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Sample records for programmed ventricular stimulation

  1. Programmed Ventricular Stimulation for Risk Stratification in the Brugada Syndrome: A Pooled Analysis

    NARCIS (Netherlands)

    Sroubek, Jakub; Probst, Vincent; Mazzanti, Andrea; Delise, Pietro; Hevia, Jesus Castro; Ohkubo, Kimie; Zorzi, Alessandro; Champagne, Jean; Kostopoulou, Anna; Yin, Xiaoyan; Napolitano, Carlo; Milan, David J.; Wilde, Arthur; Sacher, Frederic; Borggrefe, Martin; Ellinor, Patrick T.; Theodorakis, George; Nault, Isabelle; Corrado, Domenico; Watanabe, Ichiro; Antzelevitch, Charles; Allocca, Giuseppe; Priori, Silvia G.; Lubitz, Steven A.

    2016-01-01

    The role of programmed ventricular stimulation in identifying patients with Brugada syndrome at the highest risk for sudden death is uncertain. We performed a systematic review and pooled analysis of prospective, observational studies of patients with Brugada syndrome without a history of sudden

  2. Effect of programmed ventricular stimulation on myocardial lactate extraction in patients with and without coronary artery disease

    International Nuclear Information System (INIS)

    Morady, F.; DiCarlo, L.A. Jr.; Krol, R.B.; de Buitleir, M.; Nicklas, J.M.; Annesley, T.M.

    1986-01-01

    The arterial-coronary sinus lactate difference was measured in 17 patients after each step of a programmed ventricular stimulation protocol consisting of single, double, and triple extrastimuli, first at a basic drive cycle length of 600 msec, then at 400 msec, with an inter-train interval of 4 seconds. Four patients had no structural heart disease, four had an idiopathic dilated cardiomyopathy, and nine had coronary artery disease with a significant stenosis in at least one branch of the left coronary artery. Net myocardial lactate production during programmed ventricular stimulation was observed in three patients with coronary artery disease, but not in any patient without coronary artery disease. Among the patients who had coronary artery disease, net myocardial lactate production generally occurred in the patients who had more severe coronary artery disease. Exercise-induced ischemia, as demonstrated by a stress thallium-201 test, did not correlate with myocardial lactate production during programmed ventricular stimulation. Programmed ventricular stimulation, with a stimulation protocol typically used in many electrophysiology laboratories, is capable of inducing myocardial ischemia in at least some patients who have coronary artery disease. This finding suggests that myocardial ischemia may potentially influence the results of programmed ventricular stimulation in some patients with coronary artery disease

  3. Effects of valsartan on ventricular arrhythmia induced by programmed electrical stimulation in rats with myocardial infarction

    Science.gov (United States)

    Jiao, Kun-Li; Li, Yi-Gang; Zhang, Peng-Pai; Chen, Ren-Hua; Yu, Yi

    2012-01-01

    Abstract The impact of angiotensin II receptor blockers (ARBs) on electrical remodelling after myocardial infarction (MI) remains unclear. The purpose of the present study was to evaluate the effect of valsartan on incidence of ventricular arrhythmia induced by programmed electrical stimulation (PES) and potential link to changes of myocardial connexins (Cx) 43 expression and distribution in MI rats. Fifty-nine rats were randomly divided into three groups: Sham (n = 20), MI (n = 20) and MI + Val (20 mg/kg/day per gavage, n = 19). After eight weeks, the incidence of PES-induced ventricular tachycardia (VT) and fibrillation (VF) was compared among groups. mRNA and protein expressions of Cx43, angiotensin II type 1 receptor (AT1R) in the LV border zone (BZ) and non-infarct zone (NIZ) were determined by real-time PCR and Western blot, respectively. Connexins 43 protein and collagen distribution were examined by immunohistochemistry in BZ and NIZ sections from MI hearts. Valsartan effectively improved the cardiac function, reduced the prolonged QTc (163.7 ± 3.7 msec. versus 177.8 ± 4.5 msec., P valsartan. The mRNA and protein expressions of Cx43 in BZ were significantly reduced after MI and up-regulated by valsartan. Increased collagen deposition and reduced Cx43 expression in BZ after MI could be partly attenuated by Valsartan. Valsartan reduced the incidence of PES-induced ventricular arrhythmia, this effect was possibly through modulating the myocardial AT1R and Cx43 expression. PMID:22128836

  4. Burst stimulation improves hemodynamics during resuscitation after prolonged ventricular fibrillation.

    Science.gov (United States)

    Walcott, Gregory; Melnick, Sharon; Killingsworth, Cheryl; Ideker, Raymond

    2009-02-01

    Although return of spontaneous circulation (ROSC) is frequently achieved during resuscitation for sudden cardiac arrest, systolic blood pressure can then decrease, requiring additional myocardial support. Previous studies have shown that a series of 1-ms electrical pulses delivered through the defibrillation patches during ventricular fibrillation (VF) can stimulate the autonomic nervous system to increase myocardial function following defibrillation. We hypothesized that a similar series of electrical pulses could increase myocardial function and blood pressure during the early post-resuscitation period. Six swine were studied that underwent 6-7 min. Each animal received 5, 10, 15, or 20 pulse packets consisting of 6 10 A, 1-ms pulses every 3-4 s in random order whenever systolic blood pressure became less than 50 mmHg. All four sets of pulse packets were delivered to each animal. Systolic blood pressure and cardiac function (left ventricular +dP/dt) were increased to pre-stimulation levels or above by all four sets of pulse packets. The increases were significantly greater for the longer than the shorter number of pulse packets. The mean+/-SD duration of the time that the systolic pressure remained above 50 mmHg following pulse delivery was 4.2+/-2.5 min. Electrical stimulation during regular rhythm following prolonged VF and resuscitation can increase blood pressure and cardiac function to above prestimulation levels.

  5. Sympathetic stimulation alters left ventricular relaxation and chamber size.

    Science.gov (United States)

    Burwash, I G; Morgan, D E; Koilpillai, C J; Blackmore, G L; Johnstone, D E; Armour, J A

    1993-01-01

    Alterations in left ventricular (LV) contractility, relaxation, and chamber dimensions induced by efferent sympathetic nerve stimulation were investigated in nine anesthetized open-chest dogs in sinus rhythm. Supramaximal stimulation of acutely decentralized left stellate ganglia augmented heart rate, LV systolic pressure, and rate of LV pressure rise (maximum +dP/dt, 1,809 +/- 191 to 6,304 +/- 725 mmHg/s) and fall (maximum -dP/dt, -2,392 +/- 230 to -4,458 +/- 482 mmHg/s). It also reduced the time constant of isovolumic relaxation, tau (36.5 +/- 4.8 to 14.9 +/- 1.1 ms). Simultaneous two-dimensional echocardiography recorded reductions in end-diastolic and end-systolic LV cross-sectional chamber areas (23 and 31%, respectively), an increase in area ejection fraction (32%), and increases in end-diastolic and end-systolic wall thicknesses (14 and 13%, respectively). End-systolic and end-diastolic wall stresses were unchanged by stellate ganglion stimulation (98 +/- 12 to 95 +/- 9 dyn x 10(3)/cm2; 6.4 +/- 2.4 to 2.4 +/- 0.3 dyn x 10(3)/cm2, respectively). Atrial pacing to similar heart rates did not alter monitored indexes of contractility. Dobutamine and isoproterenol induced changes similar to those resulting from sympathetic neuronal stimulation. These data indicate that when the efferent sympathetic nervous system increases left ventricular contractility and relaxation, concomitant reductions in systolic and diastolic dimensions of that chamber occur that are associated with increasing wall thickness such that LV wall stress changes are minimized.

  6. Right ventricular bifocal stimulation in the treatment of dilated cardiomyopathy with heart failure

    Directory of Open Access Journals (Sweden)

    José Carlos Pachón Mateos

    1999-12-01

    Full Text Available OBJECTIVE: To describe a new more efficient method of endocardial cardiac stimulation, which produces a narrower QRS without using the coronary sinus or cardiac veins. METHODS: We studied 5 patients with severe dilated cardiomyopathy, chronic atrial fibrillation and AV block, who underwent definitive endocardial pacemaker implantation, with 2 leads, in the RV, one in the apex and the other in the interventricular septum (sub pulmonary, connected, respectively, to ventricular and atrial bicameral pacemaker outputs. Using Doppler echocardiography, we compared, in the same patient, conventional (VVI, high septal ("AAI" and bifocal ("DDT" with AV interval ~ 0 stimulation. RESULTS: The RV bifocal stimulation had the best results with an increase in ejection fraction and cardiac output and reduction in QRS duration, mitral regurgitation and in the left atrium area (p <= 0.01. The conventional method of stimulation showed the worst result. CONCLUSION: These results suggest that, when left ventricular stimulation is not possible, right ventricular bifocal stimulation should be used in patients with severe cardiomyopathy where a pacemaker is indicated.

  7. Atrioventricular and ventricular-to-ventricular programming in patients with cardiac resynchronization therapy: results from ALTITUDE.

    Science.gov (United States)

    Steinberg, Benjamin A; Wehrenberg, Scott; Jackson, Kevin P; Hayes, David L; Varma, Niraj; Powell, Brian D; Day, John D; Frazier-Mills, Camille G; Stein, Kenneth M; Jones, Paul W; Piccini, Jonathan P

    2015-12-01

    Cardiac resynchronization therapy (CRT) improves outcomes in patients with heart failure, yet response rates are variable. We sought to determine whether physician-specified CRT programming was associated with improved outcomes. Using data from the ALTITUDE remote follow-up cohort, we examined sensed atrioventricular (AV) and ventricular-to-ventricular (VV) programming and their associated outcomes in patients with de novo CRT from 2009-2010. Outcomes included arrhythmia burden, left ventricular (LV) pacing, and all-cause mortality at 4 years. We identified 5709 patients with de novo CRT devices; at the time of implant, 34% (n = 1959) had entirely nominal settings programmed, 40% (n = 2294) had only AV timing adjusted, 11% (n = 604) had only VV timing adjusted, and 15% (n = 852) had both AV and VV adjusted from nominal programming. Suboptimal LV pacing (5% was lowest in the AV-only adjusted group (17.9%) and highest in the nominal (27.7%) and VV-only adjusted (28.3%) groups. Adjusted all-cause mortality was significantly higher among patients with non-nominal AV delay >120 vs. 180 vs. ≤180 ms, p = 0.4). Nominal settings for de novo CRT implants are frequently altered, most commonly the AV delay. There is wide variability in reprogramming. Patients with nominal or AV-only adjustments appear to have favorable pacing and arrhythmia outcomes. Sensed AV delays less than 120 ms are associated with improved survival.

  8. Dynamic changes in left ventricular function during cold pressor stimulation assessed with gold-195m

    International Nuclear Information System (INIS)

    Dymond, D.S.; Caplin, J.; Flatman, W.

    1985-01-01

    The temporal changes in left ventricular function induced by cold pressor stimulation were assessed in 12 normal controls and 12 patients with coronary artery disease (CAD) by rapid, sequential first-pass nuclear angiography with gold-195m. Imaging was performed at rest, after 1, 2.5, and 4 min of cold pressor and after 2 min of recovery. After 1 min, LVEF (left ventricular ejection fraction) fell significantly in normals and in patients but only in the coronary patients was a significant fall maintained at 2.5 and 4 min. The number of new abnormalities on the regional ejection fraction images for normals and those with CAD, respectively, was 12 and 19 at 1 min, 1 and 21 at 2.5 min, 2 and 13 at 4 min, and 0 and 8 during recovery. The authors conclude that (1) cold pressor-induced depression of left ventricular function is transient in normals but often prolonged in patients with CAD and (2) the temporal dissociation between rise in blood pressure and fall in LVEF suggests factors other than afterload changes may be involved in depression of cardiac function

  9. [Experimental studies on the diffusion of excitation on the right ventricular surface in the dog, during normal and stimulated beats].

    Science.gov (United States)

    Arisi, G; Macchi, E; Baruffi, S; Musso, E; Spaggiari, S; Stilli, D; Taccardi, B

    1982-01-01

    Previous work on the spread of excitation on the dog's ventricular surface enabled us to locate up to 30 breakthrough points (BKTPs) where excitation reaches the ventricular surface. In particular the equipotential contour maps enabled us to detect 3 to 5 BKTPs on the anterior right ventricular surface, near the a-v groove when a large part of ventricular surface was still at rest. With a view to investigating the mechanism underlying the early excitation of these basal regions, we stimulated the heart at several right ventricular BKTPs and in other points located at a distance from the BKTPs. The instantaneous equipotential maps showed that after stimulation most right ventricular BKTPs remained in the same position as observed the normal beats. The early appearance of epicardial wavefronts in the basal region and generally in other areas of the right ventricle was attributed to the rapid propagation of excitation waves through the Purkinje network, probably associated to a short transmural crossing time, due to a local thinness of the ventricular wall.

  10. The influence of adrenergic stimulation on sex differences in left ventricular twist mechanics.

    Science.gov (United States)

    Williams, Alexandra M; Shave, Rob E; Cheyne, William S; Eves, Neil D

    2017-06-15

    Sex differences in left ventricular (LV) mechanics occur during acute physiological challenges; however, it is unknown whether sex differences in LV mechanics are fundamentally regulated by differences in adrenergic control. Using two-dimensional echocardiography and speckle tracking analysis, this study compared LV mechanics in males and females matched for LV length during post-exercise ischaemia (PEI) and β 1 -adrenergic receptor blockade. Our data demonstrate that while basal rotation was increased in males, LV twist was not significantly different between the sexes during PEI. In contrast, during β 1 -adrenergic receptor blockade, LV apical rotation, twist and untwisting velocity were reduced in males compared to females. Significant relationships were observed between LV twist and LV internal diameter and sphericity index in females, but not males. These findings suggest that LV twist mechanics may be more sensitive to alterations in adrenergic stimulation in males, but more highly influenced by ventricular structure and geometry in females. Sex differences in left ventricular (LV) mechanics exist at rest and during acute physiological stress. Differences in cardiac autonomic and adrenergic control may contribute to sex differences in LV mechanics and LV haemodynamics. Accordingly, this study aimed to investigate sex differences in LV mechanics with altered adrenergic stimulation achieved through post-handgrip-exercise ischaemia (PEI) and β 1 -adrenergic receptor (AR) blockade. Twenty males (23 ± 5 years) and 20 females (22 ± 3 years) were specifically matched for LV length (males: 8.5 ± 0.5 cm, females: 8.2 ± 0.6 cm, P = 0.163), and two-dimensional speckle-tracking echocardiography was used to assess LV structure and function at baseline, during PEI and following administration of 5 mg bisoprolol (β 1 -AR antagonist). During PEI, LV end-diastolic volume and stroke volume were increased in both groups (P adrenergic stimulation

  11. Long pacing pulses reduce phrenic nerve stimulation in left ventricular pacing.

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    Hjortshøj, Søren; Heath, Finn; Haugland, Morten; Eschen, Ole; Thøgersen, Anna Margrethe; Riahi, Sam; Toft, Egon; Struijk, Johannes Jan

    2014-05-01

    Phrenic nerve stimulation is a major obstacle in cardiac resynchronization therapy (CRT). Activation characteristics of the heart and phrenic nerve are different with higher chronaxie for the heart. Therefore, longer pulse durations could be beneficial in preventing phrenic nerve stimulation during CRT due to a decreased threshold for the heart compared with the phrenic nerve. We investigated if long pulse durations decreased left ventricular (LV) thresholds relatively to phrenic nerve thresholds in humans. Eleven patients, with indication for CRT and phrenic nerve stimulation at the intended pacing site, underwent determination of thresholds for the heart and phrenic nerve at different pulse durations (0.3-2.9 milliseconds). The resulting strength duration curves were analyzed by determining chronaxie and rheobase. Comparisons for those parameters were made between the heart and phrenic nerve, and between the models of Weiss and Lapicque as well. In 9 of 11 cases, the thresholds decreased faster for the LV than for the phrenic nerve with increasing pulse duration. In 3 cases, the thresholds changed from unfavorable for LV stimulation to more than a factor 2 in favor of the LV. The greatest change occurred for pulse durations up to 1.5 milliseconds. The chronaxie of the heart was significantly higher than the chronaxie of the phrenic nerve (0.47 milliseconds vs. 0.22 milliseconds [P = 0.029, Lapicque] and 0.79 milliseconds vs. 0.27 milliseconds [P = 0.033, Weiss]). Long pulse durations lead to a decreased threshold of the heart relatively to the phrenic nerve and may prevent stimulation of the phrenic nerve in a clinical setting. © 2013 Wiley Periodicals, Inc.

  12. Stimulation of ICa by basal PKA activity is facilitated by caveolin-3 in cardiac ventricular myocytes.

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    Bryant, Simon; Kimura, Tomomi E; Kong, Cherrie H T; Watson, Judy J; Chase, Anabelle; Suleiman, M Saadeh; James, Andrew F; Orchard, Clive H

    2014-03-01

    L-type Ca channels (LTCC), which play a key role in cardiac excitation-contraction coupling, are located predominantly at the transverse (t-) tubules in ventricular myocytes. Caveolae and the protein caveolin-3 (Cav-3) are also present at the t-tubules and have been implicated in localizing a number of signaling molecules, including protein kinase A (PKA) and β2-adrenoceptors. The present study investigated whether disruption of Cav-3 binding to its endogenous binding partners influenced LTCC activity. Ventricular myocytes were isolated from male Wistar rats and LTCC current (ICa) recorded using the whole-cell patch-clamp technique. Incubation of myocytes with a membrane-permeable peptide representing the scaffolding domain of Cav-3 (C3SD) reduced basal ICa amplitude in intact, but not detubulated, myocytes, and attenuated the stimulatory effects of the β2-adrenergic agonist zinterol on ICa. The PKA inhibitor H-89 also reduced basal ICa; however, the inhibitory effects of C3SD and H-89 on basal ICa amplitude were not summative. Under control conditions, myocytes stained with antibody against phosphorylated LTCC (pLTCC) displayed a striated pattern, presumably reflecting localization at the t-tubules. Both C3SD and H-89 reduced pLTCC staining at the z-lines but did not affect staining of total LTCC or Cav-3. These data are consistent with the idea that the effects of C3SD and H-89 share a common pathway, which involves PKA and is maximally inhibited by H-89, and suggest that Cav-3 plays an important role in mediating stimulation of ICa at the t-tubules via PKA-induced phosphorylation under basal conditions, and in response to β2-adrenoceptor stimulation. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Cognitive stimulation in healthy older adults: a cognitive stimulation program using leisure activities compared to a conventional cognitive stimulation program.

    Science.gov (United States)

    Grimaud, Élisabeth; Taconnat, Laurence; Clarys, David

    2017-06-01

    The aim of this study was to compare two methods of cognitive stimulation for the cognitive functions. The first method used an usual approach, the second used leisure activities in order to assess their benefits on cognitive functions (speed of processing; working memory capacity and executive functions) and psychoaffective measures (memory span and self esteem). 67 participants over 60 years old took part in the experiment. They were divided into three groups: 1 group followed a program of conventional cognitive stimulation, 1 group a program of cognitive stimulation using leisure activities and 1 control group. The different measures have been evaluated before and after the training program. Results show that the cognitive stimulation program using leisure activities is as effective on memory span, updating and memory self-perception as the program using conventional cognitive stimulation, and more effective on self-esteem than the conventional program. There is no difference between the two stimulated groups and the control group on speed of processing. Neither of the two cognitive stimulation programs provides a benefit over shifting and inhibition. These results indicate that it seems to be possible to enhance working memory and to observe far transfer benefits over self-perception (self-esteem and memory self-perception) when using leisure activities as a tool for cognitive stimulation.

  14. Efeitos da estimulação ventricular convencional em pacientes com função ventricular normal Efectos de la estimulación ventricular convencional en pacientes con función ventricular normal Conventional ventricular stimulation effects on patients with normal ventricular function

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Batista de Sá

    2009-08-01

    (CF, test de marcha, dosificación de BNP, ecocardiograma (convencional y parámetros de desincronía intraventricular y prueba de calidad de vida (SF36. Esas mediciones se hicieron con 10 días(d (t1, 120d(t2 y 240 d(t3. Los datos se compararon a lo largo del tiempo según el método ANOVA. Comparaciones múltiples de promedios se efectuaron utilizándose el método de Tukey. RESULTADOS: Desde los datos evaluados, los siguientes no presentaron variación estadística significante (p>0,05: clase funcional, dosificación de BNP, parámetros ecocardiográficos convencionales, desincronía intraventricular (Doppler tisular. Presentaron empeoramiento (pBACKGROUND: The stimulation of the right ventricle (RV may be deleterious in patients with ventricular dysfunction; however there is little evidence about the impact of this stimulation in patients with normal ventricular function. OBJECTIVES: To assess the clinical and laboratory evolution of patients with normal ventricular function submitted to implant of artificial cardiac pacemaker (PM. METHODS: 16 patients enrolled according to the following inclusion criteria: normal ventricular function defined by echocardiogram and presence of upper ventricular stimulation > 90% (generator telemetry assessment submitted to a PM implant were prospectively studied. The following parameters were assessed: Functional Class (FC, walk test, BNP levels, echocardiography evaluation (conventional and intraventricular dyssynchrony and quality of life test (SF36. The patients were assessed after 10 (t1, 120 (t2 and 240 days (t3. Data was compared throughout time according to ANOVA. Multiple comparisons of means were performed through Tukey's test. RESULTS: Among the assessed data, the following did not present significant statistic variation (p> 0.05: functional class, BNP levels, conventional echocardiographic parameters, intraventricular dyssynchrony (tissue Doppler. The walk test (between t2 and t3 and the time between septal contraction

  15. A level stimulator programmed for audiometry

    International Nuclear Information System (INIS)

    Fayart, Gerard

    1976-02-01

    This stimulator has been designed for automated audiometric experiments on lemurians. The variations of the transmission level are programmed on punched tape whose reading is controlled by an audiofrequency attenuator. The positive answers of the animal are stored in a seven-counter memory and the results are read by display [fr

  16. Occurrence of phrenic nerve stimulation in cardiac resynchronization therapy patients: the role of left ventricular lead type and placement site.

    Science.gov (United States)

    Biffi, Mauro; Exner, Derek V; Crossley, George H; Ramza, Brian; Coutu, Benoit; Tomassoni, Gery; Kranig, Wolfgang; Li, Shelby; Kristiansen, Nina; Voss, Frederik

    2013-01-01

    Unwanted phrenic nerve stimulation (PNS) has been reported in ∼1 in 4 patients undergoing left ventricular (LV) pacing. The occurrence of PNS over mid-term follow-up and the significance of PNS are less certain. Data from 1307 patients enrolled in pre-market studies of LV leads manufactured by Medtronic (models 4193 and 4195 unipolar, 4194, 4196, 4296, and 4396 bipolar) were pooled. Left ventricular lead location was recorded at implant using a common classification scheme. Phrenic nerve stimulation symptoms were either spontaneously reported or identified at scheduled follow-up visits. A PNS-related complication was defined as PNS resulting in invasive intervention or the termination of LV pacing. Average follow-up was 14.9 months (range 0.0-46.6). Phrenic nerve stimulation symptoms occurred in 169 patients (12.9%). Phrenic nerve stimulation-related complications occurred in 21 of 1307 patients (1.6%); 16 of 738 (2.2%) in the unipolar lead studies, and 5 of 569 (0.9%) in the bipolar lead studies (P = 0.08). Phrenic nerve stimulation was more frequent at middle-lateral/posterior, and apical LV sites (139/1010) vs. basal-posterior/lateral/anterior, and middle-anterior sites (20/297; P= 0.01). As compared with an anterior LV lead position, a lateral LV pacing site was associated with over a four-fold higher risk of PNS (P= 0.005) and an apical LV pacing site was associated with over six-fold higher risk of PNS (P= 0.001). Phrenic nerve stimulation occurred in 13% of patients undergoing LV lead placement and was more common at mid-lateral/posterior, and LV apical sites. Most cases (123/139; 88%) of PNS were mitigated via electrical reprogramming, without the need for invasive intervention.

  17. Ventricular tachyarrhythmia-related basal cardiomyopathy in rabbits with vagal stimulation--a novel experimental model for inverted Takotsubo-like cardiomyopathy.

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    Takato, Tetsuya; Ashida, Terunao; Seko, Yoshinori; Fujii, Jun; Kawai, Sachio

    2010-07-01

    Electrical stimulation of the intact (unsectioned) cervical vagus in rabbits frequently provokes ventricular tachyarrhythmias that are often accompanied by mitral regurgitation. Unique pathological lesions often arise on the mitral valve, papillary muscles, and mitral annulus (mitral complex), the latter two of which become swollen and stiffened. These lesions are reversible in nature. Previous studies have essentially ignored the basal portion except for the mitral annulus. Therefore, the present study examined pathological lesions on the left ventricular basal portion in rabbits. The intact right vagal nerves of 20 anesthetized rabbits were repeatedly electrically stimulated under electrocardiographic monitoring. Colloidal carbon (lml) was injected intravenously immediately after the end of the stimulation and all animals were killed 1 week later. Pathological lesions were identified as carbon deposits visible at gross examination. Ventricular bigeminy was induced after vagal stimulation in 15 (75%) of the 20 rabbits. Pathological lesions were evident on the basal portion in 16 (80%) and on the mitral valve and papillary muscles of 15 (75%) of the 20 rabbits. Ventricular bigeminy was closely associated with the development of the pathological lesions, which were rarely observed on the ventricular apex. Cardiomyopathic lesions involving the basal portion and mitral complex were frequently induced in rabbits by vagal stimulation. These lesions bear a close similarity in distribution and reversibility to inverted Takotsubo cardiomyopathy. Copyright 2010 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  18. Geothermal Reservoir Well Stimulation Program: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    Each of the following types of well stimulation techniques are summarized and explained: hydraulic fracturing; thermal; mechanical, jetting, and drainhole drilling; explosive and implosive; and injection methods. Current stimulation techniques, stimulation techniques for geothermal wells, areas of needed investigation, and engineering calculations for various techniques. (MHR)

  19. Geothermal Reservoir Well Stimulation Program: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    A literature search on reservoir and/or well stimulation techniques suitable for application in geothermal fields is presented. The literature on stimulation techniques in oil and gas field applications was also searched and evaluated as to its relevancy to geothermal operations. The equivalent low-temperature work documented in the open literature is cited, and an attempt is made to evaluate the relevance of this information as far as high-temperature stimulation work is concerned. Clays play an important role in any stimulation work. Therefore, special emphasis has been placed on clay behavior anticipated in geothermal operations. (MHR)

  20. Idiopathic ventricular tachycardia and fibrillation.

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    Belhassen, B; Viskin, S

    1993-06-01

    Important data have recently been added to our understanding of sustained ventricular tachyarrhythmias occurring in the absence of demonstrable heart disease. Idiopathic ventricular tachycardia (VT) is usually of monomorphic configuration and can be classified according to its site of origin as either right monomorphic (70% of all idiopathic VTs) or left monomorphic VT. Several physiopathological types of monomorphic VT can be presently individualized, according to their mode of presentation, their relationship to adrenergic stress, or their response to various drugs. The long-term prognosis is usually good. Idiopathic polymorphic VT is a much rarer type of arrhythmia with a less favorable prognosis. Idiopathic ventricular fibrillation may represent an underestimated cause of sudden cardiac death in ostensibly healty patients. A high incidence of inducibility of sustained polymorphic VT with programmed ventricular stimulation has been found by our group, but not by others. Long-term prognosis on Class IA antiarrhythmic medications that are highly effective at electrophysiologic study appears excellent.

  1. Left Phrenic Nerve Stimulation Due to Breakage of the Endocardial Right Ventricular Lead at the Costoclavicular Ligament

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    Mariko Fujimori, MD

    2007-01-01

    Full Text Available A 78-year-old man with a permanent pacemaker (PM implanted in his left prepectoral area reported twitches in his left lateral abdominal region. Chest X-rays revealed a broken right atrial (RA lead and a fracture of the right ventricular (RV lead at the left costoclavicular ligament. The electrocardiogram (ECG and the Holler ECG revealed atrial fibrillation (AF and an improperly functioning PM. We observed that the twitching seemed to correspond with each pacing beat and that it did not appear with his own beat. We suspected that the twitching was due to electric current leakage from the broken RV lead. We performed a PM re-implantation with a screw-in RV lead using the extrathoracic approach. After re-implantation the twitching disappeared. Costoclavicular ligament related electrode lead fractures are not uncommon and electric current leaks can be a source of problems in cardiac pacing. In this case, the electric current leak from the broken RV lead at the costoclavicular ligament stimulated the left phrenic nerve.

  2. Dobutamine use for arrhythmia induction during electrical programmed heart stimulation

    International Nuclear Information System (INIS)

    Vanegas, Diego I; Perez, Climaco de J; Montenegro, Juan de J; Orjuela, Alejandro

    2006-01-01

    isoproterenol is the traditionally used drug for incrementing arrhythmia induction when this induction is not achieved during electric programmed heart stimulation under basal conditions. Dobutamine is an adrenergic agent, chemical precursor of isoproterenol, which can be an alternative for inducing arrhythmia during electrical programmed heart stimulation (PES). Patients and methods: a retrospective comparative study of the experience with dobutamine for inducing arrhythmia during electrical programmed heart stimulation was performed. The following data were collected: number of studies, data about the patient (medical record, age, gender, and study indication) protocol of programmed electrical stimulation, basal and under dobutamine or isoproterenol, and result of the study. Isoproterenol was used in doses of 1 to 3 micrograms per minute until the basal heart rate was incremented at least in 25%. Dobutamine was used in doses of 10 to 40 micrograms per kg of body weight, until obtaining the same increment in the basal heart rate. Results: 1054 electrophysiological studies were evaluated. In 144 patients (group A) isoproterenol was used and in 140, dobutamine (group B). In A group the mean age was 39.2 ± 16.2 and 58.3% were females. In-group B, mean age was 41.9 ± 18.6 and 51% were females. The most frequent symptom was palpitation and the most commonly induced arrhythmia was AV nodal reentry tachycardia in both groups. The induction of arrhythmia during the electrical programmed heat stimulation under drugs was similar in-group A (isoproterenol) respect to group B (dobutamine). Conclusions: There were no statistical significant differences in the induction of arrhythmia during electrical programmed heart stimulation using dobutamine or isoproterenol. Dobutamine may be safe and may be successfully used as an alternative to isoproterenol for arrhythmia induction during electrical programmed stimulation

  3. Performance of a fully automated program for measurement of left ventricular ejection fraction

    International Nuclear Information System (INIS)

    Douglass, K.H.; Tibbits, P.; Kasecamp, W.; Han, S.T.; Koller, D.; Links, J.M.; Wagner, H.H. Jr.

    1982-01-01

    A fully automated program developed by us for measurement of left ventricular ejection fraction from equilibrium gated blood studies was evaluated in 130 additional patients. Both of 6-min (130 studies) and 2-min (142 studies in 31 patients) gated blood pool studies were acquired and processed. The program successfully generated ejection fractions in 86% of the studies. These automatically generated ejection fractions were compared with ejection fractions derived from manually drawn regions the interest. When studies were acquired for 6-min with the patient at rest, the correlation between automated and manual ejection fractions was 0.92. When studies were acquired for 2-min, both at rest and during bicycle exercise, the correlation was 0.81. In 25 studies from patients who also underwent contrast ventriculography, the program successfully generated regions of interest in 22 (88%). The correlation between the ejection fraction determined by contrast ventriculography and the automatically generated radionuclide ejection fraction was 0.79. (orig.)

  4. Prospective Randomized Evaluation of Implantable Cardioverter-Defibrillator Programming in Patients With a Left Ventricular Assist Device.

    Science.gov (United States)

    Richardson, Travis D; Hale, Leslie; Arteaga, Christopher; Xu, Meng; Keebler, Mary; Schlendorf, Kelly; Danter, Matthew; Shah, Ashish; Lindenfeld, JoAnn; Ellis, Christopher R

    2018-02-23

    Ventricular arrhythmias are common in patients with left ventricular assist devices (LVADs) but are often hemodynamically tolerated. Optimal implantable cardioverter defibrillator (ICD) tachy-programming strategies in patients with LVAD have not been determined. We sought to determine if an ultra-conservative ICD programming strategy in patients with LVAD affects ICD shocks. Adult patients with an existing ICD undergoing continuous flow LVAD implantation were randomized to standard ICD programming by their treating physician or an ultra-conservative ICD programming strategy utilizing maximal allowable intervals to detection in the ventricular fibrillation and ventricular tachycardia zones with use of ATP. Patients with cardiac resynchronization therapy (CRT) devices were also randomized to CRT ON or OFF. Patients were followed a minimum of 6 months. The primary outcome was time to first ICD shock. Among the 83 patients studied, we found no statistically significant difference in time to first ICD shock or total ICD shocks between groups. In the ultra-conservative group 16% of patients experienced at least one shock compared with 21% in the control group ( P =0.66). There was no difference in mortality, arrhythmic hospitalization, or hospitalization for heart failure. In the 41 patients with CRT ICDs fewer shocks were observed with CRT-ON but this was not statistically significant: 10% of patients with CRT-ON (n=21) versus 38% with CRT-OFF (n=20) received shocks ( P =0.08). An ultra-conservative programming strategy did not reduce ICD shocks. Programming restrictions on ventricular tachycardia and ventricular fibrillation zone therapy should be reconsidered for the LVAD population. The role of CRT in patients with LVAD warrants further investigation. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01977703. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  5. Experience of a patient with an extracorporeal ventricular assist system who participated in a sleepover program.

    Science.gov (United States)

    Gon, Shigeyoshi; Suematsu, Yoshihito; Morizumi, Sei; Shimizu, Tsuyoshi

    2011-09-01

    A 19-year-old woman suffered fulminant myocarditis owing to a mycoplasma infection and was inserted with an intra-aortic balloon pump and a percutaneous cardiopulmonary support. Antibiotics and gamma globulin were administered, however, the patient's cardiac function did not recover, and the TOYOBO ventricular assist device (VAD) was implanted. She had rehabilitation training such as maintaining a standing position at the bedside and walking in the hospital, and a hospital outing program to a family restaurant was conducted two times with the VAD. The patient wished to attend the coming-of-age ceremony in Tachikawa city, which is 3 h away from our hospital by car. Therefore, we planned the program including a night stay at her home. The patient and her family fully understood the risks and wished to participate in the sleepover program. In preparing for the sleepover, the patient and her family learned to operate the VAD, and she was able to move to the lavatory and through the house with the help of only her family. A physician and a clinical engineer stayed at her house for infusion of antibiotics and management of sudden changes. There was no adverse event. In Japan, the community support of patients with VAD is not yet established, and we hope that our experience becomes a help to support return to society for patients with VAD.

  6. Potassium and magnesium distribution, ECG changes, and ventricular ectopic beats during beta 2-adrenergic stimulation with terbutaline in healthy subjects

    DEFF Research Database (Denmark)

    Tveskov, C; Djurhuus, M S; Klitgaard, N A

    1994-01-01

    OBJECTIVE: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects. DESIGN: Randomized double-blind, placebo-controlled crossover. Subjects received either placebo or terbu......OBJECTIVE: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects. DESIGN: Randomized double-blind, placebo-controlled crossover. Subjects received either placebo......-potassium pump number. Urinary excretion of potassium and magnesium. ECG changes (T-wave and QTC interval) and the number of ventricular ectopic beats. MAIN RESULTS: Terbutaline produced an immediate decrease in serum potassium level from 4.17 (4.04 to 4.30) mmol/L to a nadir of 3.32 (3.06 to 3.58) mmol/L (p ... of sodium-potassium pumps. Furthermore, terbutaline induced changes in ECG with a highly significant lengthening of the QTc interval but with an unchanged number of ventricular ectopic beats in healthy subjects....

  7. Dual-dye optical mapping after myocardial infarction: does the site of ventricular stimulation alter the properties of electrical propagation?

    Science.gov (United States)

    Saba, Samir; Mathier, Michael A; Mehdi, Haider; Liu, Tong; Choi, Bum-Rak; London, Barry; Salama, Guy

    2008-02-01

    Myocardial infarction (MI) disrupts electrical conduction in affected ventricular areas. We investigated the effect of MI on the regional voltage and calcium (Ca) signals and their propagation properties, with special attention to the effect of the site of ventricular pacing on these properties. New Zealand White rabbits were divided into four study groups: sham-operated (C, n = 6), MI with no pacing (MI, n = 7), MI with right ventricular pacing (MI + RV, n = 6), and MI with BIV pacing (MI + BIV, n = 7). At 4 weeks, hearts were excised, perfused, and optically mapped. As previously shown, systolic and diastolic dilation of the LV were prevented by BIV pacing, as was the reduction in LV fractional shortening. Four weeks after MI, optical mapping revealed markedly reduced action potential amplitudes and conduction velocities (CV) in MI zones, and these increased gradually in the border zone and normal myocardial areas. Also, Ca transients were absent in the infarcted areas and increased gradually 3-5 mm from the border of the normal zone. Neither BIV nor RV pacing affected these findings in any of the MI, border, or normal zones. MI has profound effects on the regional electrical and Ca signals and on their propagation properties in this rabbit model. The absence of differences in these parameters by study group suggests that altering the properties of myocardial electrical conduction and Ca signaling are unlikely mechanisms by which BIV pacing confers its benefits. Further studies into the regional, cellular, and molecular benefits of BIV pacing are therefore warranted.

  8. Effect of right ventricular electrode location (outflow tract vs. apex) on mechanical Ventricular synchrony in patients that underwent pacemaker implant therapy

    International Nuclear Information System (INIS)

    Rincon, Oscar S; Saenz, Luis C; Salazar, Gabriel; Hernandez, Edgar

    2008-01-01

    Objective: to assess in depth the effect of ventricular stimulation from the right ventricular outflow tract and the apex on mechanical ventricular synchrony. Materials And Methods: cohort analytical study. 20 patients with indication of definitive pacemaker indication underwent trans thoracic echocardiogram before and after pacemaker implant with electrode implantation in the right ventricular outflow tract and in the apex (10 patients in each group). There was no structural cardiopathy, ejection fraction was ? 50%, QRS and AV conduction were normal. Mechanical ventricular asynchrony (M mode and tissue doppler) and implant and device parameters were evaluated. Statistical Analysis: results are given as mean values, standard deviation or percentages.Continuous variables were compared using Chi-square test and ANOVA. A p <0.05 value was considered statistically significant. Results: in five patients (25%) a pre-implant ventricular asynchrony was found; in seven (70%) ventricular asynchrony post-implant in the right ventricle outflow tract and in 5 (50%) in the apex. Mean interventricular pot-implant delay was 21,6 ms in the right ventricular outflow tract and 11,5 ms in the apex (p = 0,8); mean septal to lateral wall delay was 73 ms in the right ventricular outflow tract and 26 ms in the apex (p = 0,8). QRS post-implant delay was 134 ms in the right ventricular outflow tract and 140 ms in the apex (p = 0,1). No differences between implant parameters and device programming were found. Conclusions: presence of ventricular asynchrony was evidenced in patients with normal QRS and structurally healthy heart. Ventricular stimulation with pacemaker from the apex or the right ventricular outflow tract suggests acute ventricular asynchrony at least in 60% of the cases, without statistically significant difference between both groups.

  9. Particle swarm optimization for programming deep brain stimulation arrays.

    Science.gov (United States)

    Peña, Edgar; Zhang, Simeng; Deyo, Steve; Xiao, YiZi; Johnson, Matthew D

    2017-02-01

    Deep brain stimulation (DBS) therapy relies on both precise neurosurgical targeting and systematic optimization of stimulation settings to achieve beneficial clinical outcomes. One recent advance to improve targeting is the development of DBS arrays (DBSAs) with electrodes segmented both along and around the DBS lead. However, increasing the number of independent electrodes creates the logistical challenge of optimizing stimulation parameters efficiently. Solving such complex problems with multiple solutions and objectives is well known to occur in biology, in which complex collective behaviors emerge out of swarms of individual organisms engaged in learning through social interactions. Here, we developed a particle swarm optimization (PSO) algorithm to program DBSAs using a swarm of individual particles representing electrode configurations and stimulation amplitudes. Using a finite element model of motor thalamic DBS, we demonstrate how the PSO algorithm can efficiently optimize a multi-objective function that maximizes predictions of axonal activation in regions of interest (ROI, cerebellar-receiving area of motor thalamus), minimizes predictions of axonal activation in regions of avoidance (ROA, somatosensory thalamus), and minimizes power consumption. The algorithm solved the multi-objective problem by producing a Pareto front. ROI and ROA activation predictions were consistent across swarms (<1% median discrepancy in axon activation). The algorithm was able to accommodate for (1) lead displacement (1 mm) with relatively small ROI (⩽9.2%) and ROA (⩽1%) activation changes, irrespective of shift direction; (2) reduction in maximum per-electrode current (by 50% and 80%) with ROI activation decreasing by 5.6% and 16%, respectively; and (3) disabling electrodes (n  =  3 and 12) with ROI activation reduction by 1.8% and 14%, respectively. Additionally, comparison between PSO predictions and multi-compartment axon model simulations showed discrepancies

  10. Particle Swarm Optimization for Programming Deep Brain Stimulation Arrays

    Science.gov (United States)

    Peña, Edgar; Zhang, Simeng; Deyo, Steve; Xiao, YiZi; Johnson, Matthew D.

    2017-01-01

    Objective Deep brain stimulation (DBS) therapy relies on both precise neurosurgical targeting and systematic optimization of stimulation settings to achieve beneficial clinical outcomes. One recent advance to improve targeting is the development of DBS arrays (DBSAs) with electrodes segmented both along and around the DBS lead. However, increasing the number of independent electrodes creates the logistical challenge of optimizing stimulation parameters efficiently. Approach Solving such complex problems with multiple solutions and objectives is well known to occur in biology, in which complex collective behaviors emerge out of swarms of individual organisms engaged in learning through social interactions. Here, we developed a particle swarm optimization (PSO) algorithm to program DBSAs using a swarm of individual particles representing electrode configurations and stimulation amplitudes. Using a finite element model of motor thalamic DBS, we demonstrate how the PSO algorithm can efficiently optimize a multi-objective function that maximizes predictions of axonal activation in regions of interest (ROI, cerebellar-receiving area of motor thalamus), minimizes predictions of axonal activation in regions of avoidance (ROA, somatosensory thalamus), and minimizes power consumption. Main Results The algorithm solved the multi-objective problem by producing a Pareto front. ROI and ROA activation predictions were consistent across swarms (<1% median discrepancy in axon activation). The algorithm was able to accommodate for (1) lead displacement (1 mm) with relatively small ROI (≤9.2%) and ROA (≤1%) activation changes, irrespective of shift direction; (2) reduction in maximum per-electrode current (by 50% and 80%) with ROI activation decreasing by 5.6% and 16%, respectively; and (3) disabling electrodes (n=3 and 12) with ROI activation reduction by 1.8% and 14%, respectively. Additionally, comparison between PSO predictions and multi-compartment axon model simulations

  11. Effects of AV delay programming on ventricular resynchronisation: role of radionuclide ventriculography

    Energy Technology Data Exchange (ETDEWEB)

    Siegrist, Patrick T.; Comte, Nathalie; Holzmeister, Johannes; Suetsch, Gabor; Koepfli, Pascal; Namdar, Mehdi; Duru, Firat; Brunckhorst, Corinna; Scharf, Christoph [Universitiy Hospital Zurich NUK C 32, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [Universitiy Hospital Zurich NUK C 32, Cardiovascular Center, Zurich (Switzerland); University of Zurich, Zurich Center for Integrative Human Physiology, Zurich (Switzerland)

    2008-08-15

    Optimal atrioventricular delay (AVD) setting for cardiac resynchronisation therapy, i.e. biventricular pacing in patients with heart failure, remains a formidable challenge. Thus, the purpose of this study was to evaluate the effects of different AVD on inter- and intra-ventricular resynchronisation using phase histograms of radionuclide ventriculography (RNV). In 17 consecutive patients (mean age 64 {+-} 6 years), RNV was performed 236 {+-} 350 days after pacemaker implantation for cardiac resynchronisation therapy. Images were acquired during atrial pacing at 80 bpm and during biventricular pacing with AVD ranging from 80 to 160 ms. Inter-ventricular dyssynchrony was measured by the delay between the mean phase angles of the left and right ventricles. Intra-ventricular dyssynchrony was measured by the standard deviation (SD) of left ventricular phase histograms. Left ventricular (LV) ejection fraction (EF) was inversely correlated to LV dyssynchrony (SD of LV phase histogram, R = -0.82, p < 0.0001). However, the increase in LVEF by biventricular pacing (mean +4.4 {+-} 4%) showed only modest correlation to the resulting resynchronisation effect (characterised by a -13 {+-} 8 decrease in LV phase histogram SD, R = -0.38, p < 0.0001). RNV is helpful in optimising pacing parameters for resynchronisation therapy. Varying AVD did not have a major impact on intra- or inter-ventricular resynchronisation. Thus, the benefit of AVD-based LVEF optimisation seems to result from atrioventricular resynchronisation. (orig.)

  12. Remodelling of cardiac sympathetic re-innervation with thoracic spinal cord stimulation improves left ventricular function in a porcine model of heart failure.

    Science.gov (United States)

    Liao, Song-Yan; Liu, Yuan; Zuo, Mingliang; Zhang, Yuelin; Yue, Wensheng; Au, Ka-Wing; Lai, Wing-Hon; Wu, Yangsong; Shuto, Chika; Chen, Peter; Siu, Chung-Wah; Schwartz, Peter J; Tse, Hung-Fat

    2015-12-01

    Thoracic spinal cord stimulation (SCS) has been shown to improve left ventricular ejection fraction (LVEF) in heart failure (HF). Nevertheless, the optimal duration (intermittent vs. continuous) of stimulation and the mechanisms of action remain unclear. We performed chronic thoracic SCS at the level of T1-T3 (50 Hz, pulse width 0.2 ms) in 30 adult pigs with HF induced by myocardial infarction and rapid ventricular pacing for 4 weeks. All the animals were treated with daily oral metoprolol succinate (25 mg) plus ramipril (2.5 mg), and randomized to a control group (n = 10), intermittent SCS (4 h ×3, n = 10) or continuous SCS (24 h, n = 10) for 10 weeks. Serial measurements of LVEF and +dP/dt and serum levels of norepinephrine and B-type natriuretic peptide (BNP) were measured. After sacrifice, immunohistological studies of myocardial sympathetic and parasympathetic nerve sprouting and innervation were performed. Echocardiogram revealed a significant increase in LVEF and +dP/dt at 10 weeks in both the intermittent and continuous SCS group compared with controls (P < 0.05). In both SCS groups, there was diffuse sympathetic nerve sprouting over the infarct, peri-infarct, and normal regions compared with only the peri-infarct and infarct regions in the control group. In addition, sympathetic innervation at the peri-infarct and infarct regions was increased following SCS, but decreased in the control group. Myocardium norepinephrine spillover and serum BNP at 10 weeks was significantly decreased only in the continuous SCS group (P < 0.05). In a porcine model of HF, SCS induces significant remodelling of cardiac sympathetic innervation over the peri-infarct and infarct regions and is associated with improved LV function and reduced myocardial norepinephrine spillover. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  13. An Echocardiography Training Program for Improving the Left Ventricular Function Interpretation in Emergency Department; a Brief Report

    Directory of Open Access Journals (Sweden)

    Mary S. Jacob

    2017-06-01

    Full Text Available Introduction: Focused training in transthoracic echocardiography enables emergency physicians (EPs to accurately estimate the left ventricular function. This study aimed to evaluate the efficacy of a brief training program utilizing standardized echocardiography video clips in this regard. Methods: A before and after design was used to determine the efficacy of a 1 hour echocardiography training program using PowerPoint presentation and standardized echocardiography video clips illustrating normal and abnormal left ventricular ejection fraction (LVEF as well as video clips emphasizing the measurement of mitral valve E-point septal separation (EPSS. Pre- and post-test evaluation used unique video clips and asked trainees to estimate LVEF and EPSS based on the viewed video clips. Results: 21 EPs with no prior experience with the echocardiographic technical methods completed this study. The EPs had very limited prior echocardiographic training. The mean score on the categorization of LVEF estimation improved from 4.9 (95% CI: 4.1-5.6 to 7.6 (95%CI: 7-8.3 out of a possible 10 score (p<0.0001. Categorization of EPSS improved from 4.1 (95% CI: 3.1-5.1 to 8.1 (95% CI: 7.6- 8.7 after education (p<0.0001. Conclusions: The results of this study demonstrate a statistically significant improvement of EPs’ ability to categorize left ventricular function as normal or depressed, after a short lecture utilizing a commercially available DVD of standardized echocardiography clips.

  14. Different brain activation under left and right ventricular stimulation: an fMRI study in anesthetized rats.

    Science.gov (United States)

    Suzuki, Hideaki; Sumiyoshi, Akira; Kawashima, Ryuta; Shimokawa, Hiroaki

    2013-01-01

    Myocardial ischemia in the anterior wall of the left ventricule (LV) and in the inferior wall and/or right ventricle (RV) shows different manifestations that can be explained by the different innervations of cardiac afferent nerves. However, it remains unclear whether information from different areas of the heart, such as the LV and RV, are differently processed in the brain. In this study, we investigated the brain regions that process information from the LV or RV using cardiac electrical stimulation and functional magnetic resonance imaging (fMRI) in anesthetized rats because the combination of these two approaches cannot be used in humans. An electrical stimulation catheter was inserted into the LV or RV (n = 12 each). Brain fMRI scans were recorded during LV or RV stimulation (9 Hz and 0.3 ms width) over 10 blocks consisting of alternating periods of 2 mA for 30 sec followed by 0.2 mA for 60 sec. The validity of fMRI signals was confirmed by first and second-level analyses and temporal profiles. Increases in fMRI signals were observed in the anterior cingulate cortex and the right somatosensory cortex under LV stimulation. In contrast, RV stimulation activated the right somatosensory cortex, which was identified more anteriorly compared with LV stimulation but did not activate the anterior cingulate cortex. This study provides the first evidence for differences in brain activation under LV and RV stimulation. These different brain processes may be associated with different clinical manifestations between anterior wall and inferoposterior wall and/or RV myocardial ischemia.

  15. [Cognitive plasticity in Alzheimer's disease patients receiving cognitive stimulation programs].

    Science.gov (United States)

    Zamarrón Cassinello, Ma Dolores; Tárraga Mestre, Luis; Fernández-Ballesteros, Rocío

    2008-08-01

    The main purpose of this article is to examine whether cognitive plasticity increases after cognitive training in Alzheimer's disease patients. Twenty six patients participated in this study, all of them diagnosed with mild Alzheimer's disease, 17 of them received a cognitive training program during 6 months, and the other 9 were assigned to the control group. Participants were assigned to experimental or control conditions for clinical reasons. In order to assess cognitive plasticity, all patients were assessed before and after treatment with three subtests from the "Bateria de Evaluación de Potencial de Aprendizaje en Demencias" [Assessment Battery of Learning Potential in Dementia] (BEPAD). After treatment, Alzheimer's disease patients improved their performance in all the tasks assessing cognitive plasticity: viso-spatial memory, audio-verbal memory and verbal fluency. However, the cognitive plasticity scores of the patients in the control group decreased. In conclusion, this study showed that cognitive stimulation programs can improve cognitive functioning in mildly demented patients, and patients who do not receive any cognitive interventions may reduce their cognitive functioning.

  16. Right ventricular function in patients with ischemic heart disease

    International Nuclear Information System (INIS)

    Araki, Haruo; Hisano, Ryuichi; Nagata, Yoshiyuki; Caglar, N.; Nakamura, Motoomi

    1985-01-01

    Thirty-five patients with ischemic heart disease (IHD) and 10 normal subjects were studied. Right and left ventricular ejecction fractions (EF) were determined using equilibrium radionuclide ventriculography with technetium-99m. Furthermore, abnormal motion of the right ventricular septal wall was obtained by cardiac cathetelization, and its relation to the right ventricular EF was examined. In IHD patients with anterior myocardial infarction, left ventricular EF decreased, but right ventricular EF was normal. This suggested that left ventricular dysfunction does not always have an effect on right ventricular function. Right ventricular EF was normal even when akinesis or dyskinesis was present in the ventricular septul, suggesting that abnormal motion of the ventricular septal wall has no significantly stimulant effect on right ventricular function. A decreased right ventricular EF was likely to occur only when the right ventricular free wall became ischemic or necrotic simultaneously with occurrence of posterior myocardial infarction. (Namekawa, K.)

  17. Chinese expert consensus on programming deep brain stimulation for patients with Parkinson's disease.

    Science.gov (United States)

    Chen, Shengdi; Gao, Guodong; Feng, Tao; Zhang, Jianguo

    2018-01-01

    Deep Brain Stimulation (DBS) therapy for the treatment of Parkinson's Disease (PD) is now a well-established option for some patients. Postoperative standardized programming processes can improve the level of postoperative management and programming, relieve symptoms and improve quality of life. In order to improve the quality of the programming, the experts on DBS and PD in neurology and neurosurgery in China reviewed the relevant literatures and combined their own experiences and developed this expert consensus on the programming of deep brain stimulation in patients with PD in China. This Chinese expert consensus on postoperative programming can standardize and improve postoperative management and programming of DBS for PD.

  18. Programming Deep Brain Stimulation for Parkinson's Disease: The Toronto Western Hospital Algorithms.

    Science.gov (United States)

    Picillo, Marina; Lozano, Andres M; Kou, Nancy; Puppi Munhoz, Renato; Fasano, Alfonso

    2016-01-01

    Deep brain stimulation (DBS) is an established and effective treatment for Parkinson's disease (PD). After surgery, a number of extensive programming sessions are performed to define the most optimal stimulation parameters. Programming sessions mainly rely only on neurologist's experience. As a result, patients often undergo inconsistent and inefficient stimulation changes, as well as unnecessary visits. We reviewed the literature on initial and follow-up DBS programming procedures and integrated our current practice at Toronto Western Hospital (TWH) to develop standardized DBS programming protocols. We propose four algorithms including the initial programming and specific algorithms tailored to symptoms experienced by patients following DBS: speech disturbances, stimulation-induced dyskinesia and gait impairment. We conducted a literature search of PubMed from inception to July 2014 with the keywords "deep brain stimulation", "festination", "freezing", "initial programming", "Parkinson's disease", "postural instability", "speech disturbances", and "stimulation induced dyskinesia". Seventy papers were considered for this review. Based on the literature review and our experience at TWH, we refined four algorithms for: (1) the initial programming stage, and management of symptoms following DBS, particularly addressing (2) speech disturbances, (3) stimulation-induced dyskinesia, and (4) gait impairment. We propose four algorithms tailored to an individualized approach to managing symptoms associated with DBS and disease progression in patients with PD. We encourage established as well as new DBS centers to test the clinical usefulness of these algorithms in supplementing the current standards of care. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Alteration of left ventricular endocardial function by intracavitary high-power ultrasound interacts with volume, inotropic state, and alpha 1-adrenergic stimulation

    NARCIS (Netherlands)

    de Hert, S. G.; Gillebert, T. C.; Brutsaert, D. L.

