbach's alpha coefficient of 0.97 showed its high reliability. The APSES' content validity index was excellent (S-CVI/Ave=0.95). Predictive and concurrent validity analysis demonstrated the good criterion validity of the tool. Supporting the APSES' sensitivity and specificity, known-groups analysis evidenced significant differences (pgood psychometric properties for measuring self-efficacy in arterial puncture for ABG analysis. Copyright © 2016 Elsevier Ltd. All rights

BILATERAL DUPLICATION OF RENAL ARTERIES

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Prajkta A Thete; Mehera Bhoir; M.V.Ambiye

2014-01-01

Routine dissection of a male cadaver revealed the presence of bilateral double renal arteries. On the right side the accessory renal artery originated from the abdominal aorta just above the main renal artery. On the left side the accessory renal artery originated from the abdominal aorta about 1 cm above the main renal artery. Knowledge of the variations of renal vascular anatomy has importance in exploration and treatment of renal trauma, renal transplantation, renal artery embolization, su...

Effect of 1-week yoga-based residential program on cardiovascular variables of hypertensive patients: A Comparative Study

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Kashinath G Metri

2018-01-01

Full Text Available Introduction: Hypertension (HTN is an important public health concern and a leading cause of morbidity and mortality worldwide. Yoga is a form of mind–body medicine shown to be effective in controlling blood pressure (BP and reduces cardiac risk factors in HTN. Integrated approach of Yoga therapy (IAYT is a residential yoga-based lifestyle intervention proven to be beneficial in several health conditions. Aim: To study the efficacy of 1 week of residential IAYT intervention on cardiovascular parameters in hypertensive patients. Methodology: Twenty hypertensive individuals (7 females within age range between 30 and 60 years (average; 46.62 ± 9.9 years, who underwent 1 week of IAYT treatment for HTN, were compared with age- gender-matched non-IAYT group (5 females; average age; 47.08 ± 9.69 years in terms of systolic BP (SBP, diastolic BP (DBP, mean arterial pressure (MAP, cardiac output (CO, stroke volume (SV, baroreflex sensitivity (BRS, and total peripheral vascular resistance (TPVR, IAYT program consisted of sessions of asanas, breathing practices, meditation and relaxation techniques, low salt, low-calorie diet, devotional session, and counseling. Individuals in non-IAYT group followed their normal routine. All the variables were assessed before and after one week. Data were analyzed using SPSS version 16. RM-ANOVA was applied to assess within group and between group changes after intervention. Results: There was a significant improvement in SBP (P = 0.004, DBP (P = 0.008, MAP (0.03, BRS (P < 0.001, and TPVR (P = 0.007 in IAYT, group whereas in control group, we did not find significant difference in any of the variables. Between-group comparison showed a significant improvement in SBP (P = 0.038, BRS (P = 0.034, and TPVR (P = 0.015 in IAYT group as compared to non-IAYT group. Conclusion: One-week IAYT intervention showed an improvement in baroreflex sensitivity, systolic BP, and total peripheral vascular resistance in hypertensive

Effect of 1-Week Yoga-Based Residential Program on Cardiovascular Variables of Hypertensive Patients: A Comparative Study.

Science.gov (United States)

Metri, Kashinath G; Pradhan, Balaram; Singh, Amit; Nagendra, H R

2018-01-01

Hypertension (HTN) is an important public health concern and a leading cause of morbidity and mortality worldwide. Yoga is a form of mind-body medicine shown to be effective in controlling blood pressure (BP) and reduces cardiac risk factors in HTN. Integrated approach of Yoga therapy (IAYT) is a residential yoga-based lifestyle intervention proven to be beneficial in several health conditions. Aim: To study the efficacy of 1 week of residential IAYT intervention on cardiovascular parameters in hypertensive patients. Twenty hypertensive individuals (7 females) within age range between 30 and 60 years (average; 46.62 ± 9.9 years), who underwent 1 week of IAYT treatment for HTN, were compared with age- gender-matched non-IAYT group (5 females; average age; 47.08 ± 9.69 years) in terms of systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), cardiac output (CO), stroke volume (SV), baroreflex sensitivity (BRS), and total peripheral vascular resistance (TPVR), IAYT program consisted of sessions of asanas, breathing practices, meditation and relaxation techniques, low salt, low-calorie diet, devotional session, and counseling. Individuals in non-IAYT group followed their normal routine. All the variables were assessed before and after one week. Data were analyzed using SPSS version 16. RM-ANOVA was applied to assess within group and between group changes after intervention. There was a significant improvement in SBP ( P = 0.004), DBP ( P = 0.008), MAP (0.03), BRS ( P < 0.001), and TPVR ( P = 0.007) in IAYT, group whereas in control group, we did not find significant difference in any of the variables. Between-group comparison showed a significant improvement in SBP ( P = 0.038), BRS ( P = 0.034), and TPVR ( P = 0.015) in IAYT group as compared to non-IAYT group. One-week IAYT intervention showed an improvement in baroreflex sensitivity, systolic BP, and total peripheral vascular resistance in hypertensive patients. However, further randomized control

Intra-arterial thrombolysis of digital artery occlusions in a patient with polycythemia vera.

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Jud, Philipp; Hafner, Franz; Gary, Thomas; Ghanim, Leyla; Lipp, Rainer; Brodmann, Marianne

2017-01-01

There are limited therapeutic options for the resolution of digital artery occlusions. Intra-arterial thrombolysis with anticoagulative and thrombolytic drugs successfully restored the blood flow in the affected digital arteries.

Cardiointegram: detection of coronary artery disease in males with chest pain and a normal resting electrocardiogram

International Nuclear Information System (INIS)

Teichholz, L.E.; Steinmetz, M.Y.; Escher, D.; Herman, M.V.; Naimi, S.; Mahony, D.V.; Ellestad, M.H.

1986-01-01

The cardiointegram is a non-invasive technique for the analysis of the electrical signals of the heart obtained by a transformation of the voltage vs. time format by a series of integrations. This multicenter study compares the results of the cardiointegram with coronary arteriography in 140 male patients with chest pain and a normal resting electrocardiogram. The cardiointegram was determined on two resting complexes of Leads I, II, V4, V5 and V6 and called abnormal if greater than or equal to four of ten complexes were abnormal, i.e., fell outside of a previously determined template of normality. The sensitivity was 73% and specificity was 78% for the diagnosis of occlusive coronary artery disease. When greater than or equal to five of ten abnormal complexes were used as the cut-off for an abnormal test and ''equivocal'' results (four of ten abnormal, n = 18) were excluded from analysis there was a sensitivity of 69% and specificity of 88%. Thirty-seven of 38 patients (97%) with an abnormal cardiointegram and a positive exercise stress test had coronary artery disease. Thus, the cardiointegram appears to be a useful non-invasive test for the detection of coronary artery disease in males with chest pain and a normal resting electrocardiogram in whom the diagnosis of coronary artery disease is being considered

Increased sensitivity to ET-1 in rat cerebral arteries following organ culture

DEFF Research Database (Denmark)

Hansen-Schwartz, J; Edvinsson, L

2000-01-01

Endothelin-1 (ET-1) is recognized as being involved in the pathophysiology of cerebrovascular diseases. Using organ culture as a model for possible pathological changes we studied changes in ET(A) and ETB receptor function using a sensitive in vitro method. We observed an up-regulation of the ET......(B) receptor and an amazingly increased sensitivity to ET-1 by 3 log units in pEC50; pEC50(fresh) was 8.7 +/- 0.1, and pEC50(cultured) was 11.7 +/- 0.3. pA2 for FR139317 in the fresh vessel was 7.0 +/- 0.2 whereas it could not be obtained for the cultured vessel, indicating a possible cross-talk between the ET......(A) and ET(B) receptors. The increased sensitivity to ET-1 could also take place during cerebrovascular disease such as stroke or haemorrhage rendering the vessels considerably more sensitive to ET-1....

X-ray micro computed tomography for the visualization of an atherosclerotic human coronary artery

Science.gov (United States)

Matviykiv, Sofiya; Buscema, Marzia; Deyhle, Hans; Pfohl, Thomas; Zumbuehl, Andreas; Saxer, Till; Müller, Bert

2017-06-01

Atherosclerosis refers to narrowing or blocking of blood vessels that can lead to a heart attack, chest pain or stroke. Constricted segments of diseased arteries exhibit considerably increased wall shear stress, compared to the healthy ones. One of the possibilities to improve patient’s treatment is the application of nano-therapeutic approaches, based on shear stress sensitive nano-containers. In order to tailor the chemical composition and subsequent physical properties of such liposomes, one has to know precisely the morphology of critically stenosed arteries at micrometre resolution. It is often obtained by means of histology, which has the drawback of offering only two-dimensional information. Additionally, it requires the artery to be decalcified before sectioning, which might lead to deformations within the tissue. Micro computed tomography (μCT) enables the three-dimensional (3D) visualization of soft and hard tissues at micrometre level. μCT allows lumen segmentation that is crucial for subsequent flow simulation analysis. In this communication, tomographic images of a human coronary artery before and after decalcification are qualitatively and quantitatively compared. We analyse the cross section of the diseased human coronary artery before and after decalcification, and calculate the lumen area of both samples.