    1993-01-01

    BACKGROUND: High-power intracavitary ultrasound abbreviates left ventricular (LV) ejection duration, thereby decreasing mechanical LV performance, presumably by selective impairment of endocardial endothelial function. METHODS AND RESULTS: Effects of ultrasound were evaluated in the ejecting LV of

  20. The CCH Vision Stimulation Program for Infants with Low Vision: Preliminary Results.

    Science.gov (United States)

    Leguire, L. E.; And Others

    1992-01-01

    This study evaluated the Columbus (Ohio) Children's Hospital vision stimulation program, involving in-home intervention with 15 visually impaired infants. Comparison with controls indicated benefits of appropriate vision stimulation in increasing the neural foundation for vision and visual-motor function in visually impaired infants. (Author/DB)

  1. A Mobile Early Stimulation Program to Support Children with Developmental Delays in Brazil.

    Science.gov (United States)

    Dias, Raquel da Luz; Silva, Kátia Cristina Correa Guimarães; Lima, Marcela Raquel de Oliveira; Alves, João Guilherme Bezerra; Abidi, Syed Sibte Raza

    2018-01-01

    Developmental delay is a deviation development from the normative milestones during the childhood and it may be caused by neurological disorders. Early stimulation is a standardized and simple technique to treat developmental delays in children (aged 0-3 years), allowing them to reach the best development possible and to mitigate neuropsychomotor sequelae. However, the outcomes of the treatment depending on the involvement of the family, to continue the activities at home on a daily basis. To empower and educate parents of children with neurodevelopmental delays to administer standardized early stimulation programs at home, we developed a mobile early stimulation program that provides timely and evidence-based clinical decision support to health professionals and a personalized guidance to parents about how to administer early stimulation to their child at home.

  2. Comparison of skin sensory thresholds using pre-programmed or single-frequency transcutaneous electrical nerve stimulation.

    Science.gov (United States)

    Kang, Jong Ho

    2015-12-01

    [Purpose] The purpose of the present study was to compare the sensory thresholds of healthy subjects using pre-programmed or single-frequency transcutaneous electrical nerve stimulation. [Subjects] Ninety healthy adult subjects were randomly assigned to pre-programmed or single-frequency stimulation groups, each consisting of 45 participants. [Methods] Sensory thresholds were measured in the participants' forearms using von Frey filaments before and after pre-programmed or single-frequency transcutaneous electrical nerve stimulation, and the result in values were analyzed. [Results] Significant increases in sensory threshold after stimulation were observed in both groups. However, there were no significant differences between the two groups in sensory thresholds after stimulation or in the magnitude of threshold increases following stimulation. [Conclusion] Our results show that there are no differences between sensory threshold increases induced by pre-programmed and single-frequency transcutaneous electrical nerve stimulation.

  3. Alternative right ventricular pacing sites.

    Science.gov (United States)

    Łuciuk, Dariusz; Łuciuk, Marek; Gajek, Jacek

    2015-01-01

    The main adverse effect of chronic stimulation is stimulation-induced heart failure in case of ventricular contraction dyssynchrony. Because of this fact, new techniques of stimulation should be considered to optimize electrotherapy. One of these methods is pacing from alternative right ventricular sites. The purpose of this article is to review currently accumulated data about alternative sites of cardiac pacing. Medline and PubMed bases were used to search English and Polish reports published recently. Recent studies report a deleterious effect of long term apical pacing. It is suggested that permanent apical stimulation, by omitting physiological conduction pattern with His-Purkinie network, may lead to electrical and mechanical dyssynchrony of heart muscle contraction. In the long term this pathological situation can lead to severe heart failure and death. Because of this, scientists began to search for some alternative sites of cardiac pacing to reduce the deleterious effect of stimulation. Based on current accumulated data, it is suggested that the right ventricular outflow tract, right ventricular septum, direct His-bundle or biventricular pacing are better alternatives due to more physiological electrical impulse propagation within the heart and the reduction of the dyssynchrony effect. These methods should preserve a better left ventricular function and prevent the development of heart failure in permanent paced patients. As there is still not enough, long-term, randomized, prospective, cross-over and multicenter studies, further research is required to validate the benefits of using this kind of therapy. The article should pay attention to new sites of cardiac stimulation as a better and safer method of treatment.

  4. Probe code: a set of programs for processing and analysis of the left ventricular function - User's manual

    International Nuclear Information System (INIS)

    Piva, R.M.V.

    1987-01-01

    The User's Manual of the Probe Code is an addendum to the M.Sc. thesis entitled A Microcomputer System of Nuclear Probe to Check the Left Ventricular Function. The Probe Code is a software which was developed for processing and off-line analysis curves from the Left Ventricular Function, that were obtained in vivo. These curves are produced by means of an external scintigraph probe, which was collimated and put on the left ventricule, after a venous inoculation of Tc-99 m. (author)

  5. Programming Deep Brain Stimulation for Tremor and Dystonia: The Toronto Western Hospital Algorithms.

    Science.gov (United States)

    Picillo, Marina; Lozano, Andres M; Kou, Nancy; Munhoz, Renato Puppi; Fasano, Alfonso

    2016-01-01

    Deep brain stimulation (DBS) is an effective treatment for essential tremor (ET) and dystonia. After surgery, a number of extensive programming sessions are performed, mainly relying on neurologist's personal experience as no programming guidelines have been provided so far, with the exception of recommendations provided by groups of experts. Finally, fewer information is available for the management of DBS in ET and dystonia compared with Parkinson's disease. Our aim is to review the literature on initial and follow-up DBS programming procedures for ET and dystonia and integrate the results with our current practice at Toronto Western Hospital (TWH) to develop standardized DBS programming protocols. We conducted a literature search of PubMed from inception to July 2014 with the keywords "balance", "bradykinesia", "deep brain stimulation", "dysarthria", "dystonia", "gait disturbances", "initial programming", "loss of benefit", "micrographia", "speech", "speech difficulties" and "tremor". Seventy-six papers were considered for this review. Based on the literature review and our experience at TWH, we refined three algorithms for management of ET, including: (1) initial programming, (2) management of balance and speech issues and (3) loss of stimulation benefit. We also depicted algorithms for the management of dystonia, including: (1) initial programming and (2) management of stimulation-induced hypokinesia (shuffling gait, micrographia and speech impairment). We propose five algorithms tailored to an individualized approach to managing ET and dystonia patients with DBS. We encourage the application of these algorithms to supplement current standards of care in established as well as new DBS centers to test the clinical usefulness of these algorithms in supplementing the current standards of care. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Programming Cardiac Resynchronization Therapy for Electrical Synchrony: Reaching Beyond Left Bundle Branch Block and Left Ventricular Activation Delay.

    Science.gov (United States)

    Varma, Niraj; O'Donnell, David; Bassiouny, Mohammed; Ritter, Philippe; Pappone, Carlo; Mangual, Jan; Cantillon, Daniel; Badie, Nima; Thibault, Bernard; Wisnoskey, Brian

    2018-02-06

    QRS narrowing following cardiac resynchronization therapy with biventricular (BiV) or left ventricular (LV) pacing is likely affected by patient-specific conduction characteristics (PR, qLV, LV-paced propagation interval), making a universal programming strategy likely ineffective. We tested these factors using a novel, device-based algorithm (SyncAV) that automatically adjusts paced atrioventricular delay (default or programmable offset) according to intrinsic atrioventricular conduction. Seventy-five patients undergoing cardiac resynchronization therapy (age 66±11 years; 65% male; 32% with ischemic cardiomyopathy; LV ejection fraction 28±8%; QRS duration 162±16 ms) with intact atrioventricular conduction (PR interval 194±34, range 128-300 ms), left bundle branch block, and optimized LV lead position were studied at implant. QRS duration (QRSd) reduction was compared for the following pacing configurations: nominal simultaneous BiV (Mode I: paced/sensed atrioventricular delay=140/110 ms), BiV+SyncAV with 50 ms offset (Mode II), BiV+SyncAV with offset that minimized QRSd (Mode III), or LV-only pacing+SyncAV with 50 ms offset (Mode IV). The intrinsic QRSd (162±16 ms) was reduced to 142±17 ms (-11.8%) by Mode I, 136±14 ms (-15.6%) by Mode IV, and 132±13 ms (-17.8%) by Mode II. Mode III yielded the shortest overall QRSd (123±12 ms, -23.9% [ P <0.001 versus all modes]) and was the only configuration without QRSd prolongation in any patient. QRS narrowing occurred regardless of QRSd, PR, or LV-paced intervals, or underlying ischemic disease. Post-implant electrical optimization in already well-selected patients with left bundle branch block and optimized LV lead position is facilitated by patient-tailored BiV pacing adjusted to intrinsic atrioventricular timing using an automatic device-based algorithm. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  7. Analysis of the Thermal and Hydraulic Stimulation Program at Raft River, Idaho

    Science.gov (United States)

    Bradford, Jacob; McLennan, John; Moore, Joseph; Podgorney, Robert; Plummer, Mitchell; Nash, Greg

    2017-05-01

    The Raft River geothermal field, located in southern Idaho, roughly 100 miles northwest of Salt Lake City, is the site of a Department of Energy Enhanced Geothermal System project designed to develop new techniques for enhancing the permeability of geothermal wells. RRG-9 ST1, the target stimulation well, was drilled to a measured depth of 5962 ft. and cased to 5551 ft. The open-hole section of the well penetrates Precambrian quartzite and quartz monzonite. The well encountered a temperature of 282 °F at its base. Thermal and hydraulic stimulation was initiated in June 2013. Several injection strategies have been employed. These strategies have included the continuous injection of water at temperatures ranging from 53 to 115 °F at wellhead pressures of approximately 275 psi and three short-term hydraulic stimulations at pressures up to approximately 1150 psi. Flow rates, wellhead and line pressures and fluid temperatures are measured continuously. These data are being utilized to assess the effectiveness of the stimulation program. As of August 2014, nearly 90 million gallons have been injected. A modified Hall plot has been used to characterize the relationships between the bottom-hole flowing pressure and the cumulative injection fluid volume. The data indicate that the skin factor is decreased, and/or the permeability around the wellbore has increased since the stimulation program was initiated. The injectivity index also indicates a positive improvement with values ranging from 0.15 gal/min psi in July 2013 to 1.73 gal/min psi in February 2015. Absolute flow rates have increased from approximately 20 to 475 gpm by February 2 2015. Geologic, downhole temperature and seismic data suggest the injected fluid enters a fracture zone at 5650 ft and then travels upward to a permeable horizon at the contact between the Precambrian rocks and the overlying Tertiary sedimentary and volcanic deposits. The reservoir simulation program FALCON developed at the Idaho National

  8. Timing of granulocyte-colony stimulating factor treatment after acute myocardial infarction and recovery of left ventricular function: results from the STEMMI trial

    DEFF Research Database (Denmark)

    Overgaard, Mikkel; Ripa, Rasmus Sejersten; Wang, Yongzhong

    2010-01-01

    Granulocyte-colony stimulating factor (G-CSF) therapy after ST-elevation myocardial infarction (STEMI) have not demonstrated impact on systolic recovery compared to placebo. However, recent studies suggest that timing of G-CSF therapy is crucial.......Granulocyte-colony stimulating factor (G-CSF) therapy after ST-elevation myocardial infarction (STEMI) have not demonstrated impact on systolic recovery compared to placebo. However, recent studies suggest that timing of G-CSF therapy is crucial....

  9. A Mixed Integer Linear Programming Approach to Electrical Stimulation Optimization Problems.

    Science.gov (United States)

    Abouelseoud, Gehan; Abouelseoud, Yasmine; Shoukry, Amin; Ismail, Nour; Mekky, Jaidaa

    2018-02-01

    Electrical stimulation optimization is a challenging problem. Even when a single region is targeted for excitation, the problem remains a constrained multi-objective optimization problem. The constrained nature of the problem results from safety concerns while its multi-objectives originate from the requirement that non-targeted regions should remain unaffected. In this paper, we propose a mixed integer linear programming formulation that can successfully address the challenges facing this problem. Moreover, the proposed framework can conclusively check the feasibility of the stimulation goals. This helps researchers to avoid wasting time trying to achieve goals that are impossible under a chosen stimulation setup. The superiority of the proposed framework over alternative methods is demonstrated through simulation examples.

  10. Efecto de la localización del electrodo ventricular derecho (tracto de salida vs. ápex sobre la sincronía ventricular mecánica, en pacientes sometidos a terapia de implante de marcapaso cardiaco Effect of right ventricular electrode location (outflow tract vs. apex on mechanical ventricular synchrony in patients that underwent pacemaker implant therapy

    Directory of Open Access Journals (Sweden)

    Oscar S Rincón

    2008-12-01

    post-implant in the right ventricle outflow tract and in 5 (50% in the apex. Mean interventricular pot-implant delay was 21,6 ms in the right ventricular outflow tract and 11,5 ms in the apex (p = 0,8; mean septal to lateral wall delay was 73 ms in the right ventricular outflow tract and 26 ms in the apex (p = 0,8. QRS post-implant delay was 134 ms in the right ventricular outflow tract and 140 ms in the apex (p = 0,1. No differences between implant parameters and device programming were found. Conclusions: presence of ventricular asynchrony was evidenced in patients with normal QRS and structurally healthy heart. Ventricular stimulation with pacemaker from the apex or the right ventricular outflow tract suggests acute ventricular asynchrony at least in 60% of the cases, without statistically significant difference between both groups.

  11. Survival After Ventricular Fibrillation Cardiac Arrest in the Sao Paulo Metropolitan Subway System: First Successful Targeted Automated External Defibrillator (AED) Program in Latin America.

    Science.gov (United States)

    Gianotto-Oliveira, Renan; Gonzalez, Maria Margarita; Vianna, Caio Brito; Monteiro Alves, Maurício; Timerman, Sergio; Kalil Filho, Roberto; Kern, Karl B

    2015-10-09

    Targeted automated external defibrillator (AED) programs have improved survival rates among patients who have an out-of-hospital cardiac arrest (OHCA) in US airports, as well as European and Japanese railways. The Sao Paulo (Brazil) Metro subway carries 4.5 million people per day. A targeted AED program was begun in the Sao Paulo Metro with the objective to improve survival from cardiac arrest. A prospective, longitudinal, observational study of all cardiac arrests in the Sao Paulo Metro was performed from September 2006 through November 2012. This study focused on cardiac arrest by ventricular arrhythmias, and the primary endpoint was survival to hospital discharge with minimal neurological impairment. A total of 62 patients had an initial cardiac rhythm of ventricular fibrillation. Because no data on cardiac arrest treatment or outcomes existed before beginning this project, the first 16 months of the implementation was used as the initial experience and compared with the subsequent 5 years of full operation. Return of spontaneous circulation was not different between the initial 16 months and the subsequent 5 years (6 of 8 [75%] vs. 39 of 54 [72%]; P=0.88). However, survival to discharge was significantly different once the full program was instituted (0 of 8 vs. 23 of 54 [43%]; P=0.001). Implementation of a targeted AED program in the Sao Paulo Metro subway system saved lives. A short interval between arrest and defibrillation was key for good long-term, neurologically intact survival. These results support strategic expansion of targeted AED programs in other large Latin American cities. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  12. Surgical neuroanatomy and programming in deep brain stimulation for obsessive compulsive disorder.

    Science.gov (United States)

    Morishita, Takashi; Fayad, Sarah M; Goodman, Wayne K; Foote, Kelly D; Chen, Dennis; Peace, David A; Rhoton, Albert L; Okun, Michael S

    2014-06-01

    Deep brain stimulation (DBS) has been established as a safe, effective therapy for movement disorders (Parkinson's disease, essential tremor, etc.), and its application is expanding to the treatment of other intractable neuropsychiatric disorders including depression and obsessive-compulsive disorder (OCD). Several published studies have supported the efficacy of DBS for severely debilitating OCD. However, questions remain regarding the optimal anatomic target and the lack of a bedside programming paradigm for OCD DBS. Management of OCD DBS can be highly variable and is typically guided by each center's individual expertise. In this paper, we review the various approaches to targeting and programming for OCD DBS. We also review the clinical experience for each proposed target and discuss the relevant neuroanatomy. A PubMed review was performed searching for literature on OCD DBS and included all articles published before March 2012. We included all available studies with a clear description of the anatomic targets, programming details, and the outcomes. Six different DBS approaches were identified. High-frequency stimulation with high voltage was applied in most cases, and predictive factors for favorable outcomes were discussed in the literature. DBS remains an experimental treatment for medication refractory OCD. Target selection and programming paradigms are not yet standardized, though an improved understanding of the relationship between the DBS lead and the surrounding neuroanatomic structures will aid in the selection of targets and the approach to programming. We propose to form a registry to track OCD DBS cases for future clinical study design. © 2013 International Neuromodulation Society.

  13. Physical activity stimulation program for children with cerebral palsy did not improve physical activity: a randomised trial

    NARCIS (Netherlands)

    van Wely, L.; Balemans, A.C.J.; Becher, J.G.; Dallmeijer, A.J.

    2014-01-01

    Question: In children with cerebral palsy, does a 6-month physical activity stimulation program improve physical activity, mobility capacity, fitness, fatigue and attitude towards sports more than usual paediatric physiotherapy? Design: Multicentre randomised controlled trial with concealed

  14. Co-regulation of the atrial natriuretic factor and cardiac myosin light chain-2 genes during alpha-adrenergic stimulation of neonatal rat ventricular cells. Identification of cis sequences within an embryonic and a constitutive contractile protein gene which mediate inducible expression.

    Science.gov (United States)

    Knowlton, K U; Baracchini, E; Ross, R S; Harris, A N; Henderson, S A; Evans, S M; Glembotski, C C; Chien, K R

    1991-04-25

    To study the mechanisms which mediate the transcriptional activation of cardiac genes during alpha adrenergic stimulation, the present study examined the regulated expression of three cardiac genes, a ventricular embryonic gene (atrial natriuretic factor, ANF), a constitutively expressed contractile protein gene (cardiac MLC-2), and a cardiac sodium channel gene. alpha 1-Adrenergic stimulation activates the expression and release of ANF from neonatal ventricular cells. As assessed by RNase protection analyses, treatment with alpha-adrenergic agonists increases the steady-state levels of ANF mRNA by greater than 15-fold. However, a rat cardiac sodium channel gene mRNA is not induced, indicating that alpha-adrenergic stimulation does not lead to an increase in the expression of all cardiac genes. Studies employing a series of rat ANF luciferase and rat MLC-2 luciferase fusion genes identify 315- and 92-base pair cis regulatory sequences within an embryonic gene (ANF) and a constitutively expressed contractile protein gene (MLC-2), respectively, which mediate alpha-adrenergic-inducible gene expression. Transfection of various ANF luciferase reporters into neonatal rat ventricular cells demonstrated that upstream sequences which mediate tissue-specific expression (-3003 to -638) can be segregated from those responsible for inducibility. The lack of inducibility of a cardiac Na+ channel gene, and the segregation of ANF gene sequences which mediate cardiac specific from those which mediate inducible expression, provides further insight into the relationship between muscle-specific and inducible expression during cardiac myocyte hypertrophy. Based on these results, a testable model is proposed for the induction of embryonic cardiac genes and constitutively expressed contractile protein genes and the noninducibility of a subset of cardiac genes during alpha-adrenergic stimulation of neonatal rat ventricular cells.

  15. Can electrical stimulation enhance effects of a functional training program in hospitalized geriatric patients?

    Science.gov (United States)

    Zinglersen, Amanda Hempel; Halsteen, Malte Bjoern; Kjaer, Michael; Karlsen, Anders

    2018-06-01

    Hospitalization of older medical patients may lead to functional decline. This study investigated whether simultaneously applied neuromuscular electrical stimulation (NMES) can enhance the effects of a functional training program in hospitalized geriatric patients. This was a quasi-randomized controlled trial in geriatric hospitalized patients (N = 16, age = 83.1 ± 8.1 years, mean ± SD). The patients performed a simple and time efficient chair-stand based functional exercise program daily, either with (FT + NMES, N = 8) or without (FT, N = 8) simultaneous NMES to the knee extensor muscles. Physical function was assessed at day 2 and 6-10 of the hospitalization with the De Morton Mobility Index (DEMMI), a 30-second chair stand test (30 s-CST) and a 4-meter gait speed test (4 m-GST). Additionally, the pooled results of training from the two training groups (TRAINING, N = 16) was compared to a similar historical control-group (CON, N = 48) receiving only standard-care. Eight patients were assigned to FT, 12 to FT+NMES with 4 dropouts during intervention. During the 6-10 days of hospitalization, both groups improved in all functional measures (p  0.05). The training sessions within the FT+NMES-group were more time consuming (~11 vs ~7 min) and entailed higher levels of discomfort than FT-training sessions. Compared to standard-care, training resulted in significantly larger improvements in the 30 s-CST (TRAINING: +3.8 repetitions; CON: +1.4 repetitions, p functional training program improves chair stand performance in hospitalized geriatric patients, with no additional effect of simultaneous electrical muscle stimulation. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Optimized programming algorithm for cylindrical and directional deep brain stimulation electrodes.

    Science.gov (United States)

    Anderson, Daria Nesterovich; Osting, Braxton; Vorwerk, Johannes; Dorval, Alan D; Butson, Christopher R

    2018-04-01

    Deep brain stimulation (DBS) is a growing treatment option for movement and psychiatric disorders. As DBS technology moves toward directional leads with increased numbers of smaller electrode contacts, trial-and-error methods of manual DBS programming are becoming too time-consuming for clinical feasibility. We propose an algorithm to automate DBS programming in near real-time for a wide range of DBS lead designs. Magnetic resonance imaging and diffusion tensor imaging are used to build finite element models that include anisotropic conductivity. The algorithm maximizes activation of target tissue and utilizes the Hessian matrix of the electric potential to approximate activation of neurons in all directions. We demonstrate our algorithm's ability in an example programming case that targets the subthalamic nucleus (STN) for the treatment of Parkinson's disease for three lead designs: the Medtronic 3389 (four cylindrical contacts), the direct STNAcute (two cylindrical contacts, six directional contacts), and the Medtronic-Sapiens lead (40 directional contacts). The optimization algorithm returns patient-specific contact configurations in near real-time-less than 10 s for even the most complex leads. When the lead was placed centrally in the target STN, the directional leads were able to activate over 50% of the region, whereas the Medtronic 3389 could activate only 40%. When the lead was placed 2 mm lateral to the target, the directional leads performed as well as they did in the central position, but the Medtronic 3389 activated only 2.9% of the STN. This DBS programming algorithm can be applied to cylindrical electrodes as well as novel directional leads that are too complex with modern technology to be manually programmed. This algorithm may reduce clinical programming time and encourage the use of directional leads, since they activate a larger volume of the target area than cylindrical electrodes in central and off-target lead placements.

  17. Working memory training and poetry-based stimulation programs: are there differences in cognitive outcome in healthy older adults?

    Science.gov (United States)

    Zimmermann, Nicolle; Netto, Tania Maria; Amodeo, Maria Teresa; Ska, Bernadette; Fonseca, Rochele Paz

    2014-01-01

    Neuropsychological interventions have been mainly applied with clinical populations, in spite of the need of preventing negative changes across life span. Among the few studies of cognitive stimulation in elderly, surprisingly there is no enough research comparing direct and indirect active stimulation programs. This study aims to verify wheter there are differences between two cognitive interventions approaches in older adults: a structured Working Memory (WM) Training Program versus a Poetry-based Stimulation Program. Fourteen older adults were randomly assigned to participate into one of the two intervention groups. The assessed neurocognitive components were attention, episodic and working memory, communicative and executive functions. WM Training activities were based on Baddeley's model; Poetry-based Stimulation Program was composed by general language activities. Data were analyzed with one-way ANCOVA with Delta scores and pre and post-training tests raw scores. WM group improved performance on WM, inhibition, and cognitive flexibility measures, while Poetry group improved on verbal fluency and narrative discourse tasks. Both approaches presented benefits; however WM Training improved its target function with transfer effects to executive functions, being useful for future studies with a variety of dementias. Poetry-based Stimulation also improved complex linguistic abilities. Both approaches may be helpful as strategies to prevent dysfunctional aging changes.

  18. Can cardiac rehabilitation programs improve functional capacity and left ventricular diastolic function in patients with mechanical reperfusion after ST elevation myocardial infarction?: A double-blind clinical trial

    Directory of Open Access Journals (Sweden)

    Allahyar Golabchi

    2012-10-01

    Full Text Available BACKGROUND: Current guidelines recommend cardiac rehabilitation programs (CRP as a means to improve functional status of patients after coronary revascularization. However, research supporting this recommendation has been limited and positive effects of CRP on diastolic function are controversial. The aim of this study was to examine the effects of an 8-week CRP on left ventricular diastolic function.    METHODS: This randomized, clinical trial included 29 men with ST elevation myocardial infarction (MI who had received reperfusion therapy, i.e. coronary artery bypass grafting (CABG or percutaneous coronary intervention (PCI. They were randomized to a training group (n = 15; mean age: 54.2 ± 9.04 years old and a control group (n = 14; mean age: 51.71 ± 6.98 years old. Patients in the training group performed an 8-week CRP with an intensity of 60-85% of maximum heart rate. Exercise sessions lasted 60-90 minutes and were held three times a week. At the start and end of the study, all patients performed symptom-limited exercise test based on Naughton treadmill protocol. Pulsed-wave Doppler echocardiography was also used to determine peak velocity of early (E and late (A waves, E/A ratios, and the deceleration time of E (DT.    RESULTS: Left ventricular diastolic indices (E, A, E/A ratio, DT did not change significantly after the CRP. Compared to baseline, patients in the training group had significant improvements in functional capacity (8.30 ± 1.30 vs. 9.7 ± 1.7 and maximum heart rate (118.50 ± 24.48 vs. 126.85 ± 22.75. Moreover, resting heart rate of the training group was significantly better than the control group at the end of the study (75.36 ± 7.94 vs. 79.80 ± 7.67; P < 0.001.    CONCLUSION: An 8-week CRP in post-MI patients revascularized with PCI or CABG led to improved exercise capacity. However, the CRP failed to enhance diastolic function.      Keywords: Cardiac Rehabilitation, Diastolic Function, Functional Capacity

  19. The normalization of co-authorship networks in the bibliometric evaluation: the government stimulation programs of China and Korea

    NARCIS (Netherlands)

    Park, H.W.; Yoon, J.; Leydesdorff, L.

    2016-01-01

    Using co-authored publications between China and Korea in Web of Science (WoS) during the one-year period of 2014, we evaluate the government stimulation program for collaboration between China and Korea. In particular, we apply dual approaches, full integer versus fractional counting, to

  20. Lifetime stress cumulatively programs brain transcriptome and impedes stroke recovery: benefit of sensory stimulation.

    Directory of Open Access Journals (Sweden)

    Fabíola C R Zucchi

    Full Text Available Prenatal stress (PS represents a critical variable affecting lifetime health trajectories, metabolic and vascular functions. Beneficial experiences may attenuate the effects of PS and its programming of health outcomes in later life. Here we investigated in a rat model (1 if PS modulates recovery following cortical ischemia in adulthood; (2 if a second hit by adult stress (AS exaggerates stress responses and ischemic damage; and (3 if tactile stimulation (TS attenuates the cumulative effects of PS and AS. Prenatally stressed and non-stressed adult male rats underwent focal ischemic motor cortex lesion and were tested in skilled reaching and skilled walking tasks. Two groups of rats experienced recurrent restraint stress in adulthood and one of these groups also underwent daily TS therapy. Animals that experienced both PS and AS displayed the most severe motor disabilities after lesion. By contrast, TS promoted recovery from ischemic lesion and reduced hypothalamic-pituitary-adrenal axis activity. The data also showed that cumulative effects of adverse and beneficial lifespan experiences interact with disease outcomes and brain plasticity through the modulation of gene expression. Microarray analysis of the lesion motor cortex revealed that cumulative PS and AS interact with genes related to growth factors and transcription factors, which were not affected by PS or lesion alone. TS in PS+AS animals reverted these changes, suggesting a critical role for these factors in activity-dependent motor cortical reorganization after ischemic lesion. These findings suggest that beneficial experience later in life can moderate adverse consequences of early programming to improve cerebrovascular health.

  1. Effect of Developmental Stimulation Program on the Developmental Measures of Toddlers

    Directory of Open Access Journals (Sweden)

    Elahe Ghayebie

    2018-04-01

    Full Text Available Background: The variability in the developmental skills is reduced after the first three years of life; therefore, it is necessary to identify and manage early developmental delays. Aim: The aim of this study was to investigate the effect of developmental stimulation program on the developmental measures of the toddlers. Method: The present randomized controlled clinical trial was conducted on 31 toddlers aged 1-3 years residing at Ali Asghar Foster Care Center within 2016-2017. Developmental interventions were carried out based on the modified guidelines of West Virginia Early Learning Standards Framework for eight weeks (three 2-hour sessions a week. The interventions included a range of age- and developmental-specific activities described in the given guidelines. Child development age was measured based on motor dimensions (i.e., gross and fine and language development (i.e., receptive and expressive before and after the intervention. The data were analyzed in SPSS software (version 11 using independent t-test and Chi-square test. Results: The mean ages of the participants in the control and intervention groups were 19.9±5.5 and 20±6.02, respectively (P=0.62. The mean ages of receptive language development (P=0.003, expressive language development (P

  2. Frontal and parietal transcranial magnetic stimulation (TMS) disturbs programming of saccadic eye movements.

    Science.gov (United States)

    Zangemeister, W H; Canavan, A G; Hoemberg, V

    1995-11-01

    Transcranial magnetic stimulation (TMS) of human motor cortex typically evoked motor responses. TMS has failed to elicit eye movements in humans, whereas prolongations of saccadic latency have been reported with TMS. In previous studied we demonstrated that saccades can be abolished or saccadic trajectories can be changed through TMS in the 100 msec before saccade onset. This effect was especially marked when TMS was applied parietally. TMS never influenced a saccade in flight. Simulations of predictive experimental saccades that were impaired through TMS of the frontal or parietal cortex demonstrated especially that the dynamics of small saccades were markedly influenced, resulting in a significant decrease in acceleration and amplitude, or an almost complete inhibition. The impact of inhibition through TMS was critically dependent on timing: early TMS (-70 msec) had a much larger inhibitory effect than late TMS (-20 msec) on experimental saccades. Differential timing of TMS in influencing the cortical control signal is demonstrated through simulations of a reciprocally innervated eye movement model that paralleled empirically determined changes in eye movement dynamics after real TMS. There is a reasonable match between the model and the experimental data. We conclude that the inhibitory action of a presaccadic disturbance, such as a TMS pulse, on saccadic programming is inversely related to timing and amplitude of the predicted saccade.

  3. Program of neuropsychological stimulation of cognition in students: Emphasis on executive functions - development and evidence of content validity

    Directory of Open Access Journals (Sweden)

    Caroline de Oliveira Cardoso

    Full Text Available ABSTRACT Objective: The goal of this study was to describe the construction process and content validity evidence of an early and preventive intervention program for stimulating executive functions (EF in Elementary School children within the school environment. Methods: The process has followed the recommended steps for creating neuropsychological instruments: internal phase of program organization, with literature search and analyses of available materials in the classroom; program construction; analysis by expert judges; data integration and program finalization. To determine the level of agreement among the judges, a Content Validity Index (CVI was calculated. Results: Content validity was evidenced by the agreement among the experts with regards to the program, both in general and for each activity. All steps taken were deemed necessary because they contributed to the identification of positive aspects and possible flaws in the process Conclusion: The steps also helped to adapt stimuli and improve program tasks and activities. Methodological procedures implemented in this study can be adopted by other researchers to create or adapt neuropsychological stimulation and rehabilitation programs. Furthermore, the methodological approach allows the reader to understand, in detail, the technical and scientific rigor adopted in devising this program.

  4. Lone ventricular cardiomyopathy,

    African Journals Online (AJOL)

    ... (I) cardiac catheterisation, including coronary arteriography and pulmonary ... described existence of lone ventricular idiopathic ... spectrum of classic idiopathic dilated cardiomyopathy. ... endomyocardial fibrosis, and from discussions at an.

  5. Characteristics and identification of sites of chagasic ventricular tachycardia by endocardial mapping

    Directory of Open Access Journals (Sweden)

    Távora Maria Zildany P.

    1999-01-01

    Full Text Available OBJECTIVE: To study electrophysiological characteristics that enable the identification and ablation of sites of chagasic tachycardia. METHODS: Thirty-one patients with chronic Chagas' heart disease and sustained ventricular tachycardia (SVT underwent electrophysiological study to map and ablate that arrhythmia. Fifteen patients had hemodinamically stable SVT reproducible by programmed ventricular stimulation, 9 men and 6 women with ages ranging from 37 to 67 years and ejection fraction varying from 0.17 to 0.64. Endocardial mapping was performed during SVT in all patients. Radiofrequency (RF current was applied to sites of presystolic activity of at least 30 ms. Entrainment was used to identify reentrant circuits. In both successful and unsuccessful sites of RF current application, electrogram and entrainment were analyzed. RESULTS: Entrainment was obtained during all mapped SVT. In 70.5% of the sites we observed concealed entrainment and ventricular tachycardia termination in the first 15 seconds of RF current application. In the unsuccessful sites, significantly earlier electrical activity was seen than in the successful ones. Concealed entrainment was significantly associated with ventricular tachycardia termination. Bystander areas were not observed. CONCLUSION: The reentrant mechanism was responsible for the genesis of all tachycardias. In 70.5% of the studied sites, the endocardial participation of the slow conducting zone of reentrant circuits was shown. Concealed entrainment was the main electrophysiological parameter associated with successful RF current application. There was no electrophysiological evidence of bystander regions in the mapped circuits of SVT.

  6. Is applying the same exercise-based inpatient program to normal and reduced left ventricular function patients the best strategy after coronary surgery? A focus on autonomic cardiac response.

    Science.gov (United States)

    Mendes, Renata Gonçalves; Simões, Rodrigo Polaquini; Costa, Fernando de Souza Melo; Pantoni, Camila Bianca Falasco; Di Thommazo-Luporini, Luciana; Luzzi, Sérgio; Amaral-Neto, Othon; Arena, Ross; Catai, Aparecida Maria; Borghi-Silva, Audrey

    2014-01-01

    To assess whether the same exercise-based inpatient program applied to patients with normal and reduced left ventricular function (LVF) evokes a similar cardiac autonomic response after coronary artery bypass graft (CABG). Forty-four patients post-CABG, subgrouped according to normal LVF [LVFN: n = 23; left ventricular ejection fraction (LVEF) ≥ 55%] and reduced LVF (LVFR: n = 21; LVEF 35-54%), were included. All initiated the exercise protocol on post-operative day 1 (PO1), following a whole progressive program until discharge. Cardiac autonomic response was assessed by the indices of heart rate variability (HRV) at rest and during exercise (extremity range of motion and ambulation). During ambulation, lower values of HRV indices were found in the LVFR group compared with the LVFN group [standard deviation of all RR (STDRR; 6.1 ± 2.7 versus 8.9 ± 4.7 ms), baseline width of the RR histogram (TINN; 30.6 ± 14.8 versus 45.8 ± 24.9 ms), SD2 (14.8 ± 8.0 versus 21.3 ± 9.0 ms), Shannon entropy (3.6 ± 0.5 versus 3.9 ± 0.4) and correlation dimension (0.08 ± 0.2 versus 0.2 ± 0.2)]. Also, when comparing the ambulation to rest change, lower values were observed in the LVFR group for linear (STDRR, TINN, RR TRI, rMSSD) and non-linear (SD2 and correlation dimension) HRV indices (p exercise (extremity range of motion), for mean intervals between heart beats and heart rate. For patients with LVFN, the same inpatient exercise protocol triggered a more attenuated autonomic response compared with patients with LVFR. These findings have implications as to how exercise should be prescribed according to LVF in the early stages following recovery from CABG. Implications for Rehabilitation Exercise-based inpatient program, performed by post-CABG patients who have normal left ventricular function, triggered a more attenuated cardiac autonomic response compared with patients with reduced left ventricular function. Volume of the inpatient exercises should be prescribed according

  7. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study

    Science.gov (United States)

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = –2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = –1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders. PMID:27148014

  8. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study.

    Science.gov (United States)

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = -2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = -1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders.

  9. A new visual stimulation program for improving visual acuity in children with visual impairment: a pilot study

    Directory of Open Access Journals (Sweden)

    Li-Ting eTsai

    2016-04-01

    Full Text Available The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS program combining checkerboard pattern reversal (passive stimulation with oddball stimuli (attentional modulation for improving the visual acuity (VA of visually impaired (VI children and children with amblyopia and additional developmental problems. Six children (3 females, 3 males; mean age = 3.9 ± 2.3 years with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week of at least 8 sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards, visual evoked potential (VEP, and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ were carried out before and after the VS program. Significant gains in VA were found after the VS training (VA=1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z=-2.20, asymptotic significance (2-tailed =0.028. No significant changes were observed in the FVQ assessment (92.8 ± 12.6 to 100.8 ± SD=15.4, Z=-1.46, asymptotic significance (2-tailed = 0.144. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders.

  10. Effect of mobilization of bone marrow stem cells by granulocyte colony stimulating factor on clinical symptoms, left ventricular perfusion and function in patients with severe chronic ischemic heart disease

    DEFF Research Database (Denmark)

    Wang, Yongzhong; Tägil, Kristina; Ripa, Rasmus S.

    2005-01-01

    . Myocardial perfusion was unchanged at adenosine stress single photon emission computerized tomography (SPECT) or magnetic resonance images (MRI). Left ventricular ejection fraction decreased from 57% to 52% (p... with echocardiography. CONCLUSIONS: Treatment by G-CSF improved symptoms but not signs of myocardial ischemia in patients with severe IHD. The effects seemed related to mobilization of stem cells. An adverse effect on ejection fraction could not be excluded...

  11. Fibroblasts and the extracellular matrix in right ventricular disease.

    Science.gov (United States)

    Frangogiannis, Nikolaos G

    2017-10-01

    Right ventricular failure predicts adverse outcome in patients with pulmonary hypertension (PH), and in subjects with left ventricular heart failure and is associated with interstitial fibrosis. This review manuscript discusses the cellular effectors and molecular mechanisms implicated in right ventricular fibrosis. The right ventricular interstitium contains vascular cells, fibroblasts, and immune cells, enmeshed in a collagen-based matrix. Right ventricular pressure overload in PH is associated with the expansion of the fibroblast population, myofibroblast activation, and secretion of extracellular matrix proteins. Mechanosensitive transduction of adrenergic signalling and stimulation of the renin-angiotensin-aldosterone cascade trigger the activation of right ventricular fibroblasts. Inflammatory cytokines and chemokines may contribute to expansion and activation of macrophages that may serve as a source of fibrogenic growth factors, such as transforming growth factor (TGF)-β. Endothelin-1, TGF-βs, and matricellular proteins co-operate to activate cardiac myofibroblasts, and promote synthesis of matrix proteins. In comparison with the left ventricle, the RV tolerates well volume overload and ischemia; whether the right ventricular interstitial cells and matrix are implicated in these favourable responses remains unknown. Expansion of fibroblasts and extracellular matrix protein deposition are prominent features of arrhythmogenic right ventricular cardiomyopathies and may be implicated in the pathogenesis of arrhythmic events. Prevailing conceptual paradigms on right ventricular remodelling are based on extrapolation of findings in models of left ventricular injury. Considering the unique embryologic, morphological, and physiologic properties of the RV and the clinical significance of right ventricular failure, there is a need further to dissect RV-specific mechanisms of fibrosis and interstitial remodelling. Published on behalf of the European Society of

  12. Fibrilação ventricular durante atividade esportiva tratada com sucesso Fibrilación ventricular durante actividad deportiva tratada con êxito Ventricular fibrillation during sport activity successfully treated

    Directory of Open Access Journals (Sweden)

    Maria Margarita Gonzalez

    2009-08-01

    public access to defibrillation programs has increased the survival after out-of-hospital ventricular fibrillation. We should encourage the training of laypeople in relation to the use of automated external defibrillators and the Basic Life Support program by stimulating their implementation in places where large numbers of people gather or where people are at a high risk of sudden death, as is the case of sports centers.

  13. Ventricular Septal Defect (VSD)

    Science.gov (United States)

    ... Call your doctor if your baby or child: Tires easily when eating or playing Is not gaining ... heart procedures. Risk factors Ventricular septal defects may run in families and sometimes may occur with other ...

  14. Stimulating Public Interest in Lunar Exploration and Enhancing Science Literacy Through Library Programs

    Science.gov (United States)

    Shipp, S.; Nelson, B.; Stockman, S.; Weir, H.; Carter, B.; Bleacher, L.

    2008-07-01

    Libraries are vibrant learning places, seeking partners in science programming. LPI's Explore! program offers a model for public engagement in lunar exploration in libraries, as shown by materials created collaboratively with the LRO E/PO team.

  15. Behavioral analysis of preterm neonates included in a tactile and kinesthetic stimulation program during hospitalization.

    Science.gov (United States)

    Ferreira, Andréia M; Bergamasco, Niélsy H P

    2010-01-01

    To evaluate the effect of tactile and kinesthetic stimulation on behavioral and clinical development in preterm neonates while still in the hospital. Thirty-two clinically stable preterm infants weighing kinesthetic stimulation (n=16). Data on the infants' clinical progress were collected from medical charts and behavioral evaluations by means of a series of weekly, eight-minute films recorded from the time of inclusion into the study until hospital discharge. There was a trend towards a shorter duration of hospital stay, increased daily weight gain and a predominance of self-regulated behavior (regular breathing, state of alertness, balanced tonus, a range of postures, coordinated movements, hand-to-face movement control, suction, grip, support) in infants in the SG. With respect to motor control, comparative analysis of postconceptional ages according to age-bracket (I - 31-33 weeks 6/7; II - 34-36 weeks 6/7; and III - 37-39 weeks 6/7) revealed balanced tonus and coordinated voluntary movements in all three periods, a longer time spent in a range of postures (age bracket I) or in flexion (age bracket II) and more regular breathing in age bracket I in the SG. In the hospital, tactile and kinesthetic stimulation was shown to have a positive effect, contributing towards adjustment and self-regulation of behavior in the preterm newborn infant. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number ACTRN12610000133033.

  16. Systolic ventricular filling.

    Science.gov (United States)

    Torrent-Guasp, Francisco; Kocica, Mladen J; Corno, Antonio; Komeda, Masashi; Cox, James; Flotats, A; Ballester-Rodes, Manel; Carreras-Costa, Francesc

    2004-03-01

    The evidence of the ventricular myocardial band (VMB) has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium, making it possible to understand the principles governing electrical, mechanical and energetical events within the human heart. From the earliest Erasistratus' observations, principal mechanisms responsible for the ventricular filling have still remained obscured. Contemporary experimental and clinical investigations unequivocally support the attitude that only powerful suction force, developed by the normal ventricles, would be able to produce an efficient filling of the ventricular cavities. The true origin and the precise time frame for generating such force are still controversial. Elastic recoil and muscular contraction were the most commonly mentioned, but yet, still not clearly explained mechanisms involved in the ventricular suction. Classical concepts about timing of successive mechanical events during the cardiac cycle, also do not offer understandable insight into the mechanism of the ventricular filling. The net result is the current state of insufficient knowledge of systolic and particularly diastolic function of normal and diseased heart. Here we summarize experimental evidence and theoretical backgrounds, which could be useful in understanding the phenomenon of the ventricular filling. Anatomy of the VMB, and recent proofs for its segmental electrical and mechanical activation, undoubtedly indicates that ventricular filling is the consequence of an active muscular contraction. Contraction of the ascendent segment of the VMB, with simultaneous shortening and rectifying of its fibers, produces the paradoxical increase of the ventricular volume and lengthening of its long axis. Specific spatial arrangement of the ascendent segment fibers, their interaction with adjacent descendent segment fibers, elastic elements and intra-cavitary blood volume (hemoskeleton), explain the physical principles

  17. Left ventricular function in right ventricular overload

    International Nuclear Information System (INIS)

    Iwanaga, Shiro; Handa, Shunnosuke; Abe, Sumihisa; Onishi, Shohei; Nakamura, Yoshiro; Kunieda, Etsuo; Ogawa, Koichi; Kubo, Atsushi

    1989-01-01

    This study clarified regional and global functions of the distorted left ventricle due to right ventricular overload by gated radionuclide ventriculography (RNV). Cardiac catheterization and RNV were performed in 13 cases of atrial septal defect (ASD), 13 of pure mitral stenosis (MS), 10 of primary pulmonary hypertension (PPH), and 10 of normal subjects (NL). Right ventricular systolic pressure (RVSP) was 32.9±13.9, 45.0±12.2, 88.3±17.1, and 21.2±4.5 mmHg, respectively. The end-systolic LAO view of the left ventricle was halved into septal and free-wall sides. The end-diastolic halves were determined in the same plane. Ejection fractions of the global left ventricle (LVEF), global right ventricle (RVEF), the septal half of the left ventricle (SEPEF), and the free-wall half of the left ventricle (FWEF) were obtained. LVEF was 56.8±9.8% in NL, 52.8±10.5% in ASD, and 49.5±12.9% in PPH. In MS, LVEF (47.0±13.0%) was smaller than those in the other groups. RVEF was 37.0±5.2% in NL, 43.7±15.5% in ASD, and 32.8±11.5% in MS. In PPH, RVEF (25.0±10.6%) was smaller than those in the other groups. SEPEF was smaller in ASD (42.5±13.2%), MS (40.4±13.1%), PPH (40.5±12.5%) than in NL (53.5±8.5%). Systolic function of the septal half of the left ventricle was disturbed by right ventricular overload. RVEF (r=-0.35, p<0.05) and SEPEF (r=-0.51, p<0.01) had negative correlations with RVSP. As RVSP rose, systolic function of the septal half of the left ventricle was more severely disturbed. FWEF was the same among the four groups; NL (57.0±12.6%), ASD (48.6±15.2%), MS (50.5±12.0%), and PPH (51.1±12.3%). There was a good correlation between SEPEF and LVEF in NL (r=0.81), although in PPH this correlation was poor (r=0.64). These data showed that the distorted left ventricular due to right ventricular overload maintains its global function with preserved function of the free-wall side. (J.P.N.)

  18. Ventricular Effective Refraction Period and Ventricular Repolarization Analysis in Experimental Tachycardiomyopathy in Swine.

    Science.gov (United States)

    Noszczyk-Nowak, Agnieszka; Pasławska, Urszula; Gajek, Jacek; Janiszewski, Adrian; Pasławski, Robert; Zyśko, Dorota; Nicpoń, Józef

    2016-01-01

    Swine are recognized animal models of human cardiovascular diseases. However, little is known on the CHF-associated changes in the electrophysiological ventricular parameters of humans and animals. The aim of this study was to analyze changes in the durations of ventricular effective refraction period (VERP), QT and QTc intervals of pigs with chronic tachycardia-induced tachycardiomyopathy (TIC). The study was comprised of 28 adult pigs (8 females and 20 males) of the Polish Large White breed. A one-chamber pacemaker was implanted in each of the 28 pigs. Electrocardiographic, echocardiographic and electrophysiological studies were carried out prior to the pacemaker implantation and at subsequent 4-week intervals. All electrocardiographic, echocardiographic and short electrophysiological study measurements in all swine were done under general anesthesia (propofol) after premedication with midazolam, medetomidine, and ketamine. No significant changes in the duration of QT interval and corrected QT interval (QTc) were observed during consecutive weeks of the experiment. The duration of the QTc interval of female pigs was shown to be significantly longer than that of the males throughout the whole study period. Beginning from the 12th week of rapid ventricular pacing, a significant increase in duration of VERP was observed in both male and female pigs. Males and females did not differ significantly in terms of VERP duration determined throughout the whole study period. Ventricular pacing, stimulation with 2 and 3 premature impulses at progressively shorter coupling intervals and an imposed rhythm of 130 bpm or 150 bpm induced transient ventricular tachycardia in one female pig and four male pigs. One episode of permanent ventricular tachycardia was observed. The number of induced arrhythmias increased proportionally to the severity of heart failure and duration of the experiment. However, relatively aggressive protocols of stimulation were required in order to induce

  19. Forms and methods of stimulation of innovative activities in the restructuring of production program

    Directory of Open Access Journals (Sweden)

    I. I. Emtcova

    2016-01-01

    Full Text Available In the Russian economy not every business entity, implements innovative business activities. The situation generated by the complexity of perception and practical transition to an innovative economic system. On the development of innovative activities affects the overall condition of the economy, condition of material production. The research demonstrates that resource potential of innovative activities in recent years had a tendency towards absolute quantitative reduction and quality deterioration. The decrease in the level and quality of resource provision of innovative activity due to the lack of necessary financial resources. Currently, innovation has become the primary means of increasing the profit of economic entities at the expense of better meet market demand, reduce production costs compared to competitors. Given the complexity of businesses, there is a need of the state stimulation of innovative activity, which is carried out the main directions, forms and methods. In the system of direct effects of the state on business innovation is the stimulation of development of Technopark structures. Creating the most favourable conditions for innovative enterprises, the provision of various services is their main goal. For the food processing industry currently, the largest share in the investments in the investment activities have their own sources of funding, including the use of depreciation. To Finance industry-wide, cross-sectoral and regional scientific and technical problems you can create extra-budgetary funds for financing R & d and innovation support. To encourage regional interests, one of which is that innovation is available to local authorities. In the financial provision of innovative activity is given credit. A Bank loan allows you to increase the efficiency of innovation activity. The article concludes that these measures to stimulate innovative-innovative activity can effectively influence the activity of the company: will

  20. ORGANIZATION AND PLANNING IN CHILDREN WITH ADHD: EVALUATION AND PROPOSAL OF A STIMULATION PROGRAM

    Directory of Open Access Journals (Sweden)

    Josefina Rubiales

    2011-12-01

    Full Text Available The Attention Deficit Hyperactivity Disorder (ADHD is a neurobiological disorder of a complex and heterogeneous origin characterized by a persistent pattern of inattention, hyperactivity and / or impulsivity. Is one of the most common neurobehavioral disorders in childhood and adolescence, and one of the main reasons for consultation because of difficulties in school performance, behavior problems, difficulties of living at home and with peers, involvement in self-esteem and aggressiveness. The primary deficit is associated with executive dysfunction, among which is the organization and planning. The aim of this study was to compare the performance in organization and planning of children with and without a diagnosis of ADHD and submit a stimulation proposal according to their needs. MATERIALS AND METHODS: The clinical sample comprised 16 children diagnosed with ADHD and the control sample of 32 children without a diagnosis, in both cases 8 to 14 years old and from the city of Mar del Plata (Argentina. The instruments used to evaluate the organization and planning has been the subtest Torres of Mexico Child Neuropsychological Battery (ENI, and cubes subtests Construction, Completion and Management Object Test Story Weschler Intelligence for children and adolescents. The proposed treatment includes 8 sessions of stimulation. RESULTS AND CONCLUSIONS: Children with ADHD have greater difficulty in planning and organizational skills than the children of the control sample, from which it establishes a estimulation proposal, whose originality and advantage is accentuated in the ecological validity the process.

  1. Arrhythmogenic right ventricular dysplasia

    International Nuclear Information System (INIS)

    Vignolo Puglia, W.; Freire Colla, D.; Rivara Urrutia, D.; Lujambio Grene, M.; Arbiza Bruno, T.; Oliveira, G.; Cobas Rodriguez, J.

    1997-01-01

    The arrhythmogenic right ventricular dysplasia is a condition predominantly well defined with arrhythmic events. We analyze three cases diagnosed by the group. These cases were presented as ventricular tachycardia with a morphology of left bundle branch block, presenting one of them aborted sudden death in evolution. The baseline electrocardiogram and signal averaging were abnormal in two of the three cases, like the echocardiogram. The electrophysiological study was able to induce in the three patients with sustained monomorphic ventricular tachycardia morphology of left bundle branch block. The definitive diagnosis was made by right ventriculography in two cases and magnetic resonance imaging in the other. Treatment included antiarrhythmic drugs in the three cases and the placement of an automatic defibrillator which survived a sudden death (Author)

  2. An examination of factors that hinder and programs that stimulate Papuan entrepreneurs

    NARCIS (Netherlands)

    Burg, van J.C.

    2007-01-01

    This report describes the results of a study on entrepreneurship in the Indonesian province Papua. The study was performed for Oikonomos Foundation to help evaluating the current entrepreneurship support programs and to identify future challenges. Seven important difficulties for Papuan

  3. Evaluation of ventricular function in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Rocco, T.P.; Dilsizian, V.; Fischman, A.J.; Strauss, H.W.

    1989-01-01

    The recent expansion of interventional cardiovascular technologies has stimulated a concomitant expansion of noninvasive cardiac studies, both to assist in diagnosis and to evaluate treatment outcomes. Radionuclide ventricular function studies provide a reliable, reproducible means to quantify global left ventricular systolic performance, a critical determinant of prognosis in patients with cardiovascular disease. In addition, the ability to evaluate regional left ventricular wall motion and to assess ventricular performance during exercise have secured a fundamental role for such studies in the screening and treatment of patients with coronary artery disease. Radionuclide techniques have been extended to the evaluation of left ventricular relaxation/filling events, left ventricular systolic/diastolic function in the ambulatory setting, and with appropriate technical modifications, to the assessment of right ventricular performance at rest and with exercise. As a complement to radionuclide perfusion studies, cardiac blood-pool imaging allows for thorough noninvasive description of cardiac physiology and function in both normal subjects and in patients with a broad range of cardiovascular diseases. 122 references

  4. ZP123 increases gap junctional conductance and prevents reentrant ventricular tachycardia during myocardial ischemia in open chest dogs

    DEFF Research Database (Denmark)

    Xing, Dezhi; Kjølbye, Anne Louise; Nielsen, Morten S

    2003-01-01

    INTRODUCTION: The aim of this study was to determine if the stable antiarrhythmic peptide (AAP) analogue ZP123 increases gap junctional intercellular conductance and prevents reentrant ventricular tachycardia (VT) during coronary artery occlusion. METHODS AND RESULTS: Voltage clamp experiments...... demonstrated that 10 nM ZP123 improved gap junctional intercellular conductance by 69% +/- 20% in pairs of guinea pig ventricular myocytes. VT was induced by programmed stimulation in alpha-chloralose anaesthetized open chest dogs 1 to 4 hours after coronary artery occlusion. Three-dimensional activation...... AAP analogue ZP123 increased gap junctional intercellular conductance and specifically prevented the induction of reentrant VT during ischemia in a broad dose range without proarrhythmic or hemodynamic side effects. ZP123 is a promising candidate for use in preventing ischemia-induced VT....

  5. Comprehensive Early Stimulation Program for Infants. Instruction Manual [and] Early Interventionist's Workbook [and] Parent/Caregiver Workbook. William Beaumont Hospital Speech and Language Pathology Series.

    Science.gov (United States)

    Santana, Altagracia A.; Bottino, Patti M.

    This early intervention kit includes a Comprehensive Early Stimulation Program for Infants (CESPI) instruction manual, an early interventionist workbook, and ten parent/caregiver workbooks. The CESPI early intervention program is designed to provide therapists, teachers, other health professionals, and parents with a common-sense, practical guide…

  6. Ventricular fibrillation in an ambulatory patient supported by a left ventricular assist device: highlighting the ICD controversy.

    Science.gov (United States)

    Boilson, Barry A; Durham, Lucian A; Park, Soon J

    2012-01-01

    Left ventricular assist devices (LVADs) provide an effective means of managing advanced pump failure as a means of bridging to cardiac transplantation or as permanent therapy. Although ventricular arrhythmias remain common post-LVAD implantation, such therapy may allow malignant arrhythmias to be tolerated hemodynamically. This report describes the clinical findings in a patient who had likely been in a ventricular tachyarrhythmia for several days and presented in ventricular fibrillation, ambulatory, and mentating normally. This report, with previous similar reports, is additive to the body of evidence that LVADs alter the physiologic impact of ventricular arrhythmias in advanced heart failure and highlights the need for thoughtful programming of implantable cardioverter defibrillator therapies in these patients.

  7. Stimulating parent-child interaction through storytelling activities of a family literacy program

    NARCIS (Netherlands)

    Teepe, R.C.; Molenaar, I.; Oostdam, R.J.; Verhoeven, L.T.W.

    2017-01-01

    Preschool vocabulary knowledge develops mainly informally via parent-child interaction. Family literacy programs (FLP’s) aim to promote children's vocabulary by supporting parent-child interaction quantity and quality. In addition to traditional storytelling activities that are part of FLP's

  8. Does stimulating various coping strategies alleviate loneliness? Results from an online friendship enrichment program

    NARCIS (Netherlands)

    Bouwman, T.E.; Aartsen, M.J.; Tilburg, T.G. van; Stevens, N.L.

    2017-01-01

    Loneliness stems from a mismatch between the social relationships one has and those one desires. Loneliness often has severe consequences for individuals and society. Recently, an online adaptation of the friendship enrichment program (FEP) was developed and tested to gain insight in its

  9. Does stimulating various coping strategies alleviate loneliness? Results from an online friendship enrichment program.

    Science.gov (United States)

    Bouwman, Tamara E; Aartsen, Marja J; van Tilburg, Theo G; Stevens, Nan L

    2017-09-01

    Loneliness stems from a mismatch between the social relationships one has and those one desires. Loneliness often has severe consequences for individuals and society. Recently, an online adaptation of the friendship enrichment program (FEP) was developed and tested to gain insight in its contribution to the alleviation of loneliness. Three loneliness coping strategies are introduced during the program: network development, adapting relationship standards, and reducing the importance of the discrepancy between actual and desired relationships. Data were collected among 239 participants aged 50-86. Loneliness was measured four times using a multi-item scale, and on various days with a single, direct question. Loneliness assessed with the scale declined during and after the program. Scores on loneliness assessed for a specific day, however, are more ambiguous. Despite the immediate positive effect of conducting assignments, we did not observe a decline in the single loneliness item score over the course of the program. The online FEP seems to reduce loneliness in general, but these effects are not visible on today's loneliness. Nevertheless, the online intervention to reduce loneliness is a valuable new contribution to the collection of loneliness interventions.

  10. Effectiveness of weekly cognitive stimulation therapy for people with dementia and the additional impact of enhancing cognitive stimulation therapy with a carer training program

    Directory of Open Access Journals (Sweden)

    Cove J

    2014-12-01

    Full Text Available Jennifer Cove,1 Nicola Jacobi,2 Helen Donovan,3 Martin Orrell,4 Josh Stott,5 Aimee Spector5 1Department of Clinical, Educational and Health Psychology, University College London, London, 2Department of Psychology, City University, London, 3Clinical Psychology Service, South Essex Partnership NHS Foundation Trust, Bedford, 4Department of Psychiatry, 5Department of Clinical, Educational and Health Psychology, University College London, London, UKPurpose of the study: Cognitive stimulation therapy (CST is a widely used, evidence-based intervention for people with dementia (PwD. Although designed as a 14 session, twice weekly intervention, many services in the UK deliver CST once a week for 14 weeks. However, this method of delivery has yet to be evaluated. In addition, CST does not include any formal carer training. This study aimed to evaluate the effectiveness of once weekly CST and determine any additional impact when enhanced with a carer training program.Design and methods: A single blind, randomized controlled trial was conducted. Sixty eight PwD and their carers were recruited through three community Memory Assessment Services. PwD and their carers were randomized to one of three conditions: CST plus carer training, CST only, or a wait list control. PwD were administered standardized measures of cognition, quality of life, and quality of relationship with carer at baseline and the 15 week follow-up.Results: There were no baseline differences across the three groups. At follow-up, there were no significant differences between PwD in the three groups on any outcomes. Implications: Weekly CST with or without carer training may not be an effective form of delivery. Several possible explanations for the outcomes are proposed. Weekly CST may not offer the necessary “dose” required to combat decline, and equally the carer training may have been too brief to have made a difference. Services currently offering weekly CST should collect routine

  11. Acute exposure of mercury chloride stimulates the tissue regeneration program and reactive oxygen species production in the Drosophila midgut.

    Science.gov (United States)

    Chen, Zhi; Wu, Xiaochun; Luo, Hongjie; Zhao, Lingling; Ji, Xin; Qiao, Xianfeng; Jin, Yaping; Liu, Wei

    2016-01-01

    We used Drosophila as an animal model to study the digestive tract in response to the exposure of inorganic mercury (HgCl2). We found that after oral administration, mercury was mainly sequestered within the midgut. This resulted in increased cell death, which in turn stimulated the tissue regeneration program, including accelerated proliferation and differentiation of the intestinal stem cells (ISCs). We further demonstrated that these injuries correlate closely with the excessive production of the reactive oxygen species (ROS), as vitamin E, an antioxidant reagent, efficiently suppressed the HgCl2-induced phenotypes of midgut and improved the viability. We propose that the Drosophila midgut could serve as a suitable model to study the treatment of acute hydrargyrism on the digestive systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Deep brain stimulation in uncommon tremor disorders: indications, targets, and programming.

    Science.gov (United States)

    Artusi, Carlo Alberto; Farooqi, Ashar; Romagnolo, Alberto; Marsili, Luca; Balestrino, Roberta; Sokol, Leonard L; Wang, Lily L; Zibetti, Maurizio; Duker, Andrew P; Mandybur, George T; Lopiano, Leonardo; Merola, Aristide

    2018-03-06

    In uncommon tremor disorders, clinical efficacy and optimal anatomical targets for deep brain stimulation (DBS) remain inadequately studied and insufficiently quantified. We performed a systematic review of PubMed.gov and ClinicalTrials.gov. Relevant articles were identified using the following keywords: "tremor", "Holmes tremor", "orthostatic tremor", "multiple sclerosis", "multiple sclerosis tremor", "neuropathy", "neuropathic tremor", "fragile X-associated tremor/ataxia syndrome", and "fragile X." We identified a total of 263 cases treated with DBS for uncommon tremor disorders. Of these, 44 had Holmes tremor (HT), 18 orthostatic tremor (OT), 177 multiple sclerosis (MS)-associated tremor, 14 neuropathy-associated tremor, and 10 fragile X-associated tremor/ataxia syndrome (FXTAS). DBS resulted in favorable, albeit partial, clinical improvements in HT cases receiving Vim-DBS alone or in combination with additional targets. A sustained improvement was reported in OT cases treated with bilateral Vim-DBS, while the two cases treated with unilateral Vim-DBS demonstrated only a transient effect. MS-associated tremor responded to dual-target Vim-/VO-DBS, but the inability to account for the progression of MS-associated disability impeded the assessment of its long-term clinical efficacy. Neuropathy-associated tremor substantially improved with Vim-DBS. In FXTAS patients, while Vim-DBS was effective in improving tremor, equivocal results were observed in those with ataxia. DBS of select targets may represent an effective therapeutic strategy for uncommon tremor disorders, although the level of evidence is currently in its incipient form and based on single cases or limited case series. An international registry is, therefore, warranted to clarify selection criteria, long-term results, and optimal surgical targets.

  13. The Use of a Quadripolar Left Ventricular Lead Increases Successful Implantation Rates in Patients with Phrenic Nerve Stimulation and/or High Pacing Thresholds Undergoing Cardiac Resynchronisation Therapy with Conventional Bipolar Leads

    Directory of Open Access Journals (Sweden)

    Marc-Alexander Ohlow, MD

    2013-03-01

    Conclusions: Excessively HPT and/or PNS are frequently encountered when conventional bipolar leads are used for CRT. A new quadripolar LV lead increases the rate of successful biventricular stimulation. Lower pacing threshold and freedom from PNS are maintained at follow-up.

  14. Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Khuansiri Narajeenron

    2017-04-01

    Full Text Available Audience: The audience for this classic team-based learning (cTBL session is emergency medicine residents, faculty, and students; although this topic is applicable to internal medicine and family medicine residents. Introduction: A left ventricular assist device (LVAD is a mechanical circulatory support device that can be placed in critically-ill patients who have poor left ventricular function. After LVAD implantation, patients have improved quality of life.1 The number of LVAD patients worldwide continues to rise. Left-ventricular assist device patients may present to the emergency department (ED with severe, life-threatening conditions. It is essential that emergency physicians have a good understanding of LVADs and their complications. Objectives: Upon completion of this cTBL module, the learner will be able to: 1 Properly assess LVAD patients’ circulatory status; 2 appropriately resuscitate LVAD patients; 3 identify common LVAD complications; 4 evaluate and appropriately manage patients with LVAD malfunctions. Method: The method for this didactic session is cTBL.

  15. Conflicts during response selection affect response programming: reactions toward the source of stimulation.

    Science.gov (United States)

    Buetti, Simona; Kerzel, Dirk

    2009-06-01

    In the Simon effect, participants make a left or right keypress in response to a nonspatial attribute (e.g., color) that is presented on the left or right. Reaction times (RTs) increase when the response activated by the irrelevant stimulus location and the response retrieved by instruction are in conflict. The authors measured RTs and movement parameters (MPs) of pointing responses in a typical Simon task. Their results show that the trajectories veer toward the imperative stimulus. This bias decreased as RTs increased. The authors suggest that the time course of trajectory deviations reflects the resolution of the response conflict over time. Further, time pressure did not affect the size of the Simon effect in MPs or its time course, but strongly reduced the Simon effect in RTs. In contrast, response selection before the onset of a go signal on the left or right did not affect the Simon effect in RTs, but reduced the Simon effect in MPs and reversed the time course. The authors speculate about independent Simon effects associated with response selection and programming. (c) 2009 APA, all rights reserved.

  16. To Support Research Activities Under the NASA Experimental Program to Stimulate Competitive Research

    Science.gov (United States)

    Gregory, John C.

    2003-01-01

    The Alabama NASA EPSCoR Program is a collaborative venture of The Alabama Space Grant Consortium, The Alabama EPSCoR, and faculty and staff at 10 Alabama colleges and universities as well as the Alabama School of Math and Science in Mobile. There are two Research Clusters which include infrastructure-building and outreach elements embedded in their research activities. Each of the two Research Clusters is in an area of clear and demonstrable relevance to NASA's mission, to components of other Alabama EPSCoR projects, and to the State of Alabama's economic development. This Final Report summarizes and reports upon those additional activities occurring after the first report was submitted in March 2000 (included here as Appendix C). Since the nature of the activities and the manner in which they relate to one another differ by cluster, these clusters function independently and are summarized in parallel in this report. They do share a common administration by the Alabama Space Grant Consortium (ASGC) and by this means, good ideas from each group were communicated to the other, as appropriate. During the past year these research teams, involving 15 scientists, 16 graduate students, 16 undergraduates, and 7 high school students involving 10 Alabama universities had 14 peer reviewed scientific journal articles published, 21 others reviewed for publication or published in proceedings, gave 7 formal presentations and numerous informal presentations to well over 3000 people, received 3 patents and were awarded 14 research proposals for more than $213K dollars in additional research related to these investigations. Each cluster's activities are described and an Appendix summarizes these achievements.

  17. Parasympathetic neurons in the cranial medial ventricular fat pad on the dog heart selectively decrease ventricular contractility.

    Science.gov (United States)

    Dickerson, L W; Rodak, D J; Fleming, T J; Gatti, P J; Massari, V J; McKenzie, J C; Gillis, R A

    1998-05-28

    We hypothesized that selective control of ventricular contractility might be mediated by postganglionic parasympathetic neurons in the cranial medial ventricular (CMV) ganglion plexus located in a fat pad at the base of the aorta. Sinus rate, atrioventricular (AV) conduction (ventricular rate during atrial pacing), and left ventricular contractile force (LV dP/dt during right ventricular pacing) were measured in eight chloralose-anesthetized dogs both before and during bilateral cervical vagus stimulation (20-30 V, 0.5 ms pulses, 15-20 Hz). Seven of these dogs were tested under beta-adrenergic blockade (propranolol, 0.8 mg kg(-1) i.v.). Control responses included sinus node bradycardia or arrest during spontaneous rhythm, high grade AV block or complete heart block, and a 30% decrease in contractility from 2118 +/- 186 to 1526 +/- 187 mm Hg s(-1) (P 0.05) decrease in contractility but still elicited the same degree of sinus bradycardia and AV block (N = 8, P < 0.05). Five dogs were re-tested 3 h after trimethaphan fat pad injection, at which time blockade of vagally-induced negative inotropy was partially reversed, as vagal stimulation decreased LV dP/dt by 19%. The same dose of trimethaphan given either locally into other fat pads (PVFP or IVC-ILA) or systemically (i.v.) had no effect on vagally-induced negative inotropy. Thus, parasympathetic ganglia located in the CMV fat pad mediated a decrease in ventricular contractility during vagal stimulation. Blockade of the CMV fat pad had no effect on vagally-mediated slowing of sinus rate or AV conduction.

  18. The Effectiveness of Three Reading Approaches and an Oral Language Stimulation Program with Disadvantaged Children in the Primary Grades: A Follow-Up Report After the Third Grade.

    Science.gov (United States)

    Dunn, Lloyd M.; Bruininks, Robert H.

    The Cooperative Reading Project was a 2-year study designed to test the effectiveness of three initial reading approaches and an oral language stimulation program with inner-city Southern disadvantaged children. This followup study looked for differences among the treatment groups after pupils had completed their third school year. The 354…

  19. Systolic left ventricular function according to left ventricular concentricity and dilatation in hypertensive patients

    DEFF Research Database (Denmark)

    Bang, Casper; Gerdts, Eva; Aurigemma, Gerard P

    2013-01-01

    Left ventricular hypertrophy [LVH, high left ventricular mass (LVM)] is traditionally classified as concentric or eccentric based on left ventricular relative wall thickness. We evaluated left ventricular systolic function in a new four-group LVH classification based on left ventricular dilatation...... [high left ventricular end-diastolic volume (EDV) index and concentricity (LVM/EDV)] in hypertensive patients....

  20. Genetics Home Reference: arrhythmogenic right ventricular cardiomyopathy

    Science.gov (United States)

    ... cardiomyopathy Merck Manual Consumer Version: Cardiomyopathy Merck Manual Consumer Version: Overview of Abnormal Heart Rhythms Orphanet: Arrhythmogenic right ventricular cardiomyopathy Orphanet: Familial isolated arrhythmogenic right ventricular ...

  1. Marathon's imaging of Bakken fracture stimulations : NDIC oil and gas petroleum research program grants

    Energy Technology Data Exchange (ETDEWEB)

    Brimberry, D. [Marathon Oil Corp., Houston, TX (United States)

    2009-07-01

    This presentation discussed surface tiltmeter and microseismic studies conducted to image fracture stimulations at the Bakken formation. The aim of the studies was to map the fracture stimulation network of the Bakken formation, which has highly sensitive surface levels. The study determined the best fit theoretical deformation after stimulation. Stimulations from 2007 and 2006 were compared in order to determine time lapses as well as to understand data limitations and differences in time and production between jobs. The microseismic study used seismic arrays deployed at the surface of horizontal open hole wells. Data from the studies indicated the presence of a complex network. While data utility was good, noise prevented the precise location of events. The study demonstrated that both tiltmeter and microseismic technology can be used to plan well stimulation project. Data from the study can be applied in other areas in the Williston Basin. tabs., figs.

  2. Technology-based Intervention Programs to Promote Stimulation Control and Communication in Post-coma Persons with Different Levels of Disability

    Directory of Open Access Journals (Sweden)

    Giulio E. Lancioni

    2014-02-01

    Full Text Available Post-coma persons in a minimally conscious state and with extensive motor impairment or emerging/emerged from such a state, but affected by lack of speech and motor impairment, tend to be passive and isolated. A way to help them develop functional responding to control environmental events and communication involves the use of intervention programs relying on assistive technology. This paper provides an overview of technology-based intervention programs for enabling the participants to (a access brief periods of stimulation through one or two microswitches, (b pursue stimulation and social contact through the combination of a microswitch and a sensor connected to a speech generating device (SGD or through two SGD-related sensors, (c control stimulation options through computer or radio systems and a microswitch, (d communicate through modified messaging or telephone systems operated via microswitch, and (e control combinations of leisure and communication options through computer systems operated via microswitch. Twenty-six studies, involving a total of 52 participants, were included in this paper. The intervention programs were carried out using single-subject methodology, and their outcomes were generally considered positive from the standpoint of the participants and their context. Practical implications of the programs are discussed.

  3. Vagal stimulation in heart failure.

    Science.gov (United States)

    De Ferrari, Gaetano M

    2014-04-01

    Heart failure (HF) is accompanied by an autonomic imbalance that is almost always characterized by both increased sympathetic activity and withdrawal of vagal activity. Experimentally, vagal stimulation has been shown to exert profound antiarrhythmic activity and to improve cardiac function and survival in HF models. A open-label pilot clinical study in 32 patients with chronic HF has shown safety and tolerability of chronic vagal stimulation associated with subjective (improved quality of life and 6-min walk test) and objective improvements (reduced left ventricular systolic volumes and improved left ventricular ejection fraction). Three larger clinical studies, including a phase III trial are currently ongoing and will evaluate the clinical role of this new approach.

  4. A case of appropriate inappropriate device therapy: Hyperkalemia-induced ventricular oversensing

    Science.gov (United States)

    Oudit, Gavin Y; Cameron, Doug; Harris, Louise

    2008-01-01

    The present case describes a patient who received inappropriate, but potentially life-saving, therapy from her implantable cardioverter defibrillator (ICD) in the setting of acute hyperkalemia (plasma potassium concentration = 8 mM). Hyperkalemia was associated with the development of a slow sinusoidal ventricular tachycardia, at a rate of 100 beats/min to 125 beats/min (610 ms to 480 ms) in a patient who is pacemaker-dependent. There was associated fractionation of the ICD electrogram and T wave oversensing, leading to ventricular oversensing with resultant detection in the ventricular fibrillation rate zone. This was followed by shock therapy, even though the ventricular tachycardia rate was below the programmed detection rate of the ICD. The subsequent emergency treatment of the hyperkalemia normalized the electrogram, corrected the ventricular oversensing and arrhythmia, and restored rate-adaptive single-chamber ventricular pacing. PMID:18340383

  5. Ventricular Pacing via the Coronary Sinus in a Patient with a Mechanical Tricuspid Valve Prosthesis

    Directory of Open Access Journals (Sweden)

    Janice Swampillai, MD

    2011-01-01

    Full Text Available Implantation of a transvenous endocardial pacing lead in the right ventricle is contra-indicated after mechanical tricuspid valve replacement; therefore a surgical approach to the epicardium is usually required. This case report describes ventricular pacing via a branch of the coronary sinus in a patient with mechanical mitral, aortic and tricuspid valve replacements. In conclusion, this approach is minimally invasive, provides effective ventricular stimulation with low pacing threshold and stable lead position, and is a feasible option when transvenous right ventricular pacing is not possible.

  6. Measurement of ventricular function using Doppler ultrasound

    International Nuclear Information System (INIS)

    Teague, S.M.

    1986-01-01

    Doppler has wide application in the evaluation of valvular heart disease. The need to know ventricular function is a much more common reason for an echocardiographic evaluation. Interestingly, Doppler examinations can assess ventricular function from many perspectives. Description of ventricular function entails measurement of the timing, rate and volume of ventricular filling and ejection. Doppler ultrasound examination reveals all of these aspects of ventricular function noninvasively, simply, and without great expense or radiation exposure, as described in this chapter

  7. Left ventricular apical ballooning syndrome

    International Nuclear Information System (INIS)

    Rahman, N.; Tai, J.; Soofi, A.

    2007-01-01

    The transient left ventricular apical ballooning syndrome, also known as Takotsubo cardiomyopathy, is characterized by transient left ventricular dysfunction in the absence of obstructive epicardial coronary disease. Although the syndrome has been reported in Japan since 1990, it is rare in other regions. Rapid recognition of the syndrome can modify the diagnostic and therapeutic attitude i.e. avoiding thrombolysis and performing catheterization in the acute phase. (author)

  8. Ventricular arrhythmias in Chagas disease

    Directory of Open Access Journals (Sweden)

    Marco Paulo Tomaz Barbosa

    2015-02-01

    Full Text Available Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

  9. The overloaded right heart and ventricular interdependence.

    Science.gov (United States)

    Naeije, Robert; Badagliacca, Roberto

    2017-10-01

    The right and the left ventricle are interdependent as both structures are nested within the pericardium, have the septum in common and are encircled with common myocardial fibres. Therefore, right ventricular volume or pressure overloading affects left ventricular function, and this in turn may affect the right ventricle. In normal subjects at rest, right ventricular function has negligible interaction with left ventricular function. However, the right ventricle contributes significantly to the normal cardiac output response to exercise. In patients with right ventricular volume overload without pulmonary hypertension, left ventricular diastolic compliance is decreased and ejection fraction depressed but without intrinsic alteration in contractility. In patients with right ventricular pressure overload, left ventricular compliance is decreased with initial preservation of left ventricular ejection fraction, but with eventual left ventricular atrophic remodelling and altered systolic function. Breathing affects ventricular interdependence, in healthy subjects during exercise and in patients with lung diseases and altered respiratory system mechanics. Inspiration increases right ventricular volumes and decreases left ventricular volumes. Expiration decreases both right and left ventricular volumes. The presence of an intact pericardium enhances ventricular diastolic interdependence but has negligible effect on ventricular systolic interdependence. On the other hand, systolic interdependence is enhanced by a stiff right ventricular free wall, and decreased by a stiff septum. Recent imaging studies have shown that both diastolic and systolic ventricular interactions are negatively affected by right ventricular regional inhomogeneity and prolongation of contraction, which occur along with an increase in pulmonary artery pressure. The clinical relevance of these observations is being explored. Published on behalf of the European Society of Cardiology. All rights

  10. Supply chain relationships, supplier support programs and stimulating on-farm investment: evidence from the Armenian dairy sector

    NARCIS (Netherlands)

    Dries, L.K.E.; Gorton, M.; Urutyan, V.; White, J.

    2014-01-01

    Purpose – The purpose of this paper is to evaluate the determinants of supply chain relationships, the provision of supplier support measures and the role that support measures play in stimulating investment by suppliers in emerging economies. Design/methodology/approach – The paper draws on survey

  11. Importance of the atrial channel for ventricular arrhythmia therapy in the dual chamber implantable cardioverter defibrillator.

    Science.gov (United States)

    Dijkman, B; Wellens, H J

    2000-12-01

    Performance of dual chamber implantable cardioverter defibrillator (ICD) systems has been judged based on functioning of the ventricular tachycardia:supraventricular tachycardia (VT:SVT) discrimination criteria and DDD pacing. The purpose of this study was to evaluate the use of dual chamber diagnostics to improve the electrical and antiarrhythmic therapy of ventricular arrhythmias. Information about atrial and ventricular rhythm in relation to ventricular arrhythmia occurrence and therapy was evaluated in 724 spontaneous arrhythmia episodes detected and treated by three types of dual chamber ICDs in 41 patients with structural heart disease. Device programming was based on clinically documented and induced ventricular arrhythmias. In ambulatory patients, sinus tachycardia preceded ventricular arrhythmias more often than in the hospital during exercise testing. The incidence of these VTs could be reduced by increasing the dose of a beta-blocking agent in only two patients. In five patients in whom sinus tachycardia developed after onset of hemodynamic stable VT, propranolol was more effective than Class III antiarrhythmics combined with another beta-blocking agent with regard to the incidence of VT and pace termination. In all but three cases, atrial arrhythmias were present for a longer time before the onset of ventricular arrhythmias. During atrial arrhythmias, fast ventricular rates before the onset of ventricular rate were observed more often than RR irregularities and short-long RR sequences. Dual chamber diagnostics allowed proper interpretation of detection and therapy outcome in patients with different types of ventricular arrhythmia. The advantages of the dual chamber ICD system go further than avoiding the shortcomings of the single chamber system. Information from the atrial chamber allows better device programming and individualization of drug therapy for ventricular arrhythmia.

  12. Role of ventricular tachycardia ablation in arrhythmogenic right ventricular cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Alberto Cipriani

    2017-11-01

    Full Text Available Arrhythmogenic right ventricular cardiomyopathy (ARVC is characterized by progressive fibro-fatty replacement of the myocardium that represents the substrate for recurrent sustained ventricular tachycardia (VT. These arrhythmias characterize the clinical course of a sizeable proportion of patients and have significant implications for their quality of life and long-term prognosis. Antiarrhythmic drugs are often poorly tolerated and usually provide incomplete control of arrhythmia relapses. Catheter ablation is a potentially effective strategy to treat frequent VT episodes and ICD shocks in ARVC patients. The aims of this review are to discuss the electrophysiological and electroanatomic substrates of ventricular tachycardia in patients with ARVC and to analyze the role of catheter ablation in their management with particular reference to selection of patients, technical issues, potential complications and outcomes.

  13. A case of delayed cardiac perforation of active ventricular lead

    Directory of Open Access Journals (Sweden)

    Hangyuan Guo

    2011-12-01

    Full Text Available A 65-year-old man was admitted as for one month of repetitive dizziness and one episode of syncope. Electrocardiogram showed sinus bradycardia and his Holter monitoring also showed sinus bradycardia with sinus arrest, sino-atrial block and a longest pause of 4.3 s. Then sick sinus syndrome and Adam-Stokes syndrome were diagnosed. Then a dual chamber pacemaker (Medtronic SDR303 was implanted and the parameters were normal by detection. The patient was discharged 1 week later with suture removed. Then 1.5 month late the patient was presented to hospital once again for sudden onset of chest pain with exacerbation after taking deep breath. Pacemaker programming showed both pacing and sensing abnormality with threshold of?5.0V and resistance of 1200?. Lead perforation was revealed by chest X-ray and confirmed by echocardiogram. Considering the fact that there was high risk to remove ventricular lead, spiral tip of previous ventricular lead was withdrew followed by implantation of a new ventricular active lead to the septum. Previous ventricular lead was maintained. As we know that the complications of lead perforation in the clinic was rare. Here we discuss the clinical management and the possible reasons for cardiac perforation of active ventricular lead.

  14. Rationale and study protocol of the EASY Minds (Encouraging Activity to Stimulate Young Minds) program: cluster randomized controlled trial of a primary school-based physical activity integration program for mathematics

    OpenAIRE

    Riley, Nicholas; Lubans, David R; Holmes, Kathryn; Morgan, Philip J

    2014-01-01

    Background Novel strategies are required to increase school-based physical activity levels of children. Integrating physical activity in mathematics lessons may lead to improvements in students’ physical activity levels as well as enjoyment, engagement and learning. The primary aim of this study is to evaluate the impact of a curriculum-based physical activity integration program known as EASY Minds (Encouraging Activity to Stimulate Young Minds) on children’s daily school time physical activ...

  15. LEARN 2 MOVE 7-12 years: a randomized controlled trial on the effects of a physical activity stimulation program in children with cerebral palsy.

    Science.gov (United States)

    Van Wely, Leontien; Becher, Jules G; Reinders-Messelink, Heleen A; Lindeman, Eline; Verschuren, Olaf; Verheijden, Johannes; Dallmeijer, Annet J

    2010-11-02

    Regular participation in physical activities is important for all children to stay fit and healthy. Children with cerebral palsy have reduced levels of physical activity, compared to typically developing children. The aim of the LEARN 2 MOVE 7-12 study is to improve physical activity by means of a physical activity stimulation program, consisting of a lifestyle intervention and a fitness training program. This study will be a 6-month single-blinded randomized controlled trial with a 6-month follow up. Fifty children with spastic cerebral palsy, aged 7 to 12 years, with Gross Motor Function Classification System levels I-III, will be recruited in pediatric physiotherapy practices and special schools for children with disabilities. The children will be randomly assigned to either the intervention group or control group. The children in the control group will continue with their regular pediatric physiotherapy, and the children in the intervention group will participate in a 6-month physical activity stimulation program. The physical activity stimulation program consists of a 6-month lifestyle intervention, in combination with a 4-month fitness training program. The lifestyle intervention includes counseling the child and the parents to adopt an active lifestyle through Motivational Interviewing, and home-based physiotherapy to practise mobility-related activities in the daily situation. Data will be collected just before the start of the intervention (T0), after the 4-month fitness training program (T4), after the 6-month lifestyle intervention (T6), and after six months of follow-up (T12). Primary outcomes are physical activity, measured with the StepWatch Activity Monitor and with self-reports. Secondary outcomes are fitness, capacity of mobility, social participation and health-related quality of life. A random coefficient analysis will be performed to determine differences in treatment effect between the control group and the intervention group, with primary

  16. Right Ventricular Pseudoaneurysm Following Endomyocardial Biopsy.

    Science.gov (United States)

    Pita; Santos; Manteiga; Rodriguez; Beiras

    1996-03-01

    Ventricular perforation is an unusual complication after endomyocardial biopsy in heart transplanted patients. We report a case of asymptomatic right ventricular perforation and pseudoaneurysm formation, secondary to endomyocardial biopsy, diagnosed by angiography. The spontaneous obliteration of the pseudoaneurysm was observed.

  17. Dipyridamole-thallium tests are predictive of severe cardiac arrhythmias in patients with left ventricular hypertrophy

    International Nuclear Information System (INIS)

    Saragoca, M.A.; Canziani, M.E.; Gil, M.A.; Castiglioni, M.L.; Cassiolato, J.L.; Barbieri, A.; Lima, V.C.; Draibe, S.A.; Martinez, E.E.

    1991-01-01

    In a population of patients with chronic renal failure (CRF) and a high prevalence of left ventricular hypertrophy (LVH) undergoing chronic hemodialysis, the authors investigated the association between the results of dipyridamole-thallium tests (DTTs) and the occurrence of ventricular arrhythmias. They observed a positive significant association between positive DTTs and the occurrence of severe forms of ventricular arrhythmias. A significant association was also observed between the presence of severe LVH and the occurrence of severe ventricular arrhythmias. However, no association was found between the presence of LVH and the positivity of the DTT. As most of their patients with positive DTTs had unimpaired coronary circulations, they conclude that positive DTTs, although falsely indicative of impaired myocardial blood supply, does have an important clinical relevance, indicating increased risk of morbidity (and, possibly, mortality) due to ventricular arrhythmias in a population of CRF patients submitted to chronic renal function replacement program

  18. Effects of training programs based on ipsilateral voluntary and stimulated contractions on muscle strength and monopedal postural control of the contralateral limb.

    Science.gov (United States)

    Kadri, Mohamed Abdelhafid; Noé, Frederic; Nouar, Merbouha Boulahbel; Paillard, Thierry

    2017-09-01

    To compare the effects of unilateral strength training by stimulated and voluntary contractions on muscle strength and monopedal postural control of the contralateral limb. 36 non-active healthy male subjects were recruited and split randomly into three groups. Two groups of 12 subjects took part in a strength-training program (3 sessions a week over 8 weeks) comprising 43 contractions of the quadriceps femoris of the ipsilateral limb (at 20% of the MVC). One group carried out voluntary contractions exclusively (VOL group), while the other group benefited exclusively from electro-induced contractions (NMES group). The other 12 subjects formed the control (CON) group. Assessments of MVC and monopedal postural control in static and dynamic postural tasks were performed with the ipsilateral (ISPI) and contralateral (CONTRA) limbs before (PRE) and after (POST) completion of the training program. After the training program, the MVC of the IPSI and CONTRA limbs increased similarly for both experimental groups (VOL and NMES). There were no significant improvements of monopedal postural control for the IPSI or CONTRA limbs in either the VOL or NMES experimental group. No change was observed for the CON group over the protocol period. The purposed training program with NMES vs VOL contractions induced strength gains but did not permit any improvement of contralateral monopedal postural control in healthy young subjects. This has potential for therapeutic application and allows clinicians to focus their training programs on dynamic and poly-articular exercises to improve the postural control in young subjects.

  19. Spatially divergent cardiac responses to nicotinic stimulation of ganglionated plexus neurons in the canine heart.

    Science.gov (United States)

    Cardinal, René; Pagé, Pierre; Vermeulen, Michel; Ardell, Jeffrey L; Armour, J Andrew

    2009-01-28

    Ganglionated plexuses (GPs) are major constituents of the intrinsic cardiac nervous system, the final common integrator of regional cardiac control. We hypothesized that nicotinic stimulation of individual GPs exerts divergent regional influences, affecting atrial as well as ventricular functions. In 22 anesthetized canines, unipolar electrograms were recorded from 127 atrial and 127 ventricular epicardial loci during nicotine injection (100 mcg in 0.1 ml) into either the 1) right atrial (RA), 2) dorsal atrial, 3) left atrial, 4) inferior vena cava-inferior left atrial, 5) right ventricular, 6) ventral septal ventricular or 7) cranial medial ventricular (CMV) GP. In addition to sinus and AV nodal function, neural effects on atrial and ventricular repolarization were identified as changes in the area subtended by unipolar recordings under basal conditions and at maximum neurally-induced effects. Animals were studied with intact AV node or following ablation to achieve ventricular rate control. Atrial rate was affected in response to stimulation of all 7 GPs with an incidence of 50-95% of the animals among the different GPs. AV conduction was affected following stimulation of 6/7 GP with an incidence of 22-75% among GPs. Atrial and ventricular repolarization properties were affected by atrial as well as ventricular GP stimulation. Distinct regional patterns of repolarization changes were identified in response to stimulation of individual GPs. RAGP predominantly affected the RA and posterior right ventricular walls whereas CMVGP elicited biatrial and biventricular repolarization changes. Spatially divergent and overlapping cardiac regions are affected in response to nicotinic stimulation of neurons in individual GPs.

  20. Signal analysis of ventricular fibrillation

    NARCIS (Netherlands)

    Herbschleb, J.N.; Heethaar, R.M.; Tweel, L.H. van der; Zimmerman, A.N.E.; Meijler, F.L.

    Signal analysis of electro(cardio)grams during ventricular fibrillation (VF) in dogs and human patients indicates more organization and regularity than the official WHO definition suggests. The majority of the signal is characterized by a power spectrum with narrow, equidistant peaks. In a further

  1. Basal cardiomyopathy develops in rabbits with ventricular tachyarrhythmias induced by a single injection of adrenaline.

    Science.gov (United States)

    Ashida, Terunao; Takato, Tetsuya; Matsuzaki, Gen; Seko, Yoshinori; Fujii, Jun; Kawai, Sachio

    2014-01-01

    We have recently demonstrated that basal cardiomyopathy develops in rabbits with ventricular tachyarrhythmias that have been induced by electrical stimulation of the cervical vagus. This study investigated whether similar basal cardiomyopathy would develop in rabbits with ventricular tachyarrhythmias induced by a single injection of adrenaline. Adrenaline was intravenously infused for 10-360 seconds in anesthetized rabbits. Colloidal carbon was injected after adrenaline infusion. Wall movement velocity of the left ventricular base was assessed by tissue Doppler echocardiography. Animals were killed either 1 week or 3-4 weeks later. Pathological lesions were identified by deposits of carbon particles. Animals were divided into two groups according to the infused dose of adrenaline. The small-dose group (group S, n = 15) received 1-10 μg and the large-dose group (group L, n = 23) received 15-60 μg of adrenaline. Adrenaline infusion induced premature ventricular contractions followed by monomorphic ventricular tachycardias in 22 of 23 animals in group L, but in only 1 of 15 animals in group S. Wall movement velocity of the left ventricular base decreased just after adrenaline infusion, remained low after 1 week, and recovered to near-baseline levels after 3-4 weeks in group L. Unique cardiac lesions identified by deposits of carbon particles were frequently observed on the left ventricular basal portion, almost always associated with the mitral valve and papillary muscles, but were never observed in the apical area. Lesions involving all areas of the left ventricular basal portion were observed in 22 of 23 animals in group L, but in only 2 of 15 animals in group S. Basal cardiomyopathy developed in rabbits with ventricular tachycardias induced by a single injection of adrenaline.

  2. Four cases of right ventricular dysplasia

    International Nuclear Information System (INIS)

    Takamura, Ichiro; Ando, Joji; Miyamoto, Atsushi; Kobayashi, Takeshi; Sakamoto, Sanya; Yasuda, Hisakazu

    1985-01-01

    Finding of 81 Kr right ventriculography and 201 Tl myocardial perfusion imaging in 4 patients with right ventricular dysplasia (RVD) were compared with those in 28 patients with dilated cardiomyopathy. Remarkably dilated right ventricle was detected on 201 Tl myocardial perfusion imaging in the RVD group. In a patient with RVD who died suddenly, perfusion defect of the left ventricular myocardium, a decreased right ventricular ejection fraction, and an increased right ventricular end diastolic volume were seen. Perfusion defect of the left ventricular myocardium was seen in 10 of the 28 patients with dilated cardiomyopathy, 4 of whom died suddenly. In these 4 patients, a decreased left ventricular ejection fraction and an increased right ventricular end diastolic volume were seen. These findings obtained by the radionuclide techniques suggested that there are differences in cardiac dysfunction of the both ventricles between the groups with RVD and dilated cardiomyopathy. (Namekawa, K.)

  3. The right ventricular response to ventricular hypofunction in anteroseptal infarction

    International Nuclear Information System (INIS)

    Kanayama, Sugako

    1992-01-01

    Thirty-seven patients with acute anteroseptal infarction but not significant right coronary artery stenosis were examined by using thallium-201 (Tl-201) myocardial perfusion SPECT to determine how the right ventricular (RV) free wall responded to a severely impaired ventricular septum. The patients were divided into the group in which RV free wall was visualized on Tl-201 myocardial SPECT (n=19, RV(+) Group) and the group in which it was not visualized (n=18, RV(-) Group). The relationship between visualization of RV free wall and both RV and left ventricular (LV) function was evaluated. RV(+) Group had larger extent of anteroseptal necrosis and severer impairment of RV free wall, as compared with RV(-) Group. LV ejection fraction (LVEF) was significantly lower in RV(+) Group than RV(-) Group in both acute and chronic phases. Although RV ejection fraction (RVEF) in acute phase was significantly lower in RV(+) Group than RV(-) Group, it did not differ in chronic phase between the two groups. In RV(+) Group, RV stroke work index (RVSWI), pulmonary artery end diastolic pressure (PAEDP), and mean pulmonary artery pressure (MPA) in chronic phase showed a statistically significant increase compared with those in acute phase; these hemodynamic variables in chronic phase were also significantly higher than those in RV(-) Group. RV/LV ratio inversely correlated with LVEF, and both necrotic extent and impairment severity positively correlated with both PAEDP and MPA. RV free wall could be visualized more clearly, corresponding to extremely decreased LV function. These findings suggest that RV free wall may play an important role in maintaining LV and RV function when ventricular septum is severely impaired by anteroseptal infarction. (N.K.)

  4. Experimental program to stimulate competitive energy research in North Dakota: Summary and significance of DOE Trainee research

    Energy Technology Data Exchange (ETDEWEB)

    Boudjouk, Philip

    1999-07-01

    The general goals of the North Dakota DOE/EPSCoR Program are to enhance the capabilities of North Dakota's researchers to conduct nationally competitive energy-related research and to develop science and engineering human resources to meet current and future needs in energy-related areas. Doctoral students were trained and energy research was conducted.

  5. Restoration of Central Programmed Movement Pattern by Temporal Electrical Stimulation-Assisted Training in Patients with Spinal Cerebellar Atrophy.

    Science.gov (United States)

    Huang, Ying-Zu; Chang, Yao-Shun; Hsu, Miao-Ju; Wong, Alice M K; Chang, Ya-Ju

    2015-01-01

    Disrupted triphasic electromyography (EMG) patterns of agonist and antagonist muscle pairs during fast goal-directed movements have been found in patients with hypermetria. Since peripheral electrical stimulation (ES) and motor training may modulate motor cortical excitability through plasticity mechanisms, we aimed to investigate whether temporal ES-assisted movement training could influence premovement cortical excitability and alleviate hypermetria in patients with spinal cerebellar ataxia (SCA). The EMG of the agonist extensor carpi radialis muscle and antagonist flexor carpi radialis muscle, premovement motor evoked potentials (MEPs) of the flexor carpi radialis muscle, and the constant and variable errors of movements were assessed before and after 4 weeks of ES-assisted fast goal-directed wrist extension training in the training group and of general health education in the control group. After training, the premovement MEPs of the antagonist muscle were facilitated at 50 ms before the onset of movement. In addition, the EMG onset latency of the antagonist muscle shifted earlier and the constant error decreased significantly. In summary, temporal ES-assisted training alleviated hypermetria by restoring antagonist premovement and temporal triphasic EMG patterns in SCA patients. This technique may be applied to treat hypermetria in cerebellar disorders. (This trial is registered with NCT01983670.).

  6. Prophylactic implantable defibrillator in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia and no prior ventricular fibrillation or sustained ventricular tachycardia.

    LENUS (Irish Health Repository)

    Corrado, Domenico

    2010-09-21

    The role of implantable cardioverter-defibrillator (ICD) in patients with arrhythmogenic right ventricular cardiomyopathy\\/dysplasia and no prior ventricular fibrillation (VF) or sustained ventricular tachycardia is an unsolved issue.

  7. The left ventricle as a mechanical engine: from Leonardo da Vinci to the echocardiographic assessment of peak power output-to-left ventricular mass.

    Science.gov (United States)

    Dini, Frank L; Guarini, Giacinta; Ballo, Piercarlo; Carluccio, Erberto; Maiello, Maria; Capozza, Paola; Innelli, Pasquale; Rosa, Gian M; Palmiero, Pasquale; Galderisi, Maurizio; Razzolini, Renato; Nodari, Savina

    2013-03-01

    The interpretation of the heart as a mechanical engine dates back to the teachings of Leonardo da Vinci, who was the first to apply the laws of mechanics to the function of the heart. Similar to any mechanical engine, whose performance is proportional to the power generated with respect to weight, the left ventricle can be viewed as a power generator whose performance can be related to left ventricular mass. Stress echocardiography may provide valuable information on the relationship between cardiac performance and recruited left ventricular mass that may be used in distinguishing between adaptive and maladaptive left ventricular remodeling. Peak power output-to-mass, obtained during exercise or pharmacological stress echocardiography, is a measure that reflects the number of watts that are developed by 100 g of left ventricular mass under maximal stimulation. Power output-to-mass may be calculated as left ventricular power output per 100 g of left ventricular mass: 100× left ventricular power output divided by left ventricular mass (W/100 g). A simplified formula to calculate power output-to-mass is as follows: 0.222 × cardiac output (l/min) × mean blood pressure (mmHg)/left ventricular mass (g). When the integrity of myocardial structure is compromised, a mismatch becomes apparent between maximal cardiac power output and left ventricular mass; when this occurs, a reduction of the peak power output-to-mass index is observed.

  8. Arrhythmogenic Right Ventricular Cardiomyopathy in an Endurance Athlete Presenting with Ventricular Tachycardia and Normal Right Ventricular Function.

    Science.gov (United States)

    Hedley, Jeffrey S; Al Mheid, Ibhar; Alikhani, Zoubin; Pernetz, Maria A; Kim, Jonathan H

    2017-08-01

    Arrhythmogenic right ventricular cardiomyopathy, a genetically inherited disease that results in fibrofatty replacement of normal cardiac myocytes, has been associated with sudden cardiac death in athletes. Long-term participation in endurance exercise hastens the development of both the arrhythmic and structural arrhythmogenic right ventricular cardiomyopathy phenotypes. We describe the unusual case of a 34-year-old, symptomatic, female endurance athlete who had arrhythmogenic right ventricular cardiomyopathy in the presence of a structurally normal right ventricle. Clinicians should be aware of this infrequent presentation when evaluating athletic patients who have ventricular arrhythmias and normal findings on cardiac imaging studies.

  9. Flecainide attenuates rate adaptation of ventricular repolarization in guinea-pig heart

    DEFF Research Database (Denmark)

    Osadchii, Oleg E.

    2016-01-01

    examined flecainide effect on adaptation of the QT interval and ventricular action potential duration (APD) to abrupt reductions of the cardiac cycle length. DESIGN: ECG and ventricular epicardial and endocardial monophasic APD were recorded in isolated, perfused guinea-pig heart preparations upon...... a sustained cardiac acceleration (rapid pacing for 30 s), and following a single perturbation of the cycle length evoked by extrasystolic stimulation. RESULTS: Sustained increase in heart rate was associated with progressive bi-exponential shortening of the QT interval and APD. Flecainide prolonged...

  10. Surgical ablation of ventricular tachycardia secondary to congenital ventricular septal aneurysm.

    Science.gov (United States)

    Graffigna, A; Minzioni, G; Ressia, L; Vigano, M

    1994-04-01

    Three patients underwent surgical ablation for ventricular tachycardia resulting from an aneurysm of the membranous portion of the ventricular septum. Two patients had a definite history of cardiac murmur during infancy, and one of them was found at the time of operation to have a left-to-right shunt through the apex of the aneurysm. The earliest ventricular activation sites were located around the neck of the aneurysm and were ablated in 1 patient by encircling the endocardial ventriculotomy and by cryoablation in the remaining 2. After focus resection had been completed, aneurysm resection and ventricular septal reconstruction were performed. All patients were alive and free of ventricular tachycardia and did not need medication as of 61, 66, and 88 months postoperatively. Spontaneous closure of a ventricular septal defect may lead to the formation of an aneurysm in the ventricular septum that may sustain ventricular tachycardias. Such arrhythmias can be effectively treated using electrically guided surgical techniques.

  11. Arrhythmogenic right ventricular dysplasia: MRI findings

    International Nuclear Information System (INIS)

    Wall, E.E. van der; Bootsma, M.M.; Schalij, M.J.; Kayser, H.W.M.; Roos, A. de

    2000-01-01

    Arrhythmogenic right ventricular dysplasia (ARVD) is a heart muscle disorder of unknown cause that is characterized pathologically by fibrofatty replacement of the right ventricular myocardium. Clinical manifestations include structural and functional malformations of the right ventricle, electrocardiographic abnormalities, and presentation with ventricular tachycardias with left bundle branch pattern or sudden death. The disease is often familial with an autosomal inheritance. In addition to right ventricular dilatation, right ventricular aneurysms are typical deformities of ARVD and they are distributed in the so-called ''triangle of dysplasia'', i. e., right ventricular outflow tract, apex, and infundibulum. Ventricular aneurysms at these sites can be considered pathognomonic of ARVD. Another typical hallmark of ARVD is fibrofatty infiltration of the right ventricular free wall. These functional and morphologic characteristics are relevant to clinical imaging investigations such as contrast angiography, echocardiography, radionuclide angiography, ultrafast computed tomography, and magnetic resonance imaging (MRI). Among these techniques, MRI allows the clearest visualization of the heart, in particular because the right ventricle is involved, which is usually more difficult to explore with the other imaging modalities. Furthermore, MRI offers the specific advantage of visualizing adipose infiltration as a bright signal of the right ventricular myocardium. MRI provides the most important anatomic, functional, and morphologic criteria for diagnosis of ARVD within one single study. As a result, MRI appears to be the optimal imaging technique for detecting and following patients with clinical suspicion of ARVD. (orig.) [de

  12. Correlation between the sudden jump-like increases of the atrio-Hisian interval induced during burst atrial pacing and during programmed atrial stimulation in patients with atrioventricular nodal reentrant tachycardia.

    Science.gov (United States)

    Bayraktarova, Iskra H; Stoyanov, Milko K; Kunev, Boyan T; Shalganov, Tchavdar N

    To study the correlation between the sudden prolongations of the atrio-Hisian (AH) interval with ≥50 ms during burst and programmed atrial stimulation, and to define whether the AH jump during burst atrial pacing is a reliable diagnostic criterion for dual AV nodal physiology. Retrospective data on 304 patients with preliminary ECG diagnosis of AV nodal reentrant tachycardia (AVNRT), confirmed during electrophysiological study, was analyzed for the presence of AH jump during burst and programmed atrial stimulation, and for correlation between the pacing modes for inducing the jump. Wilcoxon signed-ranks test and Spearman's bivariate correlation coefficient were applied, significant was P-value jump occurred during burst atrial pacing in 81% of the patients, and during programmed stimulation - in 78%, P = 0.366. In 63.2% AH jump was induced by both pacing modes; in 17.8% - only by burst pacing; in 14.8% - only by programmed pacing; in 4.2% there was no inducible jump. There was negative correlation between both pacing modes, ρ = -0.204, Р<0.001. Burst and programmed atrial stimulation separately prove the presence of dual AV nodal physiology in 81 and 78% of the patients with AVNRT, respectively. There is negative correlation between the two pacing modes, allowing the combination of the two methods to prove diagnostic in 95.8% of the patients. Copyright © 2017 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.

  13. Central vs. peripheral neuraxial sympathetic control of porcine ventricular electrophysiology

    Science.gov (United States)

    Yamakawa, Kentaro; Howard-Quijano, Kimberly; Zhou, Wei; Rajendran, Pradeep; Yagishita, Daigo; Vaseghi, Marmar; Ajijola, Olujimi A.; Armour, J. Andrew; Shivkumar, Kalyanam; Ardell, Jeffrey L.

    2015-01-01

    Sympathoexcitation is associated with ventricular arrhythmogenesis. The aim of this study was to determine the role of thoracic dorsal root afferent neural inputs to the spinal cord in modulating ventricular sympathetic control of normal heart electrophysiology. We hypothesize that dorsal root afferent input tonically modulates basal and evoked efferent sympathetic control of the heart. A 56-electrode sock placed on the epicardial ventricle in anesthetized Yorkshire pigs (n = 17) recorded electrophysiological function, as well as activation recovery interval (ARI) and dispersion in ARI, at baseline conditions and during stellate ganglion electrical stimulation. Measures were compared between intact states and sequential unilateral T1–T4 dorsal root transection (DRTx), ipsilateral ventral root transection (VRTx), and contralateral dorsal and ventral root transections (DVRTx). Left or right DRTx decreased global basal ARI [Lt.DRTx: 369 ± 12 to 319 ± 13 ms (P < 0.01) and Rt.DRTx: 388 ± 19 to 356 ± 15 ms (P < 0.01)]. Subsequent unilateral VRTx followed by contralateral DRx+VRTx induced no further change. In intact states, left and right stellate ganglion stimulation shortened ARIs (6 ± 2% vs. 17 ± 3%), while increasing dispersion (+139% vs. +88%). There was no difference in magnitude of ARI or dispersion change with stellate stimulation following spinal root transections. Interruption of thoracic spinal afferent signaling results in enhanced basal cardiac sympathoexcitability without diminishing the sympathetic response to stellate ganglion stimulation. This suggests spinal dorsal root transection releases spinal cord-mediated tonic inhibitory control of efferent sympathetic tone, while maintaining intrathoracic cardiocentric neural networks. PMID:26661096

  14. TARGETED STELLATE DECENTRALIZATION: IMPLICATIONS FOR SYMPATHETIC CONTROL OF VENTRICULAR ELECTROPHYSIOLOGY

    Science.gov (United States)

    Buckley, Una; Yamakawa, Kentaro; Takamiya, Tatsuo; Armour, J. Andrew; Shivkumar, Kalyanam; Ardell, Jeffrey L.

    2015-01-01

    Background Selective, bilateral cervicothoracic sympathectomy has proven to be effective for managing ventricular arrhythmias in the setting of structural heart disease. The procedure currently employed removes the caudal portions of both stellate ganglia, along with thoracic chain ganglia down to T4 ganglia. Objective To define the relative contributions of T1-T2 and the T3-T4 paravertebral ganglia in modulating ventricular electrical function. Methods In anesthetized vagotomised porcine subjects (n=8), the heart was exposed via sternotomy along with right and left paravertebral sympathetic ganglia to the T4 level. A 56-electrode epicardial sock was placed over both ventricles to assess epicardial activation recovery intervals (ARI) in response to individually stimulating right and left stellate vs T3 paravertebral ganglia. Responses to T3 stimuli were repeated following surgical removal of the caudal portions of stellate ganglia and T2 bilaterally. Results In intact preparations, stellate ganglion vs T3 stimuli (4Hz, 4ms duration) were titrated to produce equivalent decreases in global ventricular ARIs (right-side 85±6 vs 55±10 ms; left-side 24±3 vs 17±7 ms). Threshold of stimulus intensity applied to T3 ganglia to achieve threshold was 3 times that of T1 threshold. ARIs in unstimulated states were unaffected by bilateral stellate-T2 ganglion removal. Following acute decentralization, T3 stimulation failed to change ARIs. Conclusion Preganglionic sympathetic efferents arising from the T1-T4 spinal cord that project to the heart transit through stellate ganglia via the paravertebral chain. T1-T2 surgical excision is thus sufficient to functionally interrupt central control of peripheral sympathetic efferent activity. PMID:26282244

  15. growth stimulant

    African Journals Online (AJOL)

    Effects of timing and duration of supplementation of LIVFIT VET ® (growth stimulant) as substitute for fish meal on the growth performance, haematology and clinical enzymes concentration of growing pigs.

  16. Delayed Repolarization Underlies Ventricular Arrhythmias in Rats With Heart Failure and Preserved Ejection Fraction.

    Science.gov (United States)

    Cho, Jae Hyung; Zhang, Rui; Kilfoil, Peter J; Gallet, Romain; de Couto, Geoffrey; Bresee, Catherine; Goldhaber, Joshua I; Marbán, Eduardo; Cingolani, Eugenio

    2017-11-21

    Heart failure with preserved ejection fraction (HFpEF) represents approximately half of heart failure, and its incidence continues to increase. The leading cause of mortality in HFpEF is sudden death, but little is known about the underlying mechanisms. Dahl salt-sensitive rats were fed a high-salt diet (8% NaCl) from 7 weeks of age to induce HFpEF (n=38). Rats fed a normal-salt diet (0.3% NaCl) served as controls (n=13). Echocardiograms were performed to assess systolic and diastolic function from 14 weeks of age. HFpEF-verified and control rats underwent programmed electrical stimulation. Corrected QT interval was measured by surface ECG. The mechanisms of ventricular arrhythmias (VA) were probed by optical mapping, whole-cell patch clamp to measure action potential duration and ionic currents, and quantitative polymerase chain reaction and Western blotting to investigate changes in ion channel expression. After 7 weeks of a high-salt diet, 31 of 38 rats showed diastolic dysfunction and preserved ejection fraction along with signs of heart failure and hence were diagnosed with HFpEF. Programmed electric stimulation demonstrated increased susceptibility to VA in HFpEF rats ( P hearts demonstrated prolonged action potentials ( P hearts. Susceptibility to VA was markedly increased in rats with HFpEF. Underlying abnormalities include QT prolongation, delayed repolarization from downregulation of potassium currents, and multiple reentry circuits during VA. Our findings are consistent with the hypothesis that potassium current downregulation leads to abnormal repolarization in HFpEF, which in turn predisposes to VA and sudden cardiac death. © 2017 American Heart Association, Inc.