Anomalous Origin of Left Coronary Artery from Pulmonary Artery (ALCAPA)

International Nuclear Information System (INIS)

Younus, Z.; Ahmed, I.; Iftikhar, R.

2013-01-01

Anomalous origin of the left coronary artery from the pulmonary artery also recognized as Bland White Garland syndrome is a very rare congenital condition. A two-months old baby boy presented with dyspnoea for two weeks and a pansystolic murmur on auscultation. The base line investigations showed cardiomegaly and bilateral basal haze on X-ray chest. ECG showed ST elevation in leads l and AVl and echocardiography showed situs solitus, levocardia, hypokinetic intraventricular septum, ejection fraction of 30%, mitral regurgitation of grade-I and an anomalous origin of the left coronary artery from pulmonary artery was diagnosed. Patient was in left heart failure. It was rectified surgically by creating a transpulmonary tunnel (Takeuchi repair). Postoperative course was uneventful and he was finally discharged in stable condition. (author)

Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment

International Nuclear Information System (INIS)

Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji; Abe, Takashi; Harada, Masafumi; Yamamoto, Nobuaki; Kaji, Ryuji

2017-01-01

Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)

Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment

Energy Technology Data Exchange (ETDEWEB)

Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji [Tokushima University Graduate School, Department of Neurosurgery, Tokushima (Japan); Abe, Takashi; Harada, Masafumi [Tokushima University Graduate School, Department of Radiology, Tokushima (Japan); Yamamoto, Nobuaki; Kaji, Ryuji [Tokushima University Graduate School, Department of Clinical Neurosciences, Institute of Biomedical Biosciences, Tokushima (Japan)

2017-06-15

Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)

Pharmacological modulation of arterial stiffness.

LENUS (Irish Health Repository)

Boutouyrie, Pierre

2011-09-10

Arterial stiffness has emerged as an important marker of cardiovascular risk in various populations and reflects the cumulative effect of cardiovascular risk factors on large arteries, which in turn is modulated by genetic background. Arterial stiffness is determined by the composition of the arterial wall and the arrangement of these components, and can be studied in humans non-invasively. Age and distending pressure are two major factors influencing large artery stiffness. Change in arterial stiffness with drugs is an important endpoint in clinical trials, although evidence for arterial stiffness as a therapeutic target still needs to be confirmed. Drugs that independently affect arterial stiffness include antihypertensive drugs, mostly blockers of the renin-angiotensin-aldosterone system, hormone replacement therapy and some antidiabetic drugs such as glitazones. While the quest continues for \\'de-stiffening drugs\\

Cardiac magnetic resonance imaging-derived pulmonary artery distensibility index correlates with pulmonary artery stiffness and predicts functional capacity in patients with pulmonary arterial hypertension

International Nuclear Information System (INIS)

Kang, Ki-Woon; Chang, Hyuk-Jae; Kim, Young-Jin; Choi, Byoung-Wook; Yang, Woo-In; Shim, Chi-Young; Ha, Jongwon; Chung, Namsik; Lee, Hye-Sun

2011-01-01

Increased stiffness of the pulmonary vascular bed is known to increase mortality in patients with pulmonary arterial hypertension (PAH); and pulmonary artery (PA) stiffness is also thought to be associated with exercise capacity. The purpose of the present study was to investigate whether cardiac magnetic resonance imaging (CMRI)-derived PA distensibility index correlates with PA stiffness estimated on right heart catheterization (RHC) and predicts functional capacity (FC) in patients with PAH. Thirty-five consecutive PAH patients (23% male, mean age, 44±13 years; 69% idiopathic) underwent CMRI, RHC, and 6-min walk test (6MWT). PA distensibility indices were derived from cross-sectional area change (%) in the transverse view, perpendicular to the axis of the main PA, on CMRI [(maximum area-minimum area)/minimum area during cardiac cycle]. Among the PA stiffness indices, pulmonary vascular resistance (PVR) and PA capacitance were calculated using hemodynamic dataset from RHC. CMRI-derived PA distensibility was inversely correlated with PVR (R 2 =0.34, P 2 =0.35, P 2 =0.61, P<0.001). Furthermore, PA distensibility <20% predicted poor FC (<400 m in 6MWT) with a sensitivity of 82% and a specificity of 94%. Non-invasive CMRI-derived PA distensibility index correlates with PA stiffness and can predict FC in patients with PAH. (author)

Frequency and predictors of renal artery stenosis in patients with coronary artery disease

International Nuclear Information System (INIS)

Shah, S.S.; Hafeezullah, M.

2010-01-01

Background: Renal artery stenosis (RAS) is a common finding in patients undergoing coronary angiography. We designed this study to look for the frequency and any predictors of renal artery stenosis in patients with coronary artery disease (CAD). Methods: A total of 201 consecutive patients with CAD confirmed by coronary angiography underwent an abdominal aortogram in the same sitting to screen for RAS. Patient demographics and co-morbidities were analysed for any association with RAS. Results: Forty-one of the patients were female (20.4%); ninety patients were hypertensive (44.8%); 49 patients (24.4%) were smokers; 19 patients (9.5%) had renal insufficiency; 88 patients (43.8%) had high cholesterol levels; 44 patients (21.9%) were diabetic. Thirty-two patients (15.9%) had single coronary artery disease, 59 patients (29.4%) had two vessel disease, and 110 patients (54.7%) had three vessel disease. Significant renal artery stenosis (less or equal to 50% stenosis) was present in 26 patients (12.9%). Among the variables studied, only female gender was found to be associated with a higher frequency of renal artery stenosis (24.39% vs 10.0%, p=0.01). Conclusions: The frequency of renal artery stenosis in patients with coronary artery disease is 12.9%. Female gender is associated with a higher frequency of renal artery stenosis in patients with CAD. (author)

Coronary Artery Anomalies in Animals

Directory of Open Access Journals (Sweden)

Brian A. Scansen

2017-04-01

Full Text Available Coronary artery anomalies represent a disease spectrum from incidental to life-threatening. Anomalies of coronary artery origin and course are well-recognized in human medicine, but have received limited attention in veterinary medicine. Coronary artery anomalies are best described in the dog, hamster, and cow though reports also exist in the horse and pig. The most well-known anomaly in veterinary medicine is anomalous coronary artery origin with a prepulmonary course in dogs, which limits treatment of pulmonary valve stenosis. A categorization scheme for coronary artery anomalies in animals is suggested, dividing these anomalies into those of major or minor clinical significance. A review of coronary artery development, anatomy, and reported anomalies in domesticated species is provided and four novel canine examples of anomalous coronary artery origin are described: an English bulldog with single left coronary ostium and a retroaortic right coronary artery; an English bulldog with single right coronary ostium and transseptal left coronary artery; an English bulldog with single right coronary ostium and absent left coronary artery with a prepulmonary paraconal interventricular branch and an interarterial circumflex branch; and a mixed-breed dog with tetralogy of Fallot and anomalous origin of all coronary branches from the brachiocephalic trunk. Coronary arterial fistulae are also described including a coronary cameral fistula in a llama cria and an English bulldog with coronary artery aneurysm and anomalous shunting vessels from the right coronary artery to the pulmonary trunk. These examples are provided with the intent to raise awareness and improve understanding of such defects.

Prevalence of significant carotid artery stenosis in Iranian patients with peripheral arterial disease

Directory of Open Access Journals (Sweden)

Ghabili K

2011-10-01

Full Text Available Abolhassan Shakeri Bavil1, Kamyar Ghabili2, Seyed Ebrahim Daneshmand3, Masoud Nemati3, Moslem Shakeri Bavil4, Hossein Namdar5, Sheyda Shaafi61Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; 2Medical Philosophy and History Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; 3Department of Radiology, Tabriz University of Medical Sciences, Tabriz, Iran; 4Department of Neurosurgery, Tabriz University of Medical Sciences, Tabriz, Iran; 5Department of Cardiology, Tabriz University of Medical Sciences, Tabriz, Iran; 6Neuroscience Research Center, Tabriz University of Medical Sciences, Tabriz, IranBackground: Generalized screening for carotid artery stenosis with carotid duplex ultrasonography in patients with peripheral arterial disease is controversial.Objectives: The aim of the present study was to determine the prevalence of significant internal carotid artery (ICA stenosis in a group of Iranian patients with peripheral arterial disease.Methods: We prospectively screened 120 patients with a known diagnosis of peripheral vascular disease for carotid artery stenosis. Based on the angiographic assessment of abdominal aorta and arteries of the lower extremities, patients with stenosis greater than 70% in the lower extremity arteries were included. A group of healthy individuals aged ≥50 years was recruited as a control. Risk factors for atherosclerosis including smoking, diabetes mellitus, hyperlipidemia, ischemic heart disease, and cerebrovascular disease were recorded. Common carotid arteries (CCAs and the origins of the internal and external arteries were scanned with B-mode ultrasonogaphy. Significant ICA stenosis, >70% ICA stenosis but less than near occlusion of the ICA, was diagnosed when the ICA/CCA peak systolic velocity ratio was ≥3.5.Results: Ninety-five patients, with a mean age of 58.52 ± 11.04 years, were studied. Twenty-five patients had a history of smoking, six

Correlations between the Poincaré plot and conventional heart rate variability parameters assessed during paced breathing

NARCIS (Netherlands)

Guzik, P.; Piskorski, J.; Krauze, T.; Schneider, R.; Wesseling, K.H.; Wykrȩtowicz, A.; Wysocki, H.