  17. THE INFLUENCE OF COMBINATION NON-MEDICAL TREATMENT INCLUDING FUNCTIONAL PROGRAMMED ELECTRICAL STIMULATION ON THE CLINICAL AND INSTRUMENTAL PARAMETERS IN PATIENTS WITH CEREBRAL PALSY WITH SPASTIC DIPLEGIA

    Directory of Open Access Journals (Sweden)

    V. V. Eliseev

    2015-01-01

    Full Text Available Background: Cerebral palsy is the leading cause of physical disability in pediatric  age. The search for new methods and improvement of old rehabil- itation techniques is ongoing, due to low efficacy of the latter. Aim: To assess the efficacy of a func- tional programmed electrical muscle stimulation as a part  of combination treatment of patients with cerebral palsy in the form of spastic diplegia. Materials and methods: We analyzed the results of treatment of 71 children with cerebral palsy and spastic diplegia, who had  been  randomized  into two groups  depending on the type of treatment. In  the  first group,  the  patients  (n = 38 received a course of functional programmed electric stim- ulation  in combination with  other  non-medical treatment  methods.  The  second   group   (n = 33 underwent a usual  course  of electrical  stimula- tion in combination with non-medical  treatment, similar to that  in the first group. The third group (control   included   41   children   without    cere- bral palsy. Clinical and  instrumental parameters were  assessed  in all study  participants. Results: After the course of combination treatment in the group  1, the  tonus  of m. gastrocnemius was de- creased significantly by 41%, that of the posterior group  of femur muscles by 43%, adductor group of femur muscles by 36%. In the group  2, the re- spective parameters decreased by 24, 21 and 21%. Muscle power  endurance was  increased  signifi- cantly in patients of both groups: that of long back extensors by 12.5 and 6.2 sec, of m. rectus abdomi- nis by 10.6 sec and 5.2 sec, of gluteal muscles by 9.3 and 4.6 sec, of m. quadriceps  by 19.8 and 7.2 sec, of m. anterior  tibialis by 12.1 and 4.6 sec, respec- tively. After the  treatment, the  active movement volume in the large joints of lower extremities  in the group 1 patients  improved as follows: by 15.6° in hip joints, by 11.1° in knee joints and by

  18. Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum

    Directory of Open Access Journals (Sweden)

    Bortolo Martini

    2015-01-01

    Full Text Available A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT. ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches.

  19. THE EFFECTIVENESS OF THREE READING APPROACHES AND AN ORAL LANGUAGE STIMULATION PROGRAM WITH DISADVANTAGED CHILDREN IN THE PRIMARY GRADES--AN INTERIM REPORT AFTER ONE YEAR OF THE COOPERATIVE READING PROJECT.

    Science.gov (United States)

    DUNN, LLOYD M.; AND OTHERS

    THE EFFECTIVENESS OF THREE APPROACHES TO TEACHING BEGINNING READING AND THE INFLUENCE OF AN ORAL LANGUAGE STIMULATION PROGRAM ON THE DEVELOPMENT OF DISADVANTAGED CHILDREN IS REPORTED IN THE FIRST-YEAR REPORT OF A 2-YEAR INTERVENTION STUDY. SUBJECTS WERE 608 FIRST-GRADE PUPILS FROM 12 ELEMENTARY SCHOOLS IN AN INNER-CITY AREA. THE THREE EXPERIMENTAL…

  20. Electrical Signs predictors of malignant ventricular arrhythmias

    International Nuclear Information System (INIS)

    Aleman Fernandez, Ailema Amelia; Dorantes Sanchez, Margarita

    2012-01-01

    Recurrence of malignant ventricular arrhythmia is frequent in cardioverter-defibrillators related patients. The risk stratification is difficult, there are numerous electrocardiographic predictors but his sensibility and specificity are not absolute. The limit between normal and pathological is not defined, besides the complexity of ventricular arrhythmias. We expose different electrocardiographic predictors that can help to better individual risk stratification

  1. Bidirectional ventricular tachycardia of unusual etiology

    Directory of Open Access Journals (Sweden)

    Praloy Chakraborty

    2015-11-01

    Full Text Available Bidirectional ventricular tachycardia (BDVT is a rare form of ventricular arrhythmia, characterized by changing QRS axis of 180 degrees. Digitalis toxicity is considered as commonest cause of BDVT; other causes include aconite toxicity, myocarditis, myocardial infarction, metastatic cardiac tumour and cardiac channelopathies. We describe a case of BDVT in a patient with Anderson-Tawil syndrome.

  2. Detection of premature ventricular contractions on a ventricular electrocardiogram for patients with left ventricular assist devices.

    Science.gov (United States)

    Park, Sung Min; Lee, Jin Hong; Choi, Seong Wook

    2014-12-01

    The ventricular electrocardiogram (v-ECG) was developed for long-term monitoring of heartbeats in patients with a left ventricular assist device (LVAD) and does not normally have the functionality necessary to detect additional heart irregularities that can progress to critical arrhythmias. Although the v-ECG has the benefits of physiological optimization and counterpulsation control, when abnormal heartbeats occur, the v-ECG does not show the distinct abnormal waveform that enables easy detection of an abnormal heartbeat among normal heartbeats on the conventional ECG. In this study, the v-ECGs of normal and abnormal heartbeats are compared with each other with respect to peak-to-peak voltage, area, and maximal slopes, and a new method to detect abnormal heartbeats is suggested. In a series of animal experiments with three porcine models (Yorkshire pigs weighing 30-40 kg), a v-ECG and conventional ECG were taken simultaneously during LVAD perfusion. Clinical experts found 104 abnormal heartbeats from the saved conventional ECG data and confirmed that the other 3159 heartbeats were normal. Almost all of the abnormal heartbeats were premature ventricular contractions (PVCs), and there was short-term tachycardia for 3 s. A personal computer was used to automatically detect abnormal heartbeats with the v-ECG according to the new method, and its results were compared with the clinicians' results. The new method found abnormal heartbeats with 90% accuracy, and less than 15% of the total PVCs were missed. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  3. Predictors of the left ventricular dysfunction induced by ventricular arrhythmia

    Directory of Open Access Journals (Sweden)

    А. І. Vytryhovskiy

    2016-08-01

    Full Text Available The most powerful predictor of life-threatening arrhythmia risk is a combination of low heart rate variability with low ejection fraction (EF of the left ventricle. Aim. To identify predictors of left ventricle dysfunction which is induced by ventricular arrhythmia. Materials and methods. To diagnose structural changes of left ventricular functional capacity and reserves in patients with previous myocardial infarction and patients with high and very high cardiovascular risk by SCORE scale and for establishment the relationship between morphological heart changes and pathological phenomenon of heart turbulence echocardiography and study of heart rate turbulence variability were performed. 603 patients were selected for the research. All patients were divided into groups: group 1 – patients with coronary heart disease, but without associated risk factors, such as smoking, obesity, metabolic syndrome; group 2 – patients who smoke tobacco more than 2 years (very high cardiovascular risk by scale SCORE; group 3 – patients with metabolic syndrome without coronary heart disease or arterial hypertension (very high cardiovascular risk by scale SCORE. The control group consisted of 149 persons. Results. The feature of structural changes in patients with myocardial infarction and in patients with a high cardiovascular risk by SCORE with heart rate turbulence compared with cases without НRT is considerably thickening of the left interventricular septum in systole. Based on this, it can be argued that the emergence of ventricular arrhythmia and accordingly phenomenon of heart rate turbulence in patients with existing cardiovascular diseases and risk factors has both morphological and functional character. Significant difference of echocardioscopy parameters in patients with postinfarction cardiosclerosis and risk factors by the SCORE system was established by index of intraventricular septum thickness in systole, and in persons with high risk – in

  4. Contemporary Tools and Techniques for Substrate Ablation of Ventricular Tachycardia in Structural Heart Disease.

    Science.gov (United States)

    Hutchinson, Mathew D; Garza, Hyon-He K

    2018-02-24

    As we have witnessed in other arenas of catheter-based therapeutics, ventricular tachycardia (VT) ablation has become increasingly anatomical in its execution. Multi-modality imaging provides anatomical detail in substrate characterization, which is often complex in nonischemic cardiomyopathy patients. Patients with intramural, intraseptal, and epicardial substrates provide challenges in delivering effective ablation to the critical arrhythmia substrate due to the depth of origin or the presence of adjacent critical structures. Novel ablation techniques such as simultaneous unipolar or bipolar ablation can be useful to achieve greater lesion depth, though at the expense of increasing collateral damage. Disruptive technologies like stereotactic radioablation may provide a tailored approach to these complex patients while minimizing procedural risk. Substrate ablation is a cornerstone of the contemporary VT ablation procedure, and recent data suggest that it is as effective and more efficient that conventional activation guided ablation. A number of specific targets and techniques for substrate ablation have been described, and all have shown a fairly high success in achieving their acute procedural endpoint. Substrate ablation also provides a novel and reproducible procedural endpoint, which may add predictive value for VT recurrence beyond conventional programmed stimulation. Extrapolation of outcome data to nonischemic phenotypes requires caution given both the variability in substrate nonischemic distribution and the underrepresentation of these patients in previous trials.

  5. Exacerbation of electrical storm subsequent to implantation of a right vagal stimulator.

    Science.gov (United States)

    Shalaby, Alaa A; El-Saed, Aiman; Nemec, Jan; Moossy, John J; Balzer, Jeffrey R

    2007-12-01

    A patient with advanced ischemic cardiomyopathy underwent implantation of a vagal stimulator in an attempt to control recurrent drug refractory ventricular arrhythmia. Electrical storm was exacerbated after the implant and continued after neurostimulation was discontinued. The report aims to provide a cautionary note to application of vagal stimulation for control of cardiac arrhythmia.

  6. Brain Stimulation Therapies

    Science.gov (United States)

    ... Magnetic Seizure Therapy Deep Brain Stimulation Additional Resources Brain Stimulation Therapies Overview Brain stimulation therapies can play ... for a shorter recovery time than ECT Deep Brain Stimulation Deep brain stimulation (DBS) was first developed ...

  7. β1-Adrenoceptor blocker aggravated ventricular arrhythmia.

    Science.gov (United States)

    Wang, Yan; Patel, Dimpi; Wang, Dao Wu; Yan, Jiang Tao; Hsia, Henry H; Liu, Hao; Zhao, Chun Xia; Zuo, Hou Juan; Wang, Dao Wen

    2013-11-01

    To assess the impact of β1 -adrenoceptor blockers (β1 -blocker) and isoprenaline on the incidence of idiopathic repetitive ventricular arrhythmia that apparently decreases with preprocedural anxiety. From January 2010 to July 2012, six patients were identified who had idiopathic ventricular arrhythmias that apparently decreased (by greater than 90%) with preprocedural anxiety. The number of ectopic ventricular beats per hour (VPH) was calculated from Holter or telemetry monitoring to assess the ectopic burden. The mean VPH of 24 hours from Holter before admission (VPH-m) was used as baseline (100%) for normalization. β1 -Blockers, isoprenaline, and/or aminophylline were administrated successively on the ward and catheter lab to evaluate their effects on the ventricular arrhythmias. Among 97 consecutive patients with idiopathic ventricular arrhythmias, six had reduction in normalized VPHs in the hour before the scheduled procedure time from (104.6 ± 4.6%) to (2.8 ± 1.6%) possibly due to preprocedural anxiety (P < 0.05), then increased to (97.9 ± 9.7%) during β1 -blocker administration (P < 0.05), then quickly reduced to (1.6 ± 1.0%) during subsequent isoprenaline infusion. Repeated β1 -blocker quickly counteracted the inhibitory effect of isoprenaline, and VPHs increased to (120.9 ± 2.4%) from (1.6 ± 1.0%; P < 0.05). Isoprenaline and β1 -blocker showed similar effects on the arrhythmias in catheter lab. In some patients with structurally normal heart and ventricular arrhythmias there is a marked reduction of arrhythmias associated with preprocedural anxiety. These patients exhibit a reproducible sequence of β1 -blocker aggravation and catecholamine inhibition of ventricular arrhythmias, including both repetitive ventricular premature beats and monomorphic ventricular tachycardia. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

  8. Remodelado ventricular y cirugía

    Directory of Open Access Journals (Sweden)

    Ignacio Moriones

    2008-01-01

    Se han diseñado anillos mitrales como el de Carpentier- McCarthy-Adams (IMR ETlogix™ para pacientes isquémicos, o el Edwards-Geoform™ en miocardiopatías. La asistencia ventricular puede conseguir en determinados casos recuperación permanente del volumen de la cavidad y función ventricular, particularmente en miocarditis y determinadas miocardiopatías. Paralelamente, se han iniciado experiencias con el sistema de contención CorCap o el sistema Myosplint. Finalmente, la actuación sobre las valvulopatías y la revascularización favorecen la restauración ventricular.

  9. [The reasonable use of right ventricular protection strategy in right ventricular outflow tract reconstruction].

    Science.gov (United States)

    Zhang, Y; Yuan, H Y; Liu, X B; Wen, S S; Xu, G; Cui, H J; Zhuang, J; Chen, J M

    2018-06-01

    As a result of right ventricular outflow tract reconstruction, which is the important and basic step of complex cardiac surgery, the blood flow of right ventricular outflow tract is unobstructed, while pulmonary valve regurgitation and right heart dysfunction could be happened. These problems are often ignored in early days, more and more cases of right heart dysfunction need clinical intervention, which is quite difficult and less effective. How to protect effectively the right ventricular function is the focus. At present main methods to protect the right ventricular function include trying to avoid or reduce length of right ventricular incision, reserving or rebuilding the function of the pulmonary valve, using growth potential material for surgery. The protection of the right ventricular function is a systemic project, it involves many aspects, single measures is difficult to provide complete protection, only the comprehensive use of various protection strategy, can help to improve the long-term prognosis.

  10. Surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration: the Karolinska approach.

    Science.gov (United States)

    Sartipy, Ulrik; Albåge, Anders; Insulander, Per; Lindblom, Dan

    2007-09-01

    This article presents a review on the efficacy of surgical ventricular restoration and direct surgery for ventricular tachycardia in patients with left ventricular aneurysm or dilated ischemic cardiomyopathy. The procedure includes a non-electrophysiologically guided subtotal endocardiectomy and cryoablation in addition to endoventricular patch plasty of the left ventricle. Coronary artery bypass surgery and mitral valve repair are performed concomitantly as needed. In our experience, this procedure yielded a 90% success rate in terms of freedom from spontaneous ventricular tachycardia, with an early mortality rate of 3.8%. A practical guide to the pre- and postoperative management of these patients is provided.

  11. Right Ventricular Endomyocardial Fibrosis Presenting With Ventricular Tachycardia And Apical Thrombus - An Interesting Presentation

    Directory of Open Access Journals (Sweden)

    Amitesh Aggarwal

    2009-11-01

    Full Text Available Endomyocardial fibrosis is a progressive disease of unknown origin affecting children and young adults. It involves inflow portion of right and/or left ventricle and apex. It may be associated with thrombus. Literature regarding right ventricular endomyocardial fibrosis with thrombus is scarce. Here we report a rare case of right ventricular endomyocardial fibrosis presenting as ventricular tachycardia and echocardiographic evidence of apical thrombus. Interestingly there was no pulmonary involvement or evidence of deep venous thrombosis. This case also underscores the importance of urgent echocardiography in diagnosis of obscure cases of ventricular tachycardia.

  12. Left ventricular function in patients with ventricular arrhythmias and aortic valve disease

    International Nuclear Information System (INIS)

    Santinga, J.T.; Kirsh, M.M.; Brady, T.J.; Thrall, J.; Pitt, B.

    1983-01-01

    Forty patients having aortic valve replacement were evaluated preoperatively for ventricular arrhythmia and left ventricular ejection fraction. Arrhythmias were classified as complex or simple using the Lown criteria on the 24-hour ambulatory electrocardiogram; ejection fractions were determined by radionuclide gated blood pool analysis and contrast angiography. The ejection fractions determined by radionuclide angiography were 59.1 +/- 13.1% for 26 patients with simple or no ventricular arrhythmias, and 43.9 +/- 20.3% for 14 patients with complex ventricular arrhythmias (p less than 0.01). Ejection fractions determined by angiography, available for 31 patients, were also lower in patients with complex ventricular arrhythmias (61.1 +/- 16.3% versus 51.4 +/- 13.4%; p less than 0.05). Seven of 9 patients showing conduction abnormalities on the electrocardiogram had complex ventricular arrhythmias. Eight of 20 patients with aortic stenosis had complex ventricular arrhythmias, while 2 of 13 patients with aortic insufficiency had such arrhythmias. It is concluded that decreased left ventricular ejection fraction, intraventricular conduction abnormalities, and aortic stenosis are associated with an increased frequency of complex ventricular arrhythmias in patients with aortic valve disease

  13. Rest and exercise ventricular function in adults with congenital ventricular septal defects

    International Nuclear Information System (INIS)

    Jablonsky, G.; Hilton, J.D.; Liu, P.P.; Morch, J.E.; Druck, M.N.; Bar-Shlomo, B.Z.; McLaughlin, P.R.

    1983-01-01

    Rest and exercise right and left ventricular function were compared using equilibrium gated radionuclide angiography in 19 normal sedentary control subjects and 34 patients with hemodynamically documented congenital ventricular septal defect (VSD). Gated radionuclide angiography was performed at rest and during each level of graded supine bicycle exercise to fatigue. Heart rate, blood pressure, maximal work load achieved, and right and left ventricular ejection fractions were assessed. The control subjects demonstrated an increase in both the left and right ventricular ejection fractions with exercise. All study groups failed to demonstrate an increase in ejection fraction in either ventricle with exercise. Furthermore, resting left ventricular ejection fraction in Groups 2 and 3 was lower than that in the control subjects and resting right ventricular ejection fraction was lower in Group 3 versus control subjects. Thus left and right ventricular function on exercise were abnormal in patients with residual VSD as compared with control subjects; rest and exercise left ventricular ejection fractions remained abnormal despite surgical closure of VSD in the remote past; resting left and right ventricular function was abnormal in patients with Eisenmenger's complex; lifelong volume overload may be detrimental to myocardial function

  14. Arrhythmogenic right ventricular dysplasia: A case report

    Directory of Open Access Journals (Sweden)

    Tessa Negrín Valdés

    2015-10-01

    Full Text Available Arrhythmogenic right ventricular dysplasia is a heart muscle disease that predominantly affects the right ventricle, bringing about the replacement of normal myocardium with fatty or fibrofatty tissue and causing sudden death in young individuals. Ventricular tachycardia is an important clinical manifestation, although there are reports of right or global heart failure. The diagnosis is confirmed by echocardiography and magnetic resonance imaging. The case of a 65-year-old former smoker, with hypertension and ischemic heart disease, a history of effort syncope symptoms and proven non-sustained ventricular tachycardia, with morphology of left bundle branch block, is reported. Relevant diagnostic studies were performed, and echocardiographic elements which were compatible with arrhythmogenic right ventricular dysplasia were found. Therefore, an implantable cardioverter defibrillator was implanted, after which the patient has had a favorable outcome.

  15. Ventricular repolarization measures for arrhythmic risk stratification

    Institute of Scientific and Technical Information of China (English)

    Francesco Monitillo; Marta Leone; Caterina Rizzo; Andrea Passantino; Massimo Iacoviello

    2016-01-01

    Ventricular repolarization is a complex electrical phenomenon which represents a crucial stage in electrical cardiac activity. It is expressed on the surface electrocardiogram by the interval between the start of the QRS complex and the end of the T wave or U wave(QT). Several physiological, pathological and iatrogenic factors can influence ventricular repolarization. It has been demonstrated that small perturbations in this process can be a potential trigger of malignant arrhythmias, therefore the analysis of ventricular repolarization represents an interesting tool to implement risk stratification of arrhythmic events in different clinical settings. The aim of this review is to critically revise the traditional methods of static analysis of ventricular repolarization as well as those for dynamic evaluation, their prognostic significance and the possible application in daily clinical practice.

  16. Salbutamol Abuse is Associated with Ventricular Fibrillation

    Directory of Open Access Journals (Sweden)

    Emin UYSAL

    2015-06-01

    Full Text Available SUMMARY: Salbutamol-induced cardiac complications are well-established. Herein, we describe a case of a 24-year female who was admitted to the emergency department because of a suicide attempt with salbutamol (76 mg. Salbutamol abuse induced the development of supraventricular tachycardia and ventricular fibrillation. Regular sinus rhythm was restored with defibrillation. The hypokalemic patient who stayed in the intensive care unit was discharged after 48 hours of hospitalization. Key words: Salbutamol, suicide, ventricular fibrillation

  17. Clustering Of Left Ventricular Wall Motion Patterns

    Science.gov (United States)

    Bjelogrlic, Z.; Jakopin, J.; Gyergyek, L.

    1982-11-01

    A method for detection of wall regions with similar motion was presented. A model based on local direction information was used to measure the left ventricular wall motion from cineangiographic sequence. Three time functions were used to define segmental motion patterns: distance of a ventricular contour segment from the mean contour, the velocity of a segment and its acceleration. Motion patterns were clustered by the UPGMA algorithm and by an algorithm based on K-nearest neighboor classification rule.

  18. Ventricular tachycardia induced by weight loss pills

    DEFF Research Database (Denmark)

    Pareek, Manan; Hansson, Nils Henrik; Grove, Erik Lerkevang

    2013-01-01

    A previously healthy 29-year-old man was admitted with palpitations, dizziness, and near-syncope after he had recently started taking weight loss pills purchased on the internet. The pills contained caffeine and ephedrine. An electrocardiogram and telemetry revealed multiple episodes of non......-sustained monomorphic ventricular tachycardia, which was successfully treated with amiodarone. In conclusion, unauthorized weight loss pills can be harmful. In particular, ephedrine-containing drugs carry a risk of ventricular tachycardia and should be discouraged....

  19. Resolving the True Ventricular Mural Architecture

    Directory of Open Access Journals (Sweden)

    Robert S. Stephenson

    2018-06-01

    Full Text Available The precise nature of packing together of the cardiomyocytes within the ventricular walls has still to be determined. The spiraling nature of the chains of interconnected cardiomyocytes has long been recognized. As long ago as the end of the nineteenth century, Pettigrew had emphasized that the ventricular cone was not arranged on the basis of skeletal muscle. Despite this guidance, subsequent anatomists described entities such as “bulbo-spiral muscles”, with this notion of subunits culminating in the suggestion that the ventricular cone could be unwrapped so as to produce a “ventricular myocardial band”. Others, in contrast, had suggested that the ventricular walls were arranged on the basis of “sheets”, or more recently “sheetlets”, with investigators seeking to establishing the angulation of these entities using techniques such as magnetic resonance imaging. Our own investigations, in contrast, have shown that the cardiomyocytes are aggregated together within the supporting fibrous matrix so as to produce a three-dimensional myocardial mesh. In this review, we summarize the previous accounts, and provide the anatomical evidence we have thus far accumulated to support the model of the myocardial mesh. We show how these anatomic findings underscore the concept of the myocardial mesh functioning in antagonistic fashion. They lend evidence to support the notion that the ventricular myocardium works as a muscular hydrostat.

  20. Large right ventricular sinusoids in an infant with aorta-left ventricular tunnel and proximal right coronary artery atresia.

    Science.gov (United States)

    Chen, Peter C; Spinner, Joseph A; Heinle, Jeffrey S

    2018-07-01

    We report a 1-month-old infant diagnosed with an aorta-left ventricular tunnel, ventricular septal defect, and right coronary atresia with right ventricular sinusoids. The patient's anatomy and physiology did not indicate right-ventricular-dependent coronary circulation, and therefore right ventricular decompression could be performed without compromising coronary perfusion during surgical correction. A detailed understanding of the coronary anatomy is critical in managing this defect when coronary anomalies are present.

  1. Rationale and study protocol of the EASY Minds (Encouraging Activity to Stimulate Young Minds) program: cluster randomized controlled trial of a primary school-based physical activity integration program for mathematics.

    Science.gov (United States)

    Riley, Nicholas; Lubans, David R; Holmes, Kathryn; Morgan, Philip J

    2014-08-08

    Novel strategies are required to increase school-based physical activity levels of children. Integrating physical activity in mathematics lessons may lead to improvements in students' physical activity levels as well as enjoyment, engagement and learning. The primary aim of this study is to evaluate the impact of a curriculum-based physical activity integration program known as EASY Minds (Encouraging Activity to Stimulate Young Minds) on children's daily school time physical activity levels. Secondary aims include exploring the impact of EASY Minds on their engagement and 'on task' behaviour in mathematics. Grade 5/6 classes from eight public schools in New South Wales, Australia will be randomly allocated to intervention (n = 4) or control (n = 4) groups. Teachers from the intervention group will receive one day of professional development, a resource pack and asked to adapt their lessons to embed movement-based learning in their daily mathematics program in at least three lessons per week over a six week period. Intervention support will be provided via a weekly email and three lesson observations. The primary outcomes will be children's physical activity levels (accelerometry) across both the school day and during mathematics lessons (moderate-to-vigorous physical activity and sedentary time). Children's 'on-task' behaviour, enjoyment of mathematics and mathematics attainment will be assessed as secondary outcomes. A detailed process evaluation will be undertaken. EASY Minds is an innovative intervention that has the potential to improve key physical and academic outcomes for primary school aged children and help guide policy and practice regarding the teaching of mathematics. Australian and New Zealand Clinical Trials Register ACTRN12613000637741 13/05/2013.

  2. Right heart failure due to loss of right ventricular capture in a patient with atrioventricular junction ablation and biventricular pacing.

    Science.gov (United States)

    Raffa, Santi; Fantoni, Cecilia; Restauri, Luigia; Auricchio, Angelo

    2005-10-01

    We describe the case of a patient with atrioventricular (AV) junction ablation and chronic biventricular pacing in which intermittent dysfunction of the right ventricular (RV) lead resulted in left ventricular (LV) stimulation alone and onset of severe right heart failure. Restoration of biventricular pacing by increasing device output and then performing lead revision resolved the issue. This case provides evidence that LV pacing alone in patients with AV junction ablation may lead to severe right heart failure, most likely as a result of iatrogenic mechanical dyssynchrony within the RV. Thus, probably this pacing mode should be avoided in pacemaker-dependent patients with heart failure.

  3. Stress induced right ventricular dysfunction: An indication of reversible right ventricular ischaemia

    International Nuclear Information System (INIS)

    Underwood, S.R.; Walton, S.; Emanuel, R.W.; Swanton, R.H.; Campos Costa, D.; Laming, P.J.; Ell, P.J.

    1987-01-01

    Stress induced changes in left ventricular ejection fraction are widely used in the detection and assessment of coronary artery disease. This study demonstrates that right ventricular dysfunction may also occur, and assesses its significance in terms of coronary artery anatomy. This study involved 14 normal subjects and 26 with coronary artery disease investigated by equilibrium radionuclide ventriculography, at rest and during maximal dynamic exercise. Mean normal resting right ventricular ejection fraction (RVEF) was 0.40 (SD 0.118), and all normal subjects increased RVEF with stress (mean ΔRVEF+0.13 SD 0.099). Mean ΔRVEF in the subjects with coronary artery disease was significantly lower at 0.00 (SD 0.080), but there was overlap between the two groups. The largest falls in RVEF were seen if the right coronary artery was occluded without retrograde filling. In this subgroup with the most severely compromised right ventricular perfusion (nine subjects), RVEF always fell with stress, and mean ΔRVEF was -0.08 (SD 0.050). There was no significant correlation between ΔLVEF and ΔRVEF, implying that the right ventricular dysfunction was due to right ventricular ischaemia, rather than secondary to left ventricular dysfunction. Stress induced right ventricular ischaemia can therefore be detected readily by radionuclide ventriculography. (orig.)

  4. Action potential conduction between a ventricular cell model and an isolated ventricular cell

    NARCIS (Netherlands)

    Wilders, R.; Kumar, R.; Joyner, R. W.; Jongsma, H. J.; Verheijck, E. E.; Golod, D.; van Ginneken, A. C.; Goolsby, W. N.

    1996-01-01

    We used the Luo and Rudy (LR) mathematical model of the guinea pig ventricular cell coupled to experimentally recorded guinea pig ventricular cells to investigate the effects of geometrical asymmetry on action potential propagation. The overall correspondence of the LR cell model with the recorded

  5. Right ventricular failure after implantation of a continuous-flow left ventricular assist device

    DEFF Research Database (Denmark)

    Cordtz, Johan Joakim; Nilsson, Jens C; Hansen, Peter B

    2014-01-01

    Right ventricular failure (RVF) is a significant complication after implantation of a left ventricular assist device. We aimed to identify haemodynamic changes in the early postoperative phase that predicted subsequent development of RVF in a cohort of HeartMate II (HMII) implanted patients....

  6. Exercise thallium testing in ventricular preexcitation

    Energy Technology Data Exchange (ETDEWEB)

    Archer, S.; Gornick, C.; Grund, F.; Shafer, R.; Weir, E.K.

    1987-05-01

    Ventricular preexcitation, as seen in Wolff-Parkinson-White syndrome, results in a high frequency of positive exercise electrocardiographic responses. Why this occurs is unknown but is not believed to reflect myocardial ischemia. Exercise thallium testing is often used for noninvasive assessment of coronary artery disease in patients with conditions known to result in false-positive electrocardiographic responses. To assess the effects of ventricular preexcitation on exercise thallium testing, 8 men (aged 42 +/- 4 years) with this finding were studied. No subject had signs or symptoms of coronary artery disease. Subjects exercised on a bicycle ergometer to a double product of 26,000 +/- 2,000 (+/- standard error of mean). All but one of the subjects had at least 1 mm of ST-segment depression. Tests were terminated because of fatigue or dyspnea and no patient had chest pain. Thallium test results were abnormal in 5 patients, 2 of whom had stress defects as well as abnormally delayed thallium washout. One of these subjects had normal coronary arteries on angiography with a negative ergonovine challenge, and both had normal exercise radionuclide ventriculographic studies. Delayed thallium washout was noted in 3 of the subjects with ventricular preexcitation and normal stress images. This study suggests that exercise thallium testing is frequently abnormal in subjects with ventricular preexcitation. Ventricular preexcitation may cause dyssynergy of ventricular activation, which could alter myocardial thallium handling, much as occurs with left bundle branch block. Exercise radionuclide ventriculography may be a better test for noninvasive assessment of coronary artery disease in patients with ventricular preexcitation.

  7. Exercise thallium testing in ventricular preexcitation

    International Nuclear Information System (INIS)

    Archer, S.; Gornick, C.; Grund, F.; Shafer, R.; Weir, E.K.

    1987-01-01

    Ventricular preexcitation, as seen in Wolff-Parkinson-White syndrome, results in a high frequency of positive exercise electrocardiographic responses. Why this occurs is unknown but is not believed to reflect myocardial ischemia. Exercise thallium testing is often used for noninvasive assessment of coronary artery disease in patients with conditions known to result in false-positive electrocardiographic responses. To assess the effects of ventricular preexcitation on exercise thallium testing, 8 men (aged 42 +/- 4 years) with this finding were studied. No subject had signs or symptoms of coronary artery disease. Subjects exercised on a bicycle ergometer to a double product of 26,000 +/- 2,000 (+/- standard error of mean). All but one of the subjects had at least 1 mm of ST-segment depression. Tests were terminated because of fatigue or dyspnea and no patient had chest pain. Thallium test results were abnormal in 5 patients, 2 of whom had stress defects as well as abnormally delayed thallium washout. One of these subjects had normal coronary arteries on angiography with a negative ergonovine challenge, and both had normal exercise radionuclide ventriculographic studies. Delayed thallium washout was noted in 3 of the subjects with ventricular preexcitation and normal stress images. This study suggests that exercise thallium testing is frequently abnormal in subjects with ventricular preexcitation. Ventricular preexcitation may cause dyssynergy of ventricular activation, which could alter myocardial thallium handling, much as occurs with left bundle branch block. Exercise radionuclide ventriculography may be a better test for noninvasive assessment of coronary artery disease in patients with ventricular preexcitation

  8. An algorithmic programming approach for back pain symptoms in failed back surgery syndrome using spinal cord stimulation with a multicolumn surgically implanted epidural lead: a multicenter international prospective study.

    Science.gov (United States)

    Rigoard, Philippe; Jacques, Line; Delmotte, Alexandre; Poon, Katherine; Munson, Russell; Monlezun, Olivier; Roulaud, Manuel; Prevost, Audrey; Guetarni, Farid; Bataille, Benoit; Kumar, Krishna

    2015-03-01

    Many studies have demonstrated the efficacy and the medical/economic value of epidural spinal cord stimulation for the treatment of "failed back surgery syndrome" (FBSS). However, the back pain component of FBSS has been recalcitrant. Recent clinical trials have suggested that multicolumn surgically implanted leads combined with enhanced programming capabilities in the newer implantable pulse generators demonstrate the ability to treat the back pain component of FBSS. The objective of our present international multicentre study is to prospectively evaluate these findings in a larger population. We conducted a prospective, nonrandomized, observational study on 76 patients with refractory FBSS, consecutively implanted with multicolumn spinal cord stimulation (SCS) between 2008 and 2011 in three neurosurgical pain management centers (Poitiers, France; Montréal, Canada; and Regina, Canada). The primary objective of this study was to prospectively analyze the effect of multicolumn lead programming on paresthesia coverage for the back pain region in these patients. The secondary objective was to assess the analgesic efficacy of this technique on the global and back pain components. Paresthesia could be induced in the lower extremities in the majority of patients with at least one of the configurations tested. Bilateral low back paresthesia was induced in 53.5% of patients, while unilateral low back paresthesia was induced in 78.9% of patients. Multicolumn configurations were statistically more effective than monocolumn configurations for all anatomic regions studied. At 6 months, 75.4% of patients receiving multicolumn stimulation (n = 57) obtained at least a 30% improvement of the back pain VAS score, while 42.1% of patients obtained at least a 50% improvement of the back pain VAS score. This study confirms the hypothesis that multicolumn SCS should be considered as an important tool in the treatment of radicular and axial pain in FBSS patients. The efficacy of this

  9. Blockade of KCa3.1 Attenuates Left Ventricular Remodeling after Experimental Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Chen-Hui Ju

    2015-07-01

    Full Text Available Background/Aims: After myocardial infarction (MI, cardiac fibrosis greatly contributes to left ventricular remodeling and heart failure. The intermediate-conductance calcium-activated potassium Channel (KCa3.1 has been recently proposed as an attractive target of fibrosis. The present study aimed to detect the effects of KCa3.1 blockade on ventricular remodeling following MI and its potential mechanisms. Methods: Myocardial expression of KCa3.1 was initially measured in a mouse MI model by Western blot and real time-polymerase chain reaction. Then after treatment with TRAM-34, a highly selective KCa3.1 blocker, heart function and fibrosis were evaluated by echocardiography, histology and immunohistochemistry. Furthermore, the role of KCa3.1 in neonatal mouse cardiac fibroblasts (CFs stimulated by angiotensin II (Ang II was tested. Results: Myocardium expressed high level of KCa3.1 after MI. Pharmacological blockade of KCa3.1 channel improved heart function and reduced ventricular dilation and fibrosis. Besides, a lower prevalence of myofibroblasts was found in TRAM-34 treatment group. In vitro studies KCa3.1 was up regulated in CFs induced by Ang II and suppressed by its blocker.KCa3.1 pharmacological blockade attenuated CFs proliferation, differentiation and profibrogenic genes expression and may regulating through AKT and ERK1/2 pathways. Conclusion: Blockade of KCa3.1 is able to attenuate ventricular remodeling after MI through inhibiting the pro-fibrotic effects of CFs.

  10. Fourth ventricular thyrotropin induces satiety and increases body temperature in rats.

    Science.gov (United States)

    Smedh, Ulrika; Scott, Karen A; Moran, Timothy H

    2018-05-01

    Besides its well-known action to stimulate thyroid hormone release, thyrotropin mRNA is expressed within the brain, and thyrotropin and its receptor have been shown to be present in brain areas that control feeding and gastrointestinal function. Here, the hypothesis that thyrotropin acts on receptors in the hindbrain to alter food intake and/or gastric function was tested. Fourth ventricular injections of thyrotropin (0.06, 0.60, and 6.00 µg) were given to rats with chronic intracerebroventricular cannulas aimed at the fourth ventricle. Thyrotropin produced an acute reduction of sucrose intake (30 min). The highest dose of thyrotropin caused inhibition of overnight solid food intake (22 h). In contrast, subcutaneous administration of corresponding thyrotropin doses had no effect on nutrient intake. The highest effective dose of fourth ventricular thyrotropin (6 µg) did not produce a conditioned flavor avoidance in a standardized two-bottle test, nor did it affect water intake or gastric emptying of glucose. Thyrotropin injected in the fourth ventricle produced a small but significant increase in rectal temperature and lowered plasma levels of tri-iodothyronin but did not affect plasma levels of thyroxine. In addition, there was a tendency toward a reduction in blood glucose 2 h after fourth ventricular thyrotropin injection ( P = 0.056). In conclusion, fourth ventricular thyrotropin specifically inhibits food intake, increases core temperature, and lowers plasma levels of tri-iodothyronin but does not affect gastromotor function.

  11. Dynamic Changes of QRS Morphology of Premature Ventricular Contractions During Ablation in the Right Ventricular Outflow Tract: A Case Report.

    Science.gov (United States)

    Yue-Chun, Li; Jia-Feng, Lin; Jia-Xuan, Lin

    2015-10-01

    Electrocardiographic characteristics can be useful in differentiating between right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) ventricular arrhythmias. Ventricular arrhythmias originating from ASC, however, show preferential conduction to RVOT that may render the algorithms of electrocardiographic characteristics less reliable. Even though there are few reports describing ventricular arrhythmias with ASC origins and endocardial breakout sites of RVOT, progressive dynamic changes in QRS morphology of the ventricular arrhythmias during ablation obtained were rare.This case report describes a patient with symptomatic premature ventricular contractions of left ASC origin presenting an electrocardiogram (ECG) characteristic of right ventricular outflow tract before ablation. Pacing at right ventricular outflow tract reproduced an excellent pace map. When radiofrequency catheter ablation was applied to the right ventricular outflow tract, the QRS morphology of premature ventricular contractions progressively changed from ECG characteristics of right ventricular outflow tract origin to ECG characteristics of left ASC origin.Successful radiofrequency catheter ablation was achieved at the site of the earliest ventricular activation in the left ASC. The distance between the successful ablation site of the left ASC and the site with an excellent pace map of the RVOT was 20 mm.The ndings could be strong evidence for a preferential conduction via the myocardial bers from the ASC origin to the breakout site in the right ventricular outflow tract. This case demonstrates that ventricular arrhythmias with a single origin and exit shift may exhibit QRS morphology changes.

  12. Muscular anatomy of the human ventricular folds.

    Science.gov (United States)

    Moon, Jerald; Alipour, Fariborz

    2013-09-01

    Our purpose in this study was to better understand the muscular anatomy of the ventricular folds in order to help improve biomechanical modeling of phonation and to better understand the role of these muscles during phonatory and nonphonatory tasks. Four human larynges were decalcified, sectioned coronally from posterior to anterior by a CryoJane tape transfer system, and stained with Masson's trichrome. The total and relative areas of muscles observed in each section were calculated and used for characterizing the muscle distribution within the ventricular folds. The ventricular folds contained anteriorly coursing thyroarytenoid and ventricularis muscle fibers that were in the lower half of the ventricular fold posteriorly, and some ventricularis muscle was evident in the upper and lateral portions of the fold more anteriorly. Very little muscle tissue was observed in the medial half of the fold, and the anterior half of the ventricular fold was largely devoid of any muscle tissue. All 4 larynges contained muscle bundles that coursed superiorly and medially through the upper half of the fold, toward the lateral margin of the epiglottis. Although variability of expression was evident, a well-defined thyroarytenoid muscle was readily apparent lateral to the arytenoid cartilage in all specimens.

  13. Quantifying the determinants of decremental response in critical ventricular tachycardia substrate.

    Science.gov (United States)

    Beheshti, Mohammadali; Nayyar, Sachin; Magtibay, Karl; Massé, Stéphane; Porta-Sanchez, Andreu; Haldar, Shouvik; Bhaskaran, Abhishek; Vigmond, Edward; Nanthakumar, Kumaraswamy

    2018-05-28

    Decremental response evoked with extrastimulation (DEEP) is a useful tool for determining diastolic return path of ventricular tachycardia (VT). Though a targeted VT ablation is feasible with this approach, determinants of DEEP response have not been studied OBJECTIVES: To elucidate the effects of clinically relevant factors, specifically, the proximity of the stimulation site to the arrhythmogenic scar, stimulation wave direction, number of channels open in the scar, size of the scar and number of extra stimuli on decrement and entropy of DEEP potentials. In a 3-dimensional bi-domain simulation of human ventricular tissue (TNNP cell model), an irregular subendocardial myopathic region was generated. An irregular channel of healthy tissue with five potential entry branches was shaped into the myopathic region. A bipolar electrogram was derived from two electrodes positioned in the centre of the myopathic region. Evoked delays between far-field and local Electrogram (EGM) following an extrastimulus (S1-S2, 500-350 ms) were measured as the stimulation site, channel branches, and inexcitable tissue size were altered. Stimulation adjacent to the inexcitable tissue from the side opposite to the point-of-entry produces longest DEEP delay. The DEEP delay shortens when the stimulation point is farther away from the scar, and it decreases maximally when stimulation is done from a site beside a conduction barrier. Entropy increases with S2 when stimulation site is from farther away. An unprotected channel structure with multiple side-branch openings had shorter DEEP delay compared to a protected channel structure with a paucity of additional side-branch openings and a point-of-entry on the side opposite to the pacing source. Addition of a second shorter extrastimulus did not universally lead to higher DEEP delay CONCLUSIONS: Location and direction of the wavefront in relation to scar entry and size of scar determine the degree of evoked response while the number of

  14. Ventricular and myocardial scintiscanning: Methodical fundamentals

    International Nuclear Information System (INIS)

    Standke, R.; Hoer, G.; Maul, F.D.

    1984-01-01

    Nuclear cardiology is concerned with non invasive procedures to quantitate global and regional left ventricular function (Radionuclide ventriculography), also the imaging of vitally perfused myocardium (Myocardial scintigraphy) is achieved. A gammacamera and a minicomputer are necessary. Radionuclide ventriculography enables the analysis of global and regional time dependent left ventricular volume curves and hence the evaluation of contraction and contractility of the heart muscle. The basis is a sequence of scans covering an average heartcycle. This sequence may be produced either by first pass or equilibrium technique. Myocardial scintigraphy at rest images vital myocardium, scans immediately after exercise represent the interference of myocardial perfusion and muscle mass. The regional difference (Redistribution) between normalized exercise- and rest scans provide quantitative parameters to detect impairment of exercise-induced myocardial perfusion anomalies. The procedures of sectorial analysis of left ventricular function and myocardial perfusion are presented. (orig.) [de

  15. Left ventricular hypertrophy: virtuous intentions, malign consequences.

    Science.gov (United States)

    Pokharel, Saraswati; Sharma, Umesh C; Pinto, Yigal M

    2003-06-01

    Left ventricular hypertrophy (LVH) is currently the focus of intense cardiovascular research, with the resultant rapid evolution of novel concepts relating to its exceedingly complex pathophysiology. In addition to the alterations in signal transduction and disturbances in Ca(2+) homeostasis, there are structural changes in myofilaments, disorganization of the cytoskeletal framework and increased collagen synthesis. LVH is associated with progressive left ventricular remodeling that culminates to heart failure. The modern treatment of left ventricular hypertrophy is now largely based on the hypothesis that neuroendocrine activation is important in the progression of the disease and inhibition of neurohormones is likely to have long-term benefit with regard to morbidity and mortality. Drugs specifically designed to unload the left ventricle, such as diuretics and vasodilators, appears to be less effective in reducing LV mass and improving prognosis. Thus, the evolution of treatment for LVH itself has provided much enlightenment for our understanding of the fundamental biology of the disorder.

  16. Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Tassi, Eduardo Marinho, E-mail: etassi@ibest.com.br [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Continentino, Marcelo Abramoff [Hospital Frei Galvão, Guaratinguetá, SP (Brazil); Nascimento, Emília Matos do; Pereira, Basílio de Bragança [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Coppe - Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia - UFRJ, Rio de Janeiro, RJ (Brazil); Pedrosa, Roberto Coury [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2014-05-15

    Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups.

  17. Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

    International Nuclear Information System (INIS)

    Tassi, Eduardo Marinho; Continentino, Marcelo Abramoff; Nascimento, Emília Matos do; Pereira, Basílio de Bragança; Pedrosa, Roberto Coury

    2014-01-01

    Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups

  18. Left cardiac sympathetic denervation for catecholaminergic polymorphic ventricular tachycardia

    NARCIS (Netherlands)

    Wilde, Arthur A. M.; Bhuiyan, Zahurul A.; Crotti, Lia; Facchini, Mario; de Ferrari, Gaetano M.; Paul, Thomas; Ferrandi, Chiara; Koolbergen, Dave R.; Odero, Attilio; Schwartz, Peter J.

    2008-01-01

    Catecholaminergic polymorphic ventricular tachycardia is a potentially lethal disease characterized by adrenergically mediated ventricular arrhythmias manifested especially in children and teenagers. Beta-blockers are the cornerstone of therapy, but some patients do not have a complete response to

  19. Evaluation of right ventricular volumes measured by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Møgelvang, J; Stubgaard, M; Thomsen, C

    1988-01-01

    stroke volume was calculated as the difference between end-diastolic and end-systolic volume and compared to left ventricular stroke volume and to stroke volume determined simultaneously by a classical indicator dilution technique. There was good agreement between right ventricular stroke volume......Right ventricular volumes were determined in 12 patients with different levels of right and left ventricular function by magnetic resonance imaging (MRI) using an ECG gated multisection technique in planes perpendicular to the diastolic position of the interventricular septum. Right ventricular...... determined by MRI and by the indicator dilution method and between right and left ventricular stroke volume determined by MRI. Thus, MRI gives reliable values not only for left ventricular volumes, but also for right ventricular volumes. By MRI it is possible to obtain volumes from both ventricles...

  20. An Incidentally Detected Right Ventricular Pseudoaneurysm

    Directory of Open Access Journals (Sweden)

    Vamsi C. Gaddipati

    2017-01-01

    Full Text Available Ventricular pseudoaneurysm is an uncommon, potentially fatal complication that has been associated with myocardial infarction, cardiac surgery, chest trauma, and infectious processes. Diagnosis can be challenging, as cases are rare and slowly progressing and typically lack identifiable features on clinical presentation. As a result, advanced imaging techniques have become the hallmark of identification. Ahead, we describe a patient who presents with acute decompensated heart failure and was incidentally discovered to have a large right ventricular pseudoaneurysm that developed following previous traumatic anterior rib fracture.

  1. Left ventricular performance during psychological stress

    International Nuclear Information System (INIS)

    Young, D.Z.; Massachusetts General Hospital, Boston; Dimsdale, J.E.; Moore, R.H.; Barlai-Kovach, M.; Newell, J.B.; McKusick, K.A.; Boucher, C.A.; Fifer, M.A.; Strauss, H.W.

    1989-01-01

    Left ventricular ejection fraction, systolic blood pressure and plasma norepinephrine were measured in six normotensive and six mildly hypertensive subjects during rest and psychological stress. Compared with rest, 8 of the 12 subjects developed significant changes in ejection fraction (increase in 6, decrease in 2); 10 of 12 subjects developed significant elevations of plasma norepinephrine; and all developed significant increases in systolic blood pressure. When the stress effects were examined for the total group, as opposed to within subjects, there were significant increases in plasma norepinephrine and systolic blood pressure but, interestingly, mean ejection fraction and stroke volume remained unchanged, implying stress led to increased left ventricular contractility. (orig.)

  2. Nuclear medical diagnostic with ventricular aneurysm

    International Nuclear Information System (INIS)

    Litter, H.

    1987-01-01

    In the diagnostic of ventricular aneurysms myocardial scintigraphy and above all radionuclide ventriculography (RNV) have special importance. Because of the non-invasive method and the as a result safe and easy use even with stress studies, RNV can provide a very valuable aid with aneurysm patients in early diagnosis, evaluation of the operability and as well as in the prognosis. It must be noted, however, that the differentiation of multivascular diseases and sometimes ventricular aneurysms can be difficult and the inclusion of an angiocardiograph as a radiological invasive examination procedure seems fitting. (orig./MG) [de

  3. Bidirectional ventricular tachycardia of unknown etiology

    International Nuclear Information System (INIS)

    Ali, M.; Khan, J.A.; Masood, T.; Shamsi, F.; Dero, M.H.; Khan, S.

    2013-01-01

    A 45 years old male presented to the emergency department with palpitations, headache and apprehension. His electrocardiogram revealed bidirectional ventricular tachycardia. He remained vitally stable and responded to intravenous beta-blocker. Initially digitalis toxicity was suspected but history was negative for digitalis intake. The cause remained unidentified in patient despite detailed investigations. During a short follow-up (of 6 months) he remained asymptomatic and no cause was further identified during this period. Some other unseen causes of bidirectional ventricular tachycardia need to be explored. (author)

  4. Catecholaminergic polymorphic ventricular tachycardia in 2012

    Directory of Open Access Journals (Sweden)

    Christian van der Werf

    2011-12-01

    Full Text Available Catecholaminergic polymorphic ventricular tachycardia (CPVT is a rare, potentially lethal inherited arrhythmia syndrome characterized by stress or emotion-induced ventricular arrhythmias. CPVT was first described in 1960, while the genetic basis underlying this syndrome was discovered in 2001. The past decade has seen substantial advances in understanding the pathophysiology of CPVT. In addition, significant advances have been made in elucidating clinical characteristics of CPVT patients and new treatment options have become available. Here, we review current literature on CPVT to present state-of-the-art knowledge on the subject of the genetic basis, pathophysiology, clinical presentation, diagnosis, treatment and prognosis.

  5. Differential responses of rabbit ventricular and atrial transient outward current (Ito) to the Ito modulator NS5806.

    Science.gov (United States)

    Cheng, Hongwei; Cannell, Mark B; Hancox, Jules C

    2017-03-01

    Transient outward potassium current (I to ) in the heart underlies phase 1 repolarization of cardiac action potentials and thereby affects excitation-contraction coupling. Small molecule activators of I to may therefore offer novel treatments for cardiac dysfunction, including heart failure and atrial fibrillation. NS5806 has been identified as a prototypic activator of canine I to This study investigated, for the first time, actions of NS5806 on rabbit atrial and ventricular I to Whole cell patch-clamp recordings of I to and action potentials were made at physiological temperature from rabbit ventricular and atrial myocytes. 10  μ mol/L NS5806 increased ventricular I to with a leftward shift in I to activation and accelerated restitution. At higher concentrations, stimulation of I to was followed by inhibition. The EC 50 for stimulation was 1.6  μ mol/L and inhibition had an IC 50 of 40.7  μ mol/L. NS5806 only inhibited atrial I to (IC 50 of 18  μ mol/L) and produced a modest leftward shifts in I to activation and inactivation, without an effect on restitution. 10  μ mol/L NS5806 shortened ventricular action potential duration (APD) at APD 20 -APD 90 but prolonged atrial APD NS5806 also reduced atrial AP upstroke and amplitude, consistent with an additional atrio-selective effect on Na + channels. In contrast to NS5806, flecainide, which discriminates between Kv1.4 and 4.x channels, produced similar levels of inhibition of ventricular and atrial I to NS5806 discriminates between rabbit ventricular and atrial I to, with mixed activator and inhibitor actions on the former and inhibitor actions against the later. NS5806 may be of significant value for pharmacological interrogation of regional differences in native cardiac I to . © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  6. Isolated left ventricular non-compaction cardiomyopathy associated with polymorphous ventricular tachycardia mimicking torsades de pointes

    Directory of Open Access Journals (Sweden)

    Oana Dickinson

    2013-02-01

    Full Text Available Left ventricular non-compaction (LVNC cardiomyopathy is a rare congenital disorder, classified by the American Heart Association as a primary genetic cardiomyopathy and characterized by multiple trabeculations within the left ventricle. LVNC cardiomyopathy has been associated with 3 major clinical manifestations: heart failure, atrial and ventricular arrhythmias and thromboembolic events, including stroke. In this case report, we describe a female patient with apparently isolated LVNC in whom pause-dependent polymorphic ventricular tachycardia suggesting torsades de pointes occurred in the presence of a normal QT interval.

  7. Hypertrophic cardiomyopathy with mid-ventricular obstruction and apical aneurysm

    Directory of Open Access Journals (Sweden)

    N.D. Oryshchyn

    2016-11-01

    Full Text Available A case report of apical left ventricular aneurysm in patient with hypertrophic cardiomyopathy with mid-ventricular obstruction (diagnosis and surgical treatment is presented. We revealed apical aneurysm and mid-ventricular obstruction during echocardiography and specified anatomical characteristics of aneurysm during computer tomography. There was no evidence of obstructive coronary artery disease during coronary angiography. Taking into consideration multiple cerebral infarcts, aneurysm resection and left ventricular plastics was performed. Electronic microscopy of myocardium confirmed the diagnosis of hypertrophic cardiomyopathy.

  8. follow-up of patients with arrhythmogenic right ventricular

    African Journals Online (AJOL)

    was sudden, 1 patient died due to left ventricular failure, and ... Arrhythmogenic right ventricular cardiomyopathy/ dysplasia .... hypertension and from atrial fibrillation that developed 2.4 .... of left ventricular function was global without regional ..... 99mTc he brain si before a acid (G minute his sem next 3 - his sem showed.

  9. Left Ventricular Geometry In Nigerians With Type II Diabetes Mellitus ...

    African Journals Online (AJOL)

    Background: Left ventricular hypertrophy is independently associated with increased incidence of cardiovascular disease, cardiovascular and all cause mortality. In a relatively healthy hypertensive adult population, type II diabetes is associated with higher left ventricular mass, concentric left ventricular geometry and lower ...

  10. Effects of local cardiac denervation on cardiac innervation and ventricular arrhythmia after chronic myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Xudong Liu

    Full Text Available Modulation of the autonomic nervous system (ANS has already been demonstrated to display antiarrhythmic effects in patients and animals with MI. In this study, we investigated whether local cardiac denervation has any beneficial effects on ventricular electrical stability and cardiac function in the chronic phase of MI.Twenty-one anesthetized dogs were randomly assigned into the sham-operated, MI and MI-ablation groups, respectively. Four weeks after local cardiac denervation, LSG stimulation was used to induce VPCs and VAs. The ventricular fibrillation threshold (VFT and the incidence of inducible VPCs were measured with electrophysiological protocol. Cardiac innervation was determined with immunohistochemical staining of growth associated protein-43 (GAP43 and tyrosine hydroxylase (TH. The global cardiac and regional ventricular function was evaluated with doppler echocardiography in this study.Four weeks after operation, the incidence of inducible VPC and VF in MI-ablation group were significantly reduced compared to the MI dogs (p<0.05. Moreover, local cardiac denervation significantly improved VFT in the infarcted border zone (p<0.05. The densities of GAP43 and TH-positive nerve fibers in the infarcted border zone in the MI-ablation group were lower than those in the MI group (p<0.05. However, the local cardiac denervation did not significantly improve cardiac function in the chronic phase of MI, determined by the left ventricle diameter (LV, left atrial diameter (LA, ejection fraction (EF.Summarily, in the chronic phase of MI, local cardiac denervation reduces the ventricular electrical instability, and attenuates spatial heterogeneity of sympathetic nerve reconstruction. Our study suggests that this methodology might decrease malignant ventricular arrhythmia in chronic MI, and has a great potential for clinical application.

  11. Flecainide Therapy Reduces Exercise-Induced Ventricular Arrhythmias in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia

    NARCIS (Netherlands)

    van der Werf, Christian; Kannankeril, Prince J.; Sacher, Frederic; Krahn, Andrew D.; Viskin, Sami; Leenhardt, Antoine; Shimizu, Wataru; Sumitomo, Naokata; Fish, Frank A.; Bhuiyan, Zahurul A.; Willems, Albert R.; van der Veen, Maurits J.; Watanabe, Hiroshi; Laborderie, Julien; Haïssaguerre, Michel; Knollmann, Björn C.; Wilde, Arthur A. M.

    2011-01-01

    Objectives This study evaluated the efficacy and safety of flecainide in addition to conventional drug therapy in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT). Background CPVT is an inherited arrhythmia syndrome caused by gene mutations that destabilize cardiac

  12. Acute Right Ventricular Dysfunction Complicating Prolonged ...

    African Journals Online (AJOL)

    We report a case of transient right ventricular dysfunction associated with prolonged cardiac tamponade, an unusual complication of uncertain etiology. We believe that in this case dynamic coronary flow restriction resulted in ischemic injury and stunning of the right ventricle. Other possible causes are briefly reviewed. Right ...

  13. Left ventricular hypertrophy : virtuous intentions, malign consequences

    NARCIS (Netherlands)

    Pokharel, S; Sharma, UC; Pinto, YM

    Left ventricular hypertrophy (LVH) is currently the focus of intense cardiovascular research, with the resultant rapid evolution of novel concepts relating to its exceedingly complex pathophysiology. In addition to the alterations in signal transduction and disturbances in Ca2+ homeostasis, there

  14. Left ventricular hypertrophy: virtuous intentions, malign consequences

    NARCIS (Netherlands)

    Pokharel, Saraswati; Sharma, Umesh C.; Pinto, Yigal M.

    2003-01-01

    Left ventricular hypertrophy (LVH) is currently the focus of intense cardiovascular research, with the resultant rapid evolution of novel concepts relating to its exceedingly complex pathophysiology. In addition to the alterations in signal transduction and disturbances in Ca(2+) homeostasis, there

  15. Right ventricular myxoma with heart failure

    International Nuclear Information System (INIS)

    Nuri, M.M.H.; Naseem, A.; Raza, A.; Ahmad, W.; Raja, M.K.; Ahmad, A.; Rasheed, A.; Gohar, A.

    2005-01-01

    Cardiac myxomas are histologically benign tumors but they may be lethal because of their strategic position. These are mostly located in the left atrium and uncommonly in the right atrium. We report a case of a large right ventricular myxoma presenting with heart failure. (author)

  16. Radionuclide analysis of right and left ventricular response to exercise in patients with atrial and ventricular septal defects

    International Nuclear Information System (INIS)

    Peter, C.A.; Bowyer, K.; Jones, R.H.

    1983-01-01

    In patients with ventricular or atrial septal defect, the ventricle which is chronically volume overloaded might not appropriately respond to increased demand for an augmentation in output and thereby might limit total cardiac function. In this study we simultaneously measured right and left ventricular response to exercise in 10 normal individuals, 10 patients with ventricular septal defect (VSD), and 10 patients with atrial septal defect (ASD). The normal subjects increased both right and left ventricular ejection fraction, end-diastolic volume, and stroke volume to achieve a higher cardiac output during exercise. Patients with VSD failed to increase right ventricular ejection fraction, but increased right ventricular end-diastolic volume and stroke volume. Left ventricular end-diastolic volume did not increase in these patients but ejection fraction, stroke volume, and forward left ventricular output achieved during exercise were comparable to the response observed in healthy subjects. In the patients with ASD, no rest-to-exercise change occurred in either right ventricular ejection fraction, end-diastolic volume, or stroke volume. In addition, left ventricular end-diastolic volume failed to increase, and despite an increase in ejection fraction, left ventricular stroke volume remained unchanged from rest to exercise. Therefore, cardiac output was augmented only by the heart rate increase in these patients. Right ventricular function appeared to be the major determinant of total cardiac output during exercise in patients with cardiac septal defects and left-to-right shunt

  17. Correlation of Ventricular Arrhythmogenesis with Neuronal Remodeling of Cardiac Postganglionic Parasympathetic Neurons in the Late Stage of Heart Failure after Myocardial Infarction.

    Science.gov (United States)

    Zhang, Dongze; Tu, Huiyin; Wang, Chaojun; Cao, Liang; Muelleman, Robert L; Wadman, Michael C; Li, Yu-Long

    2017-01-01

    Introduction: Ventricular arrhythmia is a major cause of sudden cardiac death in patients with chronic heart failure (CHF). Our recent study demonstrates that N-type Ca 2+ currents in intracardiac ganglionic neurons are reduced in the late stage of CHF rats. Rat intracardiac ganglia are divided into the atrioventricular ganglion (AVG) and sinoatrial ganglion. Only AVG nerve terminals innervate the ventricular myocardium. In this study, we tested the correlation of electrical remodeling in AVG neurons with ventricular arrhythmogenesis in CHF rats. Methods and Results: CHF was induced in male Sprague-Dawley rats by surgical ligation of the left coronary artery. The data from 24-h continuous radiotelemetry ECG recording in conscious rats showed that ventricular tachycardia/fibrillation (VT/VF) occurred in 3 and 14-week CHF rats but not 8-week CHF rats. Additionally, as an index for vagal control of ventricular function, changes of left ventricular systolic pressure (LVSP) and the maximum rate of left ventricular pressure rise (LV dP/dt max ) in response to vagal efferent nerve stimulation were blunted in 14-week CHF rats but not 3 or 8-week CHF rats. Results from whole-cell patch clamp recording demonstrated that N-type Ca 2+ currents in AVG neurons began to decrease in 8-week CHF rats, and that there was also a significant decrease in 14-week CHF rats. Correlation analysis revealed that N-type Ca 2+ currents in AVG neurons negatively correlated with the cumulative duration of VT/VF in 14-week CHF rats, whereas there was no correlation between N-type Ca 2+ currents in AVG neurons and the cumulative duration of VT/VF in 3-week CHF. Conclusion: Malignant ventricular arrhythmias mainly occur in the early and late stages of CHF. Electrical remodeling of AVG neurons highly correlates with the occurrence of ventricular arrhythmias in the late stage of CHF.

  18. Hollow mandrin facilitates external ventricular drainage placement.

    Science.gov (United States)

    Heese, O; Regelsberger, J; Kehler, U; Westphal, M

    2005-07-01

    Placement of ventricular catheters is a routine procedure in neurosurgery. Ventricle puncture is done using a flexible ventricular catheter stabilised by a solid steel mandrin in order to improve stability during brain penetration. A correct catheter placement is confirmed after removing the solid steel mandrin by observation of cerebrospinal fluid (CSF) flow out of the flexible catheter. Incorrect placement makes further punctures necessary. The newly developed device allows CSF flow observation during the puncture procedure and in addition precise intracranial pressure (ICP) measurement. The developed mandrin is hollow with a blunt tip. On one side 4-5 small holes with a diameter of 0.8 mm are drilled corresponding exactly with the holes in the ventricular catheter, allowing CSF to pass into the hollow mandrin as soon as the ventricle is reached. By connecting a small translucent tube at the distal portion of the hollow mandrin ICP can be measured without loss of CSF. The system has been used in 15 patients with subarachnoid haemorrhage (SAH) or intraventricular haemeorrhage (IVH) and subsequent hydrocephalus. The new system improved the external ventricular drainage implantation procedure. In all 15 patients catheter placement was correct. ICP measurement was easy to perform immediately at ventricle puncture. In 4 patients at puncture no spontaneous CSF flow was observed, therefore by connecting a syringe and gentle aspiration of CSF correct placement was confirmed in this unexpected low pressure hydrocephalus. Otherwise by using the conventional technique further punctures would have been necessary. Advantages of the new technique are less puncture procedures with a lower risk of damage to neural structures and reduced risk of intracranial haemorrhages. Implantation of the ventricular catheter to far into the brain can be monitored and this complication can be overcome. Using the connected pressure monitoring tube an exact measurement of the opening

  19. Left ventricular function in chronic aortic regurgitation

    International Nuclear Information System (INIS)

    Iskandrian, A.S.; Hakki, A.H.; Manno, B.; Amenta, A.; Kane, S.A.

    1983-01-01

    Left ventricular performance was determined in 42 patients with moderate or severe aortic regurgitation during upright exercise by measuring left ventricular ejection fraction and volume with radionuclide ventriculography. Classification of the patients according to exercise tolerance showed that patients with normal exercise tolerance (greater than or equal to 7.0 minutes) had a significantly higher ejection fraction at rest (probability [p] . 0.02) and during exercise (p . 0.0002), higher cardiac index at exercise (p . 0.0008) and lower exercise end-systolic volume (p . 0.01) than did patients with limited exercise tolerance. Similar significant differences were noted in younger patients compared with older patients in ejection fraction at rest and exercise (both p . 0.001) and cardiac index at rest (p . 0.03) and exercise (p . 0.0005). The end-diastolic volume decreased during exercise in 60% of the patients. The patients with a decrease in volume were significantly younger and had better exercise tolerance and a larger end-diastolic volume at rest than did patients who showed an increase in volume. The mean corrected left ventricular end-diastolic radius/wall thickness ratio was significantly greater in patients with abnormal than in those with normal exercise reserve (mean +/- standard deviation 476 +/- 146 versus 377 +/- 92 mm Hg, p less than 0.05). Thus, in patients with chronic aortic regurgitation: 1) left ventricular systolic function during exercise was related to age, exercise tolerance and corrected left ventricular end-diastolic radius/wall thickness ratio, and 2) the end-diastolic volume decreased during exercise, especially in younger patients and patients with normal exercise tolerance or a large volume at rest

  20. Dorsal spinal cord stimulation obtunds the capacity of intrathoracic extracardiac neurons to transduce myocardial ischemia.

    Science.gov (United States)

    Ardell, Jeffrey L; Cardinal, René; Vermeulen, Michel; Armour, J Andrew

    2009-08-01

    Populations of intrathoracic extracardiac neurons transduce myocardial ischemia, thereby contributing to sympathetic control of regional cardiac indices during such pathology. Our objective was to determine whether electrical neuromodulation using spinal cord stimulation (SCS) modulates such local reflex control. In 10 anesthetized canines, middle cervical ganglion neurons were identified that transduce the ventricular milieu. Their capacity to transduce a global (rapid ventricular pacing) vs. regional (transient regional ischemia) ventricular stress was tested before and during SCS (50 Hz, 0.2 ms duration at 90% MT) applied to the dorsal aspect of the T1 to T4 spinal cord. Rapid ventricular pacing and transient myocardial ischemia both activated cardiac-related middle cervical ganglion neurons. SCS obtunded their capacity to reflexly respond to the regional ventricular ischemia, but not rapid ventricular pacing. In conclusion, spinal cord inputs to the intrathoracic extracardiac nervous system obtund the latter's capacity to transduce regional ventricular ischemia, but not global cardiac stress. Given the substantial body of literature indicating the adverse consequences of excessive adrenergic neuronal excitation on cardiac function, these data delineate the intrathoracic extracardiac nervous system as a potential target for neuromodulation therapy in minimizing such effects.

  1. Contractilidad del músculo ventricular bajo la acción de prajmalina-propanolol y prajmalina-epinefrina Contractibility of the ventricular muscle under the action of prajmaline-propanolol and prajmaline-epinephrine

    Directory of Open Access Journals (Sweden)

    Jorge Pérez Valdivia

    2005-03-01

    Full Text Available Los efectos de la estimulación adrenérgica alfa y beta, pueden ser logrados por agentes agonistas y antagonistas, como la epinefrina y el propranolol respectivamente. Con el objetivo de precisar aspectos relacionados con la contractilidad del músculo ventricular, se realizaron un total de trece experimentos utilizando combinaciones de prajmalina-epinefrina y prajmalina-propanolol, prefundiendo preparaciones de tiras de músculo ventricular de trece ejemplares adultos de ranas catesbeiana. La prajmalina, antiarrítmico del grupo I, se obtuvo a partir de la Rauvvolfia viridis, planta endémica de Cuba. Las preparaciones fueron estimuladas con pulsos de corriente, y la tensión desarrollada por el músculo fue registrada por un transductor fuerza-desplazamiento. Las señales eléctricas fueron convertidas en trazos por un equipo registrador. Los resultados indican que las combinaciones de prajmalina-epinefrina y prajmanina-propanolol afectan de forma diametralmente opuesta la contractilidad del músculo cardíaco, aumentando en un 40% y disminuyendo en un 15% respectivamente la fuerza de la contracción del músculo ventricular. Por otra parte se sugiere un posible mecanismo de acción de la prajmalina sobre los receptores alfa presentes en las membranas de las células ventriculares.The effects of alfa and beta adrenergic stimulation can be accomplished by agonist and antagonist agents such as epinephrine and propanolol respectively. Aimed at determining the aspects related to contractibility of ventricular muscle, thirteen experiments were performed using combinations of prajmaline "epinephrine and prajmaline" propanolol, being perfused preparations of ventricular muscle strips of thirteen samples of adult Catesblian frogs. Prajmaline, a group I antiarrhythmic, was obtained from Rauvvolfia viridis, an endemic plant in Cuba. The preparations were stimulated with electric current pulses and the tension performed by the muscle was registered by a

  2. Arrhythmogenic right ventricular cardiomyopathy in a dog : case report

    Directory of Open Access Journals (Sweden)

    A.J. Möhr

    2000-07-01

    Full Text Available An 8-month-old Labrador retriever bitch was evaluated for sudden-onset, progressive abdominal distension. Physical examination revealed an exaggerated inspiratory effort, severe ascites, bilateral jugular vein distension, and hypokinetic femoral arterial pulses. Thoracic auscultation detected tachycardia with muffled heart sounds, without audible cardiac murmurs. Thoracic radiographs identified severe right ventricular enlargement and pleural effusion. The electrocardiogram was consistent with incomplete right bundle branch block or right ventricular enlargement. Echocardiography demonstrated severe right ventricular and atrial dilation, secondary tricuspid regurgitation, and thinning and hypocontractility of the right ventricular myocardium. Left heart chamber sizes were slightly decreased, with normal left ventricular contractility. Adiagnosis of arrhythmogenic right ventricular cardiomyopathy was reached, based on the characteristic clinical, electrocardiographic, radiographic and echocardiographic findings, and the exclusion of other causes of isolated right ventricular failure. Treatment effected good control of clinical signs, until acutely decompensated congestive right heart failure led to euthanasia after 4 months. Arrhythmogenic right ventricular cardiomyopathy is a well-described clinical entity in humans, and has previously been documented in 3 male dogs. The condition is characterised by progressive fibro-adipose replacement of right ventricular myocardium, while the left ventricle usually remains unaffected. It should be considered a differential diagnosis in any young dog presented with isolated right heart failure, syncope, or unexplained ventricular tachyarrhythmias. This article reports the 1st case of arrhythmogenic right ventricular cardiomyopathy in a female dog, and highlights its echocardiographic features.

  3. Echocardiographic left ventricular masses in distance runners and weight lifters

    Science.gov (United States)

    Longhurst, J. C.; Gonyea, W. J.; Mitchell, J. H.; Kelly, A. R.

    1980-01-01

    The relationships of different forms of exercise training to left ventricular mass and body mass are investigated by echocardiographic studies of weight lifters, long-distance runners, and comparatively sized untrained control subjects. Left ventricular mass determinations by the Penn convention reveal increased absolute left ventricular masses in long-distance runners and competitive weight lifters with respect to controls matched for age, body weight, and body surface area, and a significant correlation between ventricular mass and lean body mass. When normalized to lean body mass, the ventricular masses of distance runners are found to be significantly higher than those of the other groups, suggesting that dynamic training elevates left ventricular mass compared to static training and no training, while static training increases ventricular mass only to the extent that lean body mass is increased.

  4. Two-dimensional echocardiographic features of right ventricular infarction

    International Nuclear Information System (INIS)

    D'Arcy, B.; Nanda, N.C.

    1982-01-01

    Real-time, two-dimensional echocardiographic studies were performed in 10 patients with acute myocardial infarction who had clinical features suggestive of right ventricular involvement. All patients showed right ventricular wall motion abnormalities. In the four-chamber view, seven patients showed akinesis of the entire right ventricular diaphragmatic wall and three showed akinesis of segments of the diaphragmatic wall. Segmental dyskinetic areas involving the right ventricular free wall were identified in four patients. One patient showed a large right ventricular apical aneurysm. Other echocardiographic features included enlargement of the right ventricle in eight cases, paradoxical ventricular septal motion in seven cases, tricuspid incompetence in eight cases, dilation of the stomach in four cases and localized pericardial effusion in two cases. Right ventricular infarction was confirmed by radionuclide methods in seven patients, at surgery in one patient and at autopsy in two patients

  5. Neuromodulation therapy does not influence blood flow distribution or left-ventricular dynamics during acute myocardial ischemia.

    Science.gov (United States)

    Kingma, J G; Linderoth, B; Ardell, J L; Armour, J A; DeJongste, M J; Foreman, R D

    2001-08-13

    Electrical stimulation of the dorsal aspect of the upper thoracic spinal cord is used increasingly to treat patients with angina pectoris refractory to conventional therapeutic strategies. The purpose of this study was to determine whether spinal cord stimulation (SCS) in dogs affects regional myocardial blood flow and left-ventricular (LV) function before and during transient obstruction of the left anterior descending coronary artery (LAD). In anesthetized dogs, regional myocardial blood flow distribution was determined using radiolabeled microspheres and left-ventricular function was measured by impedance-derived pressure-volume loops. SCS was accomplished by stimulating the dorsal T1-T2 segments of the spinal cord using epidural bipolar electrodes at 90% of motor threshold (MT) (50 Hz, 0.2-ms duration). Effects of 5-min SCS were assessed under basal conditions and during 4-min occlusion of the LAD. SCS alone evoked no change in regional myocardial blood flow or cardiovascular indices. Transient LAD occlusion significantly diminished blood flow within ischemic, but not in non-ischemic myocardial tissue. Left ventricular pressure-volume loops were shifted rightward during LAD occlusion. Cardiac indices were altered similarly during LAD occlusion and concurrent SCS. SCS does not influence the distribution of blood flow within the non-ischemic or ischemic myocardium. Nor does it modify LV pressure-volume dynamics in the anesthetized experimental preparation.

  6. Assessment of ventricular excitation propagation velocity using intramyocardial electrograms and electron beam tomography images

    International Nuclear Information System (INIS)

    Kraft, A.; Schreier, G.; Hutten, H.; Kastner, P.; Rienmueller, R.; Grasser, B; Iberer, F.; Tscheliessnigg, K.H.

    1999-01-01

    The combination of intramyocardial electrogram (IEGM) recordings and 3D-reconstruction of the heart allows to relate electrophysiological with geometrical parameters of the heart. In 12 Heart transplants the distance of two epimyocardially implanted pacemaker leads d x and the propagation time f x have been correlated. Linear regression analysis revealed significant (p < 0,002) and strong (r = 0,82) correlation. The ventricular excitation propagation velocity (VEPV) within the examined patient group was found to be 0,53 m/s with an offset of 14.25 mm, which is caused by the extent of the electrodes and the region of early capture immediately after stimulation. (author)

  7. Right ventricular hydatid cyst ruptured to pericardium

    Directory of Open Access Journals (Sweden)

    Feridoun Sabzi

    2015-01-01

    Full Text Available Cardiac hydatidosis is rare presentation of body hydatidosis. Incidence of cardiac involvements range from 5% to 5% of patients with hydatid disease. Most common site of hydatid cyst in heart is interventricular septum and left ventricular free wall. Right ventricular free wall involvement by cyst that ruptured to pericardial cavity is very rare presentation of hydatid cyst. Cardiac involvement may have serious consequences such as rupture to blood steam or pericardial cavity. Both the disease and its surgical treatment carry a high complication rate, including rupture leading to cardiac tamponade, anaphylaxis and also death. In the present report, a 43-year-old man with constrictive pericarditis secondary to a pericardial hydatid cyst is described.

  8. [Ventricular tachyarrhythmias in patients with cardiomyopathy

    DEFF Research Database (Denmark)

    Henningsen, K.; Christensen, A.H.; Svendsen, Jesper Hastrup

    2008-01-01

    by disease, gender, age, previous cardiac arrest and treatment with implantable cardioverter-defibrillator (ICD). RESULTS: 993 patients were screened and 128 patients with cardiomyopathy were identified, corresponding to 13% of the screened patients. 58 (45%) of the patients had dilated cardiomyopathy (DCM......), 57 (45%) patients had arrhythmogenic right ventricular cardiomyopathy (ARVC) and 13 (10%) had hypertrophic cardiomyopathy (HCM). The average age was 44 years for HCM, 41 years for ARVC and 58 years for DCM. The majority of the patients were male. ICD treatment was used in 95% of the patients...... with ARVC, 70% of the patients with HCM and 59% of the patients with DCM. Only 5 patients had previous cardiac arrest without reversible cause. CONCLUSION: The study shows that cardiomyopathies are relatively frequent causes of ventricular tachyarrhythmias in patients discharged from a specialised...

  9. Detection of left ventricular thrombi by computerised tomography

    International Nuclear Information System (INIS)

    Nair, C.K.; Sketch, M.H.; Mahoney, P.D.; Lynch, J.D.; Mooss, A.N.; Kenney, N.P.

    1981-01-01

    Sixteen patients suspected of having left ventricular mural thrombi were studied. All had suffered transmural myocardial infarction. Fifteen patients had a ventricular aneurysm. One had had systemic emboli. The mean length of time between the myocardial infarction and the study was 14.8 months, with a range of one month to 79 months. All patients underwent computerised tomography of the heart, M-mode echocardiography (M-mode), and two-dimensional echocardiography (2-D). Eight patients underwent left ventricular cineangiography. Five patients had surgical confirmation. Computerised tomography, two-dimensional, and M-mode echocardiography predicted left ventricular mural thrombi in 10, eight, and one of the 16 patients, respectively. Left ventricular cineangiography predicted left ventricular mural thrombi in four out of eight patients. Computerised tomography and left ventricular cineangiography correctly predicted the presence or absence of left ventricular thrombi in all five patients who underwent operation. In the same group, however, two-dimensional and M-mode echocardiography failed to predict the presence of thrombi in one and three patients, respectively. Among the 11 patients without surgical confirmation, one, in whom no left ventricular thrombi were shown by M-mode and two-dimensional echocardiography, was found to have thrombi on computerised tomography. In another, two-dimensional echocardiography was positive but this finding was not confirmed either by computerised tomography or by left ventricular angiography. (author)

  10. Amiodarone for the treatment and prevention of ventricular fibrillation and ventricular tachycardia

    Directory of Open Access Journals (Sweden)

    Hugo Van Herendael

    2010-06-01

    Full Text Available Hugo Van Herendael, Paul DorianDivision of Cardiology, St. Michael’s Hospital, University of Toronto, Toronto, CanadaAbstract: Amiodarone has emerged as the leading antiarrhythmic therapy for termination and prevention of ventricular arrhythmia in different clinical settings because of its proven efficacy and safety. In patients with shock refractory out-of-hospital cardiac arrest and hemodynamically destabilizing ventricular arrhythmia, amiodarone is the most effective drug available to assist in resuscitation. Although the superiority of the transvenous implantable cardioverter defibrillator (ICD over amiodarone has been well established in the preventive treatment of patients at high risk of life-threatening ventricular arrhythmias, amiodarone (if used with a beta-blocker is the most effective antiarrhythmic drug to prevent ICD shocks and treat electrical storm. Both the pharmacokinetics and the electrophysiologic profile of amiodarone are complex, and its optimal and safe use requires careful patient surveillance with respect to potential adverse effects.Keywords: amiodarone, ventricular fibrillation, unstable ventricular tachycardia

  11. Left Ventricular Myocardial Function in Children With Pulmonary Hypertension: Relation to Right Ventricular Performance and Hemodynamics.

    Science.gov (United States)

    Burkett, Dale A; Slorach, Cameron; Patel, Sonali S; Redington, Andrew N; Ivy, D Dunbar; Mertens, Luc; Younoszai, Adel K; Friedberg, Mark K

    2015-08-01

    Through ventricular interdependence, pulmonary hypertension (PH) induces left ventricular (LV) dysfunction. We hypothesized that LV strain/strain rate, surrogate measures of myocardial contractility, are reduced in pediatric PH and relate to invasive hemodynamics, right ventricular strain, and functional measures of PH. At 2 institutions, echocardiography was prospectively performed in 54 pediatric PH patients during cardiac catheterization, and in 54 matched controls. Patients with PH had reduced LV global longitudinal strain (LS; -18.8 [-17.3 to -20.4]% versus -20.2 [-19.0 to -20.9]%; P=0.0046) predominantly because of reduced basal (-12.9 [-10.8 to -16.3]% versus -17.9 [-14.5 to -20.7]%; Pright ventricular free-wall LS (r=0.64; PBrain natriuretic peptide levels correlated moderately with septal LS (r=0.48; P=0.0038). PH functional class correlated moderately with LV free-wall LS (r=-0.48; P=0.0051). The septum, shared between ventricles and affected by septal shift, was the most affected LV region in PH. Pediatric PH patients demonstrate reduced LV strain/strain rate, predominantly within the septum, with relationships to invasive hemodynamics, right ventricular strain, and functional PH measures. © 2015 American Heart Association, Inc.

  12. The helical ventricular myocardial band: global, three-dimensional, functional architecture of the ventricular myocardium.

    Science.gov (United States)

    Kocica, Mladen J; Corno, Antonio F; Carreras-Costa, Francesc; Ballester-Rodes, Manel; Moghbel, Mark C; Cueva, Clotario N C; Lackovic, Vesna; Kanjuh, Vladimir I; Torrent-Guasp, Francisco

    2006-04-01

    We are currently witnessing the advent of new diagnostic tools and therapies for heart diseases, but, without serious scientific consensus on fundamental questions about normal and diseased heart structure and function. During the last decade, three successive, international, multidisciplinary symposia were organized in order to setup fundamental research principles, which would allow us to make a significant step forward in understanding heart structure and function. Helical ventricular myocardial band of Torrent-Guasp is the revolutionary new concept in understanding global, three-dimensional, functional architecture of the ventricular myocardium. This concept defines the principal, cumulative vectors, integrating the tissue architecture (i.e. form) and net forces developed (i.e. function) within the ventricular mass. Here we expose the compendium of Torrent-Guasp's half-century long functional anatomical investigations in the light of ongoing efforts to define the integrative approach, which would lead to new understanding of the ventricular form and function by linking across multiple scales of biological organization, as defined in ongoing Physiome project. Helical ventricular myocardial band of Torrent-Guasp may also, hopefully, allow overcoming some difficulties encountered in contemporary efforts to create a comprehensive mathematical model of the heart.

  13. Assessment of left ventricular global function

    International Nuclear Information System (INIS)

    Breuel, H.-P.; Baehre, M.

    1985-01-01

    Radionuclide ventriculography (RNV), i.e. noninvasive evaluation of left venticular performance following the application of radionuclides has had a major impact on many aspects of cardiology and has proven its clinical value and reliability in the last few years. This article deals mainly with the changes in global left ventricular function. The clinical applications of RNV for coronary artery diseases and valvular heart diseases are described. (Auth.)

  14. Left ventricular heart failure and pulmonary hypertension†

    Science.gov (United States)

    Rosenkranz, Stephan; Gibbs, J. Simon R.; Wachter, Rolf; De Marco, Teresa; Vonk-Noordegraaf, Anton; Vachiéry, Jean-Luc

    2016-01-01

    Abstract In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) and right ventricular (RV) dysfunction are frequent and have important impact on disease progression, morbidity, and mortality, and therefore warrant clinical attention. Pulmonary hypertension related to left heart disease (LHD) by far represents the most common form of PH, accounting for 65–80% of cases. The proper distinction between pulmonary arterial hypertension and PH-LHD may be challenging, yet it has direct therapeutic consequences. Despite recent advances in the pathophysiological understanding and clinical assessment, and adjustments in the haemodynamic definitions and classification of PH-LHD, the haemodynamic interrelations in combined post- and pre-capillary PH are complex, definitions and prognostic significance of haemodynamic variables characterizing the degree of pre-capillary PH in LHD remain suboptimal, and there are currently no evidence-based recommendations for the management of PH-LHD. Here, we highlight the prevalence and significance of PH and RV dysfunction in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), and provide insights into the complex pathophysiology of cardiopulmonary interaction in LHD, which may lead to the evolution from a ‘left ventricular phenotype’ to a ‘right ventricular phenotype’ across the natural history of HF. Furthermore, we propose to better define the individual phenotype of PH by integrating the clinical context, non-invasive assessment, and invasive haemodynamic variables in a structured diagnostic work-up. Finally, we challenge current definitions and diagnostic short falls, and discuss gaps in evidence, therapeutic options and the necessity for future developments in this context. PMID:26508169

  15. The helical ventricular myocardial band of Torrent-Guasp: potential implications in congenital heart defects.

    Science.gov (United States)

    Corno, Antonio F; Kocica, Mladen J; Torrent-Guasp, Francisco

    2006-04-01

    The new concepts of cardiac anatomy and physiology, based on the observations made by Francisco Torrent-Guasp's discovery of the helical ventricular myocardial band, can be useful in the context of the surgical strategies currently used to manage patients with congenital heart defects. The potential impact of the Torrent-Guasp's Heart on congenital heart defects have been analyzed in the following settings: ventriculo-arterial discordance (transposition of the great arteries), double (atrio-ventricular and ventriculo-arterial) discordance (congenitally corrected transposition of the great arteries), Ebstein's anomaly, pulmonary valve regurgitation after repair of tetralogy of Fallot, Ross operation, and complex intra-ventricular malformations. The functional interaction of right and left ventricles occurs not only through their arrangements in series but also thanks to the structural spiral features. Changes in size and function of either ventricle may influence the performance of the other ventricle. The variety and complexity of congenital heart defects make the recognition of the relationship between form and function a vital component, especially when compared to acquired disease. The new concepts of cardiac anatomy and function proposed by Francisco Torrent-Guasp, based on his observations, should stimulate further investigations of alternative surgical strategies by individuals involved with the management of patients with congenital heart defects.

  16. Ventricular enlargement in patients with affective disorders

    International Nuclear Information System (INIS)

    Murashita, Jun; Kato, Tadafumi; Shioiri, Toshiki; Hamakawa, Inubushi, Toshiro; Hiroshi; Takahashi, Saburo

    1994-01-01

    Ventricular enlargement was determined using linear measurement on MR images in a total of 71 patients with affective disorders, including bipolar affective disorder (41) and depression (30). Fourty-one healthy persons served as controls. Evans ratio, Huckman number and minimum distance of caudate nuclei (MDCN) were used as indices for ventricular enlargment. No significant difference in Evans ratio was observed between both the group of bipolar affective disorder and the group of depression and the control group. Nor did it correlate with age in any of the groups. Huckman number was significantly higher in the group of bipolar affective disorder than the other two groups. It positively correlated with age in the group of depression. MDCN was significantly increased in the group of bipolar affective disorder, as compared with the control group; and there was a positive correlation between MDCN and age in both the group of dipolar affective disorder and the group of depression. In conclusion, ventricular enlargement was dependent upon aging in affetive disorder patients. This tendency was more noticeable in the group of depression. In addition, atrophy of the caudate nuclei was likely to be severer in the group of dipolar affective disorder than the group of depression. (N.K.)

  17. Uso de dobutamina para la inducción de arritmias durante estimulación eléctrica programada del corazón Dobutamine use for arrythmia induction during electrical programmed heart stimulation

    Directory of Open Access Journals (Sweden)

    Diego I Vanegas

    xito como una alternativa al isoproterenol para la inducción de arritmias durante la estimulación eléctrica programada del corazón.Introduction: isoproterenol is the traditionally used drug for incrementing arrhythmia induction when this induction is not achieved during electric programmed heart stimulation under basal conditions. Dobutamine is an adrenergic agent, chemical precursor of isoproterenol which can be an alternative for inducing arrhythmia during electrical programmed heart stimulation (PES. Patients and methods: a retrospective comparative study of the experience with dobutamine for inducing arrhythmia during electrical programmed heart stimulation was performed. The following data were collected: number of studies, data about the patient (medical record, age, gender, and study indication protocol of programmed electrical stimulation, basal and under dobutamine or isoproterenol, and result of the study. Isoproterenol was used in doses of 1 to 3 micrograms per minute until the basal heart rate was incremented at least in 25%. Dobutamine was used in doses of 10 to 40 micrograms per kg of body weight, until obtaining the same increment in the basal heart rate. Results: 1054 electrophysiological studies were evaluated. In 144 patients (group A isoproterenol was used and in 140, dobutamine (group B. In A group the mean age was 39.2 ± 16.2 and 58.3% were females. In group B, mean age was 41.9 ± 18.6 and 51% were females. The most frequent symptom was palpitation and the most commonly induced arrhythmia was AV nodal reentry tachycardia in both groups. The induction of arrhythmia during the electrical programmed heat stimulation under drugs was similar in group A (isoproterenol respect to group B (dobutamine. Conclusions: There were no statistical significant differences in the induction of arrhythmia during electrical programmed heart stimulation using dobutamine or isoproterenol. Dobutamine may be safe and may be successfully used as an alternative to

  18. Stimulation Technologies for Deep Well Completions

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Wolhart

    2005-06-30

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies conducted a study to evaluate the stimulation of deep wells. The objective of the project was to review U.S. deep well drilling and stimulation activity, review rock mechanics and fracture growth in deep, high-pressure/temperature wells and evaluate stimulation technology in several key deep plays. This report documents results from this project.

  19. Ventricular Septal Dissection Complicating Inferior Wall Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Lindsey Kalvin

    2017-01-01

    Full Text Available Postmyocardial infarction ventricular septal defect is an increasingly rare mechanical complication of acute myocardial infarction. We present a case of acute myocardial infarction from right coronary artery occlusion that developed hypotension and systolic murmur 12 hours after successful percutaneous coronary intervention. Although preoperative imaging suggested a large ventricular septal defect and a pseudoaneurysm, intraoperative findings concluded a serpiginous dissection of the ventricular septum. The imaging technicalities are discussed.

  20. Postexertional Supraventricular Tachycardia in Children with Catecholaminergic Polymorphic Ventricular Tachycardia

    Directory of Open Access Journals (Sweden)

    Scott D. N. Else

    2012-01-01

    Full Text Available Catecholaminergic polymorphic ventricular tachycardia (CPVT is a severe arrhythmia associated with sudden death in the young. It is caused by defective calcium handling in ventricular myocytes. The association of supraventricular tachycardia (SVT with CPVT is described in the literature, occurring in the lead-up to ventricular tachycardia during exercise testing. We describe three cases of SVT that were initiated in the recovery period of exercise testing in children with CPVT.

  1. Programming

    International Nuclear Information System (INIS)

    Jackson, M.A.

    1982-01-01

    The programmer's task is often taken to be the construction of algorithms, expressed in hierarchical structures of procedures: this view underlies the majority of traditional programming languages, such as Fortran. A different view is appropriate to a wide class of problem, perhaps including some problems in High Energy Physics. The programmer's task is regarded as having three main stages: first, an explicit model is constructed of the reality with which the program is concerned; second, this model is elaborated to produce the required program outputs; third, the resulting program is transformed to run efficiently in the execution environment. The first two stages deal in network structures of sequential processes; only the third is concerned with procedure hierarchies. (orig.)

  2. Programming

    OpenAIRE

    Jackson, M A

    1982-01-01

    The programmer's task is often taken to be the construction of algorithms, expressed in hierarchical structures of procedures: this view underlies the majority of traditional programming languages, such as Fortran. A different view is appropriate to a wide class of problem, perhaps including some problems in High Energy Physics. The programmer's task is regarded as having three main stages: first, an explicit model is constructed of the reality with which the program is concerned; second, thi...

  3. Right ventricular strain in heart failure: Clinical perspective.

    Science.gov (United States)

    Tadic, Marijana; Pieske-Kraigher, Elisabeth; Cuspidi, Cesare; Morris, Daniel A; Burkhardt, Franziska; Baudisch, Ana; Haßfeld, Sabine; Tschöpe, Carsten; Pieske, Burket

    2017-10-01

    The number of studies demonstrating the importance of right ventricular remodelling in a wide range of cardiovascular diseases has increased in the past two decades. Speckle-tracking imaging provides new variables that give comprehensive information about right ventricular function and mechanics. In this review, we summarize current knowledge of right ventricular mechanics in heart failure with reduced ejection fraction and preserved ejection fraction. We searched PubMed, MEDLINE, Ovid and Embase databases for studies published from January 2000 to December 2016 in the English language using the following keywords: "right ventricle"; "strain"; "speckle tracking"; "heart failure with reduced ejection fraction"; and "heart failure with preserved ejection fraction". Investigations showed that right ventricular dysfunction is associated with higher cardiovascular and overall mortality in patients with heart failure, irrespective of ejection fraction. The number of studies investigating right ventricular strain in patients with heart failure with reduced ejection fraction is constantly increasing, whereas data on right ventricular mechanics in patients with heart failure with preserved ejection fraction are limited. Given the high feasibility, accuracy and clinical implications of right ventricular strain in the population with heart failure, it is of great importance to try to include the evaluation of right ventricular strain as a regular part of each echocardiographic examination in patients with heart failure. However, further investigations are necessary to establish right ventricular strain as a standard variable for decision-making. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Impact of the right ventricular lead position on clinical outcome and on the incidence of ventricular tachyarrhythmias in patients with CRT-D

    DEFF Research Database (Denmark)

    Kutyifa, Valentina; Bloch Thomsen, Poul Erik; Huang, David T.

    2013-01-01

    Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited.......Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited....

  5. Left Ventricular Function Improves after Pulmonary Valve Replacement in Patients with Previous Right Ventricular Outflow Tract Reconstruction and Biventricular Dysfunction

    Science.gov (United States)

    Kane, Colin; Kogon, Brian; Pernetz, Maria; McConnell, Michael; Kirshbom, Paul; Rodby, Katherine; Book, Wendy M.

    2011-01-01

    Congenital heart defects that have a component of right ventricular outflow tract obstruction, such as tetralogy of Fallot, are frequently palliated in childhood by disruption of the pulmonary valve. Although this can provide an initial improvement in quality of life, these patients are often left with severe pulmonary valve insufficiency. Over time, this insufficiency can lead to enlargement of the right ventricle and to the deterioration of right ventricular systolic and diastolic function. Pulmonary valve replacement in these patients decreases right ventricular volume overload and improves right ventricular performance. To date, few studies have examined the effects of pulmonary valve replacement on left ventricular function in patients with biventricular dysfunction. We sought to perform such an evaluation. Records of adult patients who had undergone pulmonary valve replacement from January 2003 through November 2006 were analyzed retrospectively. We reviewed preoperative and postoperative echocardiograms and calculated left ventricular function in 38 patients. In the entire cohort, the mean left ventricular ejection fraction increased by a mean of 0.07 after pulmonary valve replacement, which was a statistically significant change (P < 0.01). In patients with preoperative ejection fractions of less than 0.50, mean ejection fractions increased by 0.10. We conclude that pulmonary valve replacement in patients with biventricular dysfunction arising from severe pulmonary insufficiency and right ventricular enlargement can improve left ventricular function. Prospective studies are needed to verify this finding. PMID:21720459

  6. Towards Early Detection and Risk Stratification of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

    NARCIS (Netherlands)

    Riele, A.S.J.M. te

    2016-01-01

    Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) is an inherited cardiomyopathy characterized by frequent ventricular arrhythmias and usually slowly progressive ventricular dysfunction. Since its initial description in 1982, sudden cardiac death (SCD) occurring in young and usually

  7. Spinal cord stimulation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007560.htm Spinal cord stimulation To use the sharing features on this page, please enable JavaScript. Spinal cord stimulation is a treatment for pain that uses ...

  8. Feldspar, Infrared Stimulated Luminescence

    DEFF Research Database (Denmark)

    Jain, Mayank

    2014-01-01

    This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars.......This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars....

  9. Growth hormone stimulation test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003377.htm Growth hormone stimulation test To use the sharing features on this page, please enable JavaScript. The growth hormone (GH) stimulation test measures the ability of ...

  10. Arrhythmogenic right ventricular dysplasia: Atypical clinical presentation.

    Science.gov (United States)

    Marçalo, José; Menezes Falcão, Luiz

    2017-03-01

    A 67-year-old man was admitted to our hospital after episodes of syncope preceded by malaise and diffuse neck and chest discomfort. No family history of cardiac disease was reported. Laboratory workup was within normal limits, including D-dimers, serum troponin I and arterial blood gases. The electrocardiogram showed sinus rhythm with T-wave inversion in leads V1 to V3. Computed tomography angiography to investigate pulmonary embolism showed no abnormal findings. Transthoracic echocardiography (TTE) displayed massive enlargement of the right ventricle with intact interatrial septum and no pulmonary hypertension. Cardiac magnetic resonance imaging (MRI) confirmed right ventricular (RV) dilatation and revealed marked hypokinesia/akinesia of the lateral wall. Exercise stress testing was negative for ischemia. According to the 2010 Task Force criteria for arrhythmogenic right ventricular dysplasia (ARVD), this patient presented two major criteria (global or regional dysfunction and structural alterations: by MRI, regional RV akinesia or dyskinesia or dyssynchronous RV contraction and RV ejection fraction ≤40%, and repolarization abnormalities: inverted T waves in right precordial leads [V1, V2, and V3]); and one minor criterion (>500 ventricular extrasystoles per 24 hours by Holter), and so a diagnosis of ARVD was made. After electrophysiologic study (EPS) the patient received an implantable cardioverter-defibrillator (ICD). This late clinical presentation of ARVD highlights the importance of TTE screening, possibly complemented by MRI. The associated risk of sudden death was assessed by EPS leading to the implantation of an ICD. Genetic association studies should be offered to the offspring of all ARVD patients. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Reduction of the pace polarization artefact for capture detection applications by a tri-phasic stimulation pulse.

    Science.gov (United States)

    Sutton, R; Fröhlig, G; de Voogt, W G; Goethals, M; Hintringer, F; Kennergren, C; Scanu, P; Guilleman, D; Treese, N; Hartung, W M; Stammwitz, E; Muetstege, A

    2004-11-01

    This study investigated the ability to minimize pace polarization artefacts (PPA) by adjusting the post-stimulus pulse duration of a tri-phasic stimulation pulse. Adjustment of the stimulation pulse was enabled by downloading special study software into an already implanted pacemaker. Tests were performed in a total of 296 atrial leads and 311 ventricular leads. Both chronic and acute leads were included in the study. Statistically significant differences were found in the initial PPA (without any adjustment of the stimulus pulse) between atrial and ventricular leads. In addition, significant differences were observed among various lead models with respect to changes over time in the initial ventricular PPA. Successful PPA reduction was defined as a reduction of the PPA below 0.5 mV for atrial leads and below 1 mV for ventricular leads. Results show a success rate for ventricular and atrial PPA reduction of 97.8% and 98.7%, respectively. Threshold tests showed that after reduction of the PPA loss of ventricular capture can be reliably detected. However, atrial threshold tests showed many false positive evoked response detections. In addition, unexpectedly high evoked response amplitudes were observed in the atrium after reduction of the PPA. Results from additional measurements suggest that these high atrial evoked response amplitudes come from the influence of the input filter of the pacemaker.

  12. Therapeutic effects of selective atrioventricular node vagal stimulation in atrial fibrillation and heart failure.

    Science.gov (United States)

    Zhang, Youhua; Popović, Zoran B; Kusunose, Kenya; Mazgalev, Todor N

    2013-01-01

    Atrial fibrillation (AF) and heart failure (HF) frequently coexist. We have previously demonstrated that selective atrioventricular node (AVN) vagal stimulation (AVN-VS) can be used to control ventricular rate during AF. Due to withdrawal of vagal activity in HF, the therapeutic effects of AVN-VS may be compromised in the combined condition of AF and HF. Accordingly, this study was designed to evaluate the therapeutic effects of AVN-VS to control ventricular rate in AF and HF. A combined model of AF and HF was created by implanting a dual chamber pacemaker in 24 dogs. A newly designed bipolar electrode was inserted into the ganglionic AVN fat pad and connected to a nerve stimulator for delivering AVN-VS. In all dogs, HF was induced by high rate ventricular pacing at 220 bpm for 4 weeks. AF was then induced and maintained by rapid atrial pacing at 600 bpm after discontinuation of ventricular pacing. These HF + AF dogs were randomized into control (n = 9) and AVN-VS (n = 15) groups. In the latter group, vagal stimulation (310 μs, 20 Hz, 3-7 mA) was delivered continuously for 6 months. Compared with the control, AVN-VS had a consistent effect on ventricular rate slowing (by >50 bpm, all P AVN-VS was well tolerated by the treated animals. AVN-VS achieved consistent rate slowing, which was associated with improved ventricular function in a canine AF and HF model. Thus, AVN-VS may be a novel, effective therapeutic option in the combined condition of AF and HF. © 2012 Wiley Periodicals, Inc.

  13. Pseudo ventricular tachycardia: a case report.

    LENUS (Irish Health Repository)

    Riaz, A

    2012-02-01

    BACKGROUND: Dramatic artifacts of pseudo flutter have been reported in the past secondary to various factors including tremor (Handwerker and Raptopoulos in N Engl J Med 356:503, 2007) and dialysis machines (Kostis et al. in J Electrocardiol 40(4):316-318, 2007). METHODS: We present this unusual case where the artifact, produced by tremor, was so pronounced to be misdiagnosed and treated as ventricular tachycardia. CONCLUSION: This case highlights the importance of correlating ECG findings with history and clinical examination and of using 12 lead ECGs for rhythm interpretation especially to confirm consistence of arrhythmias in all leads.

  14. Ventricular tachycardia in ischemic heart disease substrates

    Directory of Open Access Journals (Sweden)

    Olujimi A. Ajijola

    2014-01-01

    This review will discuss the central role of the ischemic heart disease substrate in the development MMVT. Electrophysiologic characterization of the post-infarct myocardium using bipolar electrogram amplitudes to delineate scar border zones will be reviewed. Functional electrogram determinants of reentrant circuits such as isolated late potentials will be discussed. Strategies for catheter ablation of reentrant ventricular tachycardia, including structural and functional targets will also be examined, as will the role of the epicardial mapping and ablation in the management of recurrent MMVT.

  15. Mycobacterium chimaera left ventricular assist device infections.

    Science.gov (United States)

    Balsam, Leora B; Louie, Eddie; Hill, Fred; Levine, Jamie; Phillips, Michael S

    2017-06-01

    A global outbreak of invasive Mycobacterium chimaera infections after cardiac surgery has recently been linked to bioaerosols from contaminated heater-cooler units. The majority of cases have occurred after valvular surgery or aortic graft surgery and nearly half have resulted in death. To date, infections in patients with left ventricular assist devices (LVADs) have not been characterized in the literature. We report two cases of device-associated M. chimaera infection in patients with continuous-flow LVADs and describe challenges related to diagnosis and management in this population. © 2017 Wiley Periodicals, Inc.

  16. Right ventricular pressure response to exercise in adults with isolated ventricular septal defect closed in early childhood.

    Science.gov (United States)

    Moller, Thomas; Lindberg, Harald; Lund, May Brit; Holmstrom, Henrik; Dohlen, Gaute; Thaulow, Erik

    2018-06-01

    We previously demonstrated an abnormally high right ventricular systolic pressure response to exercise in 50% of adolescents operated on for isolated ventricular septal defect. The present study investigated the prevalence of abnormal right ventricular systolic pressure response in 20 adult (age 30-45 years) patients who underwent surgery for early ventricular septal defect closure and its association with impaired ventricular function, pulmonary function, or exercise capacity. The patients underwent cardiopulmonary tests, including exercise stress echocardiography. Five of 19 patients (26%) presented an abnormal right ventricular systolic pressure response to exercise ⩾ 52 mmHg. Right ventricular systolic function was mixed, with normal tricuspid annular plane systolic excursion and fractional area change, but abnormal tricuspid annular systolic motion velocity (median 6.7 cm/second) and isovolumetric acceleration (median 0.8 m/second2). Left ventricular systolic and diastolic function was normal at rest as measured by the peak systolic velocity of the lateral wall and isovolumic acceleration, early diastolic velocity, and ratio of early diastolic flow to tissue velocity, except for ejection fraction (median 53%). The myocardial performance index was abnormal for both the left and right ventricle. Peak oxygen uptake was normal (mean z score -0.4, 95% CI -2.8-0.3). There was no association between an abnormal right ventricular systolic pressure response during exercise and right or left ventricular function, pulmonary function, or exercise capacity. Abnormal right ventricular pressure response is not more frequent in adult patients compared with adolescents. This does not support the theory of progressive pulmonary vascular disease following closure of left-to-right shunts.

  17. Quantification of left ventricular regional functions using ECG-gated myocardial perfusion SPECT. Validation of left ventricular systolic functions

    International Nuclear Information System (INIS)

    Yamamoto, Akira; Takahashi, Naoto; Iwahara, Shin-ichiro; Munakata, Kazuo; Hosoya, Tetsuo

    2006-01-01

    We have developed a program to quantify regional left ventricular (LV) function and wall motion synchrony using electrocardiogram (ECG)-gated myocardial perfusion SPECT (MPS). This preliminary study was undertaken to validate the use of this program for estimating regional LV systolic function. Patients were subjected to MPS by 99m Tc-sestamibi at rest. The study included 20 patients who were confirmed to have a low probability of coronary artery disease (LPG; low probability group), 19 heart disease patients who were examined by MPS and equilibrium radionuclide angiography (ERNA) (ERG; ERNA group), and 24 patients who were examined by MPS and 2-dimensional echocardiography (2DE) (2DEG; 2DE group). The values of the ejection fraction (EF) and peak ejection rate (PER) were estimated. The global functions evaluated by this program were compared with those obtained by ERNA in the ERG. For regional assessment, the reference values of the functional indices were obtained for 17 LV segments in LPG. The Z score, (reference average value of the segment-patient's value of the segment)/reference standard deviation of the segment, was used for the evaluation of regional functions; a score equal to or greater than 2 was defined as abnormal. Semiquantitative visual interpretation of 2DE was used as the standard to assess wall motion. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these criteria and the relationship between 2DE grading and Z scoring were validated in 2DEG. The values of the global EF and PER evaluated by this program correlated with those determined by ERNA (r=0.76 and 0.58, respectively; p -10 ). The potential of this program to quantify the regional systolic function was validated. (author)

  18. [Catecholaminergic polymorphic ventricular tachycardia is a rare inherited heart disease.

    DEFF Research Database (Denmark)

    Holst, Anders Gaarsdal; Tfelt-Hansen, 1jacob; Olesen, Morten S

    2010-01-01

    Catecholaminergic polymorphic ventricular tachycardia is a rare inherited heart disease, which can lead to life-threatening ventricular arrhythmias in patients with a structurally normal heart. The age of onset is usually between two and 12 years and the initial symptom is frequently syncope...

  19. Right ventricular function in patients with dilated cardiomyopathy

    International Nuclear Information System (INIS)

    Kubota, Shuhei; Kubota, Sachio; Iwase, Takashi; Iizuka, Toshio; Imai, Susumu; Murata, Kazuhiko; Inoue, Tomio; Suzuki, Tadashi; Sasaki, Yasuhito.

    1993-01-01

    The characteristics and pathogenesis of right ventricular dysfunction in 14 patients with dilated cardiomyopathy (DCM) were investigated by equilibrium right ventricular blood pool scintigraphy using ultrashort-lifetime 81m Kr. Thirteen patients with severe left ventricular dysfunction due to old anterior myocardial infarction (OMI) and nine normal subjects were used as controls. The right ventricular end-diastolic pressure and volume index, mean pulmonary arterial pressure, and total pulmonary vascular resistance index were almost the same in the DCM and OMI patients. The right ventricular ejection fraction was 44.2±6.0% (mean±SD) in DCM patients and 47.1±7.9% in OMI patients, both significantly lower than those in the normal subjects (54.5±5.3%), but with no difference between the two case groups. The right ventricular peak filling rate was significantly reduced in both case groups as compared with the normal subjects (2.46±0.81 EDV/sec). The reduction was significantly greater (p 81m Kr blood pool scintigraphy is useful in the study of the right ventricular systolic and diastolic function. The diastolic parameters are more sensitive indicators for evaluation of right ventricular function in DCM than the systolic parameters. (author)

  20. Ventricular septal defect closure in a patient with achondroplasia.

    Science.gov (United States)

    Nakanishi, Keisuke; Kawasaki, Shiori; Amano, Atsushi

    2017-01-01

    Achondroplasia with co-morbid CHD is rare, as are reports of surgical treatment for such patients. We present the case of a 13-year-old girl with achondroplasia and ventricular septal defect. Her ventricular septal defect was surgically repaired focussing on the cardiopulmonary bypass flow, healing of the sternum, and her frail neck cartilage. The surgery and recovery were without complications.

  1. Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy.

    Science.gov (United States)

    Lanjewar, Swapnil S; Chhabra, Lovely; Chaubey, Vinod K; Joshi, Saurabh; Kulkarni, Ganesh; Kothagundla, Chandrasekhar; Kaul, Sudesh; Spodick, David H

    2013-01-01

    The electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration. We reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1) were computed and compared between the two subgroups. There was no statistically significant difference in qualitative lung function (FEV1) between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy. The presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration.

  2. Intermittent′ restrictive ventricular septal defect in Tetralogy of Fallot

    Directory of Open Access Journals (Sweden)

    Sudhir S Shetkar

    2015-01-01

    Full Text Available Ventricular septal defect (VSD in Tetralogy of Fallot (TOF is usually large and non-restrictive with equalization of right and left ventricular pressures. Restrictive VSD in TOF is rare. We present an unusual case of TOF with restriction to VSD caused by accessory tricuspid valve tissue that varied with respiration.