2007-01-01

Aim: To analyze the correlation of the Poincaré plot descriptors of RR intervals with standard measures of heart rate variability (HRV) and spontaneous baroreflex sensitivity (BRS). A physiological model of changing respiratory rates from 6 to 15 breaths/min provided a wide range of RR intervals for

MRI in giant cell (temporal) arteritis; Magnetresonanztomografie der Arteriitis temporalis Horton

Energy Technology Data Exchange (ETDEWEB)

Bley, T.A.; Uhl, M.; Frydrychowicz, A.; Langer, M. [Uniklinik Freiburg (Germany). Roentgendiagnostik; Markl, M. [Uniklinik Freiburg (Germany). Roentgendiagnostik - Medizinische Physik

2007-07-15

Giant cell (temporal) arteritis is a diagnostic challenge. Blindness is a dreaded complication, especially if high-dose steroid treatment is delayed. With an optimized MR protocol, noninvasive diagnosis of giant cell arteritis is facilitated. Submillimeter in-plane resolution makes it possible to distinguish healthy segments from inflamed segments. The lumen and arterial wall can be depicted in high detail. Post-contrast high-resolution MRI visualizes the superficial cranial arteries bilaterally and simultaneously, allowing assessment of the cranial involvement pattern. In combination with MR angiography of the aortic arch and supra-aortic arteries, the extracranial involvement pattern can be demonstrated in a single comprehensive MR examination assessing the cranial, cervical and thoracic vasculature. Good diagnostic image quality can be achieved at 1.5 Tesla and at 3 Tesla. However, due to higher signal-to-noise ratios, image quality seems to be superior at 3 Tesla. Over the course of successful long-term treatment, MR signs of mural inflammation decrease significantly and eventually vanish entirely. In contrast to color-coded Duplex sonography, which is a comparatively cost-efficient imaging modality, acquisition of high-resolution MRI is almost independent of the investigator's expertise. Compared to positron emission tomography with 18F-fluoro-2-deoxy-D-glucose, which is a very sensitive whole-body screening tool for detecting extracranial involvement of large vessel vasculitis, MRI allows visualization and assessment of both the superficial cranial arteries in high detail and the extracranial large artery involvement in the same investigation. (orig.)

Anatomic distribution of renal artery stenosis in children: implications for imaging.

Science.gov (United States)

Vo, Nghia J; Hammelman, Ben D; Racadio, Judy M; Strife, C Frederic; Johnson, Neil D; Racadio, John M

2006-10-01

Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty.

Anatomic distribution of renal artery stenosis in children: implications for imaging

Energy Technology Data Exchange (ETDEWEB)

Vo, Nghia J.; Racadio, Judy M.; Johnson, Neil D. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Division of Pediatric Interventional Radiology, Cincinnati, OH (United States); Hammelman, Ben D. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Strife, C.F. [Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Division of Nephrology and Hypertension, Cincinnati, OH (United States); Racadio, John M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Division of Pediatric Interventional Radiology, Cincinnati, OH (United States); Cincinnati Children' s Hospital, Department of Radiology, Cincinnati, OH (United States)

2006-10-15

Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty. (orig.)

Anatomic distribution of renal artery stenosis in children: implications for imaging

International Nuclear Information System (INIS)

Vo, Nghia J.; Racadio, Judy M.; Johnson, Neil D.; Hammelman, Ben D.; Strife, C.F.; Racadio, John M.

2006-01-01

Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty. (orig.)

Establishing experimental model of human internal carotid artery siphon segment in canine common carotid artery

International Nuclear Information System (INIS)

Cui Xuee; Li Minghua; Wang Yongli; Cheng Yingsheng; Li Wenbin

2005-01-01

Objective: To study the feasibility of establishing experimental model of human internal carotid artery siphon segment in canine common carotid artery (CCA) by end-to-end anastomoses of one side common carotid artery segment with the other side common carotid artery. Methods: Surgical techniques were used to make siphon model in 8 canines. One side CCA was taken as the parent artery and anastomosing with the cut off contra-lateral CCA segment which has passed through within the S-shaped glass tube. Two weeks after the creation of models angiography showed the model siphons were patent. Results: Experimental models of human internal carotid artery siphon segment were successfully made in all 8 dogs. Conclusions: It is practically feasible to establish experimental canine common carotid artery models of siphon segment simulating human internal carotid artery. (authors)

Hemodynamic effects of innominate artery occlusive disease on anterior cerebral artery.

Science.gov (United States)

Tan, Teng-Yeow; Lien, Li-Ming; Schminke, Ulf; Tesh, Paul; Reynolds, Patrick S; Tegeler, Charles H

2002-01-01

Stenoses of the innominate artery (IA) may affect flow conditions in the carotid arteries. However, alternating flow in ipsilateral anterior cerebral artery (ACA) due to IA stenosis is extremely rare. A 49-year-old woman who was evaluated for symptomatic cerebrovascular disease presented with right latent subclavian and right carotid system steal. Transcranial Doppler examination displayed systolic deceleration wave-forms in the right terminal internal carotid artery and alternating flow in the right ACA. Magnetic resonance angiography demonstrated tight stenosis of the right IA. For a thorough study of the hemodynamic effects of IA stenosis, a combination of duplex and transcranial Doppler examination is required.

Jet pump assisted artery

Science.gov (United States)

1975-01-01

A procedure for priming an arterial heat pump is reported; the procedure also has a means for maintaining the pump in a primed state. This concept utilizes a capillary driven jet pump to create the necessary suction to fill the artery. Basically, the jet pump consists of a venturi or nozzle-diffuser type constriction in the vapor passage. The throat of this venturi is connected to the artery. Thus vapor, gas, liquid, or a combination of the above is pumped continuously out of the artery. As a result, the artery is always filled with liquid and an adequate supply of working fluid is provided to the evaporator of the heat pipe.

Evaluation of Contrast MR Angiography in the Study of Internal Carotid Artery Stenosis. Systematic Review of the Literature

International Nuclear Information System (INIS)

Rodriguez Perez, P.; Martinez Cantarero, J.; Ruiz Diaz, M.; Blazquez Morera, J. A.; Llano Senaris, J. E. de

2004-01-01

To evaluate the diagnostic benefit of using contrast MR Angiography (MRA) in the study of extracranial internal carotid artery stenosis as opposed to intraarterial digital subtraction arteriography (LADSA). A search for relevant articles from 1990 to 2000 using MDLINE and EMBASE databases. Initial selection criteria: 1. articles which compare MRA and IADSA in the study of extracranial internal carotid artery stenosis; and 2, sample size of 10 or more subjects. Studies employing contrast MRA were subsequently selected. Contrast MRA diagnostic results were studied, as were those of non-contrast MRA (TOF) if included. Roc curves and 95% confidence intervals were calculated. In the studies, 324 patients and 648 extracranial internal carotid arteries were evaluated (12 articles). The diagnostic results in carotid artery stenosis discrimination using contrast MRA as opposed to IADSA were sensitivity and specificity=97.28% and 96.08%. With regard to contrast MRA vs. non-contrast MRA (TOF), significant differences favoring contrast MRA in both sensitivity and specificity were observed. (p=0.08 and p<0.001, respectively). MRA techniques demonstrate very high diagnostic capabilities in the detection of carotid stenosis, with contrast MRA being more effective than non-contrast. MRA. In spite of not being superior to IADSA, given the morbimortality risk which the latter is associated (0.7-1.2%). many authors defend contrast MRA (in association with Doppler echography) having become the method of choice for presurgical study of extracranial internal carotid artery stenosis. (Author) 53 refs

Calcified Plaque of Coronary Artery: Factors Influencing Overestimation of Coronary Artery Stenosis on Coronary CT Angiography

International Nuclear Information System (INIS)

Kim, Mok Hee; Kim, Yun Hyeon; Choi, Song; Seon, Hyun Ju; Jeong, Gwang Woo; Park, Jin Gyoon; Kang, Heoung Keun; Ko, Joon Seok

2010-01-01

To assess the influence of calcified plaque characteristics on the overestimation of coronary arterial stenosis on a coronary CT angiography (CCTA). The study included 271 coronary arteries with calcified plaques identified by CCTA, and based on 928 coronary arteries from 232 patients who underwent both CCTA and invasive coronary angiography (ICA). Individual coronary arteries were classified into two groups by agreement based on the degree of stenosis from each CCTA and ICA: 1) group A includes patients with concordant CCTA and ICA results and, 2) group B includes patients with an overestimation of CCTA compared to ICA. Parameters including total calcium score, calcium score of an individual coronary artery, calcium burden number of an individual coronary artery, and the density of each calcified plaque (calcium score / number of calcium burden) for each individual coronary artery were compared between the two groups. Of the 271 coronary arteries, 164 (60.5%) were overestimated on CCTA. The left anterior descending artery (LAD) had a significantly low rate of overestimation (47.1%) compared to the other coronary arteries (p=0.001). No significant differences for total calcium score, calcium score of individual coronary artery, and the density of each calcified plaque from individual coronary arteries between two groups was observed. However, a decreasing tendency for the rate of overestimation on CCTA was observed with an increase in calcium burden of individual coronary arteries (p<0.05). The evaluation of coronary arteries suggests that the degree of coronary arterial stenosis had a tendency to be overestimated by calcified plaques on CCTA. However, the rate of overestimation for the degree of coronary arterial stenosis by calcified plaques was not significantly influenced by total calcium score, calcium score of individual coronary artery, and density of each calcified plaque

Bilateral renal artery variation

OpenAIRE

Üçerler, Hülya; Üzüm, Yusuf; İkiz, Z. Aslı Aktan

2014-01-01

Each kidney is supplied by a single renal artery, although renal artery variations are common. Variations of the renal arteryhave become important with the increasing number of renal transplantations. Numerous studies describe variations in renalartery anatomy. Especially the left renal artery is among the most critical arterial variations, because it is the referred side forresecting the donor kidney. During routine dissection in a formalin fixed male cadaver, we have found a bilateral renal...