  3. Normal left ventricular function does not protect against propafenone ...

    African Journals Online (AJOL)

    Normal left ventricular function does not protect against propafenone-induced incessant ventricular tachycardia. R. N. Scott Millar, J. B. Lawrenson, D.A. Milne. Abstract. Propafenone is a class Ic anti-arrhythmic agent with mild B-blocking properties which has recently become available in South Africa. We have used the ...

  4. Reversible left ventricular dysfunction - important clinical problem of contemporary cardiology

    International Nuclear Information System (INIS)

    Witkowski, A.

    1994-01-01

    An important clinical issue there is determination whether left ventricular damages are reversible or not single photon emission computed tomography and positron computed tomography techniques are shown to provide valuable data in this problem. Article describes basic syndromes connected with left ventricular dysfunction, namely: hibernating myocardium, stunned myocardium and ischemic myocardium preconditioning. (author). 18 refs

  5. Transcatheter closure of ventricular septal defect with Occlutech Duct Occluder.

    Science.gov (United States)

    Atik-Ugan, Sezen; Saltik, Irfan Levent

    2018-04-01

    Patent ductus arteriosus occluders are used for transcatheter closure of ventricular septal defects, as well as for closure of patent ductus arteriosus. The Occlutech Duct Occluder is a newly introduced device for transcatheter closure of patent ductus arteriosus. Here, we present a case in which the Occlutech Duct Occluder was successfully used on a patient for the closure of a perimembraneous ventricular septal defect.

  6. Evaluation of left ventricular volumes measured by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Møgelvang, J; Thomsen, C; Mehlsen, J

    1986-01-01

    Left ventricular end-diastolic and end-systolic volumes were determined in 17 patients with different levels of left ventricular function by magnetic resonance imaging (MRI). A 1.5 Tesla Magnet was used obtaining ECG triggered single and multiple slices. Calculated cardiac outputs were compared...

  7. Genetic bases of arrhythmogenic right ventricular cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Alessandra Rampazzo

    2010-05-01

    Full Text Available Arrhythmogenic right ventricular cardiomyopathy (ARVC is a heart muscle disease in which the pathological substrate is a fibro-fatty replacement of the right ventricular myocardium. The major clinical features are different types of arrhythmias with a left branch block pattern. ARVC shows autosomal dominant inheritance with incomplete penetrance. Recessive forms were also described, although in association with skin disorders. Ten genetic loci have been discovered so far and mutations were reported in five different genes. ARVD1 was associated with regulatory mutations of transforming growth factor beta-3 (TGFβ3, whereas ARVD2, characterized by effort-induced polymorphic arrhythmias, was associated with mutations in cardiac ryanodine receptor-2 (RYR2. All other mutations identified to date have been detected in genes encoding desmosomal proteins: plakoglobin (JUP which causes Naxos disease (a recessive form of ARVC associated with palmoplantar keratosis and woolly hair; desmoplakin (DSP which causes the autosomal dominant ARVD8 and plakophilin-2 (PKP2 involved in ARVD9. Desmosomes are important cell-to-cell adhesion junctions predominantly found in epidermis and heart; they are believed to couple cytoskeletal elements to plasma membrane in cell-to-cell or cell-to-substrate adhesions.

  8. Left ventricular noncompaction: Clinical-echocardiographic study

    Directory of Open Access Journals (Sweden)

    Nikolić Aleksandra

    2012-01-01

    Full Text Available Background/Aim. Left ventricular noncompaction (LVNC is a disorder in endomyocardial morphogenesis, seen either isolated (in the absence of other cardiac anomalies or in association with congenital heart disease and some neuromuscular diseases. Intrauterine arrest of the compaction of myocardial fibers is postulated to be the reason of LVNC. Recognition of this condition is extremely important due to its high mortality and morbidity that lead to progressive heart failure, ventricular arrhythmias and thromboembolic events. The aim of this study was to determine the prevalence and clinical presentation of LVNC among consecutive outpatients according to clinical and echocardiographyic findings. Methode. A total of 3,854 consecutive patients examined at the Institute for Cardiovascular Diseases within a period January 2006 - January 2007 were included in the study. All the patients underwent echocardiographic examination using the same equipment (Vivid 7, GE Medical System. Echocardiographic parameters and clinical presentation in patients with echocardiographic criteria for LVNC were analyzed. Results. Analyzing 3,854 consecutive outpatients, using two-dimensional Color Doppler echocardiography from January 2006 to January 2007, 12 patients met the criteria for LVNC. Seven of them were male. The mean age at diagnosis was 45 ± 15 years. Analyzing clinical manifestation of LVNC it was found that seven patients had signs of heart failure, six had arrhythmias with no embolic events. Conclusion. Our results suggest that the real prevalence of LVNC may be higher than expected. New studies have to be done to solve this problem.

  9. Evaluation of left ventricular function by cardiac CT

    International Nuclear Information System (INIS)

    Naito, Hiroaki; Kozuka, Takahiro

    1982-01-01

    Left ventricular function was evaluated by CT, which was compared with the data of left ventriculography for various cardiac diseases. The end diastolic volume of the left ventricle can be readily computed from CT, with a satisfactory correlation with that of left ventriculography (r = 0.95). The left ventricular ejection fraction, calculated from the areal ratio of the left ventricular lumen in end-diastolic imaging to that in end-sytolic imaging, also roughly reflects left ventricular contractile function, but shows correlation with left ventriculography by only r = 0.79. Although the cardiac output is not sensitive for functional evaluation, it can be directly calculated by means of dynamic scanning and shows a satisfactory correlation with the ear piece pigment dilution (r = 0.85). Evaluation of left ventricular function by CT shows a high precision in comparison with left ventriculography, but still lacks temporal resolving power. (Chiba, N.)

  10. Ventricular rhythm in atrial fibrillation under anaesthetic infusion with propofol

    International Nuclear Information System (INIS)

    Cervigón, R; Moreno, J; Pérez-Villacastín, J; Reilly, R B; Castells, F

    2009-01-01

    Changes in patients' autonomic tone and specific pharmacologic interventions may modify the ventricular response (actual heart rate) during atrial fibrillation (AF). Hypnotic agents such as propofol may modify autonomic balance as they promote a sedative state. It has been shown that propofol slightly slows atrial fibrillatory activity, but the net global effect on the ventricular response remains unknown. We aimed to evaluate in patients in AF the effect of a propofol bolus on the ventricular rate and regularity at ECG. We analysed the possible relation with local atrial fibrillatory activities, as ratios between atrial and ventricular rates (AVRs), analysing atrial activity from intracardiac electrograms at the free wall of the right and left atria and at the interatrial septum. We compared data at the baseline and after complete hypnosis. Propofol was associated with a more homogeneous ventricular response and lower AVR values at the interatrial septum

  11. Malignant ventricular tachycardia in acromegaly: a case report

    Directory of Open Access Journals (Sweden)

    Zhe An

    Full Text Available CONTEXT: In patients with acromegaly, cardiovascular complications are the main cause of death; sudden death has been associated with ventricular tachyarrhythmias. In other patients with life-threatening malignant ventricular tachyarrhythmias, surgical placement of an implantable cardioverter-defibrillator (ICD has proved highly effective in reducing sudden death rates. CASE REPORT: The present article reports the case of a 50-year-old male acromegalic patient who presented symptoms of syncope induced by ventricular tachycardia. An ICD was surgically implanted and a pituitary adenoma, which was responsible for the acromegaly, was completely removed in the same procedure. The surgery was successful and the ventricular arrhythmias were effectively terminated. During six months of follow-up, no documented arrhythmic episodes occurred. CONCLUSION: In patients with acromegaly, malignant ventricular tachyarrhythmia might be effectively controlled by implantation of an ICD and surgical removal of the pituitary adenoma.

  12. Ventricular filling slows epicardial conduction and increases action potential duration in an optical mapping study of the isolated rabbit heart

    Science.gov (United States)

    Sung, Derrick; Mills, Robert W.; Schettler, Jan; Narayan, Sanjiv M.; Omens, Jeffrey H.; McCulloch, Andrew D.; McCullough, A. D. (Principal Investigator)

    2003-01-01

    INTRODUCTION: Mechanical stimulation can induce electrophysiologic changes in cardiac myocytes, but how mechanoelectric feedback in the intact heart affects action potential propagation remains unclear. METHODS AND RESULTS: Changes in action potential propagation and repolarization with increased left ventricular end-diastolic pressure from 0 to 30 mmHg were investigated using optical mapping in isolated perfused rabbit hearts. With respect to 0 mmHg, epicardial strain at 30 mmHg in the anterior left ventricle averaged 0.040 +/- 0.004 in the muscle fiber direction and 0.032 +/- 0.006 in the cross-fiber direction. An increase in ventricular loading increased average epicardial activation time by 25%+/- 3% (P action potential duration at 20% repolarization (APD20) but did at 80% repolarization (APD80), from 179 +/- 7 msec to 207 +/- 5 msec (P action potential duration by a load-dependent mechanism that may not involve stretch-activated channels.

  13. Left ventricular mass in borderline hypertension assessed by echo cardiography

    International Nuclear Information System (INIS)

    Mezzasalma, L.; Ghione, S.; Palonebo, C.

    1989-01-01

    The relationship between clinical measurement of blood pressure (BP) and left ventricular hypertrophy in arterial hypertension appears to be weak in most studies. On the contrary, stronger correlations with target organ damage in general, and left ventricular hypertrophy in particular, have been reported for blood pressure measurements obtained by ambulatory monitoring; this finding may indicate a possible role for blood pressure response to naturally occurring stresses in determining left ventricular hypertrophy. Aim of this study was to investigate, in 18 patients with borderline arterial hypertension, the relationships between echocardiographically assessed left ventricular mass and, respectively, casual BP and BP responses to some standardized stress tests. Only three patients had a diastolic wall thickness of the interventricular septum and of the posterior wall ≥1.2 cm and none had a pathologically increased left ventricular mass index. The following statistically significant correlations were found: casual diastolic BP vs. left ventricular mass index (r=0.53, p<0.02), systolic BP response to bicycle exercise test vs. left ventricular mass index (r=0.55, p<0.05). Multiple regression analysis showed that almost fifty percent of the variability of left ventricular mass index could be predicted by these two BP measurements. These findings suggest that besides the chronically increased afterload, also the transient hypertensive responses to naturally occuring physical stresses may have a role in determining the extent of cardiac structural changes in borderline hypertensive patients. In addition, they indicate a direct relation between left ventricular mass and blood pressure levels also in borderline hypertension, as previously shown for established hypertension, despite the fact that left ventricular hypertrophy represents only an occasional finding in early stages of hypertension

  14. Complex Association of Sex Hormones on Left Ventricular Systolic Function: Insight into Sexual Dimorphism.

    Science.gov (United States)

    Salem, Joe-Elie; Nguyen, Lee S; Hammoudi, Nadjib; Preud'homme, Gisèle; Hulot, Jean-Sebastien; Leban, Monique; Funck-Brentano, Christian; Touraine, Philippe; Isnard, Richard; Bachelot, Anne

    2018-02-01

    Normal values of left ventricular ejection fraction (LVEF) and absolute values of global longitudinal strain (GLS) are lower in men than in women. Data concerning the association of sex hormone levels on these left ventricular systolic function surrogates are scarce. The aim of this study was to determine the association of sex hormones with systolic left ventricular function in healthy subjects and patients with congenital adrenal hyperplasia (CAH) as a model of testosterone dysregulation. Eighty-four adult patients with CAH (58 women; median age, 27 years; interquartile range, 23-36 years) and 84 healthy subjects matched for sex and age were prospectively included. Circulating concentrations of sex hormones were measured within 48 hours of echocardiography with assessment of LVEF and left ventricular longitudinal, radial, and circumferential strain. LVEF and GLS were higher in healthy women than in healthy men (63.9 ± 4.2% vs 60.9 ± 5.1% [P interquartile range, 0.04-0.14 ng/mL] vs 0.16 ng/mL [interquartile range, 0.04-0.3 ng/mL], P interquartile range, 1.3-3 ng/mL] vs 2.9 ng/mL [interquartile range, 2.5-3.4 ng/mL], P < .05). In men, LVEF and GLS were negatively correlated with bioavailable testosterone levels (r = -0.3, P ≤ .05, and r = -0.45, P < .01, respectively), while midventricular radial strain was positively correlated with bioavailable testosterone level (r = 0.38, P < .05). The absolute value of circumferential strain was positively correlated with follicle-stimulating hormone (r = 0.65, P < .0001). These data support that the existence of sex dimorphism concerning left ventricular systolic cardiac function is significantly associated with testosterone levels. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

  15. Risk factors and predictors of Torsade de pointes ventricular tachycardia in patients with left ventricular systolic dysfunction receiving Dofetilide

    DEFF Research Database (Denmark)

    Pedersen, Henriette Sloth; Elming, Hanne; Seibaek, Marie

    2007-01-01

    The purpose of this study was to identify risk factors of Torsade de pointes (TdP) ventricular tachycardia in patients medicated with a class III antiarrhythmic drug (dofetilide) and left ventricular systolic dysfunction with heart failure (HF) or recent myocardial infarction (MI). The 2 Danish...

  16. Stimulation Technologies for Deep Well Completions

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-09-30

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a study to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. An assessment of historical deep gas well drilling activity and forecast of future trends was completed during the first six months of the project; this segment of the project was covered in Technical Project Report No. 1. The second progress report covers the next six months of the project during which efforts were primarily split between summarizing rock mechanics and fracture growth in deep reservoirs and contacting operators about case studies of deep gas well stimulation.

  17. Application of radionuclide ventriculography phase analysis in patients with atrial or ventricular pacing for detecting ventricular abnormal excitation

    International Nuclear Information System (INIS)

    Shi Rongfang; Wang Zhonggan; Li Shengting

    1996-01-01

    The aim of the study was to increase the accuracy of detecting ventricular abnormal excitation. During atrial or ventricular pacing, radionuclide ventriculography phase analysis (RNV-PA) was performed in 17 patients with Wolff-Parkinson-White (W-P-W) syndrome and paroxysmal supra ventricular tachycardia (PSVT) and ventricular tachycardia (PVT). During pacing, detection rate of abnormal excitation by RNV-PA was 95.5%, compared with 68.2% during basic conduction. Atrial or ventricular pacing can significantly increase the detection rate of abnormal excitation by RNV-PA in patients with W-P-W syndrome. It may be a valuable method for identifying the abnormal excitation and estimating the therapeutic effect of ablation

  18. Evaluation of Right Ventricular Function with Radionuclide Cardiac Angiography - Right Ventricular Ejection Fraction in Chronic Obstructive Lung Disease

    International Nuclear Information System (INIS)

    Sohn, In; Shin, Sung Hae; Chung, June Key; Lee, Myung Chul; Cho, Bo Youn; Lee, Young Woo; Han, Yong Cheol; Koh, Chang Soon

    1982-01-01

    To evaluate the usefulness of radionuclide cardiac angiography in the assessment of the right ventricular function, we measured right ventricular ejection fraction (RVEF) using single pass method. In 12 normal persons, RVEF averaged 52.7±5.9% (mean±S.D.). In 25 patients with chronic obstructive lung disease, RVEF was 37.2±10.6% and significantly lower than that of normal person (p<0.01). All 10 patients with right ventricular failure had abnormal RVEF, which was significantly lower than that of 14 persons without right ventricular failure (27.6±5.7%, 43.9±8.5%, respectively, p<0.01). It concluded that RVEF measured by single pass radionuclide cardiac angiography was a useful, noninvasive method to assess right ventricular function.

  19. Excito-oscillatory dynamics as a mechanism of ventricular fibrillation.

    Science.gov (United States)

    Gray, Richard A; Huelsing, Delilah J

    2008-04-01

    The instabilities associated with reentrant spiral waves are of paramount importance to the initiation and maintenance of tachyarrhythmias, especially ventricular fibrillation (VF). In addition to tissue heterogeneities, there are only a few basic purported mechanisms of spiral wave breakup, most notably restitution. We test the hypothesis that oscillatory membrane properties act to destabilize spiral waves. We recorded transmembrane potential (V(m)) from isolated rabbit myocytes using a constant current stimulation protocol. We developed a mathematical model that included both the stable excitable equilibrium point at resting V(m) (-80 mV) and the unstable oscillatory equilibrium point at elevated V(m) (-10 mV). Spiral wave dynamics were studied in 2-dimensional grids using variants of the model. All models showed restitution and reproduced the experimental values of transmembrane resistance at rest and during the action potential plateau. Stable spiral waves were observed when the model showed only 1 equilibrium point. However, spatio-temporal complexity was observed if the model showed both excitable and oscillatory equilibrium points (i.e., excito-oscillatory models). The initial wave breaks resulted from oscillatory waves expanding in all directions; after a few beats, the patterns were characterized by a combination of unstable spiral waves and target patterns consistent with the patterns observed on the heart surface during VF. In our model, this VF-like activity only occurred when the single cell period of V(m) oscillations was within a specific range. The VF-like patterns observed in our excito-oscillatory models could not be explained by the existing proposed instability mechanisms. Our results introduce the important suggestion that membrane dynamics responsible for V(m) oscillations at elevated V(m) levels can destabilize spiral waves and thus may be a novel therapeutic target for preventing VF.

  20. Modern management of epilepsy: Vagus nerve stimulation.

    Science.gov (United States)

    Ben-Menachem, E

    1996-12-01

    Vagus nerve stimulation (VNS) was first tried as a treatment for seizure patients in 1988. The idea to stimulate the vagus nerve and disrupt or prevent seizures was proposed by Jacob Zabarra. He observed a consistent finding among several animal studies which indicated that stimulation of the vagus nerve could alter the brain wave patterns of the animals under study. His hypothesis formed the basis for the development of the vagus nerve stimulator, an implantable device similar to a pacemaker, which is implanted in the left chest and attached to the left vagus nerve via a stimulating lead. Once implanted, the stimulator is programmed by a physician to deliver regular stimulation 24 hours a day regardless of seizure activity. Patients can also activate extra 'on-demand' stimulation with a handheld magnet. Clinical studies have demonstrated VNS therapy to be a safe and effective mode of treatment when added to the existing regimen of severe, refractory patients with epilepsy. Efficacy ranges from seizure free to no response with the majority of patients (> 50%) reporting at least a 50% improvement in number of seizures after 1.5 years of treatment. The side-effect profile is unique and mostly includes stimulation-related sensations in the neck and throat. The mechanism of action for VNS is not clearly understood although two theories have emerged. First, the direct connection theory hypothesizes that the anticonvulsant action of VNS is caused by a threshold raising effect of the connections to the nucleus of the solitary tract and on to other structures. The second is the concept that chronic stimulation of the vagus nerve increases the amount of inhibitory neurotransmitters and decreases the amount of excitatory neurotransmitters. Additional research into the optimal use of VNS is ongoing. Animal and clinical research have produced some interesting new data suggesting there are numerous ways to improve the clinical performance of vagus nerve stimulation as a

  1. Preemptive, but not reactive, spinal cord stimulation mitigates transient ischemia-induced myocardial infarction via cardiac adrenergic neurons

    NARCIS (Netherlands)

    Southerland, E. M.; Milhorn, D. M.; Foreman, R. D.; Linderoth, B.; DeJongste, M. J. L.; Armour, J. A.; Subramanian, V.; Singh, M.; Singh, K.; Ardell, J. L.

    2007-01-01

    Our objective was to determine whether electrical neuromodulation using spinal cord stimulation ( SCS) mitigates transient ischemia-induced ventricular infarction and, if so, whether adrenergic neurons are involved in such cardioprotection. The hearts of anesthetized rabbits, subjected to 30 min of

  2. Prognosis of ventricular fibrillation in hospital

    DEFF Research Database (Denmark)

    Jensen, G V; Torp-Pedersen, C; Køber, L

    1992-01-01

    In a retrospective study of 520 patients with in-hospital ventricular fibrillation 421 (81%) had acute myocardial infarction (MI), 66 (13%) had ischaemic heart disease (IHD) without MI, 33 (6%) had no signs of IHD. The in-hospital mortality of these three groups was 51%, 52%, and 27%, respectively...... (P = 0.01). Logistic regression analysis demonstrated that heart failure and cardiogenic shock were significant risk factors for in-hospital death among patients with IHD. Among discharged patients 1 and 5 years survival was 78% and 51% for patients with MI, 63% and 25% for patients with IHD, 67...... with known IHD suffering in-hospital VF without AMI have a very poor short- and long-term prognosis. These patients need extensive cardiac examination....

  3. Calculation of the ALMA Risk of Right Ventricular Failure After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Loforte, Antonio; Montalto, Andrea; Musumeci, Francesco; Amarelli, Cristiano; Mariani, Carlo; Polizzi, Vincenzo; Lilla Della Monica, Paola; Grigioni, Francesco; Di Bartolomeo, Roberto; Marinelli, Giuseppe

    2018-05-08

    Right ventricular failure after continuous-flow left ventricular assist device (LVAD) implantation is still an unsolved issue and remains a life-threatening event for patients. We undertook this study to determine predictors of the patients who are candidates for isolated LVAD therapy as opposed to biventricular support (BVAD). We reviewed demographic, echocardiographic, hemodynamic, and laboratory variables for 258 patients who underwent both isolated LVAD implantation and unplanned BVAD because of early right ventricular failure after LVAD insertion, between 2006 and 2017 (LVAD = 170 and BVAD = 88). The final study patients were randomly divided into derivation (79.8%, n = 206) and validation (20.1%, n = 52) cohorts. Fifty-seven preoperative risk factors were compared between patients who were successfully managed with an LVAD and those who required a BVAD. Nineteen variables demonstrated statistical significance on univariable analysis. Multivariable logistic regression analysis identified destination therapy (odds ratio [OR] 2.0 [1.7-3.9], p = 0.003), a pulmonary artery pulsatility index right ventricle/left ventricle end-diastolic diameter ratio >0.75 (OR 2.7 [1.5-5.5], p = 0.001), an right ventricle stroke work index 17 (OR 3.5 [1.9-6.9], p the major predictors of the need for BVAD. Using these data, we propose a simple risk calculator to determine the suitability of patients for isolated LVAD support in the era of continuous-flow mechanical circulatory support devices.

  4. Outcomes of patients with right ventricular failure on milrinone after left ventricular assist device implantation.

    Science.gov (United States)

    Tsiouris, Athanasios; Paone, Gaetano; Brewer, Robert J; Nemeh, Hassan W; Borgi, Jamil; Morgan, Jeffrey A

    2015-01-01

    Previous studies have grouped together both patients requiring right ventricular assist devices (RVADs) with patients requiring prolonged milrinone therapy after left ventricular assist device (LVAD) implantation. We retrospectively identified 149 patients receiving LVADs and 18 (12.1%) of which developed right ventricular (RV) failure. We then separated these patients into those requiring RVADs versus prolonged milrinone therapy. This included 10 patients who were treated with prolonged milrinone and eight patients who underwent RVAD placement. Overall, the RV failure group had worse survival compared with the non-RV failure cohort (p = 0.038). However, this was only for the subgroup of patients who required RVADs, who had a 1, 6, 12, and 24 month survival of 62.5%, 37.5%, 37.5%, and 37.5%, respectively, versus 96.8%, 92.1%, 86.7%, and 84.4% for patients without RV failure (p milrinone therapy for RV failure had similar survivals compared with patients without RV failure. In the RV failure group, age, preoperative renal failure, and previous cardiac surgery were predictors of the need for prolonged postoperative milrinone. As LVADs become a more widely used therapy for patients with refractory, end-stage heart failure, it will be important to reduce the incidence of RV failure, as it yields significant morbidity and increases cost.

  5. Case report: paradoxical ventricular septal motion in the setting of primary right ventricular myocardial failure.

    Science.gov (United States)

    Maslow, Andrew; Schwartz, Carl; Mahmood, Feroze; Singh, Arun; Heerdt, Paul M

    2009-07-01

    In this report, a case of right ventricular (RV) failure, hemodynamic instability, and systemic organ failure is described to highlight how paradoxical ventricular systolic septal motion (PVSM), or a rightward systolic displacement of the interventricular septum, may contribute to RV ejection. Multiple inotropic medications and vasopressors were administered to treat right heart failure and systemic hypotension in a patient following combined aortic and mitral valve replacement. In the early postoperative period, echocardiographic evaluation revealed adequate left ventricular systolic function, akinesis of the RV myocardial tissues, and PVSM. In the presence of PVSM, RV fractional area of contraction was > or =35% despite akinesis of the primary RV myocardial walls. The PVSM appeared to contribute toward RV ejection. As a result, the need for multiple inotropes was re-evaluated, in considering that end-organ dysfunction was the result of systemic hypotension and prolonged vasopressor administration. After discontinuation of phosphodiesterase inhibitors, native vascular tone returned and the need for vasopressors declined. This was followed by recovery of systemic organ function. Echocardiographic re-evaluation two years later, revealed persistent akinesis of the RV myocardial tissues and PVSM, the latter appearing to contribute toward RV ejection. This case highlights the importance of left to RV interactions, and how PVSM may mediate these hemodynamic interactions.

  6. Effect of chronic right ventricular apical pacing on left ventricular function.

    Science.gov (United States)

    O'Keefe, James H; Abuissa, Hussam; Jones, Philip G; Thompson, Randall C; Bateman, Timothy M; McGhie, A Iain; Ramza, Brian M; Steinhaus, David M

    2005-03-15

    The determinants of change in left ventricular (LV) ejection fraction (EF) over time in patients with impaired LV function at baseline have not been clearly established. Using a nuclear database to assess changes in LV function over time, we included patients with a baseline LVEF of 25% to 40% on a gated single-photon emission computed tomographic study at rest and only if second-gated photon emission computed tomography performed approximately 18 months after the initial study showed an improvement in LVEF at rest of > or =10 points or a decrease in LVEF at rest of > or =7 points. In all, 148 patients qualified for the EF increase group and 59 patients for the EF decrease group. LVEF on average increased from 33 +/- 4% to 51 +/- 8% in the EF increase group and decreased from 35 +/- 4% to 25 +/- 5% in the EF decrease group. The strongest multivariable predictor of improvement of LVEF was beta-blocker therapy (odds ratio 3.9, p = 0.002). The strongest independent predictor of LVEF decrease was the presence of a permanent right ventricular apical pacemaker (odds ratio 6.6, p = 0.002). Thus, this study identified beta-blocker therapy as the major independent predictor for improvement in LVEF of > or =10 points, whereas a permanent pacemaker (right ventricular apical pacing) was the strongest predictor of a LVEF decrease of > or =7 points.

  7. Intraoperative Transesophageal Echocardiography and Right Ventricular Failure After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Silverton, Natalie A; Patel, Ravi; Zimmerman, Josh; Ma, Jianing; Stoddard, Greg; Selzman, Craig; Morrissey, Candice K

    2018-02-15

    To determine whether intraoperative measures of right ventricular (RV) function using transesophageal echocardiography are associated with subsequent RV failure after left ventricular assist device (LVAD) implantation. Retrospective, nonrandomized, observational study. Single tertiary-level, university-affiliated hospital. The study comprised 100 patients with systolic heart failure undergoing elective LVAD implantation. Transesophageal echocardiographic images before and after cardiopulmonary bypass were analyzed to quantify RV function using tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (S'), fractional area change (FAC), RV global longitudinal strain, and RV free wall strain. A chart review was performed to determine which patients subsequently developed RV failure (right ventricular assist device placement or prolonged inotrope requirement ≥14 days). Nineteen patients (19%) subsequently developed RV failure. Postbypass FAC was the only measure of RV function that distinguished between the RV failure and non-RV failure groups (21.2% v 26.5%; p = 0.04). The sensitivity, specificity, and area under the curve of an abnormal RV FAC (failure after LVAD implantation were 84%, 20%, and 0.52, respectively. No other intraoperative measure of RV function was associated with subsequent RV failure. RV failure increased ventilator time, intensive care unit and hospital length of stay, and mortality. Intraoperative measures of RV function such as tricuspid annular plane systolic excursion, tricuspid annular systolic velocity, and RV strain were not associated with RV failure after LVAD implantation. Decreased postbypass FAC was significantly associated with RV failure but showed poor discrimination. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Wave Intensity Analysis of Right Ventricular Function during Pulsed Operation of Rotary Left Ventricular Assist Devices.

    Science.gov (United States)

    Bouwmeester, J Christopher; Park, Jiheum; Valdovinos, John; Bonde, Pramod

    2018-05-29

    Changing the speed of left ventricular assist devices (LVADs) cyclically may be useful to restore aortic pulsatility; however, the effects of this pulsation on right ventricular (RV) function are unknown. This study investigates the effects of direct ventricular interaction by quantifying the amount of wave energy created by RV contraction when axial and centrifugal LVADs are used to assist the left ventricle. In 4 anesthetized pigs, pressure and flow were measured in the main pulmonary artery and wave intensity analysis was used to identify and quantify the energy of waves created by the RV. The axial pump depressed the intensity of waves created by RV contraction compared with the centrifugal pump. In both pump designs, there were only minor and variable differences between the continuous and pulsed operation on RV function. The axial pump causes the RV to contract with less energy compared with a centrifugal design. Diminishing the ability of the RV to produce less energy translates to less pressure and flow produced, which may lead to LVAD-induced RV failure. The effects of pulsed LVAD operation on the RV appear to be minimal during acute observation of healthy hearts. Further study is necessary to uncover the effects of other modes of speed modulation with healthy and unhealthy hearts to determine if pulsed operation will benefit patients by reducing LVAD complications.

  9. Multicenter, prospective, randomized safety and efficacy study of a new atrial-based managed ventricular pacing mode (MVP) in dual chamber ICDs.

    Science.gov (United States)

    Sweeney, Michael O; Ellenbogen, Kenneth A; Casavant, David; Betzold, Robert; Sheldon, Todd; Tang, Feng; Mueller, Megan; Lingle, John

    2005-08-01

    Ventricular desynchronization caused by right ventricular pacing may impair ventricular function and increase risk of heart failure (CHF), atrial fibrillation (AF), and death. Conventional DDD/R mode often results in high cumulative percentage ventricular pacing (Cum%VP). We hypothesized that a new managed ventricular pacing mode (MVP) would safely provide AAI/R pacing with ventricular monitoring and DDD/R during AV block (AVB) and reduce Cum%VP compared to DDD/R. MVP RAMware was downloaded in 181 patients with Marquis DR ICDs. Patients were initially randomized to either MVP or DDD/R for 1 month, then crossed over to the opposite mode for 1 month. ICD diagnostics were analyzed for cumulative percentage atrial pacing (Cum%AP), Cum%VP, and duration of DDD/R pacing for spontaneous AVB. Baseline characteristics included age 66 +/- 12 years, EF 36 +/- 14%, and NYHA Class II-III 36%. Baseline PR interval was 190 +/- 53 msec and programmed AV intervals (DDD/R) were 216 +/- 50 (paced)/189 +/- 53 (sensed) msec. Mean Cum%VP was significantly lower in MVP versus DDD/R (4.1 +/- 16.3 vs 73.8 +/- 32.5, P MVP were 85.0 and 99.9, respectively. Mean Cum%AP was not different between MVP versus DDD/R (48.7 +/- 38.5 vs 47.3 +/- 38.4, P = 0.83). During MVP overall time spent in AAI/R was 89.6% (intrinsic conduction), DDD/R 6.7% (intermittent AVB), and DDI/R 3.7% (AF). No adverse events were attributed to MVP. MVP safely achieves functional atrial pacing by limiting ventricular pacing to periods of intermittent AVB and AF in ICD patients, significantly reducing Cum%VP compared to DDD/R. MVP is a universal pacing mode that adapts to AVB and AF, providing both atrial pacing and ventricular pacing support when needed.

  10. Evaluation of left ventricular function using digital subtraction ventriculography

    International Nuclear Information System (INIS)

    Yiannikas, J.; Detrano, R.

    1986-01-01

    Digital subtraction ventriculography following injections of contrast via peripheral veins provides excellent images to assess left ventricular function. The images are essentially identical to those following DCV, but allow more uniform mixing of contrast in the left ventricular chamber. Furthermore, few, if any, cardiac arrhythmias occur, hence obviating difficulties that arise from DCV. The spatial resolution of the method is such that regional wall motion assessment of ventricular function is more accurate than that of other noninvasive imaging methods. The use of video-densitometry allows accurate assessment of left ventricular function even when the left ventricular cavity is nonsymmetrically deformed and aneurysmal. In the setting of the cardiac catheterization laboratory, digital ventriculography may provide a safer means of assessing left ventricular function when critical coronary or myocardial disease is present and allows multiple assessments of ventricular function during the same study. Although excellent correlations with standard ventriculography have been noted by all workers, significant discrepancies still exist in individual patients, particularly in the calculations of end diastolic volumes. In the authors experience and in those of most workers, the largest discrepancies existed in patients in whom suboptimal studies are included for analysis. The most frequent reason for the occasional suboptimal study as with all digital subtraction work is the misregistration that results from motion

  11. Arrhythmogenic right ventricular cardiomyopathy: contribution of different electrocardiographic techniques.

    Science.gov (United States)

    Moreira, Davide; Delgado, Anne; Marmelo, Bruno; Correia, Emanuel; Gama, Pedro; Pipa, João; Nunes, Luís; Santos, Oliveira

    2014-04-01

    Arrhythmogenic right ventricular cardiomyopathy, also known as arrhythmogenic right ventricular dysplasia, is a condition in which myocardium is replaced by fibrous or fibrofatty tissue, predominantly in the right ventricle. It is clinically characterized by potentially lethal ventricular arrhythmias, and is a leading cause of sudden cardiac death. Its prevalence is not known exactly but is estimated at approximately 1:5000 in the adult population. Diagnosis can be on the basis of structural and functional alterations of the right ventricle, electrocardiographic abnormalities (including depolarization and repolarization alterations and ventricular arrhythmias) and family history. Diagnostic criteria facilitate the recognition and interpretation of non-specific clinical features of this disease. The authors present a case in which the diagnosis of arrhythmogenic right ventricular cardiomyopathy was prompted by the suspicion of right ventricular disease on transthoracic echocardiography. This was confirmed by detection of epsilon waves on analysis of the ECG, which generally go unnoticed but in this case were the key to the diagnosis. Their presence was also shown by non-conventional ECG techniques such as modified Fontaine ECG. The course of the disease culminated in the occurrence of ventricular tachycardia, which prompted placement of an implantable cardioverter-defibrillator. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  12. Free and conjugated dopamine in human ventricular fluid

    International Nuclear Information System (INIS)

    Sharpless, N.S.; Thal, L.J.; Wolfson, L.I.; Tabaddor, K.; Tyce, G.M.; Waltz, J.M.

    1981-01-01

    Free dopamine and an acid hydrolyzable conjugate of dopamine were measured in human ventricular fluid specimens with a radioenzymatic assay and by high performance liquid chromatography (HPLC) with electrochemical detection. Only trace amounts of free norepinephrine and dopamine were detected in ventricular fluid from patients with movement disorders. When the ventricular fluid was hydrolyzed by heating in HClO 4 or by lyophilization in dilute HClO 4 , however, a substantial amount of free dopamine was released. Values for free plus conjugated dopamine in ventricular fluid from patients who had never taken L-DOPA ranged from 139 to 340 pg/ml when determined by HPLC and from 223 to 428 pg/ml when measured radioenzymatically. The correlation coefficient for values obtained by the two methods in the same sample of CSF was 0.94 (P<0.001). Patients who had been treated with L-DOPA had higher levels of conjugated dopamine in their ventricular CSF which correlated inversely with the time between the last dose of L-DOPA and withdrawal of the ventricular fluid. Additionally, one patient with acute cerebral trauma had elevated levels of free norepinephrine and both free and conjugated dopamine in his ventricular fluid. Conjugation may be an important inactivation pathway for released dopamine in man. (Auth.)

  13. [Idiopathic ventricular arrhythmia in children. Apropos of 24 cases].

    Science.gov (United States)

    Coeurderoy, A; Almange, C; Laurent, M; Biron, Y; Leborgne, P

    1985-12-01

    The severity and prognosis of idiopathic ventricular arrhythmias in childhood were studied in 24 patients (12 boys, 12 girls) with an average age of 8 years at the time of diagnosis of the arrhythmia. Investigations included clinical assessment and analysis of basal ECG (morphology of the arrhythmias) and dynamic recordings (Holter and exercise stress testing). The clinical course was followed for an average of 3.8 years. The patients were classified in two groups: monomorphic arrhythmias (Group I) and polymorphic arrhythmias (Group II). Group I was divided into 4 subgroups: isolated ventricular extrasystoles (IA), 11 patients; ventricular extrasystoles with bursts of ventricular tachycardia (IB), 6 patients; sustained ventricular tachycardia without intercritical extrasystoles (IC), 1 patient; accelerated idioventricular rhythm (ID), 2 patients. Subgroups IA, IB and ID were characterised by the absence of symptoms, the disappearance of the arrhythmia on exercise, the decreased efficacy of antiarrhythmic drugs and an excellent prognosis. Therapeutic abstention was the rule in these patients. Patients in Group IC were characterised by the variability of their symptoms, the absence of exercise induced arrhythmias, the need for treatment in most cases and a good long-term prognosis. Group II was divided into 2 subgroups: adrenergic polymorphic ventricular tachycardia (IIA), 2 patients, and non-adrenergic polymorphic ventricular tachycardia (IIB), 2 patients. Patients in Subgroup IIA were characterised by syncope on exercise or emotion, the need for betablocker therapy which considerably improved the patients symptoms but which did not usually prevent sudden death.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Cerebroventricular Microinjection (CVMI) into Adult Zebrafish Brain Is an Efficient Misexpression Method for Forebrain Ventricular Cells

    Science.gov (United States)

    Kizil, Caghan; Brand, Michael

    2011-01-01

    The teleost fish Danio rerio (zebrafish) has a remarkable ability to generate newborn neurons in its brain at adult stages of its lifespan-a process called adult neurogenesis. This ability relies on proliferating ventricular progenitors and is in striking contrast to mammalian brains that have rather restricted capacity for adult neurogenesis. Therefore, investigating the zebrafish brain can help not only to elucidate the molecular mechanisms of widespread adult neurogenesis in a vertebrate species, but also to design therapies in humans with what we learn from this teleost. Yet, understanding the cellular behavior and molecular programs underlying different biological processes in the adult zebrafish brain requires techniques that allow manipulation of gene function. As a complementary method to the currently used misexpression techniques in zebrafish, such as transgenic approaches or electroporation-based delivery of DNA, we devised a cerebroventricular microinjection (CVMI)-assisted knockdown protocol that relies on vivo morpholino oligonucleotides, which do not require electroporation for cellular uptake. This rapid method allows uniform and efficient knockdown of genes in the ventricular cells of the zebrafish brain, which contain the neurogenic progenitors. We also provide data on the use of CVMI for growth factor administration to the brain – in our case FGF8, which modulates the proliferation rate of the ventricular cells. In this paper, we describe the CVMI method and discuss its potential uses in zebrafish. PMID:22076157

  15. Development of automatic extraction method of left ventricular contours on long axis view MR cine images

    International Nuclear Information System (INIS)

    Utsunomiya, Shinichi; Iijima, Naoto; Yamasaki, Kazunari; Fujita, Akinori

    1995-01-01

    In the MRI cardiac function analysis, left ventricular volume curves and diagnosis parameters are obtained by extracting the left ventricular cavities as regions of interest (ROI) from long axis view MR cine images. The ROI extractions had to be done by manual operations, because automatization of the extraction is difficult. A long axis view left ventricular contour consists of a cardiac wall part and an aortic valve part. The above mentioned difficulty is due to the decline of contrast on the cardiac wall part, and the disappearance of edge on the aortic valve part. In this paper, we report a new automatic extraction method for long axis view MR cine images, which needs only 3 manually indicated points on the 1st image to extract all the contours from the total sequence of images. At first, candidate points of a contour are detected by edge detection. Then, selecting the best matched combination of candidate points by Dynamic Programming, the cardiac wall part is automatically extracted. The aortic valve part is manually extracted for the 1st image by indicating both the end points, and is automatically extracted for the rest of the images, by utilizing the aortic valve motion characteristics throughout a cardiac cycle. (author)

  16. Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy

    Directory of Open Access Journals (Sweden)

    Lanjewar SS

    2013-11-01

    Full Text Available Swapnil S Lanjewar,1 Lovely Chhabra,1 Vinod K Chaubey,1 Saurabh Joshi,1 Ganesh Kulkarni,1 Chandrasekhar Kothagundla,1 Sudesh Kaul,1 David H Spodick21Department of Internal Medicine, 2Department of Cardiovascular Medicine, Saint Vincent Hospital, University of Massachusetts Medical School, Worcester, MA, USABackground: The electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration.Methods: We reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1 were computed and compared between the two subgroups.Results: There was no statistically significant difference in qualitative lung function (FEV1 between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy.Conclusion: The presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration.Keywords: emphysema, electrocardiogram, left ventricular hypertrophy, chronic

  17. Electrophysiological and functional effects of sphingosine-1-phosphate in mouse ventricular fibroblasts

    International Nuclear Information System (INIS)

    Benamer, Najate; Fares, Nassim; Bois, Patrick; Faivre, Jean-Francois

    2011-01-01

    Highlights: → In cardiac fibroblasts, SUR2/Kir6.1 channel is activated by S1P via the S1P3R. → S1P increases cell proliferation through SUR2/Kir6.1 activation. → S1P decreases collagen and IL-6 secretion through SUR2/Kir6.1 activation. → S1P stimulates fibroblast migration independently from SUR2/Kir6.1 channel. -- Abstract: The aim of this study was to characterize the effects of sphingosine-1-phosphate (S1P) on cardiac ventricular fibroblasts. Impacts of S1P on fibroblast excitability, cell migration, proliferation and secretion were characterized. The patch-clamp technique in the whole-cell configuration was used to study the S1P-induced current from mouse ventricular fibroblasts. The expression level of the S1P receptor during cell culture duration was evaluated by western-blot. Fibroblast proliferation and migration were quantified using the methylene blue assay and the Boyden chamber technique, respectively. Finally, fibroblast secretion properties were estimated by quantification of the IL-6 and collagen levels using ELISA and SIRCOL collagen assays, respectively. We found that S1P activated SUR2/Kir6.1 channel and that this effect was sensitive to specific inhibition of the S1P receptor of type 3 (S1P3R). In contrast, S1P1R receptor inhibition had no effect. Moreover, the S1P-induced current increased with cell culture duration whereas S1P3R expression level remained constant. The activation of SUR2/Kir6.1 channel by S1P via S1P3R stimulated cell proliferation and decreased IL-6 and collagen secretions. S1P also stimulated fibroblast migration via S1P3R but independently from SUR2/Kir6.1 channel activation. This study demonstrates that S1P, via S1P3R, affects cardiac ventricular fibroblasts function independently or through activation of SUR2/Kir6.1 channel. The latter effect occurs after fibroblasts differentiate into myofibroblasts, opening a new potential therapeutic strategy to modulate fibrosis after cardiac physiopathological injury.

  18. Electrophysiological and functional effects of sphingosine-1-phosphate in mouse ventricular fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Benamer, Najate [UMR CNRS/Universite de Poitiers No. 6187, Pole Biologie Sante Bat B36, BP 633, 1 rue Georges Bonnet, 86022 Poitiers (France); Fares, Nassim [Laboratoire de Physiologie, Faculte de Medecine, Universite Saint Joseph, Beyrouth (Lebanon); Bois, Patrick [UMR CNRS/Universite de Poitiers No. 6187, Pole Biologie Sante Bat B36, BP 633, 1 rue Georges Bonnet, 86022 Poitiers (France); Faivre, Jean-Francois, E-mail: Jean-Francois.Faivre@univ-poitiers.fr [UMR CNRS/Universite de Poitiers No. 6187, Pole Biologie Sante Bat B36, BP 633, 1 rue Georges Bonnet, 86022 Poitiers (France)

    2011-04-29

    Highlights: {yields} In cardiac fibroblasts, SUR2/Kir6.1 channel is activated by S1P via the S1P3R. {yields} S1P increases cell proliferation through SUR2/Kir6.1 activation. {yields} S1P decreases collagen and IL-6 secretion through SUR2/Kir6.1 activation. {yields} S1P stimulates fibroblast migration independently from SUR2/Kir6.1 channel. -- Abstract: The aim of this study was to characterize the effects of sphingosine-1-phosphate (S1P) on cardiac ventricular fibroblasts. Impacts of S1P on fibroblast excitability, cell migration, proliferation and secretion were characterized. The patch-clamp technique in the whole-cell configuration was used to study the S1P-induced current from mouse ventricular fibroblasts. The expression level of the S1P receptor during cell culture duration was evaluated by western-blot. Fibroblast proliferation and migration were quantified using the methylene blue assay and the Boyden chamber technique, respectively. Finally, fibroblast secretion properties were estimated by quantification of the IL-6 and collagen levels using ELISA and SIRCOL collagen assays, respectively. We found that S1P activated SUR2/Kir6.1 channel and that this effect was sensitive to specific inhibition of the S1P receptor of type 3 (S1P3R). In contrast, S1P1R receptor inhibition had no effect. Moreover, the S1P-induced current increased with cell culture duration whereas S1P3R expression level remained constant. The activation of SUR2/Kir6.1 channel by S1P via S1P3R stimulated cell proliferation and decreased IL-6 and collagen secretions. S1P also stimulated fibroblast migration via S1P3R but independently from SUR2/Kir6.1 channel activation. This study demonstrates that S1P, via S1P3R, affects cardiac ventricular fibroblasts function independently or through activation of SUR2/Kir6.1 channel. The latter effect occurs after fibroblasts differentiate into myofibroblasts, opening a new potential therapeutic strategy to modulate fibrosis after cardiac

  19. Effects of Resistance Training on Ventricular Function and Hypertrophy in a Rat Model

    Science.gov (United States)

    Barauna, Valério Garrone; Rosa, Kaleizu Teodoro; Irigoyen, Maria Cláudia; de Oliveira, Edilamar Menezes

    2007-01-01

    Objective: The purpose of this study was to follow the ventricular function and cardiac hypertrophy in rats undergoing a resistance-training program for a period of 3 months. Design: Forty animals were divided into two major groups: control (n=16) and resistance trained (n=24). From the resistance-trained group, 12 animals were resistance trained for 1 month and another 12 for 3 months. The resistance-training protocol was performed with 4 sets of 12 repetitions using 65% to 75% of one repetition maximum (maximum lifted weight with the exercise apparatus). Methods: Echocardiographic analysis was performed at the beginning of the resistance-training period and at the end of each month. The repetition maximum was measured every 2 weeks. Cardiac hypertrophy was determined by echocardiography, by the absolute weight of the cardiac chambers and by histology of the left ventricle. Results: Before resistance training, both groups had similar repetition maximums, ranging from 1.8-fold to 2-fold the body weight; however, at the end of the resistance-training period, the repetition maximum of the resistance-trained group was 6-fold greater than the body weight. The left ventricular mass as assessed by echocardiography was 8%, 12% and 16% larger in the resistance-trained group than in the control group in the first, second and third months, respectively. This hypertrophy showed a similar increase in the interventricular septum and in the free posterior wall mass. There was no reduction in the end-diastolic left ventricular internal diameter during the 3-month resistance-training period. Systolic function did not differ between the groups throughout the resistance-training period. Conclusion: Resistance training induces the development of concentric cardiac hypertrophy without ventricular dysfunction or cavity reduction. Although diastolic function was not completely investigated, we cannot exclude the possibility that resistance training results in diastolic dysfunction. PMID

  20. Ultrasound-guided probe-generated artifacts stimulating ventricular tachycardia: A rare phenomenon

    Directory of Open Access Journals (Sweden)

    Rafat Shamim

    2017-01-01

    Full Text Available Electrocardiographic (ECG artifacts may arise due to interference, faulty earthing, and current leakages in biomedical equipment which might create clinical dilemmas in the perioperative settings. Piezoelectric signals generated by ultrasonography probe are another uncommon source which might be sensed by the ECG electrodes and produce tracings similar to pathological arrhythmias triggering false alarms and avoidable therapies. Anesthesiologists should be familiar with these uncommon sources which might produce these artifacts and they should be identified swiftly.

  1. Correlation between right ventricular T1 mapping and right ventricular dysfunction in non-ischemic cardiomyopathy.

    Science.gov (United States)

    Jellis, Christine L; Yingchoncharoen, Teerapat; Gai, Neville; Kusunose, Kenya; Popović, Zoran B; Flamm, Scott; Kwon, Deborah

    2018-01-01

    Right ventricular (RV) fibrosis is increasingly recognized as the underlying pathological substrate in a variety of clinical conditions. We sought to employ cardiac magnetic resonance (CMR) techniques of strain imaging and longitudinal relaxation time (T 1 ) mapping to better examine the relationship between RV function and structure. Our aim was to initially evaluate the feasibility of these techniques to evaluate the right ventricle. We then sought to explore the relationship between RV function and underlying fibrosis, along with examining the evolution of RV remodeling according to the amount of baseline fibrosis. Echocardiography was performed in 102 subjects with non-ischemic cardiomyopathy. Right ventricular parameters were assessed including: fractional area change (FAC) and longitudinal strain. The same cohort underwent CMR. Post-contrast T 1 mapping was performed as a marker of fibrosis with a Look-Locker technique using inversion recovery imaging. Mid-ventricular post-contrast T 1 values of the RV free wall, RV septum and lateral LV were calculated using prototype analysis software. Biventricular volumetric data including ejection fraction was measured by CMR using a cine short axis stack. CMR strain analysis was also performed to assess 2D RV longitudinal and radial strain. Simultaneous biochemical and anthropometric data were recorded. Subjects were followed over a median time of 29 months (IQR 20-37 months) with echocardiography to evaluate temporal change in RV FAC according to baseline post-contrast T 1 values. Longitudinal data analysis was performed to adjust for patient loss during follow-up. Subjects (62% men, 51 ± 15 years) had mild to moderately impaired global RV systolic function (RVEF = 39 ± 15%; RVEDV = 187 ± 69 ml; RVESV = 119 ± 68 ml) and moderate left ventricular dysfunction at baseline (LVEF 30 ± 17%). Good correlation was observed between mean LV and RV post-contrast T 1 values (r = 0.652, p

  2. What is the clinical significance of ventricular mural antagonism?

    DEFF Research Database (Denmark)

    Lunkenheimer, Paul P; Niederer, Peter; Stephenson, Robert S

    2018-01-01

    alignment, thus deviating from the prevailing tangential orientation. Upon contraction, they produce, in addition to a tangential force, a radial force component that counteracts ventricular constriction and aids widening of the ventricular cavity. In experimental studies, we have provided evidence...... for the existence of such forces, which are auxotonic in nature. This is in contrast to the tangentially aligned myocytes that produce constrictive forces, which are unloading in nature. The ventricular myocardium is, therefore, able to function in an antagonistic fashion, with the prevailing constrictive forces...

  3. Advanced quantitative echocardiography in arrhythmogenic right ventricular cardiomyopathy

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Hastrup Svendsen, Jesper; Sogaard, Peter

    2007-01-01

    BACKGROUND: Arrhythmogenic right ventricular (RV) cardiomyopathy (ARVC) is a regional disease of the RV myocardium with variable degrees of left ventricular involvement. Three-dimensional echocardiography and Doppler tissue imaging (DTI) are new echocardiographic modalities for the evaluation......, patients with ARVC had a decreased RV ejection fraction (0.47 +/- 0.08 vs 0.53 +/- 0.05, P vs 15.1 +/- 3.7 cm/s, P left ventricle (7.0 +/- 2.6 vs 9.5 +/- 1.9 cm/s, P ... of the longitudinal motility appears to be a sensitive marker of preclinical left ventricular involvement....

  4. Real-time observation of the dehydrogenation processes of methanol on clean Ru(001) and Ru(001)-p(2×2) O surfaces by a temperature-programmed electron-stimulated desorption ion angular distribution/time-of-flight system

    Science.gov (United States)

    Sasaki, Takehiko; Itai, Yuichiro; Iwasawa, Yasuhiro

    1999-12-01

    Decomposition processes of methanol on clean and oxygen-precovered Ru(001) surfaces have been visualized in real time with a temperature-programmed (TP) electron-stimulated desorption ion angular distribution (ESDIAD)/time-of-flight (TOF) system. The mass of desorbed ions during temperature-programmed surface processes was identified by TOF measurements. In the case of methanol (CH 3OD) adsorption on Ru(001)-p(2×2)-O, a halo pattern of H + from the methyl group of methoxy species was observed at 100-200 K, followed by a broad pattern from the methyl group at 230-250 K and by a near-center pattern from O + ions originating from adsorbed CO above 300 K. The halo pattern is attributed to a perpendicular conformation of the CO bond axis of the methoxy species, leading to off-normal CH bond scission. On the other hand, methanol adsorbed on clean Ru(001) did not give any halo pattern but a broad pattern was observed along the surface normal, indicating that the conformation of the methoxy species is not ordered on the clean surface. Comparison between the ESDIAD images of the oxygen-precovered surface and the clean surface suggests that the precovered oxygen adatoms induce ordering of the methoxy species. Real-time ESDIAD measurements revealed that the oxygen atoms at the Ru(001)-p(2×2)-O surface have a positive effect on selective dehydrogenation of the methoxy species to CO+H 2 and a blocking effect on CO bond breaking of the methoxy species.

  5. Effects of perfusion detect on the measurement of left ventricular mass, ventricular volume and post-stress left ventricular ejection fraction in gated myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Ahn, Byeong Cheol; Bae, Sun Keun; Lee, Sang Woo; Jeong, Sin Young; Lee, Jae Tae; Lee, Kyu Bo

    2002-01-01

    The presence of perfusion defect may influence the left ventricular mass (LVM) measurement by quantitative gated myocardial perfusion SPECT (QGS), and ischemic myocardium, usually showing perfusion defect may produce post-stress LV dysfunction. This study was aimed to evaluated the effects of extent and reversibility of perfusion defect on the automatic measurement of LVM by QGS and to investigate the effect of reversibility of perfusion defect on post-stress LV dysfunction. Forty-six patients (male/female=34:12, mean age=64 years) with perfusion defect on myocardial perfusion SPECT underwent rest and post-stress QGS. Forty patients (87%) showed reversible defect. End-diastolic volume (EDV), end-systolic volume (ESV), LV ejection fraction (EF), and LV myocardial volume were obtained from QGS by autoquant program, and LVM was calculated by multiplying the LV myocardial volume by the specific gravity of myocardium. LVMs measured at rest and post-stress QGS showed good correlation, and higher correlation was founded in the subjects with fixed perfusion defect and with small defect (smaller than 20%). There were no significant differences in EDVs, ESVs and EFs between obtained by rest and post-stress QGS in patients with fixed myocardial defect. Whereas, EF obtained by post-stress QGS was lower than that by rest QGS in patients with reversible defect and 10 (25%) of them showed decreases in EF more than 5% in post-stress QGS, as compared to that of rest QGS. Excellent correlations of EDVs, ESVs, EFs between rest and post-stress QGS were noted. Patients with fixed defect had higher correlation between defect can affect LVM measurement by QGS and patients with reversible defect shows post-stress LV dysfunction more frequently than patients with fixed perfusion defect

  6. A case of short-coupled premature ventricular beat-induced ventricular fibrillation with early repolarization in the inferolateral leads

    Directory of Open Access Journals (Sweden)

    Hidekazu Kondo, MD

    2015-02-01

    Full Text Available This case report describes a 19-year-old man with early repolarization (ER in the inferolateral leads and a normal QT interval who survived a cardiac arrest that was likely related to polymorphic ventricular tachycardia (VT. Electrocardiograms (ECGs also showed unifocal premature ventricular beats (PVBs with a relatively narrow QRS duration. A Holter ECG documented occasional short-coupled PVBs following non-sustained VTs. Pharmacological stress testing was also performed to assess the effects of anti-arrhythmic drugs on ER (the J wave and PVBs. We performed successful radiofrequency catheter ablation to prevent the recurrence of ventricular fibrillation after cardioverter-defibrillator implantation.