Perforating arteries originating from the posterior communicating artery: a 7.0-Tesla MRI study

Energy Technology Data Exchange (ETDEWEB)

Conijn, Mandy M.A.; Hendrikse, Jeroen; Takahara, Taro; Mali, Willem P.T.M. [University Medical Center Utrecht, Department of Radiology (Hp E 01.132), P.O. Box 85500, Utrecht (Netherlands); Zwanenburg, Jaco J.M. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Geerlings, Mirjam I. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Luijten, Peter R. [University Medical Center Utrecht, Department of Radiology (Hp E 01.132), P.O. Box 85500, Utrecht (Netherlands); University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)

2009-12-15

The aim of this study was to investigate the ability of time-of-flight (TOF) magnetic resonance (MR) angiography at 7.0 Tesla to show the perforating branches of the posterior communicating artery (PCoA), and to investigate the presence of such visible perforating branches in relation to the size of the feeding PCoA. The secondary aim was to visualise and describe the anterior choroidal artery and the perforating branches of the P1-segment of posterior cerebral artery (P1). Forty-six healthy volunteers underwent TOF MR angiography at 7.0 Tesla. With 7.0-Tesla imaging, we visualised for the first time perforating arteries originating from the PCoA in vivo without the use of contrast agents. A perforating artery from the PCoA was found in a large proportion of the PCoAs (64%). The presence was associated with a larger diameter of the underlying PCoA (1.23 versus 1.06 mm, P = 0.03). The anterior choroidal artery was visible bilaterally in all participants. In 83% of all P1s, one or two perforating branches were visible. Non-invasive assessment of the perforating arteries of the PCoA together with the anterior choroidal artery and the perforating arteries of the P1 may increase our understanding of infarcts in the deep brain structures supplied by these arteries. (orig.)

Perforating arteries originating from the posterior communicating artery: a 7.0-Tesla MRI study

International Nuclear Information System (INIS)

Conijn, Mandy M.A.; Hendrikse, Jeroen; Takahara, Taro; Mali, Willem P.T.M.; Zwanenburg, Jaco J.M.; Geerlings, Mirjam I.; Luijten, Peter R.

2009-01-01

The aim of this study was to investigate the ability of time-of-flight (TOF) magnetic resonance (MR) angiography at 7.0 Tesla to show the perforating branches of the posterior communicating artery (PCoA), and to investigate the presence of such visible perforating branches in relation to the size of the feeding PCoA. The secondary aim was to visualise and describe the anterior choroidal artery and the perforating branches of the P1-segment of posterior cerebral artery (P1). Forty-six healthy volunteers underwent TOF MR angiography at 7.0 Tesla. With 7.0-Tesla imaging, we visualised for the first time perforating arteries originating from the PCoA in vivo without the use of contrast agents. A perforating artery from the PCoA was found in a large proportion of the PCoAs (64%). The presence was associated with a larger diameter of the underlying PCoA (1.23 versus 1.06 mm, P = 0.03). The anterior choroidal artery was visible bilaterally in all participants. In 83% of all P1s, one or two perforating branches were visible. Non-invasive assessment of the perforating arteries of the PCoA together with the anterior choroidal artery and the perforating arteries of the P1 may increase our understanding of infarcts in the deep brain structures supplied by these arteries. (orig.)

Perforating arteries originating from the posterior communicating artery: a 7.0-Tesla MRI study.

Science.gov (United States)

Conijn, Mandy M A; Hendrikse, Jeroen; Zwanenburg, Jaco J M; Takahara, Taro; Geerlings, Mirjam I; Mali, Willem P Th M; Luijten, Peter R

2009-12-01

The aim of this study was to investigate the ability of time-of-flight (TOF) magnetic resonance (MR) angiography at 7.0 Tesla to show the perforating branches of the posterior communicating artery (PCoA), and to investigate the presence of such visible perforating branches in relation to the size of the feeding PCoA. The secondary aim was to visualise and describe the anterior choroidal artery and the perforating branches of the P1-segment of posterior cerebral artery (P1). Forty-six healthy volunteers underwent TOF MR angiography at 7.0 Tesla. With 7.0-Tesla imaging, we visualised for the first time perforating arteries originating from the PCoA in vivo without the use of contrast agents. A perforating artery from the PCoA was found in a large proportion of the PCoAs (64%). The presence was associated with a larger diameter of the underlying PCoA (1.23 versus 1.06 mm, P = 0.03). The anterior choroidal artery was visible bilaterally in all participants. In 83% of all P1s, one or two perforating branches were visible. Non-invasive assessment of the perforating arteries of the PCoA together with the anterior choroidal artery and the perforating arteries of the P1 may increase our understanding of infarcts in the deep brain structures supplied by these arteries.

Choice of marker for assessment of RV dysfunction in acute pulmonary embolism : NT-proBNP, pulmonary artery systolic pressure, mean arterial pressure, or blood pressure index.

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Ates, H; Ates, I; Kundi, H; Yilmaz, F M

2017-12-01

We aimed to examine the value of NT-proBNP, pulmonary artery systolic pressure (PASP), blood pressure index (BPI), and mean arterial pressure (MAP) in the determination of right ventricular dysfunction (RVD) in patients with acute pulmonary embolism (APE). A total of 547 patients diagnosed with APE were included in the study. Demographic characteristics and comorbid conditions of patients were recorded in patient files. For blood pressure measurement, a calibrated digital blood pressure monitor was used at regular intervals. Blood samples were taken from patients at the time of admission for hemogram, biochemical, and hemostasis blood tests. Echocardiography was performed on all patients to detect RVD and evaluate pulmonary artery pressure. PASP (p blood pressure (p blood cell (p AUC ± SE = 0.975 ± 0.006; p < 0.001) was found to be the best predictor of RVD with a higher sensitivity (92.8%) and specificity (100%). We found that BPI had a better diagnostic discrimination for RVD compared with PASP and NT-proBNP.

MRI in coronary artery disease

International Nuclear Information System (INIS)

Barkhausen, Joerg; Hunold, Peter; Waltering, Kai-Uwe

2004-01-01

Diagnosis of coronary artery disease (CAD) is a major challenge for medical imaging, because CAD is the leading cause of death in developed nations. Several non-invasive tests are used in clinical routine for the detection of CAD. However, due to limited sensitivity and specificity, the reliable diagnosis as well as the exclusion of CAD can only be established by catheter angiography. In patients with known CAD, therapeutic decisions require accurate information on myocardial function, ischemia and viability. Recently, magnetic resonance (MR) imaging has emerged as a non-invasive cardiac imaging technique that provides information on cardiac morphology, cardiac function, myocardial viability, and coronary morphology. This review discusses technical aspects and the clinical impact of different MR techniques. (orig.)

Physiological basis for human autonomic rhythms

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Eckberg, D. L.

2000-01-01

Oscillations of arterial pressures, heart periods, and muscle sympathetic nerve activity have been studied intensively in recent years to explore otherwise obscure human neurophysiological mechanisms. The best-studied rhythms are those occurring at breathing frequencies. Published evidence indicates that respiratory fluctuations of muscle sympathetic nerve activity and electrocardiographic R-R intervals result primarily from the action of a central 'gate' that opens during expiration and closes during inspiration. Parallel respiratory fluctuations of arterial pressures and R-R intervals are thought to be secondary to arterial baroreflex physiology: changes in systolic pressure provoke changes in the R-R interval. However, growing evidence suggests that these parallel oscillations result from the influence of respiration on sympathetic and vagal-cardiac motoneurones rather than from baroreflex physiology. There is a rapidly growing literature on the use of mathematical models of low- and high-frequency (respiratory) R-R interval fluctuations in characterizing instantaneous 'sympathovagal balance'. The case for this approach is based primarily on measurements made with patients in upright tilt. However, the strong linear relation between such measures as the ratio of low- to high-frequency R-R interval oscillations and the angle of the tilt reflects exclusively the reductions of the vagal (high-frequency) component. As the sympathetic component does not change in tilt, the low- to high-frequency R-R interval ratio provides no proof that sympathetic activity increases. Moreover, the validity of extrapolating from measurements performed during upright tilt to measurements during supine rest has not been established. Nonetheless, it is clear that measures of heart rate variability provide important prognostic information in patients with cardiovascular diseases. It is not known whether reduced heart rate variability is merely a marker for the severity of disease or a

Isolated anomalous origin of the vertebral artery from the common carotid artery.

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Kesler, William W; Sabat, Shyamsunder B

2018-04-18

Anomalous origins of the vertebral arteries are uncommon and typically associated with other abnormalities of the great vessels. We present a case of an isolated origin of the right vertebral artery from the ipsilateral common carotid artery detected using magnetic resonance angiography. Such variants can significantly affect endovascular and surgical planning.

Central retinal and posterior ciliary artery occlusion after particle embolization of the external carotid artery system.

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Mames, R N; Snady-McCoy, L; Guy, J

1991-04-01

A 15-year-old boy underwent neuroradiologic embolization of the left internal maxillary artery with polyvinyl alcohol to stop traumatic epistaxis after failure of surgical clipping and nasal packing. Selective catheterization of the external carotid artery before embolization showed a faint choroidal blush. Although the procedure provided hemostasis, embolization to the central retinal artery and ciliary arteries resulted in loss of vision. The route of the emboli to the eye was via the anastomotic network of the lacrimal artery supplied by the external carotid artery system. Neuroradiologic embolization of the external carotid artery is an effective mode of therapy for dural-cavernous fistulas when fed by the external carotid artery system. Because the blood flow to the brain and eye is predominantly supplied by the internal carotid artery, embolization of the external carotid artery is considered relatively safe. The authors document the importance of recognition of the choroidal blush during selective external carotid artery angiography as a sign of collateral blood flow to the eye. Physicians and patients need to be aware of the risk of blindness as a complication of external carotid artery embolization when this sign is present.

An unreported type of coronary artery naomaly in congenitally corrected transposition of great arteries

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Kwak, Min Kyu; Jeong, Yeon Joo; Lee, Gee Won; Lee, Nam Kyung; Choi, Jung Hyun; Lee, Ji Won [Medical Research Institute, Pusan National University Hospital, Busan (Korea, Republic of)

2016-07-15

Coronary artery variations are associated anomalies in 45% of congenitally corrected transposition of the great arteries (ccTGA) cases, and it is important to detect any coronary artery anomalies before cardiac surgery. We report a case of a 51-year-old woman with ccTGA and an unreported type of coronary artery anomaly.

Missed Total Occlusion Due to the Occipital Artery Arising from the Internal Carotid Artery

International Nuclear Information System (INIS)

Ustunsoz, Bahri; Gumus, Burcak; Koksal, Ali; Koroglu, Mert; Akhan, Okan

2007-01-01

A 56-year-old man was referred for digital subtraction angiography (DSA) with an ultrasound diagnosis of right proximal internal carotid artery (ICA) stenosis for possible carotid artery stenting. DSA revealed total occlusion of the ICA and an occipital artery arising from the stump and simulating continuation of the ICA. An ascending pharyngeal artery also arose from the same occipital artery. This case is of interest because this is a rare variation besides being a cause of misdiagnosis at carotid ultrasound

Efficacy of plain radiography and computer tomography in localizing the site of pelvic arterial bleeding in trauma patients

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Dormagen, Johann B. (Dept. of Radiology, Oslo Univ. Hospital, Ullevaal, Oslo (Norway)), e-mail: johannd@medisin.uio.no; Toetterman, Anna (Dept. of Orthopedic Surgery, Uppsala Univ. Hospital, Uppsala (Sweden)); Roeise, Olav (Div. of Neuroscience and Musculoskeletal Medicine, Oslo Univ. Hospital, Ullevaal, Oslo (Norway)); Sandvik, Leiv (Center for Clinical Research, Oslo Univ. Hospital, Ullevaal, Oslo (Norway)); Kloew, Nils-E. (Dept. of Cardiovascular Radiology, Oslo Univ. Hospital - Ullevaal, Oslo (Norway))

2010-01-15

Background: Immediate angiography is warranted in pelvic trauma patients with suspected arterial injury (AI) in order to stop ongoing bleeding. Prior to angiography, plain pelvic radiography (PPR) and abdominopelvic computer tomography (CT) are performed to identify fracture and hematoma sites. Purpose: To investigate if PPR and CT can identify the location of AI in trauma patients undergoing angiography. Material and Methods: 95 patients with pelvic fractures on PPR (29 women, 66 men), at a mean age of 44 (9-92) years, underwent pelvic angiography for suspected AI. Fifty-six of them underwent CT additionally. Right and left anterior and posterior fractures on PPR were registered, and fracture displacement was recorded for each quadrant. Arterial blush on CT was registered, and the size of the hematoma in each region was measured in cm2. AIs were registered for anterior and posterior segments of both internal iliac arteries. Presence of fractures, arterial blush, and hematomas were correlated with AI. Results: Presence of fracture in the corresponding skeletal segment on PPR showed sensitivity and specificity of 0.86 and 0.58 posteriorly, and 0.87 and 0.44 anteriorly. The area under the curve (AUC) was 0.77 and 0.69, respectively. Fracture displacement on PPR >0.9 cm posteriorly and >1.9 cm anteriorly revealed specificity of 0.84. Sensitivities of arterial blush and hematoma on CT were 0.38 and 0.82 posteriorly, and 0.24 and 0.82 anteriorly. The specificities were 0.96 and 0.58 posteriorly, and 0.79 and 0.53 anteriorly, respectively. For hematomas, the AUC was 0.79 posteriorly and 0.75 anteriorly. Size of hematoma >22 cm2 posteriorly and >29 cm2 anteriorly revealed specificity of 0.85 and 0.86, respectively. Conclusion: CT findings of arterial blush and hematoma predicted site of arterial bleeding on pelvic angiography. Also, PPR predicted the site of bleeding using location of fracture and size of displacement. In the hemodynamically unstable patient, PPR may

Efficacy of plain radiography and computer tomography in localizing the site of pelvic arterial bleeding in trauma patients.

Science.gov (United States)

Dormagen, Johann B; Tötterman, Anna; Røise, Olav; Sandvik, Leiv; Kløw, Nils-E

2010-02-01

Immediate angiography is warranted in pelvic trauma patients with suspected arterial injury (AI) in order to stop ongoing bleeding. Prior to angiography, plain pelvic radiography (PPR) and abdominopelvic computer tomography (CT) are performed to identify fracture and hematoma sites. To investigate if PPR and CT can identify the location of AI in trauma patients undergoing angiography. 95 patients with pelvic fractures on PPR (29 women, 66 men), at a mean age of 44 (9-92) years, underwent pelvic angiography for suspected AI. Fifty-six of them underwent CT additionally. Right and left anterior and posterior fractures on PPR were registered, and fracture displacement was recorded for each quadrant. Arterial blush on CT was registered, and the size of the hematoma in each region was measured in cm(2). AIs were registered for anterior and posterior segments of both internal iliac arteries. Presence of fractures, arterial blush, and hematomas were correlated with AI. Presence of fracture in the corresponding skeletal segment on PPR showed sensitivity and specificity of 0.86 and 0.58 posteriorly, and 0.87 and 0.44 anteriorly. The area under the curve (AUC) was 0.77 and 0.69, respectively. Fracture displacement on PPR >0.9 cm posteriorly and >1.9 cm anteriorly revealed specificity of 0.84. Sensitivities of arterial blush and hematoma on CT were 0.38 and 0.82 posteriorly, and 0.24 and 0.82 anteriorly. The specificities were 0.96 and 0.58 posteriorly, and 0.79 and 0.53 anteriorly, respectively. For hematomas, the AUC was 0.79 posteriorly and 0.75 anteriorly. Size of hematoma >22 cm(2) posteriorly and >29 cm(2) anteriorly revealed specificity of 0.85 and 0.86, respectively. CT findings of arterial blush and hematoma predicted site of arterial bleeding on pelvic angiography. Also, PPR predicted the site of bleeding using location of fracture and size of displacement. In the hemodynamically unstable patient, PPR may contribute equally to effective assessment of injured arteries.

Modulation of Cardiac Autonomic Dysfunction in Ischemic Stroke following Ayurveda (Indian System of Medicine Treatment

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Sriranjini Sitaram Jaideep

2014-01-01

Full Text Available Objectives. Cardiac autonomic dysfunction in stroke has implications on morbidity and mortality. Ayurveda (Indian system of medicine describes stroke as pakshaghata. We intended to study the effect of Ayurveda therapies on the cardiac autonomic dysfunction. Methods. Fifty patients of ischemic stroke (middle cerebral artery territory (mean age 39.26 ± 9.88 years; male 43, female 7 were recruited within one month of ictus. All patients received standard allopathic medications as advised by neurologist. In addition, patients were randomized to receive physiotherapy (Group I or Ayurveda treatment (Group II for 14 days. Continuous electrocardiogram and finger arterial pressure were recorded for 15 min before and after treatments and analyzed offline to obtain heart rate and blood pressure variability and baroreflex sensitivity (BRS. Results were analysed by RMANOVA. Results. Patients in Group II showed statistically significant improvement in cardiac autonomic parameters. The standard deviation of normal to normal intervals,and total and low frequency powers were significantly enhanced (F=8.16, P=0.007, F=9.73, P=0.004, F=13.51, and P=0.001, resp.. The BRS too increased following the treatment period (F=10.129, P=0.004. Conclusions. The current study is the first to report a positive modulation of cardiac autonomic activity after adjuvant Ayurveda treatment in ischemic stroke. Further long term studies are warranted.

Surco diagonal en el lóbulo de la oreja: ¿signo de enfermedad arterial coronaria? Diagonal earlobe crease: a sign of coronary artery disease?