  7. [Transcranial magnetic stimulation].

    Science.gov (United States)

    Tormos, J M; Catalá, M D; Pascual-Leone, A

    Transcranial magnetic stimulation (TMS) permits stimulation of the cerebral cortex in humans without requiring open access to the brain and is one of the newest tools available in neuroscience. There are two main types of application: single-pulse TMS and repetitive TMS. The magnetic stimulator is composed of a series of capacitors that store the voltage necessary to generate a stimulus of the sufficient intensity of generate an electric field in the stimulation coil. The safety of TMS is supported by the considerable experience derived from studies involving electrical stimulation of the cortex in animals and humans, and also specific studies on the safety of TMS in humans. In this article we review historical and technical aspects of TMS, describe its adverse effects and how to avoid them, summarize the applications of TMS in the investigation of different cerebral functions, and discuss the possibility of using TMS for the treatment of neuropsychiatric disorders.

  8. Assessment of right ventricular systolic function by tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjærgaard, Jesper

    2012-01-01

    This thesis summarizes a series of studies performed in order to assess the clinical usefulness of a novel echocardiographic technology that allows non-invasive assessment of regional right ventricular myocardial velocities and deformation: tissue Doppler echocardiography. While the technology...... is a promising tool for improving our understanding of right ventricular hemodynamics, several aspects of the technology must be evaluated. The accuracy and reproducibility of the technology is evaluated in vitro, and normal values, impact of changes in loading of the right ventricle, response to exercise...... on right ventricular hemodynamics: pulmonary embolism, Arrhythmogenic right ventricular cardiomyopathy and pulmonary regurgitation, the latter in an animal model. The conclusions of the thesis are: Color tissue Doppler echocardiography accurately measures velocities, SR and strain in vitro. No systematic...

  9. A case report of arrhythmogenic right ventricular dysplasia

    Directory of Open Access Journals (Sweden)

    Henry Anselmo Mayala

    2013-07-01

    Full Text Available Background Arrhythmogenic right ventricular dysplasia is an autosomal dominant disorder affecting parts of myocardium known as desmosomes, areas on the surface of heart muscle cells which link the cells together. The hallmark feature is fibro-fatty replacement of the right ventricle myocardium characterized by hypokinetic areas with associated arrhythmias originating in the right ventricle. Case Presentation In this report a 42 year old man was admitted at Wuhan union Hospital with the presenting complaints of visual hallucination and difficulty in breathing on exertion, with a family history of sudden death. Clinical and imaging findings are suggestive of Arrhythmogenic right ventricular dysplasia. Conclusion Despite being among the rare cardiac disease, Arrhythmogenic right ventricular dysplasia is an important cause of ventricular arrhythmias in children and young adults, it is also responsible for sudden cardiac death in the young population, making it necessary for this case report.

  10. A case report of arrhythmogenic right ventricular dysplasia

    Directory of Open Access Journals (Sweden)

    Henry Anselmo Mayala

    2013-01-01

    Full Text Available Background Arrhythmogenic right ventricular dysplasia is an autosomal dominant disorder affecting parts of myocardium known as desmosomes, areas on the surface of heart muscle cells which link the cells together. The hallmark feature is fibro-fatty replacement of the right ventricle myocardium characterized by hypokinetic areas with associated arrhythmias originating in the right ventricle. CasePresentation Inthisreporta42yearoldmanwasadmittedatWuhanunion Hospital with the presenting complaints of visual hallucination and difficulty in breathing on exertion, with a family history of sudden death. Clinical and imaging findings are suggestive of Arrhythmogenic right ventricular dysplasia. Conclusion Despitebeingamongtherarecardiacdisease,Arrhythmogenicright ventricular dysplasia is an important cause of ventricular arrhythmias in children and young adults, it is also responsible for sudden cardiac death in the young population, making it necessary for this case report.

  11. Ventricular Zone Disruption in Human Neonates With Intraventricular Hemorrhage

    NARCIS (Netherlands)

    McAllister, James P.; Guerra, Maria Montserrat; Ruiz, Leandro Castaneyra; Jimenez, Antonio J.; Dominguez-Pinos, Dolores; Sival, Deborah; den Dunnen, Wilfred; Morales, Diego M.; Schmidt, Robert E.; Rodriguez, Esteban M.; Limbrick, David D.

    2017-01-01

    To determine if ventricular zone (VZ) and subventricular zone (SVZ) alterations are associated with intraventricular hemorrhage (IVH) and posthemorrhagic hydrocephalus, we compared postmortem frontal and subcortical brain samples from 12 infants with IVH and 3 nonneurological disease controls

  12. Assessment of ventricular function by radionuclide ventriculography in hyperthyroidism

    International Nuclear Information System (INIS)

    Dong Weiyu; He Pinyu; Zhuang Weite

    1996-01-01

    Left ventricular(LV) and right ventricular(RV) function were determined using radionuclide ventriculography in 50 patients with hyperthyroidism. LVEF, LVPFR, SV of the hyperthyroidism group were decreased in comparison with the normal group (P<0.01), whereas CO of the hyperthyroidism patients were higher than that of normal (P<0.01). Except LVPER, the LVEF, SV had significant difference between two groups. Compared to normal group, RVEF, RVPER, RVPFR were also decreased (P<0.01). Besides 30 cases of the hyperthyroidism were examined by impedance cardiogram (ICG) and impedance pulmonary rheogram (IPR), all showed closely correlation with the parameters determined by ventriculography. There was the involvement of right ventricular function insufficiency, especially in ejection phase. When compared with pre-therapy, pos-therapy cases showed significant improvement in EF, PER, PFR of left and right ventricular

  13. Ethical Analysis of Withdrawing Ventricular Assist Device Support

    OpenAIRE

    Mueller, Paul S.; Swetz, Keith M.; Freeman, Monica R.; Carter, Kari A.; Crowley, Mary Eliot; Severson, Cathy J. Anderson; Park, Soon J.; Sulmasy, Daniel P.

    2010-01-01

    OBJECTIVE: To describe a series of patients with heart failure supported with a ventricular assist device (VAD) who requested (or whose surrogates requested) withdrawal of VAD support and the legal and ethical aspects pertaining to these requests.

  14. Ventricular fibrillation after accidental injection of bupivacaine into the pericardium

    NARCIS (Netherlands)

    Even, B. J.; de Jongh, R. F.; de Hert, S. G.

    1992-01-01

    A postoperative cardiac surgical patient developed ventricular fibrillation immediately after accidental pericardial injection of bupivacaine at room temperature. The possible causes, which include systemic toxicity, local vasoconstriction with myocardial ischaemia, local toxic effect of bupivacaine

  15. Right and left ventricular performance by nuclear stethoscope

    International Nuclear Information System (INIS)

    Nishimura, T.; Uehara, T.; Hayashida, K.; Kozuka, T.

    1983-01-01

    Right and left ventricular performance by Nuclear Stethoscope using Kr-81m and Tc-99m-RBC were performed. And physiological and pharmacological interventions were also investigated for the evaluation of coronary artery diseases (CAD)

  16. Annular subvalvular left ventricular aneurysm in Bahia, Brazil.

    Science.gov (United States)

    Guimarães, A C; Filho, A S; Esteves, J P; Abreu, W N; Vinhaes, L A; de Almeida Souza, J A; Machado, A

    1976-10-01

    Two cases of left ventricular aneurysm, a 16-year-old black boy and a 23-year-old white girl, from Bahia, Brazil, are presented. In both patients there was enlargement of the cardiac silhouette and a prominent bulge of the left inferior border. On the right oblique view a ring of calcium at the ventricular opening of the aneurysms was visualized. A left ventriculogram showed a huge aneurysm in the first case and a bulge on the lateral wall of the left ventricle in the other. Cardiac catheterization showed a rise in left and right ventricular end-diastolic pressures and in the mean pulmonary artery pressure. In the first case the contour of the right ventricular pressure curve showed a restrictive pattern. The similarities of these aneurysms with the annular submitral type described in young black Africans are stressed.

  17. Eisenmenger ventricular septal defect in a Humboldt penguin (Spheniscus humboldti).

    Science.gov (United States)

    Laughlin, D S; Ialeggio, D M; Trupkiewicz, J G; Sleeper, M M

    2016-09-01

    The Eisenmenger ventricular septal defect is an uncommon type of ventricular septal defect characterised in humans by a traditionally perimembranous ventricular septal defect, anterior deviation (cranioventral deviation in small animal patients) of the muscular outlet septum causing malalignment relative to the remainder of the muscular septum, and overriding of the aortic valve. This anomaly is reported infrequently in human patients and was identified in a 45-day-old Humboldt Penguin, Spheniscus humboldti, with signs of poor growth and a cardiac murmur. This case report describes the findings in this penguin and summarises the anatomy and classification of this cardiac anomaly. To the authors' knowledge this is the first report of an Eisenmenger ventricular septal defect in a veterinary patient. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Adenosine induced ventricular arrhythmias in the emergency room

    NARCIS (Netherlands)

    Tan, H. L.; Spekhorst, H. H.; Peters, R. J.; Wilde, A. A.

    2001-01-01

    While adenosine effectively terminates most supraventricular tachycardias (SVT), rare case reports have demonstrated its proarrhythmic potential, including induction of ventricular tachycardia (VT). The aim of this study was to define the proarrhythmic effects of adenosine in a large, unselected

  19. Dynamic electrocardiographic changes in patients with arrhythmogenic right ventricular cardiomyopathy.

    LENUS (Irish Health Repository)

    Quarta, Giovanni

    2010-04-01

    Electrocardiographic (ECG) abnormalities of depolarisation and repolarisation contribute to the diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC). The development of diagnostic ECG features were investigated in a genotyped cohort with ARVC to provide more sensitive markers of early disease.

  20. Contemporary Assessment of Left Ventricular Diastolic Function in Older Adults

    DEFF Research Database (Denmark)

    Shah, Amil M.; Claggett, Brian; Kitzman, Dalane

    2017-01-01

    Background: Although age-Associated changes in left ventricular diastolic function are well recognized, limited data exist characterizing measures of diastolic function in older adults, including both reference ranges reflecting the older adult population and prognostically relevant values...

  1. Left ventricular structure and function in black normotensive type 2 ...

    African Journals Online (AJOL)

    Keywords: Black normotensive patients, left ventricular function, type 2 DM. Résumé ... sickle cell disease and structural heart disease were excluded ... Pulmonary venous flow (PVF) velocity ... had abnormal ECG pattern compared with 30%.

  2. Quantitation of global and regional left ventricular function by MRI

    NARCIS (Netherlands)

    van der Geest, RJ; Reiber, JHC; Reiber, JHC; VanDerWall, EE

    1998-01-01

    Magnetic resonance imaging (MRI) provides several imaging strategies for assessing left ventricular function. As a three-dimensional imaging technique, all measurements can be performed without relying on geometrical assumptions. Global and regional function parameters can be derived from

  3. Delayed ventricular septal rupture complicating acute inferior wall myocardial infarction

    OpenAIRE

    Cho, Jae Hyung; Sattiraju, Srinivasan; Mehta, Sanjay; Missov, Emil

    2013-01-01

    Background Ventricular septal rupture is a potentially fatal complication of acute myocardial infarction. Its incidence has declined with modern reperfusion therapy. In the era of percutaneous coronary interventions, it occurs a median of 18?24?hours after myocardial infarction and is most commonly associated with anterior myocardial infarction. We present a case of delayed ventricular septal rupture complicating acute inferior wall myocardial infarction. Case presentation A 53-year-old Cauca...

  4. Reversibility of ventricular dysfunction: clinical experience in a medical office

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Pereira Barretto

    2001-12-01

    Full Text Available OBJECTIVE - To describe clinical observations of marked improvement in ventricular dysfunction in a medical office environment under circumstances differing from those in study protocols and multicenter studies performed in hospital or with outpatient cohorts. METHODS - Eleven cardiac failure patients with marked ventricular dysfunction receiving treatment at a doctors office between 1994 and 1999 were studied. Their ages ranged from 20 and 66 years (mean 39.42±14.05 years; 7 patients were men, 4 were women. Cardiopathic etiologies were arterial hypertension in 5 patients, peripartum cardiomyopathy in 2, nondefined myocarditis in 2, and alcoholic cardiomyopathy in 4. Initial echocardiograms revealed left ventricular dilatation (average diastolic diameter, 69.45±8.15mm, reduced left ventricular ejection fraction (0.38±0.08 and left atrial dilatation (43.36±5.16mm. The therapeutic approach followed consisted of patient orientation, elimination of etiological or causal factors of cardiac failure, and prescription of digitalis, diuretics, and angiotensinconverting enzyme inhibitors. RESULTS - Following treatment, left ventricular ejection fraction changed to 0.63±0.09; left ventricular diameters changed to 57.18±8.13mm, and left atrium diameters changed to 37.27±8.05mm. Maximum improvement was noted after 16.9±8.63 (6 to 36 months. CONCLUSION - Patients with serious cardiac failure and ventricular dysfunction caused by hypertension, alcoholism, or myocarditis can experience marked improvement in ventricular dysfunction after undergoing appropriate therapy within the venue of the doctor's office.

  5. THE CLINICAL-SIGNIFICANCE OF CORONARY ANATOMY IN POST-INFARCT PATIENTS WITH LATE SUSTAINED VENTRICULAR-TACHYCARDIA OR VENTRICULAR-FIBRILLATION

    NARCIS (Netherlands)

    WIESFELD, ACP; CRIJNS, HJGM; HILLEGE, HL; TUININGA, YS; LIE, KI

    The role of ischaemia in post-infarct patients with ventricular tachyarrhythmias is not firmly established Using coronary angiography, 82 post-infarct patients with sustained ventricular tachycardia or fibrillation were subclassified into three groups. Fourteen patients (17%) had significant

  6. Plasma YKL-40 and recovery of left ventricular function after acute myocardial infarction

    DEFF Research Database (Denmark)

    Hedegaard, A.; Ripa, Maria Sejersten; Johansen, J.S.

    2010-01-01

    Background: Plasma YKL-40 is increased early in patients with ST-elevation myocardial infarction (STEMI). It is not known whether plasma YKL-40 is related to infarct size and recovery of ventricular function after primary percutaneous coronary intervention (PCI) of STEMI and whether granulocyte...... colony-stimulating factor (G-CSF) therapy influence plasma YKL-40 concentration. Materials and methods: A total of 72 patients (age: 56 +/- 9 years (mean +/- SD), 56 men and 16 women) with STEMI treated with PCI were included in a double-blind, randomized, placebo-controlled trial with subcutaneous G...... to LVEF recovery (p = 0.04) but not infarct size. G-CSF injections increased YKL-40 compared to placebo (p recovery. Conclusion: Plasma YKL-40 was significantly increased in STEMI patients at admission and G-CSF treatment caused a further increase...

  7. Skin Sodium Concentration Correlates with Left Ventricular Hypertrophy in CKD.

    Science.gov (United States)

    Schneider, Markus P; Raff, Ulrike; Kopp, Christoph; Scheppach, Johannes B; Toncar, Sebastian; Wanner, Christoph; Schlieper, Georg; Saritas, Turgay; Floege, Jürgen; Schmid, Matthias; Birukov, Anna; Dahlmann, Anke; Linz, Peter; Janka, Rolf; Uder, Michael; Schmieder, Roland E; Titze, Jens M; Eckardt, Kai-Uwe

    2017-06-01

    The pathogenesis of left ventricular hypertrophy in patients with CKD is incompletely understood. Sodium intake, which is usually assessed by measuring urinary sodium excretion, has been inconsistently linked with left ventricular hypertrophy. However, tissues such as skin and muscle may store sodium. Using 23 sodium-magnetic resonance imaging, a technique recently developed for the assessment of tissue sodium content in humans, we determined skin sodium content at the level of the calf in 99 patients with mild to moderate CKD (42 women; median [range] age, 65 [23-78] years). We also assessed total body overhydration (bioimpedance spectroscopy), 24-hour BP, and left ventricular mass (cardiac magnetic resonance imaging). Skin sodium content, but not total body overhydration, correlated with systolic BP ( r =0.33, P =0.002). Moreover, skin sodium content correlated more strongly than total body overhydration did with left ventricular mass ( r =0.56, P skin sodium content is a strong explanatory variable for left ventricular mass, unaffected by BP and total body overhydration. In conclusion, we found skin sodium content to be closely linked to left ventricular mass in patients with CKD. Interventions that reduce skin sodium content might improve cardiovascular outcomes in these patients. Copyright © 2017 by the American Society of Nephrology.

  8. Noninvasive assessment of right ventricular wall motion by radionuclide cardioangiography

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Uehara, Toshiisa; Naito, Hiroaki; Hayashida, Kohei; Kozuka, Takahiro

    1981-01-01

    Radionuclide cardioangiography is a useful method to evaluate the left ventricular wall motion in various heart diseases. It has been also attempted to assess the right ventricular wall motion simultaneously by radionuclide method. In this study, using the combination of first-pass (RAO 30 0 ) and multi-gate (LAO 40 0 ) method, the site of right vetricle was classified in five. (1 inflow, 2 sinus, 3 outflow, 4 septal, 5 lateral) and the degree of wall motion was classified in four stages (dyskinesis, akinesis, hypokinesis, normal) according to the AHA committee report. These methods were applied clinically to forty-eight patients with various heart diseases. In the cases with right ventricular pressure or volume overload such as COLD, pulmonary infarction, the right ventricle was dilated and the wall motion was reduced in all portions. Especially, in the cases with right ventricular infarction, the right ventricular wall motion was reduced in the infarcted area. The findings of radionuclide method were in good agreement with those of contrast right ventriculography or echocardiography. In conclusion, radionuclide cardioangiography is a useful and noninvasive method to assess not only the left but also the right ventricular wall motion. (author)

  9. Ventricular Tachycardia in the Absence of Structural Heart Disease

    Directory of Open Access Journals (Sweden)

    Luis R. P. Scott

    2005-04-01

    Full Text Available In up to 10% of patients who present with ventricular tachycardia (VT, obvious structural heart disease is not identified. In such patients, causes of ventricular arrhythmia include right ventricular outflow tract (RVOT VT, extrasystoles, idiopathic left ventricular tachycardia (ILVT, idiopathic propranolol-sensitive VT (IPVT, catecholaminergic polymorphic VT (CPVT, Brugada syndrome, and long QT syndrome (LQTS. RVOT VT, ILVT, and IPVT are referred to as idiopathic VT and generally do not have a familial basis. RVOT VT and ILVT are monomorphic, whereas IPVT may be monomorphic or polymorphic. The idiopathic VTs are classified by the ventricle of origin, the response to pharmacologic agents, catecholamine dependence, and the specific morphologic features of the arrhythmia. CPVT, Brugada syndrome, and LQTS are inherited ion channelopathies. CPVT may present as bidirectional VT, polymorphic VT, or catecholaminergic ventricular fibrillation. Syncope and sudden death in Brugada syndrome are usually due to polymorphic VT. The characteristic arrhythmia of LQTS is torsades de pointes. Overall, patients with idiopathic VT have a better prognosis than do patients with ventricular arrhythmias and structural heart disease. Initial treatment approach is pharmacologic and radiofrequency ablation is curative in most patients. However, radiofrequency ablation is not useful in the management of inherited ion channelopathies. Prognosis for patients with VT secondary to ion channelopathies is variable. High-risk patients (recurrent syncope and sudden cardiac death survivors with inherited ion channelopathies benefit from implantable cardioverter-defibrillator placement. This paper reviews the mechanism, clinical presentation, and management of VT in the absence of structural heart disease.

  10. Radionuclide evaluation of left ventricular function with nonimaging probes.

    Science.gov (United States)

    Wexler, J P; Blaufox, M D

    1979-10-01

    Portable nonimaging probes have been developed that can evaluate left ventricular function using radionuclide techniques. Two modes of data acquisition are possible with these probe systems, first-pass and gated. Precordial radiocardiograms obtained after a bolus injection can be used to determine cardiac output, pulmonary transit time, pulmonary blood volume, left ventricle ejection fraction, and left-to-right shunts. Gated techniques can be used to determine left ventricular ejection fraction and sytolic time intervals. Probe-determined indices of left ventricular function agree excellently with comparable measurements determined by conventional camera-computer methods as well as by invasive techniques. These have begun to be used in a preliminary manner in a variety of clinical problems associated with left ventricular dysfunction. This review discusses the types of probe systems available, the methods used in positioning them, and details the specifics of their data acquisition and processing capacity. The major criticisms of probe methods are that they are nonimaging and that they measure global rather than regional left ventricular function. In spite of these criticisms, probe systems, because of their portability, high sensitivity, and relatively low cost are useful supplements to conventional camera-computer systems for the measurement of parameters of left ventricular performance using radionuclide techniques.

  11. The helical ventricular myocardial band of Torrent-Guasp.

    Science.gov (United States)

    Kocica, Mladen J; Corno, Antonio F; Lackovic, Vesna; Kanjuh, Vladimir I

    2007-01-01

    We live in an era of substantial progress in understanding myocardial structure and function at genetic, molecular, and microscopic levels. Yet, ventricular myocardium has proven remarkably resistant to macroscopic analyses of functional anatomy. Pronounced and practically indefinite global and local structural anisotropy of its fibers and other ventricular wall constituents produces electrical and mechanical properties that are nonlinear, anisotropic, time varying, and spatially inhomogeneous. The helical ventricular myocardial band of Torrent-Guasp is a revolutionary new concept in understanding global, 3-dimensional, functional architecture of the ventricular myocardium. This concept defines the principal, cumulative vectors, integrating the tissue architecture (ie, form) and net forces developed (ie, function) within the ventricular mass. The primary purpose of this review is to emphasize the importance of this concept, in the light of collaborative efforts to establish an integrative approach, defining ventricular form and function by linking across multiple scales of biological organization, as explained in the ongoing Physiome project. Because one of the most important scientific missions in this century is integration of basic research with clinical medicine, we believe that this knowledge is not of merely academic importance, but is also the essential prerequisite in clinical evaluation and treatment of different heart diseases.

  12. Ventricular arrhythmias in the absence of structural heart disease.

    Science.gov (United States)

    Prystowsky, Eric N; Padanilam, Benzy J; Joshi, Sandeep; Fogel, Richard I

    2012-05-15

    Ventricular arrhythmia (VA) in structurally normal hearts can be broadly considered under non-life-threatening monomorphic and life-threatening polymorphic rhythms. Monomorphic VA is classified on the basis of site of origin in the heart, and the most common areas are the ventricular outflow tracts and left ventricular fascicles. The morphology of the QRS complexes on electrocardiogram is an excellent tool to identify the site of origin of the rhythm. Although these arrhythmias are common and generally carry an excellent prognosis, rare sudden death events have been reported. Very frequent ventricular ectopy may also result in a cardiomyopathy in a minority of patients. Suppression of VA may be achieved using calcium-channel blockers, beta-adrenergic blockers, and class I or III antiarrhythmic drugs. Radiofrequency ablation has emerged as an excellent option to eliminate these arrhythmias, although certain foci including aortic cusps and epicardium may be technically challenging. Polymorphic ventricular tachycardia (VT) is rare and generally occurs in patients with genetic ion channel disorders including long QT syndrome, Brugada syndrome, catecholaminergic polymorphic VT, and short QT syndrome. Unlike monomorphic VT, these arrhythmic syndromes are associated with sudden death. While the cardiac gross morphology is normal, suggesting a structurally normal heart, abnormalities exist at the molecular level and predispose them to arrhythmias. Another fascinating area, idiopathic ventricular fibrillation and early repolarization syndrome, are undergoing research for a genetic basis. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  13. Left ventricular dysfunction after closure of large patent ductus arteriosus.

    Science.gov (United States)

    Galal, M Omar; Amin, Mohamed; Hussein, Arif; Kouatli, Amjad; Al-Ata, Jameel; Jamjoom, Ahmed

    2005-03-01

    Changes in left ventricular dimensions and performance were studied in 43 patients after transcatheter occlusion or surgical ligation of patent ductus arteriosus. The patients were assigned to 2 groups based on their ductal diameter: >/= 3.1 mm to group A (n = 27) and ventricular end-diastolic diameter than group B, while all patients had normal shortening fraction and ejection fraction. Within 1 month after intervention, left ventricular end-diastolic diameter showed a trend towards regression while shortening fraction and ejection fraction decreased significantly in group A. There were no significant changes in these parameters in group B. Between 1 and 6 months after intervention, left ventricular performance improved in most of the group A patients who were followed up. We conclude that closure of large ductus arteriosus in children leads to significant immediate deterioration of left ventricular performance, which appears to recover within a few months. Echocardiographic study before hospital discharge is recommended in these patients. Serious deterioration of ventricular performance after closure may warrant the use of angiotensin converting enzyme inhibitors.

  14. Late deterioration of left ventricular function after right ventricular pacemaker implantation.

    Science.gov (United States)

    Bellmann, Barbara; Muntean, Bogdan G; Lin, Tina; Gemein, Christopher; Schmitz, Kathrin; Schauerte, Patrick

    2016-09-01

    Right ventricular (RV) pacing induces a left bundle branch block pattern on ECG and may promote heart failure. Patients with dual chamber pacemakers (DCPs) who present with progressive reduction in left ventricular ejection fraction (LVEF) secondary to RV pacing are candidates for cardiac resynchronization therapy (CRT). This study analyzes whether upgrading DCP to CRT with the additional implantation of a left ventricular (LV) lead improves LV function in patients with reduced LVEF following DCP implantation. Twenty-two patients (13 males) implanted with DCPs and a high RV pacing percentage (>90%) were evaluated in term of new-onset heart failure symptoms. The patients were enrolled in this retrospective single-center study after obvious causes for a reduced LVEF were excluded with echocardiography and coronary angiography. In all patients, DCPs were then upgraded to biventricular devices. LVEF was analyzed with a two-sided t-test. QRS duration and brain natriuretic peptide (BNP) levels were analyzed with the unpaired t-test. LVEF declined after DCP implantation from 54±10% to 31±7%, and the mean QRS duration was 161±20 ms during RV pacing. NT-pro BNP levels were elevated (3365±11436 pmol/L). After upgrading to a biventricular device, a biventricular pacing percentage of 98.1±2% was achieved. QRS duration decreased to 108±16 ms and 106±20 ms after 1 and 6 months, respectively. There was a significant increase in LVEF to 38±8% and 41±11% and a decrease in NT-pro BNP levels to 3088±2326 pmol/L and 1860±1838 pmol/L at 1 and 6 months, respectively. Upgrading to CRT may be beneficial in patients with DCPs and heart failure induced by a high RV pacing percentage.

  15. Music acupuncture stimulation method.

    Science.gov (United States)

    Brătilă, F; Moldovan, C

    2007-01-01

    Harmonic Medicine is the model using the theory that the body rhythms synchronize to an outer rhythm applied for therapeutic purpose, can restores the energy balance in acupuncture channels and organs and the condition of well-being. The purpose of this scientific work was to demonstrate the role played by harmonic sounds in the stimulation of the Lung (LU) Meridian (Shoutaiyin Feijing) and of the Kidney (KI) Meridian (Zushaoyin Shenjing). It was used an original method that included: measurement and electronic sound stimulation of the Meridian Entry Point, measurement of Meridian Exit Point, computer data processing, bio feed-back adjustment of the music stimulation parameters. After data processing, it was found that the sound stimulation of the Lung Meridian Frequency is optimal between 122 Hz and 128 Hz, with an average of 124 Hz (87% of the subjects) and for Kidney Meridian from 118 Hz to 121 Hz, with an average of 120 Hz (67% of the subjects). The acupuncture stimulation was more intense for female subjects (> 7%) than for the male ones. We preliminarily consider that an informational resonance phenomenon can be developed between the acupuncture music stimulation frequency and the cellular dipole frequency, being a really "resonant frequency signature" of an acupoint. The harmonic generation and the electronic excitation or low-excitation status of an acupuncture point may be considered as a resonance mechanism. By this kind of acupunctural stimulation, a symphony may act and play a healer role.

  16. The influence of type 2 diabetes and gender on ventricular repolarization dispersion in patients with sub-clinic left ventricular diastolic dysfunction

    OpenAIRE

    Jani, Ylber; Kamberi, Ahmet; Xhunga, Sotir; Pocesta, Bekim; Ferati, Fatmir; Lala, Dali; Zeqiri, Agim; Rexhepi, Atila

    2015-01-01

    Objective: To assess the influence of type 2 DM and gender, on the QT dispersion, Tpeak-Tend dispersion of ventricular repolarization, in patients with sub-clinic left ventricular diastolic dysfunction of the heart. Background: QT dispersion, that reflects spatial inhomogeneity in ventricular repolarization, Tpeak-Tend dispersion, this on the other hand reflects transmural inhomogeneity in ventricular repolarization, that is increased in an early stage of cardiomyopathy, and in patients with ...

  17. Relationship of left ventricular systolic function to persistence or development of electrocardiographic left ventricular hypertrophy in hypertensive patients

    DEFF Research Database (Denmark)

    Okin, Peter M; Wachtell, Kristian; Gerdts, Eva

    2014-01-01

    left ventricular systolic function in patients with new or persistent ECG LVH. METHODS: Baseline and year-3 ECG LVH and left ventricular midwall shortening (MWS) were examined in 725 hypertensive patients in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) echocardiographic...... 1.03-3.50, P = 0.040) at year 3. CONCLUSION: Persistence or development of new ECG LVH during antihypertensive therapy is associated with an increased risk of left ventricular systolic dysfunction after 3 years' follow-up. These findings provide insight into a possible mechanism by which changes......BACKGROUND: Persistence or development of ECG left ventricular hypertrophy (LVH) by Cornell product criteria is associated with an increased risk of developing heart failure compared with regression or continued absence of LVH. We postulated that this association might be in part mediated via worse...

  18. 10-year follow-up after radiofrequency ablation of idiopathic ventricular arrhythmias from right ventricular outflow tract

    Directory of Open Access Journals (Sweden)

    Synne Dragesund Rørvik

    2016-05-01

    Conclusions: A reduction of symptoms and use of antiarrhythmic medication, as well as an improvement in the general health perception and fitness to work after RFA of idiopathic ventricular arrhythmias can be demonstrated at ten-year follow-up.

  19. Right ventricular involvement in cardiac sarcoidosis demonstrated with cardiac magnetic resonance.

    Science.gov (United States)

    Smedema, Jan-Peter; van Geuns, Robert-Jan; Ainslie, Gillian; Ector, Joris; Heidbuchel, Hein; Crijns, Harry J G M

    2017-11-01

    Cardiac involvement in sarcoidosis is reported in up to 30% of patients. Left ventricular involvement demonstrated by contrast-enhanced cardiac magnetic resonance has been well validated. We sought to determine the prevalence and distribution of right ventricular late gadolinium enhancement in patients diagnosed with pulmonary sarcoidosis. We prospectively evaluated 87 patients diagnosed with pulmonary sarcoidosis with contrast-enhanced cardiac magnetic resonance for right ventricular involvement. Pulmonary artery pressures were non-invasively evaluated with Doppler echocardiography. Patient characteristics were compared between the groups with and without right ventricular involvement, and right ventricular enhancement was correlated with pulmonary hypertension, ventricular mass, volume, and systolic function. Left ventricular late gadolinium enhancement was demonstrated in 30 patients (34%). Fourteen patients (16%) had right ventricular late gadolinium enhancement, with sole right ventricular enhancement in only two patients. The pattern of right ventricular enhancement consisted of right ventricular outflow tract enhancement in 1 patient, free wall enhancement in 8 patients, ventricular insertion point enhancement in 10 patients, and enhancement of the right side of the interventricular septum in 11 patients. Pulmonary arterial hypertension correlated with the presence of right ventricular enhancement (P Right ventricular enhancement correlated with systolic ventricular dysfunction (P Right ventricular enhancement was present in 16% of patients diagnosed with pulmonary sarcoidosis and in 48% of patients with left ventricular enhancement. The presence of right ventricular enhancement correlated with pulmonary arterial hypertension, right ventricular systolic dysfunction, hypertrophy, and dilation. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

  20. Ventricular septal necrosis after blunt chest trauma

    Directory of Open Access Journals (Sweden)

    Alireza Ahmadi

    2012-07-01

    Full Text Available Ventricular Septal Defect (VSD after blunt chest trauma is a very rare traumatic affection.We report here a case of blunt chest injury-related VSD and pseudoaneurysm.A 30-year old male truck driver was referred from a trauma center to our hospital seven days after a blunt chest trauma and rib fracture. The patient had severe pulmonary edemaand echocardiography showed large VSD. Several mechanisms are involved in the pathogenesis of this affection including an acute compression of the heart muscle between the sternum and the spine, leading to excessive changes in the intrathoracic and most likely theintracardiac pressure after blunt chest injury. Traumatical patients with the same symptoms may be at risk of sudden death. Therefore, a high grade of suspicion is mandatory even without solid evidence of myocardial damage on the initial evaluation. In continue somehidden angles of this case was discussed. Given the prognostic implications of traumatic VSD with associated pseudoaneurysm, its detection has critical value for preventing its clinicalsequelae.

  1. Right Ventricular Adaptation in Congenital Heart Diseases

    Directory of Open Access Journals (Sweden)

    Beatrijs Bartelds

    2014-05-01

    Full Text Available In the last four decades, enormous progress has been made in the treatment of congenital heart diseases (CHD; most patients now survive into adulthood, albeit with residual lesions. As a consequence, the focus has shifted from initial treatment to long-term morbidity and mortality. An important predictor for long-term outcome is right ventricular (RV dysfunction, but knowledge on the mechanisms of RV adaptation and dysfunction is still scarce. This review will summarize the main features of RV adaptation to CHD, focusing on recent knowledge obtained in experimental models of the most prevalent abnormal loading conditions, i.e., pressure load and volume load. Models of increased pressure load for the RV have shown a similar pattern of responses, i.e., increased contractility, RV dilatation and hypertrophy. Evidence is accumulating that RV failure in response to increased pressure load is marked by progressive diastolic dysfunction. The mechanisms of this progressive dysfunction are insufficiently known. The RV response to pressure load shares similarities with that of the LV, but also has specific features, e.g., capillary rarefaction, oxidative stress and inflammation. The contribution of these pathways to the development of failure needs further exploration. The RV adaptation to increased volume load is an understudied area, but becomes increasingly important in the growing groups of survivors of CHD, especially with tetralogy of Fallot. Recently developed animal models may add to the investigation of the mechanisms of RV adaptation and failure, leading to the development of new RV-specific therapies.

  2. Loperamide Induced Life Threatening Ventricular Arrhythmia

    Directory of Open Access Journals (Sweden)

    Ankit Upadhyay

    2016-01-01

    Full Text Available Loperamide is over-the-counter antidiarrheal agent acting on peripherally located μ opioid receptors. It is gaining popularity among drug abusers as opioid substitute. We report a case of a 46-year-old male that was presented after cardiac arrest. After ruling out ischemia, cardiomyopathy, pulmonary embolism, central nervous system pathology, sepsis, and other drug toxicity, we found out that patient was using around 100 mg of Loperamide to control his chronic diarrhea presumably because of irritable bowel syndrome for last five years and consumed up to 200 mg of Loperamide daily for last two days before the cardiac arrest. We hypothesize that the patient’s QTc prolongation and subsequent cardiac arrest are due to Loperamide toxicity. Patient experienced gradual resolution of tachyarrhythmia and gradual decrease in QTc interval during hospitalization which supports the evidence of causal relationship between Loperamide overdose and potentially fatal arrhythmias. It also provided the clue that patient may have congenital long QT syndrome which was unmasked by Loperamide causing ventricular arrhythmias. This case adds one more pearl in the literature to support that Loperamide overdose related cardiac toxicity does exist and it raises concerns over Loperamide abuse in the community.

  3. Ventricular fibrillation time constant for swine

    International Nuclear Information System (INIS)

    Wu, Jiun-Yan; Sun, Hongyu; Nimunkar, Amit J; Webster, John G; O'Rourke, Ann; Huebner, Shane; Will, James A

    2008-01-01

    The strength–duration curve for cardiac excitation can be modeled by a parallel resistor–capacitor circuit that has a time constant. Experiments on six pigs were performed by delivering current from the X26 Taser dart at a distance from the heart to cause ventricular fibrillation (VF). The X26 Taser is an electromuscular incapacitation device (EMD), which generates about 50 kV and delivers a pulse train of about 15–19 pulses s −1 with a pulse duration of about 150 µs and peak current about 2 A. Similarly a continuous 60 Hz alternating current of the amplitude required to cause VF was delivered from the same distance. The average current and duration of the current pulse were estimated in both sets of experiments. The strength–duration equation was solved to yield an average time constant of 2.87 ms ± 1.90 (SD). Results obtained may help in the development of safety standards for future electromuscular incapacitation devices (EMDs) without requiring additional animal tests

  4. App-assisted external ventricular drain insertion.

    Science.gov (United States)

    Eftekhar, Behzad

    2016-09-01

    The freehand technique for insertion of an external ventricular drain (EVD) is based on fixed anatomical landmarks and does not take individual variations into consideration. A patient-tailored approach based on augmented-reality techniques using devices such as smartphones can address this shortcoming. The Sina neurosurgical assist (Sina) is an Android mobile device application (app) that was designed and developed to be used as a simple intraoperative neurosurgical planning aid. It overlaps the patient's images from previously performed CT or MRI studies on the image seen through the device camera. The device is held by an assistant who aligns the images and provides information about the relative position of the target and EVD to the surgeon who is performing EVD insertion. This app can be used to provide guidance and continuous monitoring during EVD placement. The author describes the technique of Sina-assisted EVD insertion into the frontal horn of the lateral ventricle and reports on its clinical application in 5 cases as well as the results of ex vivo studies of ease of use and precision. The technique has potential for further development and use with other augmented-reality devices.

  5. MicroRNAs in right ventricular remodelling.

    Science.gov (United States)

    Batkai, Sandor; Bär, Christian; Thum, Thomas

    2017-10-01

    Right ventricular (RV) remodelling is a lesser understood process of the chronic, progressive transformation of the RV structure leading to reduced functional capacity and subsequent failure. Besides conditions concerning whole hearts, some pathology selectively affects the RV, leading to a distinct RV-specific clinical phenotype. MicroRNAs have been identified as key regulators of biological processes that drive the progression of chronic diseases. The role of microRNAs in diseases affecting the left ventricle has been studied for many years, however there is still limited information on microRNAs specific to diseases in the right ventricle. Here, we review recently described details on the expression, regulation, and function of microRNAs in the pathological remodelling of the right heart. Recently identified strategies using microRNAs as pharmacological targets or biomarkers will be highlighted. Increasing knowledge of pathogenic microRNAs will finally help improve our understanding of underlying distinct mechanisms and help utilize novel targets or biomarkers to develop treatments for patients suffering from right heart diseases. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

  6. Pulsatile flow in ventricular catheters for hydrocephalus

    Science.gov (United States)

    Giménez, Á.; Galarza, M.; Thomale, U.; Schuhmann, M. U.; Valero, J.; Amigó, J. M.

    2017-05-01

    The obstruction of ventricular catheters (VCs) is a major problem in the standard treatment of hydrocephalus, the flow pattern of the cerebrospinal fluid (CSF) being one important factor thereof. As a first approach to this problem, some of the authors studied previously the CSF flow through VCs under time-independent boundary conditions by means of computational fluid dynamics in three-dimensional models. This allowed us to derive a few basic principles which led to designs with improved flow patterns regarding the obstruction problem. However, the flow of the CSF has actually a pulsatile nature because of the heart beating and blood flow. To address this fact, here we extend our previous computational study to models with oscillatory boundary conditions. The new results will be compared with the results for constant flows and discussed. It turns out that the corrections due to the pulsatility of the CSF are quantitatively small, which reinforces our previous findings and conclusions. This article is part of the themed issue `Mathematical methods in medicine: neuroscience, cardiology and pathology'.

  7. Endocarditis in left ventricular assist device

    Science.gov (United States)

    Thyagarajan, Braghadheeswar; Kumar, Monisha Priyadarshini; Sikachi, Rutuja R; Agrawal, Abhinav

    2016-01-01

    Summary Heart failure is one of the leading causes of death in developed nations. End stage heart failure often requires cardiac transplantation for survival. The left ventricular assist device (LVAD) has been one of the biggest evolvements in heart failure management often serving as bridge to transplant or destination therapy in advanced heart failure. Like any other medical device, LVAD is associated with complications with infections being reported in many patients. Endocarditis developing secondary to the placement of LVAD is not a frequent, serious and difficult to treat condition with high morbidity and mortality. Currently, there are few retrospective studies and case reports reporting the same. In our review, we found the most common cause of endocarditis in LVAD was due to bacteria. Both bacterial and fungal endocarditis were associated with high morbidity and mortality. In this review we will be discussing the risk factors, organisms involved, diagnostic tests, management strategies, complications, and outcomes in patients who developed endocarditis secondary to LVAD placement. PMID:27672540

  8. The medical physics of ventricular assist devices

    International Nuclear Information System (INIS)

    Wood, Houston G; Throckmorton, Amy L; Untaroiu, Alexandrina; Song Xinwei

    2005-01-01

    Millions of patients, from infants to adults, are diagnosed with congestive heart failure each year all over the world. A limited number of donor hearts available for these patients results in a tremendous demand for alternative, supplemental circulatory support in the form of artificial heart pumps or ventricular assist devices (VADs). The development procedure for such a device requires careful consideration of biophysical factors, such as biocompatibility, haemolysis, thrombosis, implantability, physiologic control feasibility and pump performance. Conventional pump design equations based on Newton's law and computational fluid dynamics (CFD) are readily used for the initial design of VADs. In particular, CFD can be employed to predict the pressure-flow performance, hydraulic efficiencies, flow profile through the pump, stress levels and biophysical factors, such as possible blood cell damage. These computational flow simulations may involve comprehensive steady and transient flow analyses. The transient simulations involve time-varying boundary conditions and virtual modelling of the impeller rotation in the blood pumps. After prototype manufacture, laser flow measurements with sophisticated optics and mock circulatory flow loop testing assist with validation of pump design and identification of irregular flow patterns for optimization. Additionally, acute and chronic animal implants illustrate the blood pump's ability to support life physiologically. These extensive design techniques, coupled with fundamental principles of physics, ensure a reliable and effective VAD for thousands of heart failure patients each year

  9. Right ventricular volume estimation with cine MRI

    International Nuclear Information System (INIS)

    Sawachika, Takashi

    1993-01-01

    To quantitate right ventricular (RV) volumes easily using cine MRI, we developed a new method called 'modified area-length method (MOAL method)'. To validate this method, we compared it to the conventional Simpson's rule. Magnetom H15 (Siemens) was used and 6 normal volunteers and 21 patients with various RV sizes were imaged with ECG triggered gradient echo method (FISP, TR 50 ms, TE 12 ms, slice thickness 9 mm). For Simpson's rule transverse images of 12 sequential views which cover whole heart were acquired. For the MOAL method, two orthogonal views were imaged. One was the sagittal view which includes RV outflow tract and the other was the coronal view defined from the sagittal image to cover the whole RV. From these images the area (As, Ac) of RV and the longest distance between RV apex and pulmonary valve (Lmax) were determined. By correlating RV volumes measured by Simpson's rule to As*Ac/Lmax the RV volume could be estimated as follows: V=0.85*As*Ac/Lmax+4.55. Thus the MOAL method demonstrated excellent accuracy to quantitate RV volume and the acquisition time abbreviated to one fifth compared with Simpson's rule. This should be a highly promising method for routine clinical application. (author)

  10. Longitudinal strain predicts left ventricular mass regression after aortic valve replacement for severe aortic stenosis and preserved left ventricular function.

    Science.gov (United States)

    Gelsomino, Sandro; Lucà, Fabiana; Parise, Orlando; Lorusso, Roberto; Rao, Carmelo Massimiliano; Vizzardi, Enrico; Gensini, Gian Franco; Maessen, Jos G

    2013-11-01

    We explored the influence of global longitudinal strain (GLS) measured with two-dimensional speckle-tracking echocardiography on left ventricular mass regression (LVMR) in patients with pure aortic stenosis (AS) and normal left ventricular function undergoing aortic valve replacement (AVR). The study population included 83 patients with severe AS (aortic valve area regression (all P regression in patients with pure AS undergoing AVR. Our findings must be confirmed by further larger studies.

  11. Right ventricular function assessed by 2D strain analysis predicts ventricular arrhythmias and sudden cardiac death in patients after acute myocardial infarction

    DEFF Research Database (Denmark)

    Risum, Niels; Valeur, Nana; Søgaard, Peter

    2017-01-01

    Aims: Left ventricular function is a well-established predictor of malignant ventricular arrhythmias, but little is known about the importance of right ventricular (RV) function. The aim of this study was to investigate the importance of RV function for prediction of sudden cardiac death (SCD) or...

  12. Thoracoscopic phrenic nerve patch insulation to avoid phrenic nerve stimulation with cardiac resynchronization therapy

    OpenAIRE

    Nozoe, Masatsugu; Tanaka, Yasuaki; Koyama, Junjiroh; Oshitomi, Takashi; Honda, Toshihiro; Yoshioka, Masakazu; Iwatani, Kazunori; Hirayama, Touitsu; Nakao, Koichi

    2014-01-01

    A 76-year-old female was implanted with a cardiac resynchronization therapy (CRT) device, with the left ventricular lead implanted through a transvenous approach. One day after implantation, diaphragmatic stimulation was observed when the patient was in the seated position, which could not be resolved by device reprogramming. We performed thoracoscopic phrenic nerve insulation using a Gore-Tex patch. The left phrenic nerve was carefully detached from the pericardial adipose tissue, and a Gore...

  13. Noninvasive reconstruction of the three-dimensional ventricular activation sequence during pacing and ventricular tachycardia in the rabbit heart.

    Science.gov (United States)

    Han, Chengzong; Pogwizd, Steven M; Killingsworth, Cheryl R; He, Bin

    2011-01-01

    Ventricular arrhythmias represent one of leading causes for sudden cardiac death, a significant problem in public health. Noninvasive imaging of cardiac electric activities associated with ventricular arrhythmias plays an important role in better our understanding of the mechanisms and optimizing the treatment options. The present study aims to rigorously validate a novel three-dimensional (3-D) cardiac electrical imaging (3-DCEI) technique with the aid of 3-D intra-cardiac mapping during paced rhythm and ventricular tachycardia (VT) in the rabbit heart. Body surface potentials and intramural bipolar electrical recordings were simultaneously measured in a closed-chest condition in thirteen healthy rabbits. Single-site pacing and dual-site pacing were performed from ventricular walls and septum. VTs and premature ventricular complexes (PVCs) were induced by intravenous norepinephrine (NE). The non-invasively imaged activation sequence correlated well with invasively measured counterparts, with a correlation coefficient of 0.72 and a relative error of 0.30 averaged over all paced beats and NE-induced PVCs and VT beats. The averaged distance from imaged site of initial activation to measured site determined from intra-cardiac mapping was ∼5mm. These promising results suggest that 3-DCEI is feasible to non-invasively localize the origins and image activation sequence of focal ventricular arrhythmias.

  14. Diastolic And Systolic Right Ventricular Dysfunction Precedes Left Ventricular Dysfunction In Patients Paced From Right Ventricular Apex

    Directory of Open Access Journals (Sweden)

    Dwivedi SK

    2006-07-01

    Full Text Available Background: Cardiac dysfunction after right ventricular (RV apical pacing is well known but its extent, time frame of appearance and individual effect on left ventricular (LV, RV systolic and diastolic parameters has not evaluated in a systematic fashion. Methods: Patients with symptomatic bradycardia and ACC-AHA Class I indication for permanent pacemaker implantation (PPI were implanted a single chamber (VVI pacemaker. They were followed prospectively by echocardiographic examination which was done at baseline, 1 week, 1 month and 6 months after implantation. Parameters observed were chamber dimensions (M-line, chamber volumes, cardiac output (modified Simpson's method, systolic functions (ejection fraction, pre-ejection period, ejection time and ratio and diastolic functions( isovolumic relaxation time & deceleration time of left and right heart. Results: Forty eight consecutive patients (mean age 65.6±11.8 yrs, 66.7% males, mean EF 61.82±10.36% implanted a VVI pacemaker were enrolled in this study. The first significant change to appear in cardiac function after VVI pacing was in diastolic properties of RV as shown by increase in RV isovolumic relaxation time (IVRT from 65.89±15.93 to 76.58±17.00 ms,(p<0.001 at 1week and RV deceleration time (DT from 133.84±38.13 to 153.09±31.41 ms, (p=0.02 at 1 month. Increase in RV internal dimension (RVID from 1.26±0.41 to 1.44±0.44, (p<0.05 was also noticed at 1 week. The LV diastolic parameters were significantly altered after 1 month with increase in LV-IVRT from 92.36±21.47 to 117.24±27.21ms, (p<0.001 and increase in LV DT from 147.56±31.84 to 189.27±28.49ms,(p<0.01. This was followed by LV systolic abnormality which appeared at 6 months with an increase in LVPEP from 100.33±14.43 to 118.41±21.34ms, (p<0.001 and increase in LVPEP/LVET ratio from 0.34±0.46 to 0.44±0.10, (p<0.001]. The reduction in LV EF was manifested at 6 months falling from 61.82±10.36% to52.52±12.11%, (p<0

  15. Effects of stimulation parameters and electrode location on thresholds for epidural stimulation of cat motor cortex

    Science.gov (United States)

    Wongsarnpigoon, Amorn; Grill, Warren M.

    2011-12-01

    Epidural electrical stimulation (ECS) of the motor cortex is a developing therapy for neurological disorders. Both placement and programming of ECS systems may affect the therapeutic outcome, but the treatment parameters that will maximize therapeutic outcomes and minimize side effects are not known. We delivered ECS to the motor cortex of anesthetized cats and investigated the effects of electrode placement and stimulation parameters on thresholds for evoking motor responses in the contralateral forelimb. Thresholds were inversely related to stimulation frequency and the number of pulses per stimulus train. Thresholds were lower over the forelimb representation in motor cortex (primary site) than surrounding sites (secondary sites), and thresholds at sites 4 mm away. Electrode location and montage influenced the effects of polarity on thresholds: monopolar anodic and cathodic thresholds were not significantly different over the primary site, cathodic thresholds were significantly lower than anodic thresholds over secondary sites and bipolar thresholds were significantly lower with the anode over the primary site than with the cathode over the primary site. A majority of bipolar thresholds were either between or equal to the respective monopolar thresholds, but several bipolar thresholds were greater than or less than the monopolar thresholds of both the anode and cathode. During bipolar stimulation, thresholds were influenced by both electric field superposition and indirect, synaptically mediated interactions. These results demonstrate the influence of stimulation parameters and electrode location during cortical stimulation, and these effects should be considered during the programming of systems for therapeutic cortical stimulation.

  16. SERUM IGF-I AND HORMONAL RESPONSES TO INCREMENTAL EXERCISE IN ATHLETES WITH AND WITHOUT LEFT VENTRICULAR HYPERTROPHY

    Directory of Open Access Journals (Sweden)

    Aleksandra Zebrowska

    2009-03-01

    Full Text Available We investigated the response of insulin-like growth factor (IGF- I, insulin-like growth factor binding protein-3 (IGFBP-3 and some hormones, i.e., testosterone (T, growth hormone (GH, cortisol (C, and insulin (I, to maximal exercise in road cyclists with and without diagnosed left ventricular hypertrophy. M-mode and two-dimensional Doppler echocardiography was performed in 30 professional male endurance athletes and a group of 14 healthy untrained subjects using a Hewlett-Packard Image Point HX ultrasound system with standard imaging transducers. Echocardiography and an incremental physical exercise test were performed during the competitive season. Venous blood samples were drawn before and immediately after the maximal cycling exercise test for determination of somatomedin and hormonal concentrations. The basal concentration of IGF-I was statistically higher (p < 0.05 in athletes with left ventricular muscle hypertrophy (LVH when compared to athletes with a normal upper limit of the left ventricular wall (LVN (p < 0.05 and to the control group (CG (p < 0.01. The IGF-I level increased significantly at maximal intensity of incremental exercise in CG (p < 0.01, LVN (p < 0.05 and LVH (p < 0.05 compared to respective values at rest. Long-term endurance training induced an increase in resting (p < 0.01 and post-exercise (p < 0.05 IGF-I/IGFBP-3 ratio in athletes with LVH compared to LVN. The testosterone (T level was lower in LVH at rest compared to LVN and CG groups (p < 0.05. These results indicate that resting serum IGF-I concentration were higher in trained subjects with LVH compared to athletes without LVH. Serum IGF- I/IGFBP-3 elevation at rest and after exercise might suggest that IGF-I act as a potent stimulant of left ventricular hypertrophy in chronically trained endurance athletes

  17. Stimulating the senses with multi-media

    International Nuclear Information System (INIS)

    Rehn, H.; Majohr, N.; Staude, F.; Haferburg, M.; Foerster, K.

    1995-01-01

    Difficult subjects have always been better taught by example, demonstration and repetition than simply through book learning. Multi-media computer systems deliver these through learning programs which combine text, video, animation, graphics and sound to stimulate and motivate students. (author)

  18. Management of Arrhythmias in Athletes: Atrial Fibrillation, Premature Ventricular Contractions, and Ventricular Tachycardia.

    Science.gov (United States)

    Lai, Ernest; Chung, Eugene H

    2017-10-09

    Management of atrial fibrillation, premature ventricular contractions, and ventricular tachycardia without underlying cardiac disease or arrhythmogenic conditions differs in athletes from the general population. Athletes tend to be younger, healthier individuals with few comorbidities. Therapies that work well in the general population may not be appropriate or preferable for athletes. Management strategies include deconditioning, pharmacologic therapy, such as rate control with β-blockers or non-dihydropyridine calcium channel blockers and rhythm control with class I or class III antiarrhythmic drugs, and catheter ablation. Deconditioning is not preferred by athletes because of lost playing time. Pharmacologic therapy is well tolerated among most individuals, but is not as favorable in athletes. Rate control medications can reduce performance and β-blockers, in particular, are prohibited in many sports. Antiarrhythmic drugs are preferred over rate control with athletes, but many, especially younger athletes, may not like the idea of long-term medical therapy. Catheter ablation has been proven to be safe and efficacious, may eliminate the need for long-term medical therapy, and is supported by the major societies (AHA, ACC, ESC).