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Sebastián B. Lamot

2007-08-01

Full Text Available El surco diagonal es un signo encontrado en el lóbulo de la oreja, que estaría relacionado con la enfermedad arterial coronaria. Nuestro objetivo fue estudiar la utilidad del signo. Se examinaron 104 pacientes (entre 30 y 80 años clasificados por sexo y edad. Cuarenta y nueve tenían enfermedad arterial coronaria diagnosticada por coronariografía (obstrucción > del 70% en una de las grandes arterias y/o gamagrafía de perfusión miocárdica con Talio 201 (defecto fijo. El grupo control estuvo compuesto por 55 pacientes (asintomáticos, con electrocardiograma normal. Los datos obtenidos fueron sensibilidad (61.2%, especificidad (78.2%, valor predictivo positivo de (71.4% y valor predictivo negativo (69.3%.. Observamos una relación significativa entre la presencia de surco diagonal y enfermedad arterial coronaria. Consideramos que este signo podría resultar de utilidad en la práctica clínica, fundamentalmente para los pacientes entre 30 y 60 años.The diagonal earlobe crease is a sign theorically related to coronary artery disease. The purpose of this study was to prove the usefulness of this sign. A total of 104 patients were examined (ages 30 to 80 grouped by age and sex. Forty nine of them were diagnosed of having coronary artery disease by coronary angiography (a 70% obstruction of one of the major arteries, and/or myocardial perfusion imaging with Thallium 201 (fixed defects. The control group included 55 patients (asymptomatic with normal electrocardiogram. Data here obtained included sensitivity (61.2%, specificity (78.2%, positive predictive value (71.4% and negative predictive value (69.3%. We found a significant relation between the presence of the diagonal earlobe crease and coronary artery disease. We consider it a sign that could prove useful in clinical practice, mainly among patients aged between 30 and 60.

Segmental quantitative analysis of digital thallium-201 myocardial scintigrams in diagnosis of coronary artery disease

International Nuclear Information System (INIS)

Wainwright, R.J.; Maisey, M.N.; Sowton, E.

1981-01-01

One hundred and forty-nine patients with suspected ischaemic heart disease were evaluated by exercise thallium-201 myocardial scintigraphy ( 201 Tl SMS), single lead exercise electrocardiography, and coronary arteriography. Myocardial distribution of tracer was assessed semi-quantitatively from digital 201 Tl scintigrams and compared with tracer distribution in subjects with normal hearts. Fifty-two of 54 (96%) patients with normal coronary arteries had normal myocardial scintigrams whereas three patients had a positive ischaemic exercise electrocardiogram and were scan normal. Conversely, 36 of 95 (38%) patients with coronary artery disease had a positive ischaemic electrocardiogram compared with 94 of 95 (99%) patients who had a positive myocardial scintigram. Disease was predicted correctly in 76 out of 80 (95%) of left anterior descending coronary stenoses, in 48 out of 64 (75%) of right coronary artery stenoses, and in 55 out of 64 (85%) of left circumflex coronary artery stenoses, despite the presence of infarcted myocardium in other territories. 201 Tl SMS with segmental quantitative analysis is a highly sensitive and specific technique in the diagnosis of coronary artery disease and may be a useful screening procedure to select patients for further investigation, particularly those with evidence of life-threatening severe left coronary artery disease. (author)

Arterial mapping of lower limbs

International Nuclear Information System (INIS)

Acuna Allen, Rafael

2011-01-01

A bibliographic review is realized in the arterial mapping of lower limbs by ultrasonographic. The physical properties of the Doppler effect applied to diagnostic ultrasound are described. The anatomical characteristics of the general arterial system and specifically of the lower limbs arterial system are mentioned. Pathologies of the ischemic arterial disease of lower limbs are explained. The study characteristics of lower limbs arterial mapping are documented to determine its importance as appropriate method for the assessment of lower limb ischemia. An adequate arterial mapping of lower limbs is recognized in atherosclerotic ischemic disease as a reliable initial method alternative to arteriography. Arteriography is considered as reference pattern for therapeutic decision making in patients with critical ischemia of the lower limbs. Non-invasive methods to assess the arterial system of lower limbs has evidenced the advantages of the arterial mapping with Doppler, according to the consulted literature. The combination morphological and hemodynamic information has been possible and a map of the explored zone is made. The arterial mapping by ultrasonography has offered similar reliability to angiography [es

Diagnostic value of myocardial perfusion SPECT in the prediction of restenosis after coronary artery bypass graft surgery

International Nuclear Information System (INIS)

Paeng, J. C.; Lee, D. S.; Kang, W. J.; Kim, K. B.; Chung, J. K.; Lee, M. C.

2002-01-01

Myocardial SPECT has been reported to be sensitive in the detection of restenosis after revascularization. However, the diagnostic value is not well established in bypass graft surgery (CABG), due to significant influences of characteristics of graft vessels and the time interval between CABG and the SPECT. In this study, we evaluated the diagnostic value of myocardial SPECT for the restenosis after CABG. A total of 160 patients with coronary artery disease (M:F=118:42, 60±8 yr) who had undergone CABG were included. Rest T1-201/ dipyridamole stress Tc-99m-MIBI SPECT was performed 3 months (103±16 days) after CABG. Segmental perfusion was quantified using a 20-segment model, and segments of reversible perfusion defect (REV) were defined. Follow-up coronary angiography was performed 1 year (397±104 days) after CABG. The segments of REV were compared between arterial and venous graft groups. And the diagnostic power of 3-month SPECT was evaluated for the prediction of restenosis. On the 3-month SPECT, 620 segments showed REV. The segments of REV were 37% of artery-grafted segments and 36% of vein-grafted segments (p=n.s.). On 1-year coronary angiography, 113 graft vessels (28%) showed restenosis. The overall sensitivity and specificity of REV on 3-month SPECT for the prediction of restenosis were 46% and 67%, respectively, but 52% and 68%, in artery-graft group. REV detected on 3-month SPECT has a predictive value, especially, high specificity for the prediction of restenosis after CABG, which was more definite in artery-graft group

Duplicated middle cerebral artery

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Perez, Jesus; Machado, Calixto; Scherle, Claudio; Hierro, Daniel

2009-01-01

Duplicated middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery. The incidence DMCA is relatively law, and an association between this anomaly and cerebral aneurysms has been documented. There is a controversy whether DMCA may have perforating arteries. This is an important fact to consider in aneurysm surgery. We report the case of a 34-year-old black woman who suffered a subarachnoid hemorrhage and the angiography a left DMCA, and an aneurysm in an inferior branch of the main MCA. The DMCA and the MCA had perforating arteries. The aneurysm was clipped without complications. The observation of perforating arteries in our patient confirms that the DMCA may have perforating arteries. This is very important to be considered in cerebral aneurysms surgery. Moreover, the DMCA may potentially serve as a collateral blood supply to the MCA territory in cases of MCA occlusion. PMID:22140405

Transcatheter Arterial Embolization of Cystic Artery Pseudoaneurysm in Acalculous Cholecystitis: A Case Report

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Lee, Hyung Ook; Lee, Young Hwan [Dept. of Radiology, Daegu Catholic University College of Medicine, Daegu (Korea, Republic of); Kim, Young Hwan [Dept. of Diagnostic Radiology, Dongsan Medical Center, Keimyung University College of Medicine, Daegu (Korea, Republic of)

2011-04-15

A pseudoaneurysm of the cystic artery is a rare complication of cholecystitis, and is manifested by hemobilia or hematemesis. An early diagnosis is required for the successful treatment by cholecystectomy and ligation of the cystic artery. Herein, we report a case of a pseudoaneurysm of the cystic artery diagnosed by color Doppler ultrasonography and CT, and successfully treated by transcatheter arterial embolization with N-butyl cyanoacrylate in a high-risk surgical patient.

Value of Resistive lndex of the lntrascrotal Artery in ScrotaI Inflammatory Disease

International Nuclear Information System (INIS)

Jee, Won Hee; Yoon, Yeo Dong; Hwang, Sung Su; Choi, Byung Gil; Son, Kyung Myung; Lee, Sung Yong; Kim, Ki Tae; Shinn, Kyung Sub

1995-01-01

This prospective study was designed to investigate the utility of resistive indices(RIs) of intratesticular and epididymal arteries in inflammatory scrotal disease. Gray-scale and color Doppler ultrasonographic images were obtained in 19 consecutive patients of scrotal inflammatory disease from Nov.1993 to Oct. 1994. Eleven cases of epididymitis and 11 of epididymoorchitis(EO) were included. RIs of epididymal and centripetal arteries were calculated in 19 patients and 30 cases of control. All EO and epididymitis cases showed increased color signal at color Doppler ultrasonogram at representative sites. Mean RI of centripetal artery was 0.46±0.06 in EO and 0.66±0.07 in normal control, hence RI in EO was significantly lower than that of normal control(P<0.001). The diagnostic sensitivity was 91% when the value of 0.5 or less is estimated abnormal.Mean RI of centripetal artery was 0.67±0.07 in epididymitis, and was not significantly different from that of normal control(P=0.687). Mean RI of epididymal artery in epididymitis and EO was 0.48±0.12 and resistive index of all patients were below 0.7. Color Doppler can demonstrate the hyperemic response to scrotal inflammatory disease that it can supplement the gray scale finding leading to increased diagnostic confidence. RI of centripetal artery may be confirmative in the diagnosis of inflammatory scrotal inflammatory scrotal diseases when increased color flow on color flow imaging is present

Bilateral triple renal arteries

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Pestemalci, Turan; Yildiz, Yusuf Zeki; Yildirim, Mehmet; Mavi, Ayfer; Gumusburun, Erdem

2009-01-01

Knowledge of the variations of the renal artery has grown in importance with increasing numbers of renal transplants, vascular reconstructions and various surgical and radio logic techniques being performed in recent years. We report the presence of bilateral triple renal arteries, discovered on routine dissection of a male cadaver. On the right side, one additional renal artery originated from the abdominal aorta (distributed to superior pole of the kidney) and one other originated from the right common iliac artery (distributed to lower pole of the kidney). On the left side, both additional renal arteries originated from the abdominal aorta. Our observation has been compared with variations described in the literature and their clinical importance has been emphasized. (author)

Statin Intake Is Associated With Decreased Insulin Sensitivity During Cardiac Surgery

Science.gov (United States)

Sato, Hiroaki; Carvalho, George; Sato, Tamaki; Hatzakorzian, Roupen; Lattermann, Ralph; Codere-Maruyama, Takumi; Matsukawa, Takashi; Schricker, Thomas

2012-01-01

OBJECTIVE Surgical trauma impairs intraoperative insulin sensitivity and is associated with postoperative adverse events. Recently, preprocedural statin therapy is recommended for patients with coronary artery disease. However, statin therapy is reported to increase insulin resistance and the risk of new-onset diabetes. Thus, we investigated the association between preoperative statin therapy and intraoperative insulin sensitivity in nondiabetic, dyslipidemic patients undergoing coronary artery bypass grafting. RESEARCH DESIGN AND METHODS In this prospective, nonrandomized trial, patients taking lipophilic statins were assigned to the statin group and hypercholesterolemic patients not receiving any statins were allocated to the control group. Insulin sensitivity was assessed by the hyperinsulinemic-normoglycemic clamp technique during surgery. The mean, SD of blood glucose, and the coefficient of variation (CV) after surgery were calculated for each patient. The association between statin use and intraoperative insulin sensitivity was tested by multiple regression analysis. RESULTS We studied 120 patients. In both groups, insulin sensitivity gradually decreased during surgery with values being on average ∼20% lower in the statin than in the control group. In the statin group, the mean blood glucose in the intensive care unit was higher than in the control group (153 ± 20 vs. 140 ± 20 mg/dL; P statin group (SD, P statin use was independently associated with intraoperative insulin sensitivity (β = −0.16; P = 0.03). CONCLUSIONS Preoperative use of lipophilic statins is associated with increased insulin resistance during cardiac surgery in nondiabetic, dyslipidemic patients. PMID:22829524

Role of Doppler ultrasonography evaluation of superior mesenteric artery flow volume in the assessment of Crohn's disease activity

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Fabiana Paiva Martins

2013-09-01

Full Text Available Objective To investigate superior mesenteric artery flow measurement by Doppler ultrasonography as a means of characterizing inflammatory activity in Crohn's disease. Materials and Methods Forty patients were examined and divided into two groups – disease activity and remission – according to their Crohn's disease activity index score. Mean superior mesenteric artery flow volume was calculated for each group and correlated with Crohn's disease activity index score. Results The mean superior mesenteric artery flow volume was significantly greater in the patients with active disease (626 ml/min ± 236 × 376 ml/min ± 190; p = 0.001. As a cut off corresponding to 500 ml/min was utilized, the superior mesenteric artery flow volume demonstrated sensitivity of 83% and specificity of 82% for the diagnosis of Crohn's disease activity. Conclusion The present results suggest that patients with active Crohn's disease have increased superior mesenteric artery flow volume as compared with patients in remission. Superior mesenteric artery flow measurement had a good performance in the assessment of disease activity in this study sample.

Arterial vascularization of the pineal gland.

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Kahilogullari, Gokmen; Ugur, Hasan Caglar; Comert, Ayhan; Brohi, Recep Ali; Ozgural, Onur; Ozdemir, Mevci; Karahan, Suleyman Tuna

2013-10-01

The arterial vascularization of the pineal gland (PG) remains a debatable subject. This study aims to provide detailed information about the arterial vascularization of the PG. Thirty adult human brains were obtained from routine autopsies. Cerebral arteries were separately cannulated and injected with colored latex. The dissections were carried out using a surgical microscope. The diameters of the branches supplying the PG at their origin and vascularization areas of the branches of the arteries were investigated. The main artery of the PG was the lateral pineal artery, and it originated from the posterior circulation. The other arteries included the medial pineal artery from the posterior circulation and the rostral pineal artery mainly from the anterior circulation. Posteromedial choroidal artery was an important artery that branched to the PG. The arterial supply to the PG was studied comprehensively considering the debate and inadequacy of previously published studies on this issue available in the literature. This anatomical knowledge may be helpful for surgical treatment of pathologies of the PG, especially in children who develop more pathology in this region than adults.

Neurofibromatosis Type 1: Transcatheter Arterial Embolization for Ruptured Occipital Arterial Aneurysms

International Nuclear Information System (INIS)

Kanematsu, Masayuki; Kato, Hiroki; Kondo, Hiroshi; Goshima, Satoshi; Tsuge, Yusuke; Kojima, Toshiaki; Watanabe, Haruo

2011-01-01

Two cases of ruptured aneurysms in the posterior cervical regions associated with type-1 neurofibromatosis treated by transcatheter embolization are reported. Patients presented with acute onset of swelling and pain in the affected areas. Emergently performed contrast-enhanced CT demonstrated aneurysms and large hematomas widespread in the posterior cervical regions. Angiography revealed aneurysms and extravasations of the occipital artery. Patients were successfully treated by percutaneous transcatheter arterial microcoil embolization. Transcatheter arterial embolization therapy was found to be an effective method for treating aneurysmal rupture in the posterior cervical regions occurring in association with type-1 neurofibromatosis. A literature review revealed that rupture of an occipital arterial aneurysm, in the setting of neurofibromatosis type 1, has not been reported previously.

Congenital coronary-pulmonary artery fistula originating from right and left coronary artery

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Ali Kemal Gür

2013-12-01

Full Text Available Coronary artery fistula (CAF is a rare congenital anomalywith an incidence of 1 in 50 000 live births. The fistula wasobserved at the right coronary artery in 53%, the left coronaryartery in 42% and both coronary artery in 5% of thecases. Echocardiography examination in a 46 year-oldwoman with the symptoms of chest pain, palpitation anddyspnea revealed a severe mitral valve insufficiency anda moderate to severe tricuspid valve insufficiency. A CAForiginating from the proximal part of the left anterior descendingartery (LAD and another fistula originating fromosteal part of the right coronary artery (RCA were detectedby coronary angiography. Both fistulas were draininginto the main pulmonary artery. The coronary artery fistulaclosed under cardiopulmonary by-pass. Mitral insufficiencyoriginated from the posterior leaflet was diagnosedintra-operative exploration, and thereafter it was repairedwith mitral annuloplasty including a quadrangular resectionand use of a 32 No St Jude mitral ring. Tricuspid valvewas repaired with Calangos Ring annuloplasty. Followingsix day hospital stay, the woman was discharged free ofany symptom.Key words: Dyspnea, double arteriovenous fistula, mitral and tricuspid insufficiency

A Renal Perforating Artery Mistaken for Arterial Bleeding after Percutaneous Renal Biopsy: A Case Report

International Nuclear Information System (INIS)

Kim, Ye Lim; Lee, Chang Hee; Kim, Kyeong Ah; Park, Cheol Min

2009-01-01

Perirenal hematoma after a renal biopsy is a common complication that usually resolves spontaneously, but this rarely requires transfusions or surgical/radiological intervention. We report here on a case of a renal perforating artery that was mistaken for renal arterial bleeding in a 53-year-old woman who was complicated with perirenal hematoma after undergoing a percutaneous renal biopsy. On the color and pulsed wave Doppler ultrasonography, linear blood flow was seen in the perirenal hematoma, which extended perpendicularly from the renal parenchyma into the perirenal space, and this linear blood flow exhibited an arterial pulse wave. On CT angiography, the renal perforating artery was demonstrated as a curvilinear vessel coursing tangentially to the renal margin and we decided that it was a pseudolesion caused by the renal perforating artery. A renal perforating artery may be mistaken for renal arterial bleeding after a percutaneous renal biopsy. A renal perforating artery and arterial bleeding can be differentiated by the location and shape seen on a color Doppler examination and the pulse waves characteristics

A Renal Perforating Artery Mistaken for Arterial Bleeding after Percutaneous Renal Biopsy: A Case Report

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Kim, Ye Lim; Lee, Chang Hee; Kim, Kyeong Ah; Park, Cheol Min [Korea University College of Medicine, Seoul (Korea, Republic of)

2009-12-15

Perirenal hematoma after a renal biopsy is a common complication that usually resolves spontaneously, but this rarely requires transfusions or surgical/radiological intervention. We report here on a case of a renal perforating artery that was mistaken for renal arterial bleeding in a 53-year-old woman who was complicated with perirenal hematoma after undergoing a percutaneous renal biopsy. On the color and pulsed wave Doppler ultrasonography, linear blood flow was seen in the perirenal hematoma, which extended perpendicularly from the renal parenchyma into the perirenal space, and this linear blood flow exhibited an arterial pulse wave. On CT angiography, the renal perforating artery was demonstrated as a curvilinear vessel coursing tangentially to the renal margin and we decided that it was a pseudolesion caused by the renal perforating artery. A renal perforating artery may be mistaken for renal arterial bleeding after a percutaneous renal biopsy. A renal perforating artery and arterial bleeding can be differentiated by the location and shape seen on a color Doppler examination and the pulse waves characteristics

Duplication of Inferior Gluteal Artery and Course of Superior Gluteal Artery Through the Lumbosacral Trunk

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Satheesha Nayak B

2017-07-01

Full Text Available Internal iliac artery (IIA shows great deal of variations in its branching pattern. The knowledge of its variant branches is required for successful surgical, orthopedic, plastic surgery and radiological procedures. We observed variations of some of the branches of right IIA in an adult male cadaver. The iliolumbar artery originated from the main trunk of the IIA. After this, IIA divided into anterior and posterior divisions. The posterior division gave lateral sacral and superior gluteal arteries. Superior gluteal artery pierced the lumbosacral trunk before leaving the pelvis. The anterior division further divided into anterior and posterior trunks. Anterior trunk gave rise to superior vesical, inferior vesical, middle rectal and obturator arteries. The posterior trunk gave two inferior gluteal arteries and an internal pudendal artery.

Arterial Stiffness and its Correlation with the Extent of Coronary Artery Disease

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Hourak Poorzand

2018-06-01

Full Text Available Introduction: Coronary artery disease secondary to atherosclerosis is the most common cause of mortality. Coronary angiography is the most precise method for determining the extent of disease in the coronary vascular bed. Arterial stiffness has been proposed as a marker of atherosclerosis in some studies. One of the noninvasive methods for the determination of arterial stiffness is Doppler echocardiography. In this study, we aimed to find the correlation between arterial stiffness as measured by echocardiography and the extent of coronary artery disease as evaluated through angiography. Materials and Methods: Aortic pulse wave velocity (APWV was measured by using the Doppler method in 70 patients, who were candidates for coronary angiography. The extent of coronary artery disease was determined quantitatively in terms of Friesinger index and semi-quantitatively as the number of vessels with stenosis of over 50%. Then, the correlation between arterial stiffness and these factors was evaluated. Results: The mean APWV was 9.1±5 m/s. There was a direct relationship between APWV and Friesinger index, which was not statistically significant (P=0.67. The mean APWV for patients with one-vessel disease was 4.4±1.8 m/s, while it was 9.9±3.6 m/s in patients with two and 7.9±4 m/s in three-vessel disease which did not show statistically significant difference. Conclusion: Doppler echocardiography to measure APWV was not considered as a promising tool to predict the extent of coronary artery disease.

Long-term outcomes of internal carotid artery disease treated using radial artery graft

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Murai, Yasuo; Teramoto, Akira; Mizunari, Takayuki; Kobayashi, Shiro; Umeoka, Katsuya; Tateyama, Kojiro

2009-01-01

Complex internal carotid artery disease presents a surgical challenge because limitations and difficulty are encountered with either clipping or endovascular treatment. Our review of previous reports suggests that no current vascular assessment can accurately predict occurrence of ischemic complications after internal carotid artery ligation. The present study concerns long-term clinical outcome of radial artery grafting followed by parent artery trapping or proximal occlusion for management of these difficult lesions. Between September 1997 and October 2007, we performed radial artery grafting followed immediately by parent artery occlusion in 20 sides of 19 patients with complex internal carotid arteries disease with follow-up for more than 36 months (5 men, 14 women; mean follow-up duration, 62 months). All patients underwent postoperative MRI and MR angiography (MRA) every year to assess graft patency, ischemic complications, and de novo aneurysm. Another 20 carotid aneurysms with visual disturbance were assessed concerning outcome. Among 13 patients with cranial nerve (III and VI) disturbances, all dysfunctions were improved in cases treated within 8 months of onset to operation. On the other hand, patients with second cranial nerve disturbances were not improved in cases treated after 4 months of onset. No long-term complications were discovered with MRI and MRA. With appropriate attention to surgical technique, radial artery grafting followed by acute parent artery occlusion is a safe treatment for complex internal carotid artery aneurysms. Long-term safety is satisfactory, with no delayed complications such as graft stenosis, ischemic complications or de novo aneurysm formations in follow-up periods of more than 3 years. Good clinical outcome of cranial nerve palsy was achieved in patients treated within 8 months of onset for cranial nerve (CN) III and VI, and 4 of CN II palsy. (author)

Hepatocellular carcinoma with extensive hepatic artery injury: transcatheter arterial chemoembolization through collaterals after coil embolizatoin of gastric arteries

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Kim, Gab Choul; Yoon, Hyun Ki; Hwang, Jae Cheol; Lee, Duck Hee; Song, Ho Young; Suh, Dong Jin; Lee, Yung Sang; Chung, Young Hwa; Sung, Gyu Bo; Ko, Ki Young

1999-01-01

To evaluate the efficacy and safety of transcatheter arterial chemoembolization(TACE) after coil embolization of the gastroduodenal artery in hepatocellular carcinoma cases with multiple collateral arteries caused by proper hepatic artery injury. Between March 1997 and November 1998, a prospective trial of transcatheter arterial chemoembolization (TACE) was performed through collaterals from the gastroduodenal artery of 31 hepatocellular carcinoma patients with extensive proper hepatic artery injury due to repeated TACE. Among this number, 16 (group A) underwent TACE after coil embolization of the right gastric and gastroduodenal artery. The other 15 patients (group B) underwent TACE without coil embolization. The two groups had the same TNM stage and Clild-Pugh status. During the follow-up period, group A underwent additional TACE 3.3 times, and group B 2.8 times. The therapeutic effect of TACE was evaluated with computed tomography and by measuring alpha-fetoprotein levels. Complications were evaluated by means of gastrofibroscopy, laboratory data, and evaluation of the patients' clinical symptoms. The results obtained after six months and one year were compared within and between each group. At six months follow-up, CT findings had improved or were unchanged in 11 patients(69 %) in group A, and four patients(27 %) in group B(p = 0.032). In ten patients in each group, the level of alpha-fetoprotein was above 200 ng/ml. Its level was decreased in five patients(50 %) and three patients(30 %), respectively. The six-month survival rate was 81 % (13/16) in group A and 67% (10/15) in group B (p 0.43), while the one-year survival figures for these two groups were 50 % (8/16) and 20 % (3/15), respectively(p = 0.135). In group A, the CT findings were steady in five out of eight patients(63 %), while in groupB, CT findings showed that tumors with increased alpha-fetoprotein levels had increased in size and/or number. In group A, it was found that in two (33 %) of six

Hepatocellular carcinoma with extensive hepatic artery injury: transcatheter arterial chemoembolization through collaterals after coil embolizatoin of gastric arteries

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Kim, Gab Choul; Yoon, Hyun Ki; Hwang, Jae Cheol; Lee, Duck Hee; Song, Ho Young; Suh, Dong Jin; Lee, Yung Sang; Chung, Young Hwa; Sung, Gyu Bo [Ulsan Univ. College of Medicine, Seoul (Korea, Republic of); Ko, Ki Young [Catholic Univ. College of Medicine, Seoul (Korea, Republic of)

1999-09-01

To evaluate the efficacy and safety of transcatheter arterial chemoembolization(TACE) after coil embolization of the gastroduodenal artery in hepatocellular carcinoma cases with multiple collateral arteries caused by proper hepatic artery injury. Between March 1997 and November 1998, a prospective trial of transcatheter arterial chemoembolization (TACE) was performed through collaterals from the gastroduodenal artery of 31 hepatocellular carcinoma patients with extensive proper hepatic artery injury due to repeated TACE. Among this number, 16 (group A) underwent TACE after coil embolization of the right gastric and gastroduodenal artery. The other 15 patients (group B) underwent TACE without coil embolization. The two groups had the same TNM stage and Clild-Pugh status. During the follow-up period, group A underwent additional TACE 3.3 times, and group B 2.8 times. The therapeutic effect of TACE was evaluated with computed tomography and by measuring alpha-fetoprotein levels. Complications were evaluated by means of gastrofibroscopy, laboratory data, and evaluation of the patients' clinical symptoms. The results obtained after six months and one year were compared within and between each group. At six months follow-up, CT findings had improved or were unchanged in 11 patients(69 %) in group A, and four patients(27 %) in group B(p = 0.032). In ten patients in each group, the level of alpha-fetoprotein was above 200 ng/ml. Its level was decreased in five patients(50 %) and three patients(30 %), respectively. The six-month survival rate was 81 % (13/16) in group A and 67% (10/15) in group B (p 0.43), while the one-year survival figures for these two groups were 50 % (8/16) and 20 % (3/15), respectively(p = 0.135). In group A, the CT findings were steady in five out of eight patients(63 %), while in groupB, CT findings showed that tumors with increased alpha-fetoprotein levels had increased in size and/or number. In group A, it was found that in two (33 %) of six