  19. Stem cell mobilization induced by subcutaneous granulocyte-colony stimulating factor to improve cardiac regeneration after acute ST-elevation myocardial infarction: result of the double-blind, randomized, placebo-controlled stem cells in myocardial infarction (STEMMI) trial

    DEFF Research Database (Denmark)

    Ripa, RS; Jorgensen, E; Wang, Y

    2006-01-01

    BACKGROUND: Phase 1 clinical trials of granulocyte-colony stimulating factor (G-CSF) treatment after myocardial infarction have indicated that G-CSF treatment is safe and may improve left ventricular function. This randomized, double-blind, placebo-controlled trial aimed to assess the efficacy of......: Bone marrow stem cell mobilization with subcutaneous G-CSF is safe but did not lead to further improvement in ventricular function after acute myocardial infarction compared with the recovery observed in the placebo group...

  20. Does reducing unnecessary right ventricular pacing improve sympathetic activity and innervation of heart in sinus node disease patients? MVP and SafeR study.

    Science.gov (United States)

    Miyamoto, Mihoko; Kimura, Yuichiro; Hosoda, Junya; Matsumoto, Katsumi; Matsushita, Kohei; Ishikawa, Toshiyuki; Umemura, Satoshi

    2012-01-01

    Ventricular desynchronization imposed by ventricular pacing causes regional disturbances of adrenergic innervation in the left ventricular myocardium and increases the risk of heart failure and atrial fibrillation (AF) in patients with sinus node disease (SND). As a result, decreased iodine-123 metaiodobenzylguanidine (I-(123 )MIBG) uptake occurs in patients with an implanted permanent pacemaker. Fourteen SND patients with an implanted pacemaker equipped with an algorithm for reducing unnecessary right ventricular pacing (RURVP) were enrolled. Pacemakers were programmed to RURVP mode for the first 12 weeks, and then reprogrammed to DDD for the last 12 weeks. At the end of each mode, data on cumulative percent ventricular pacing (%Vp), atrial high rate episodes (%AHR), I-(123 )MIBG myocardial scintigraphy, brain natriuretic peptide (BNP), human atrial natriuretic peptide (hANP), and myocardial damage indices typified by troponin T and C-reactive protein (CRP) were collected. %Vp was lower in RURVP than in DDD (0.2% versus 95.7%, P = 0.00098). BNP, hANP, troponin T, and CRP did not differ significantly between the pacing modes. However, I-(123 )MIBG findings of patients with full ventricular pacing in DDD improved in RURVP. In contrast, among patients without full ventricular pacing in DDD, their I-(123 )MIBG findings did not differ significantly between the pacing modes. In SND patients with normal cardiac function and intact atrioventricular conduction, the reduction of %Vp in RURVP was due to the reduction of ineffective pacing and fusion pacing in DDD. Therefore, these 2 types of pacing do not affect cardiac pump function.

  1. Right ventricular function during acute exacerbation of severe equine asthma.

    Science.gov (United States)

    Decloedt, A; Borowicz, H; Slowikowska, M; Chiers, K; van Loon, G; Niedzwiedz, A

    2017-09-01

    Pulmonary hypertension has been described in horses with severe equine asthma, but its effect on the right ventricle has not been fully elucidated. To evaluate right ventricular structure and function after a 1-week period of pulmonary hypertension secondary to acute exacerbation of severe equine asthma. Prospective study. A clinical episode of severe equine asthma was induced experimentally in six susceptible horses. Examinations in remission and on day 7 of the clinical episode included a physical examination with clinical scoring, echocardiography, arterial blood gas measurements, venous blood sampling for cardiac biomarkers, intracardiac pressure measurements, right ventricular and right atrial myocardial biopsies, airway endoscopy and bronchoalveolar lavage. After 1 month of recovery, physical examination, echocardiography and cardiac biomarker analysis were repeated. Echocardiographic and pressure measurements were compared with those in 10 healthy control horses. All horses developed clinical signs of acute pulmonary obstruction. Right heart pressures increased significantly. Altered right ventricular function could be detected by tissue Doppler and speckle tracking echocardiography. Cardiac troponin concentrations did not increase significantly, but were highly elevated in one horse which exercised in the paddock prior to sampling. Focal neutrophil infiltration was present in two myocardial samples. Even in remission, asthmatic horses showed a thicker right ventricular wall, an increased left ventricular end-systolic eccentricity index at chordal level and decreased right ventricular longitudinal strain compared with controls. The induced clinical episode was rather mild and the number of horses was limited because of the invasive nature of the study. Pulmonary obstruction in asthmatic horses induces pulmonary hypertension with right ventricular structural and functional changes. © 2017 EVJ Ltd.

  2. Thoracoscopic phrenic nerve patch insulation to avoid phrenic nerve stimulation with cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Masatsugu Nozoe, MD, PhD

    2014-04-01

    Full Text Available A 76-year-old female was implanted with a cardiac resynchronization therapy (CRT device, with the left ventricular lead implanted through a transvenous approach. One day after implantation, diaphragmatic stimulation was observed when the patient was in the seated position, which could not be resolved by device reprogramming. We performed thoracoscopic phrenic nerve insulation using a Gore-Tex patch. The left phrenic nerve was carefully detached from the pericardial adipose tissue, and a Gore-Tex patch was inserted between the phrenic nerve and pericardium using a thoracoscopic technique. This approach represents a potential option for the management of uncontrollable phrenic nerve stimulation during CRT.

  3. Central-Approach Surgical Repair of Coarctation of the Aorta with a Back-up Left Ventricular Assist Device for an Infant Presenting with Severe Left Ventricular Dysfunction

    Directory of Open Access Journals (Sweden)

    Tae Hoon Kim

    2015-12-01

    Full Text Available A two-month-old infant presented with coarctation of the aorta, severe left ventricular dysfunction, and moderate to severe mitral regurgitation. Through median sternotomy, the aortic arch was repaired under cardiopulmonary bypass and regional cerebral perfusion. The patient was postoperatively supported with a left ventricular assist device for five days. Left ventricular function gradually improved, eventually recovering with the concomitant regression of mitral regurgitation. Prompt surgical repair of coarctation of the aorta is indicated for patients with severe left ventricular dysfunction. A central approach for surgical repair with a back-up left ventricular assist device is a safe and effective treatment strategy for these patients.

  4. Central-Approach Surgical Repair of Coarctation of the Aorta with a Back-up Left Ventricular Assist Device for an Infant Presenting with Severe Left Ventricular Dysfunction.

    Science.gov (United States)

    Kim, Tae Hoon; Shin, Yu Rim; Kim, Young Sam; Kim, Do Jung; Kim, Hyohyun; Shin, Hong Ju; Htut, Aung Thein; Park, Han Ki

    2015-12-01

    A two-month-old infant presented with coarctation of the aorta, severe left ventricular dysfunction, and moderate to severe mitral regurgitation. Through median sternotomy, the aortic arch was repaired under cardiopulmonary bypass and regional cerebral perfusion. The patient was postoperatively supported with a left ventricular assist device for five days. Left ventricular function gradually improved, eventually recovering with the concomitant regression of mitral regurgitation. Prompt surgical repair of coarctation of the aorta is indicated for patients with severe left ventricular dysfunction. A central approach for surgical repair with a back-up left ventricular assist device is a safe and effective treatment strategy for these patients.

  5. Catheter ablation of epicardial ventricular tachycardia

    Directory of Open Access Journals (Sweden)

    Takumi Yamada, MD, PhD

    2014-08-01

    Full Text Available Ventricular tachycardias (VTs can usually be treated by endocardial catheter ablation. However, some VTs can arise from the epicardial surface, and their substrate can be altered only by epicardial catheter ablation. There are two approaches to epicardial catheter ablation: transvenous and transthoracic. The transvenous approach through the coronary venous system (CVS has been commonly used because it is easily accessible. However, this approach may be limited by the distribution of the CVS and insufficient radiofrequency energy delivery. Transthoracic epicardial catheter ablation has been developed to overcome these limitations of the transvenous approach. It is a useful supplemental or even preferred strategy to eliminate epicardial VTs in the electrophysiology laboratory. This technique has been applied for scar-related VTs secondary to often non-ischemic cardiomyopathy and sometimes ischemic cardiomyopathy, and idiopathic VTs as the epicardial substrates of these VTs have become increasingly recognized. When endocardial ablation and epicardial ablation through the CVS are unsuccessful, transthoracic epicardial ablation should be the next option. Intrapericardial access is usually obtained through a subxiphoidal pericardial puncture. This approach might not be possible in patients with pericardial adhesions caused by prior cardiac surgery or pericarditis. In such cases, a hybrid procedure involving surgical access with a subxiphoid pericardial window and a limited anterior or lateral thoracotomy might be a feasible and safe method of performing an epicardial catheter ablation in the electrophysiology laboratory. Potential complications associated with this technique include bleeding and collateral damage to the coronary arteries and phrenic nerve. Although the risk of these complications is low, electrophysiologists who attempt epicardial catheter ablation should know the complications associated with this technique, how to minimize their

  6. A new intracavitary probe for detecting the site of origin of ectopic ventricular beats during one cardiac cycle.

    Science.gov (United States)

    Taccardi, B; Arisi, G; Macchi, E; Baruffi, S; Spaggiari, S

    1987-01-01

    An olive-shaped probe (25 X 12 mm) with 41 evenly distributed recording electrodes on its surface was introduced into the left ventricles of seven open-chest dogs via the left atrium. In two other dogs a cylindrical probe (40 X 3 mm) was used. Electrical stimuli were delivered at 66 endocardial, midwall, or epicardial sites in the left and right ventricular walls and the septum. Mechanical stimuli were also applied at various epicardial sites. On-line mapping of equipotential contour lines on the surface of the probe invariably revealed a clear-cut potential minimum on the electrode that faced the pacing site. Time of appearance of potential minimum was 3 to 5 msec after endocardial stimuli, 10 to 25 msec for midwall and epicardial pacing, and 30 msec or more for right ventricular stimulation. Simultaneous stimulation at two sites 1.2 cm apart gave rise to two separate minima on the maps. "Pseudoisochrones" derived from electrograms recorded by the new probe were slightly less accurate in indicating the site of origin of extrasystoles. We conclude that equipotential and "isochrone" contour maps recorded from an array of semidirect electrodes, regularly distributed on the surface of an intraventricular probe, provide information on the site of origin (location and intramural depth) of ectopic paced beats in a normal dog heart.

  7. Technological Advances in Deep Brain Stimulation.

    Science.gov (United States)

    Ughratdar, Ismail; Samuel, Michael; Ashkan, Keyoumars

    2015-01-01

    Functional and stereotactic neurosurgery has always been regarded as a subspecialty based on and driven by technological advances. However until recently, the fundamentals of deep brain stimulation (DBS) hardware and software design had largely remained stagnant since its inception almost three decades ago. Recent improved understanding of disease processes in movement disorders as well clinician and patient demands has resulted in new avenues of development for DBS technology. This review describes new advances both related to hardware and software for neuromodulation. New electrode designs with segmented contacts now enable sophisticated shaping and sculpting of the field of stimulation, potentially allowing multi-target stimulation and avoidance of side effects. To avoid lengthy programming sessions utilising multiple lead contacts, new user-friendly software allows for computational modelling and individualised directed programming. Therapy delivery is being improved with the next generation of smaller profile, longer-lasting, re-chargeable implantable pulse generators (IPGs). These include IPGs capable of delivering constant current stimulation or personalised closed-loop adaptive stimulation. Post-implantation Magnetic Resonance Imaging (MRI) has long been an issue which has been partially overcome with 'MRI conditional devices' and has enabled verification of DBS lead location. Surgical technique is considering a shift from frame-based to frameless stereotaxy or greater role for robot assisted implantation. The challenge for these contemporary techniques however, will be in demonstrating equivalent safety and accuracy to conventional methods. We also discuss potential future direction utilising wireless technology allowing for miniaturisation of hardware.

  8. Dynamic Action Potential Restitution Contributes to Mechanical Restitution in Right Ventricular Myocytes From Pulmonary Hypertensive Rats.

    Science.gov (United States)

    Hardy, Matthew E L; Pervolaraki, Eleftheria; Bernus, Olivier; White, Ed

    2018-01-01

    We investigated the steepened dynamic action potential duration (APD) restitution of rats with pulmonary artery hypertension (PAH) and right ventricular (RV) failure and tested whether the observed APD restitution properties were responsible for negative mechanical restitution in these myocytes. PAH and RV failure were provoked in male Wistar rats by a single injection of monocrotaline (MCT) and compared with saline-injected animals (CON). Action potentials were recorded from isolated RV myocytes at stimulation frequencies between 1 and 9 Hz. Action potential waveforms recorded at 1 Hz were used as voltage clamp profiles (action potential clamp) at stimulation frequencies between 1 and 7 Hz to evoke rate-dependent currents. Voltage clamp profiles mimicking typical CON and MCT APD restitution were applied and cell shortening simultaneously monitored. Compared with CON myocytes, MCT myocytes were hypertrophied; had less polarized diastolic membrane potentials; had action potentials that were triggered by decreased positive current density and shortened by decreased negative current density; APD was longer and APD restitution steeper. APD90 restitution was unchanged by exposure to the late Na + -channel blocker (5 μM) ranolazine or the intracellular Ca 2+ buffer BAPTA. Under AP clamp, stimulation frequency-dependent inward currents were smaller in MCT myocytes and were abolished by BAPTA. In MCT myocytes, increasing stimulation frequency decreased contraction amplitude when depolarization duration was shortened, to mimic APD restitution, but not when depolarization duration was maintained. We present new evidence that the membrane potential of PAH myocytes is less stable than normal myocytes, being more easily perturbed by external currents. These observations can explain increased susceptibility to arrhythmias. We also present novel evidence that negative APD restitution is at least in part responsible for the negative mechanical restitution in PAH myocytes. Thus

  9. Managed ventricular pacing vs. conventional dual-chamber pacing for elective replacements: the PreFER MVP study: clinical background, rationale, and design.

    Science.gov (United States)

    Quesada, Aurelio; Botto, Gianluca; Erdogan, Ali; Kozak, Milan; Lercher, Peter; Nielsen, Jens Cosedis; Piot, Olivier; Ricci, Renato; Weiss, Christian; Becker, Daniel; Wetzels, Gwenn; De Roy, Luc

    2008-03-01

    Several clinical studies have shown that, in patients with intact atrioventricular (AV) conduction, unnecessary chronic right ventricular (RV) pacing can be detrimental. The managed ventricular pacing (MVP) algorithm is designed to give preference to spontaneous AV conduction, thus minimizing RV pacing. The clinical outcomes of MVP are being studied in several ongoing trials in patients undergoing a first device implantation, but it is unknown to what extent MVP is beneficial in patients with a history of ventricular pacing. The purpose of the Prefer for Elective Replacement MVP (PreFER MVP) study is to assess the superiority of the MVP algorithm to conventional pacemaker and implantable cardioverter-defibrillator programming in terms of freedom from hospitalization for cardiovascular causes in a population of patients exposed to long periods of ventricular pacing. PreFER MVP is a prospective, 1:1 parallel, randomized (MVP ON/MVP OFF), single-blinded multi-centre trial. The study population consists of patients with more than 40% ventricular pacing documented with their previous device. Approximately, 600 patients will be randomized and followed for at least 24 months. The primary endpoint comprises cardiovascular hospitalization. The PreFER MVP trial is the first large prospective randomized clinical trial evaluating the effect of MVP in patients with a history of RV pacing.

  10. The effect of heart failure and left ventricular assist device treatment on right ventricular mechanics: a computational study.

    Science.gov (United States)

    Park, Jun I K; Heikhmakhtiar, Aulia Khamas; Kim, Chang Hyun; Kim, Yoo Seok; Choi, Seong Wook; Song, Kwang Soup; Lim, Ki Moo

    2018-05-22

    Although it is important to analyze the hemodynamic factors related to the right ventricle (RV) after left ventricular assist device (LVAD) implantation, previous studies have focused only on the alteration of the ventricular shape and lack quantitative analysis of the various hemodynamic parameters. Therefore, we quantitatively analyzed various hemodynamic parameters related to the RV under normal, heart failure (HF), and HF incorporated with continuous flow LVAD therapy by using a computational model. In this study, we combined a three-dimensional finite element electromechanical model of ventricles, which is based on human ventricular morphology captured by magnetic resonance imaging (MRI) with a lumped model of the circulatory system and continuous flow LVAD function in order to construct an integrated model of an LVAD implanted-cardiovascular system. To induce systolic dysfunction, the magnitude of the calcium transient function under HF condition was reduced to 70% of the normal value, and the time constant was reduced by 30% of the normal value. Under the HF condition, the left ventricular end systolic pressure decreased, the left ventricular end diastolic pressure increased, and the pressure in the right atrium (RA), RV, and pulmonary artery (PA) increased compared with the normal condition. The LVAD therapy decreased the end-systolic pressure of the LV by 41%, RA by 29%, RV by 53%, and PA by 71%, but increased the right ventricular ejection fraction by 52% and cardiac output by 40%, while the stroke work was reduced by 67% compared with the HF condition without LVAD. The end-systolic ventricular tension and strain decreased with the LVAD treatment. LVAD enhances CO and mechanical unloading of the LV as well as those of the RV and prevents pulmonary hypertension which can be induced by HF.

  11. Value of the Electrocardiogram as a Predictor of Right Ventricular Dysfunction in Patients With Chronic Right Ventricular Volume Overload.

    Science.gov (United States)

    Alonso, Pau; Andrés, Ana; Rueda, Joaquín; Buendía, Francisco; Igual, Begoña; Rodríguez, María; Osa, Ana; Arnau, Miguel A; Salvador, Antonio

    2015-05-01

    Pulmonary regurgitation is a common complication in patients with repaired tetralogy of Fallot or congenital pulmonary stenosis. Electrocardiographic variables have been correlated with parameters used to evaluate right ventricular function. We aimed to analyze the diagnostic value of the width and fragmentation of the electrocardiogram in the identification of patients with right ventricular dysfunction and/or dilation. We selected 107 consecutive patients diagnosed with severe pulmonary insufficiency after repair of pulmonary stenosis or tetralogy of Fallot. The tests included electrocardiography, echocardiography, and magnetic resonance. Each electrocardiogram was analyzed manually to measure QRS duration. We defined QRS fragmentation as the presence of low-voltage waves in the terminal portion of the QRS complex in at least 2 contiguous leads. We found a significant negative correlation between QRS width and right ventricular function, as well as a positive correlation with right ventricular volume. The receiver operating characteristic curve indicated a cut-off point for QRS width of 140ms, which showed good sensitivity for a diagnosis of right ventricular dilation (> 80%) and dysfunction (> 95%). In logistic regression models, a QRS duration > 140ms was found to be the only independent predictor of right ventricular dilation and dysfunction. Electrocardiography is a rapid, widely available, and reproducible tool. QRS width constitutes an independent predictor of the presence of right ventricular dilation and dysfunction. This study is the first to provide a cutoff value for QRS width to screen for right ventricle involvement. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  12. A Prospective Study of Ripple Mapping the Post-Infarct Ventricular Scar to Guide Substrate Ablation for Ventricular Tachycardia.

    Science.gov (United States)

    Luther, Vishal; Linton, Nick W F; Jamil-Copley, Shahnaz; Koa-Wing, Michael; Lim, Phang Boon; Qureshi, Norman; Ng, Fu Siong; Hayat, Sajad; Whinnett, Zachary; Davies, D Wyn; Peters, Nicholas S; Kanagaratnam, Prapa

    2016-06-01

    Post-infarct ventricular tachycardia is associated with channels of surviving myocardium within scar characterized by fractionated and low-amplitude signals usually occurring late during sinus rhythm. Conventional automated algorithms for 3-dimensional electro-anatomic mapping cannot differentiate the delayed local signal of conduction within the scar from the initial far-field signal generated by surrounding healthy tissue. Ripple mapping displays every deflection of an electrogram, thereby providing fully informative activation sequences. We prospectively used CARTO-based ripple maps to identify conducting channels as a target for ablation. High-density bipolar left ventricular endocardial electrograms were collected using CARTO3v4 in sinus rhythm or ventricular pacing and reviewed for ripple mapping conducting channel identification. Fifteen consecutive patients (median age 68 years, left ventricular ejection fraction 30%) were studied (6 month preprocedural implantable cardioverter defibrillator therapies: median 19 ATP events [Q1-Q3=4-93] and 1 shock [Q1-Q3=0-3]). Scar (ripple mapping conducting channels were seen within each scar (length 60 mm; initial component 0.44 mV; delayed component 0.20 mV; conduction 55 cm/s). Ablation was performed along all identified ripple mapping conducting channels (median 18 lesions) and any presumed interconnected late-activating sites (median 6 lesions; Q1-Q3=2-12). The diastolic isthmus in ventricular tachycardia was mapped in 3 patients and colocated within the ripple mapping conducting channels identified. Ventricular tachycardia was noninducible in 85% of patients post ablation, and 71% remain free of ventricular tachycardia recurrence at 6-month median follow-up. Ripple mapping can be used to identify conduction channels within scar to guide functional substrate ablation. © 2016 American Heart Association, Inc.

  13. Ventricular dysfunction in children with obstructive sleep apnea: radionuclide assessment

    International Nuclear Information System (INIS)

    Tal, A.; Leiberman, A.; Margulis, G.; Sofer, S.

    1988-01-01

    Ventricular function was evaluated using radionuclide ventriculography in 27 children with oropharyngeal obstruction and clinical features of obstructive sleep apnea. Their mean age was 3.5 years (9 months to 7.5 years). Conventional clinical assessment did not detect cardiac involvement in 25 of 27 children; however, reduced right ventricular ejection fraction (less than 35%) was found in 10 (37%) patients (mean: 19.5 +/- 2.3% SE, range: 8-28%). In 18 patients wall motion abnormality was detected. In 11 children in whom radionuclide ventriculography was performed before and after adenotonsillectomy, right ventricular ejection fraction rose from 24.4 +/- 3.6% to 46.7 +/- 3.4% (P less than 0.005), and in all cases wall motion showed a definite improvement. In five children, left ventricular ejection fraction rose greater than 10% after removal of oropharyngeal obstruction. It is concluded that right ventricular function may be compromised in children with obstructive sleep apnea secondary to adenotonsillar hypertrophy, even before clinical signs of cardiac involvement are present

  14. Ventricular Arrhythmic Storm after Initiating Sacubitril/Valsartan.

    Science.gov (United States)

    Vicent, Lourdes; Juárez, Miriam; Martín, Irene; García, Jorge; González-Saldívar, Hugo; Bruña, Vanesa; Devesa, Carolina; Sousa-Casasnovas, Iago; Fernández-Avilés, Francisco; Martínez-Sellés, Manuel

    Sacubitril/valsartan was approved recently for the treatment of patients with heart failure and reduced ejection fraction. We present 6 cases of ventricular arrhythmia, that occurred shortly after sacubitril/valsartan initiation, that required drug withdrawal. Other potential triggering factors of electrical storm were ruled out and, from the arrhythmic perspective, all of the patients were stable in the previous year. Our aim is to describe the possible association of sacubitril/valsartan with arrhythmic storm. This was an observational monocentric study performed in the first 7 months of sacubitril/valsartan commercialization in Spain (October 2016). All patients were included in the SUMA (Sacubitril/Varsartan Usado Ambulatoriamente en Madrid [Sacubitril/Valsartan Used in Outpatients in Madrid]) registry. Patients were consecutively enrolled on the day they started the drug. Ventricular arrhythmic storm was defined as ≥2 episodes of sustained ventricular arrhythmia or defibrillator therapy application in 24 h. From 108 patients who received the drug, 6 presented with ventricular arrhythmic storm (5.6%). Baseline characteristics were similar in the patients with and without ventricular arrhythmic storm. The total number of days that sacubitril/valsartan was administered to each patient was 5, 6, 44 (8 since titration), 84, 93, and 136 (105 since titration), respectively. Our data are not enough to infer a cause-and-effect relationship. Further investigations regarding a potential proarrhythmic effect of sacubitril/valsartan are probably needed. © 2018 S. Karger AG, Basel.

  15. Usefulness of tomographic phase image in ventricular conduction abnormalities

    International Nuclear Information System (INIS)

    Sakurai, Mitsuru; Watanabe, Yoshihiko; Kondo, Takeshi

    1985-01-01

    In order to evaluate three-dimensional phase changes in ventricular conduction abnormalities, tomographic phase images were constructed in 7 normal subjects, 12 patients with ventricular pacing, 21 patients with bundle branch block and 12 patients with Wolff-Parkinson-White syndrome. Eight to 12 slices of the short-axis ventricular tomographic phase image (TPI) were derived using a 7-pinhole collimator, and compared with planar phase images (PPIs) in left anterior oblique (LAO) and right anterior oblique (RAO) projections. TPIs were excellent for observing biventricular phase changes in the long-axis direction. In 6 cases of complete right bundle branch block with left axis deviation (beyond -30 0 ), the phase delay in the left ventricular anterior wall was recognized in 5 cases by TPI, although it was difficult to be detected by PPIs. The site of the pacing electrode was identified by TPI in 11 out of 12 cases, compared to 8 cases by PPIs in LAO and RAO projections. The site of the accessory pathway in Wolff-Parkinson-White syndrome was detected in the basal slice of TPIs in 10 out of 12 cases, compared to 8 cases by PPI in the LAO projection. Therefore, it is obvious that TPIs offer more valid information than PPIs. In conclusion, TPI is useful for investigation of ventricular conduction abnormalities. (author)

  16. Left ventricular systolic and diastolic function in hyperthyroidism

    International Nuclear Information System (INIS)

    Friedman, M.J.; Okada, R.D.; Ewy, G.A.; Hellman, D.J.

    1982-01-01

    In order to assess the effect of hyperthyroidism on systolic and diastolic function of the left ventricle, M-mode echocardiograms and systolic time intervals were obtained in 13 patients while they were clinically hyperthyroid and again when they were euthyroid following radioactive iodine therapy. Echocardiographic tracings of the septum and left ventricular posterior wall were digitized and analyzed to provide the maximum velocity of shortening and maximum velocity of lengthening. These velocities were normalized for left ventricular diastolic dimension. The left ventricular minor axis fractional shortening and the normalized maximum velocity of shortening were both increased during the hyperthyroid state. The normalized maximum velocity of lengthening, a measure of diastolic left ventricular function, was also increased during the hyperthyroid state when compared to the euthyroid state. The preejection period index and the preejection period/left ventricular ejection time ratio were lower when the patients were hyperthyroid than when they were euthyroid. These data confirm the increased inotropic state and demonstrated increased diastolic relaxation velocities of the hyperthyroid left ventricle

  17. Fatigue as Presenting Symptom and a High Burden of Premature Ventricular Contractions Are Independently Associated With Increased Ventricular Wall Stress in Patients With Normal Left Ventricular Function.

    Science.gov (United States)

    van Huls van Taxis, Carine F B; Piers, Sebastiaan R D; de Riva Silva, Marta; Dekkers, Olaf M; Pijnappels, Daniël A; Schalij, Martin J; Wijnmaalen, Adrianus P; Zeppenfeld, Katja

    2015-12-01

    High idiopathic premature ventricular contractions (PVC) burden has been associated with PVC-induced cardiomyopathy. Patients may be symptomatic before left ventricular (LV) dysfunction develops. N-terminal pro-B-type natriuretic peptide (NT-proBNP) and circumferential end-systolic wall stress (cESS) on echocardiography are markers for increased ventricular wall stress. This study aimed to evaluate the relation between presenting symptoms, PVC burden, and increased ventricular wall stress in patients with frequent PVCs and preserved LV function. Eighty-three patients (41 men; 49±15 years) with idiopathic PVCs and normal LV function referred for PVC ablation were included. Type of symptoms (palpitations, fatigue, and [near-]syncope), PVC burden on 24-hour Holter, NT-proBNP levels, and cESS on echocardiography were assessed before and 3 months after ablation. Sustained successful ablation was defined as ≥80% PVC burden reduction during follow-up. Patients were symptomatic for 24 months (Q1-Q3, 16-60); 73% reported palpitations, 47% fatigue, and 30% (near-)syncope. Baseline PVC burden was 23±13%, median NT-proBNP 92 pg/mL (Q1-Q3 50-156), and cESS 143±35 kdyne/cm(2). Fatigue was associated with higher baseline NT-proBNP and cESS (PFatigue was independently associated with a significantly larger reduction in NT-proBNP. In patients with nonsuccessful ablation, NT-proBNP and cESS remained unchanged. In patients with frequent PVCs and preserved LV function, fatigue was associated with higher baseline NT-proBNP and cESS, and with a significantly larger reduction in NT-proBNP after sustained successful ablation. These findings support a link between fatigue and PVC-induced increased ventricular wall stress, despite preserved LV function. © 2015 American Heart Association, Inc.

  18. Is right ventricular mid-septal pacing superior to apical pacing in patients with high degree atrio-ventricular block and moderately depressed left ventricular function?

    Science.gov (United States)

    Chen, Kang; Mao, Ye; Liu, Shao-hua; Wu, Qiong; Luo, Qing-zhi; Pan, Wen-qi; Jin, Qi; Zhang, Ning; Ling, Tian-you; Chen, Ying; Gu, Gang; Shen, Wei-feng; Wu, Li-qun

    2014-06-01

    We are aimed to investigate whether right ventricular mid-septal pacing (RVMSP) is superior to conventional right ventricular apical pacing (RVAP) in improving clinical functional capacity and left ventricular ejection fraction (LVEF) for patients with high-degree atrio-ventricular block and moderately depressed left ventricle (LV) function. Ninety-two patients with high-degree atrio-ventricular block and moderately reduced LVEF (ranging from 35% to 50%) were randomly allocated to RVMSP (n=45) and RVAP (n=47). New York Heart Association (NYHA) functional class, echocardiographic LVEF, and distance during a 6-min walk test (6MWT) were determined at 18 months after pacemaker implantation. Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured using an enzyme-linked immunosorbent assay (ELISA) kit. Compared with baseline, NYHA functional class remained unchanged at 18 months, distance during 6MWT (485 m vs. 517 m) and LVEF (36.7% vs. 41.8%) were increased, but BNP levels were reduced (2352 pg/ml vs. 710 pg/ml) in the RVMSP group compared with those in the RVAP group, especially in patients with LVEF 35%-40% (for all comparisons, Pfunction capacity and LV function measurements were not significantly changed in patients with RVAP, despite the pacing measurements being similar in both groups, such as R-wave amplitude and capture threshold. RVMSP provides a better clinical utility, compared with RVAP, in patients with high-degree atrioventricular block and moderately depressed LV function whose LVEF levels ranged from 35% to 40%.

  19. Clinical studies on myocardial perfusion imaging in patients with right ventricular overload

    International Nuclear Information System (INIS)

    Abo, Kenji; Yamagata, Takashi; Nakajima, Masao; Fujita, Kimiaki; Morita, Nobuo

    1979-01-01

    Patients with heart disease which had been clinically diagnosed underwent 201 Tl myocardial perfusion imaging. The thickness of right ventricular wall measured from original images was directly proportional to systolic pressure of the right ventricle measured by cardiac catheterization, and 201 Tl activity in the right ventricle was more directly proportional to systolic pressure of the right ventricle. Imaging patterns of various diseases were also described. Images of patients with hypertrophic cardiomyopathy revealed that right ventricular wall was thin and right ventricular cavity was small, but the thickness of septal wall and left ventricular wall were maximal. Images of patients with mitral insufficiency revealed that the thickness of right ventricular wall, septal wall, and left ventricular wall was medium, and the right ventricular cavity was smaller than the left ventricular cavity. Images of patients with congestive cardiomyopathy and congestive cardiac failure showed that enlargement of both ventricular cavities was disproportionate to the thickness of each wall. Images of patients with arterial septal defect revealed that the thickness of each wall was comparatively normal, the right ventricular cavity was maximal, and the left ventricular cavity was minimal. Images of patients with primary pulmonary hypertention, pulmonary stenosis and tetralogy of Fallot in whom pressure overload was recognized revealed severe thickenings of right ventricular wall, moderate enlargement of the right ventricle, small left ventricle, and thin left ventricular wall. (Tsunoda, M.)

  20. Terapia de resincronización con implante de electrodo ventricular izquierdo por vía epicárdica Resynchronization therapy with left ventricular electrode implant via epicardium

    Directory of Open Access Journals (Sweden)

    Francisco Gómez

    2007-12-01

    casos. No se presentaron complicaciones durante el procedimiento ni estimulación diafragmática o desalojo del eléctrodo epicárdico después de seis meses de seguimiento. Conclusión: se demostró que la implantación de marcapasos tricameral para resincronización cardiaca con la utilización de electrodo epicárdico ventricular izquierdo, es una terapia segura, con la cual se obtienen parámetros adecuados de implantación y normofunción del dispositivo.Introduction: heart resynchronization therapy is safe and effective for improving functional class and quality of life and to diminish mortality in patients with heart failure in functional state III and IV with optimal medical therapy. Methods: we report the procedure realized to a group of patients in the Cardiovascular and Transplant Unit at the University Hospital San Vicente de Paul and the Antioquia University between November 2004 and February 2006, to whom a tricameral pacemaker for cardiac resynchronization was implanted, inserting the left ventricular electrode via epicardium. Patients chosen for the insertion fulfilled the heart failure state C or D criteria, according to the NYHA III or IV classification, corroborated with functional test 120ms. and echocardiographic criteria of intra-ventricular, inter-ventricular or atrio-ventricular dyssynchronism. Results: 9 patients were included: 5 men and 4 women with mean age 57 years; 8 patients had left His bundle block. The implant procedure was realized in two times: the first one in the hemodynamics ward where an electrode in right atrium and right ventricle was put, and the second one in the operating room where an electrode in the left ventricle via epicardium through left anterior mini-thoracotomy was implanted. Total procedure time oscillated between 35 and 210 minutes with a mean of 105 minutes, and less than this in the last patients. Intra-operative measures show a mean stimulation threshold of 0.9 mV; QRST duration was less than 130 ms. after

  1. Reverse right ventricular remodeling after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension: utility of magnetic resonance imaging to demonstrate restoration of the right ventricle

    NARCIS (Netherlands)

    Reesink, Herre J.; Marcus, J. Tim; Tulevski, Igor I.; Jamieson, Stuart; Kloek, Jaap J.; Vonk Noordegraaf, Anton; Bresser, Paul

    2007-01-01

    OBJECTIVES: Pulmonary arterial hypertension causes right ventricular remodeling; that is, right ventricular dilatation, hypertrophy, and leftward ventricular septal bowing. We studied the effect of pulmonary endarterectomy on the restoration of right ventricular remodeling in patients with chronic

  2. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf; Saad, Bilal; Negara, Ardiansyah; Sun, Shuyu

    2017-01-01

    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically

  3. Usefulness of ventricular endocardial electric reconstruction from body surface potential maps to noninvasively localize ventricular ectopic activity in patients

    Science.gov (United States)

    Lai, Dakun; Sun, Jian; Li, Yigang; He, Bin

    2013-06-01

    As radio frequency (RF) catheter ablation becomes increasingly prevalent in the management of ventricular arrhythmia in patients, an accurate and rapid determination of the arrhythmogenic site is of important clinical interest. The aim of this study was to test the hypothesis that the inversely reconstructed ventricular endocardial current density distribution from body surface potential maps (BSPMs) can localize the regions critical for maintenance of a ventricular ectopic activity. Patients with isolated and monomorphic premature ventricular contractions (PVCs) were investigated by noninvasive BSPMs and subsequent invasive catheter mapping and ablation. Equivalent current density (CD) reconstruction (CDR) during symptomatic PVCs was obtained on the endocardial ventricular surface in six patients (four men, two women, years 23-77), and the origin of the spontaneous ectopic activity was localized at the location of the maximum CD value. Compared with the last (successful) ablation site (LAS), the mean and standard deviation of localization error of the CDR approach were 13.8 and 1.3 mm, respectively. In comparison, the distance between the LASs and the estimated locations of an equivalent single moving dipole in the heart was 25.5 ± 5.5 mm. The obtained CD distribution of activated sources extending from the catheter ablation site also showed a high consistency with the invasively recorded electroanatomical maps. The noninvasively reconstructed endocardial CD distribution is suitable to predict a region of interest containing or close to arrhythmia source, which may have the potential to guide RF catheter ablation.

  4. Influence of left ventricular hypertrophy on infarct size and left ventricular ejection fraction in ST-elevation myocardial infarction

    International Nuclear Information System (INIS)

    Małek, Łukasz A.; Śpiewak, Mateusz; Kłopotowski, Mariusz; Petryka, Joanna; Mazurkiewicz, Łukasz; Kruk, Mariusz; Kępka, Cezary; Miśko, Jolanta; Rużyłło, Witold; Witkowski, Adam

    2012-01-01

    Background: Left ventricular hypertrophy (LVH) predisposes to larger infarct size, which may be underestimated by the left ventricular ejection fraction (LVEF) due to supranormal systolic performance often present in patients with LVH. The aim of the study was to compare infarct size and LVEF in patients with ST-segment elevation myocardial infarction (STEMI) and increased left ventricular mass on cardiac magnetic resonance (CMR). Methods: The study included unselected group of 52 patients (61 ± 11 years, 69% male) with first STEMI who had CMR after median 5 days from the onset of the event. Left ventricular hypertrophy (LVH) was defined as left ventricular mass index exceeding 95th percentile of references values for age and gender. Infarct size was assessed with means of late gadolinium enhancement (LGE). Results: LVH was found in 16 patients (31%). In comparison to the rest of the group, patients with LVH had higher absolute and relative infarct mass (p = 0.002 and p = 0.02, respectively). LVH was related to higher prevalence of microvascular obstruction and myocardial haemorrhage and higher number of LV segments with transmural necrosis (p = 0.02, p = 0.01 and p = 0.01, respectively). Despite marked difference in the infarct size between both studied subgroups there was no difference in LVEF and mean number of dysfunctional LV segments. Conclusions: Patients with LVH undergoing STEMI have larger infarct size underestimated by the LV systolic performance in comparison to patients without LVH.

  5. Evaluation of left ventricular function by nuclear stethoscope

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, T [National Cardiovascular Center, Suita, Osaka (Japan)

    1981-03-01

    The Nuclear Stethoscope (N.S.) is a unique cardiac probe system that provides a precise, rapid, noninvasive method to directly quantify ventricular functions at the bedside or actual beat-to-beat or composite beat basis. The accuracy and validity of N.S. were studied in 42 patients with cardiac diseases in comparison with camera-computer EF. The N.S. EF was well correlated with camera-computer EF (r = 0.82). In this study, clinical application of N.S. was as follows. 1. Beat-to-beat left ventricular volume response for evaluation of arrythmia (atrial fibrillation, premature ventricular conduction, bigemy et al.) 2. exercise study by handgrip and ergometer. EF is an extremely sensitive indicator to discriminate coronary arteries diseases from normal subjects.

  6. The evaluation of right ventricular performance using krypton-81m

    International Nuclear Information System (INIS)

    Ham, H.R.; Piepsz, A.; Vandevivere, J.; Guillaume, M.; Goethals, P.; Lenaers, A.

    1983-01-01

    The availability of krypton-81m suitable for intravenous injection provides an easy means for assessing right ventricular function. The superimposition of the other heart chambers does not constitute a problem. The activity in the left heart is negligible and the study can be performed in the right anterior oblique position to obtain optimal separation between the right atrium and the right ventricle. Lung activity is quite high and should be corrected before computing the right ventricular ejection fraction. This correction can be accomplished by performing Tc-99m MAA perfusion scintigraphy. The measurement of the right ventricular ejection fraction appears to be reproducible with very small inter-and intraobserver variability. Good quality phase and amplitude images can be obtained with such high count rates

  7. Continuous monitoring of left ventricular function by VEST

    International Nuclear Information System (INIS)

    Ohtake, Tohru; Watanabe, Toshiaki; Kosaka, Noboru

    1988-01-01

    Using an ambulatory ventricular function monitor (VEST), left ventricular function (LVF) was examined in one healthy volunteer, 3 with ischemic heart disease, and one with dilated myocardiopathy (DMCP) under various conditions, such as treadmill exercise, standing, and sitting. It was also examined when two DCMP patients with associated left ventricular failure were given a nitrite (ISDM) and cardiotonic agent (E 1020). End-diastolic volume (EDV) decreased in the standing position, and increased in exercise, suggesting the involvement of venous blood pool in the legs. Ejection fraction (EF) decreased in the case of widespread ischemia during exercise. Drug tolerance test revealed decrease in EDV and end-systolic volume (ESV), no change in stroke volume (SV), and slight increase in EF on ISDM; and decrease in EDV and ESV, increase in SV, and marked increase in EF on E 1020. For EF, the VEST data were relatively well correlated with gamma camera data. (Namekawa, K.)

  8. Evaluation of left ventricular function by nuclear stethoscope

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko

    1981-01-01

    The Nuclear Stethoscope (N.S.) is a unique cardiac probe system that provides a precise, rapid, noninvasive method to directly quantify ventricular functions at the bedside or actual beat-to-beat or composite beat basis. The accuracy and validity of N.S. were studied in 42 patients with cardiac diseases in comparison with camera-computer EF. The N.S. EF was well correlated with camera-computer EF (r = 0.82). In this study, clinical application of N.S. was as follows. 1. Beat-to-beat left ventricular volume response for evaluation of arrythmia (atrial fibrillation, premature ventricular conduction, bigemy et al.) 2. exercise study by handgrip and ergometer. EF is an extremely sensitive indicator to discriminate coronary arteries diseases from normal subjects. (author)

  9. A large ventricular septal defect complicating resuscitation after blunt trauma

    Directory of Open Access Journals (Sweden)

    Henry D I De′Ath

    2012-01-01

    Full Text Available A young adult pedestrian was admitted to hospital after being hit by a car. On arrival to the Accident and Emergency Department, the patient was tachycardic, hypotensive, hypoxic, and acidotic with a Glasgow Coma Scale of 3. Despite initial interventions, the patient remained persistently hypotensive. An echocardiogram demonstrated a traumatic ventricular septal defect (VSD with right ventricular strain and increased pulmonary artery pressure. Following a period of stabilization, open cardiothoracic surgery was performed and revealed an aneurysmal septum with a single large defect. This was repaired with a bovine patch, resulting in normalization of right ventricular function. This case provides a vivid depiction of a large VSD in a patient following blunt chest trauma with hemodynamic compromise. In all thoracic trauma patients, and particularly those poorly responsive to resuscitation, VSDs should be considered. Relevant investigations and management strategies are discussed.

  10. Effect of Vericiguat, a Soluble Guanylate Cyclase Stimulator, on Natriuretic Peptide Levels in Patients With Worsening Chronic Heart Failure and Reduced Ejection Fraction

    DEFF Research Database (Denmark)

    Gheorghiade, Mihai; Greene, Stephen J; Butler, Javed

    2015-01-01

    IMPORTANCE: Worsening chronic heart failure (HF) is a major public health problem. OBJECTIVE: To determine the optimal dose and tolerability of vericiguat, a soluble guanylate cyclase stimulator, in patients with worsening chronic HF and reduced left ventricular ejection fraction (LVEF). DESIGN, ...

  11. N-terminal pro brain natriuretic peptide in arterial hypertension--a marker for left ventricular dimensions and prognosis

    DEFF Research Database (Denmark)

    Hildebrandt, Per; Boesen, Mikael; Olsen, Michael

    2004-01-01

    In arterial hypertension risk factor evaluation, including LV mass measurements, and risk stratification using risk charts or programs, is generally recommended. In heart failure NT-proBNP has been shown to be a marker of LV dimensions and of prognosis. If the same diagnostic and prognostic value...... is present in arterial hypertension, risk factor evaluation would be easier. In 36 patients with arterial hypertension, electrocardiographic LV hypertrophy and preserved left ventricular function, NT-proBNP was eight-fold higher than in healthy subjects. The log NT-proBNP correlated with LV mass index (R=0.......47, P=0.0002) measured by magnetic resonance imaging. In other subjects with arterial hypertension a significant but weak correlation to diastolic properties has been demonstrated. As for prognosis, a recent study in patients with hypertension, electrocardiographic left ventricular hypertrophy...

  12. Backscatter and attenuation characterization of ventricular myocardium

    Science.gov (United States)

    Gibson, Allyson Ann

    2009-12-01

    This Dissertation presents quantitative ultrasonic measurements of the myocardium in fetal hearts and adult human hearts with the goal of studying the physics of sound waves incident upon anisotropic and inhomogeneous materials. Ultrasound has been used as a clinical tool to assess heart structure and function for several decades. The clinical usefulness of this noninvasive approach has grown with our understanding of the physical mechanisms underlying the interaction of ultrasonic waves with the myocardium. In this Dissertation, integrated backscatter and attenuation analyses were performed on midgestational fetal hearts to assess potential differences in the left and right ventricular myocardium. The hearts were interrogated using a 50 MHz transducer that enabled finer spatial resolution than could be achieved at more typical clinical frequencies. Ultrasonic data analyses demonstrated different patterns and relative levels of backscatter and attenuation from the myocardium of the left ventricle and the right ventricle. Ultrasonic data of adult human hearts were acquired with a clinical imaging system and quantified by their magnitude and time delay of cyclic variation of myocardial backscatter. The results were analyzing using Bayes Classification and ROC analysis to quantify potential advantages of using a combination of two features of cyclic variation of myocardial backscatter over using only one or the other feature to distinguish between groups of subjects. When the subjects were classified based on hemoglobin A1c, the homeostasis model assessment of insulin resistance, and the ratio of triglyceride to high-density lipoprotein-cholesterol, differences in the magnitude and normalized time delay of cyclic variation of myocardial backscatter were observed. The cyclic variation results also suggested a trend toward a larger area under the ROC curve when information from magnitude and time delay of cyclic variation is combined using Bayes classification than when

  13. Left ventricular function in hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Takahashi, Hiromi; Yamaguchi, Ryutaro; Ifuku, Masayasu

    1985-01-01

    The present study was to investigate of left ventricular (LV) function during exercise in 26 patients with hypertrophic cardiomyopathy(HCM) usingTc-99m equilibrium angiocardiography, and to elucidate the mechanism of impaired functional reserve during exercise. In patients with HCM, LV ejection fraction decreased from 65 ± 8 (mean ± SD) % at rest to 59 ± 18 % at peak exercise, in contrast to an increase among controls (from 56 ± 9 % to 64 ± 9 %). As compared with resting values, cardiac output increased to 168 ± 24 % at peak exercise in HCM, but the increase was significantly less than that in controls (215 ± 47 %). Stroke volume decreased gradually to 83 ± 16 % during exercise in HCM, while it increased to 114 ± 10 % at an exercise level of half intensity, and it decreased slightly to 106 ± 16 % at peak exercise. LV end-systolic volume decreased among controls to 78 ± 27 % at peak exercise, but remained unchanged in HCM (118 ± 58 %). An increase in peak ejection rate at peak exercise was less in HCM than in controls (143 ± 26 % vs 170 ± 42 %). No significant differences were observed between the two groups concerning changes in indices of LV diastolic function including LV end-diastolic volume, peak filling rate or 1/3 filling rate during exercise. In the analysis of LV function curves, pulmonary arterial diastolic pressure increased to a greater extent in HCM than in controls (19 ± 6 mmHg vs 11 ± 6 mmHg); whereas, an increase in the stroke work index was less in HCM (80 ± 26 g.m/m 2 /beat vs 121 ± 21 g.m/m 2 /beat) at peak exercise. Thus, the LV function curve shifted downward and to the right in patients with HCM. The above findings indicate that LV functional reserve during exercise is impaired, especially as to systolic function in patients with HCM, while deterioration of diastolic function may be partly compromised by elevated filling pressure. (J.P.N.)

  14. Multiple ventricular septal defects: a new strategy.

    Science.gov (United States)

    Corno, Antonio F; Kandakure, Pramod R; Dhannapuneni, Ramana Rao V; Gladman, Gordon; Venugopal, Prem; Alphonso, Nelson

    2013-01-01

    A multicenter prospective study was conducted to evaluate a new strategy for multiple Ventricular Septal Defects (VSDs). From 2004 to 2012 17 consecutive children (3 premature, 14 infants), mean age 3.2 months (9 days-9 months), mean body weight 4.2 kg (3.1-6.1 kg), with multiple VSDs underwent Pulmonary Artery Banding (PAB) with an adjustable FloWatch-PAB(®). Associated cardiac anomalies included patent ductus arteriosus (1), aortic coarctation (2), hypoplastic aortic arch (2), and left isomerism (3). Five patients (5/17 = 29.4%) required pre-operative mechanical ventilation, with a mean duration of 64 days (7-240 days) There were no early or late deaths during a mean follow-up of 48 months (7-98 months), with either FloWatch removal or last observation as end-points. FloWatch-PAB(®) adjustments were required in all patients: a mean of 4.8 times/patient (2-9) to tighten the PAB, and a mean of 1.1 times/patient (0-3) to release the PAB with the patient's growth. After a mean interval of 29 months (8-69 months) 10/17 (59%) patients underwent re-operation: 7/10 PAB removal, with closure of a remaining unrestrictive VSD in 6 (peri-membranous in 3 patients, mid-muscular in 2, and inlet in 1) and Damus-Kaye-Stansel, bi-directional Glenn, and atrial septectomy in 1; 3/9 patients required only PAB removal. All muscular multiple VSDs had closed in all 10 patients. PA reconstruction was required in 1/10 patient. In 5/7 of the remaining patients with the PAB still in situ, all muscular VSDs had already closed. The only 2 patients with persistent muscular multiple VSDs are the 2 patients with the shortest follow-up. This reproducible new strategy with an adjustable PAB simplifies the management of infants with multiple VSDs and provides the following advantages: (a) good results (0% mortality), delayed surgery with a high incidence (15/17 = 88%) of spontaneous closure of multiple muscular VSDs, and facilitated closure of residual unrestrictive

  15. MULTIPLE VENTRICULAR SEPTAL DEFECTS: A NEW STRATEGY

    Directory of Open Access Journals (Sweden)

    Antonio Francesco Corno

    2013-07-01

    Full Text Available INTRODUCTIONA multicenter prospective study was conducted to evaluate a new strategy for multiple Ventricular Septal Defects (VSDs.MATERIALS AND METHODSFrom 2004 to 2012 17 consecutive children (3 premature, 14 infants, mean age 3.2months (9 days to 9 months, mean body weight 4.2kg (3.1 to 6.1 kg, with multiple VSDs underwent Pulmonary Artery Banding (PAB with an adjustable FloWatch-PAB. Associated cardiac anomalies included patent ductus arteriosus (9, aortic coarctation (2, hypoplastic aortic arch (2 and left isomerism (1. Five patients (5/17 =29.4% required pre-operative mechanical ventilation, with a mean duration of 64 days (7 to 240 daysRESULTSThere were no early or late deaths during a mean follow-up of 48 months (7 to 98 months, with either FloWatch removal or last observation as end-points.FloWatch-PAB adjustments were required in all patients: a mean of 4.8 times/patient (2 to 9 to tighten the PAB, and a mean of 1.1 times/patient (0 to 3 to release the PAB with the patient’s growth. After a mean interval of 29 months (8 to 69 months 10/17 (59% patients underwent reoperation: 7/10 PAB removal, with closure of a remaining peri-membranous VSD in 6 and Damus-Kaye-Stansel, bi-directional Glenn, and atrial septectomy in 1; 3/9 patients required only PAB removal. All muscular multiple VSDs had closed in all 10 patients. PA reconstruction was required in 1/10 patient. In 5/7 of the remaining patients with the PAB still in situ, all muscular VSDs had already closed. The only 2 patients with persistent muscular multiple VSDs are the 2 patients with the shortest follow-up.CONCLUSIONS This reproducible new strategy with an adjustable PAB simplifies the management of infants with multiple VSDs and provides the following advantages: a good results (0% mortality, delayed surgery with a high incidence (15/17=88% of spontaneous closure of multiple muscular VSDs, and facilitated closure of residual peri-membranous VSD at an older age and h

  16. New York Canyon Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Raemy, Bernard

    2012-06-21

    The New York Canyon Stimulation Project was to demonstrate the commercial application of Enhanced Geothermal System techniques in Buena Vista Valley area of Pershing County, Nevada. From October 2009 to early 2012, TGP Development Company aggressively implemented Phase I of Pre-Stimulation and Site/Wellbore readiness. This included: geological studies; water studies and analyses and procurement of initial permits for drilling. Oversubscription of water rights and lack of water needed for implementation of EGS were identified and remained primary obstacles. Despite extended efforts to find alternative solutions, the water supply circumstances could not be overcome and led TGP to determine a "No Go" decision and initiate project termination in April 2012.

  17. Assessment of left ventricular function by 201Tl FCG-gated myocardial SPECT

    International Nuclear Information System (INIS)

    Toba, Masahiro; Ishida, Yoshio; Fukuchi, Kazuki; Fukushima, Kazuhito; Katafuchi, Tetsurou; Hayashida, Kohei; Oka, Hisashi; Takamiya, Makoto

    1999-01-01

    We applied the QGS program for LV function analysis (described by Germano, 1995) to a 201 Tl SPECT study at rest, and estimated its accuracy. We performed 201 Tl ECG-gated myocardial SPECT in 25 patients with ischemic heart disease under an acquisition time used in the routine 99m Tc ECG-gated SPECT study. The quality of the gated images was visually assessed with a 4-point grading system. LVEDV, LVESV, LVEF determined by the QGS program were compared with those by Simpson's method on biplane LVG in 25 patients. Regional wall motion scores in 7 myocardial segments were assessed on the three-dimensional display created by the QGS program and the cine display of biplane LVG with a 5-point grading system. Wall motion scores obtained by the QGS program were compared with those by LVG. Although 72.0% of 201 Tl ECG-gated SPECT images were fair or poor in image quality, there were good correlations between the values obtained by the QGS program and LVG (LVEDV: r=0.82, LVESV: r=0.88, LVEF: r=0.89). In addition, wall motion scores by the QGS program were correspondent to those by LVG in 77.1% of all 175 myocardial segments. We conclude that the QGS program provides high accuracy in evaluating left ventricular function even from 201 Tl ECG-gated myocardial SPECT data. (author)

  18. β-Adrenergic receptor stimulation inhibits proarrhythmic alternans in postinfarction border zone cardiomyocytes: a computational analysis.

    Science.gov (United States)

    Tomek, Jakub; Rodriguez, Blanca; Bub, Gil; Heijman, Jordi

    2017-08-01

    The border zone (BZ) of the viable myocardium adjacent to an infarct undergoes extensive autonomic and electrical remodeling and is prone to repolarization alternans-induced cardiac arrhythmias. BZ remodeling processes may promote or inhibit Ca 2+ and/or repolarization alternans and may differentially affect ventricular arrhythmogenesis. Here, we used a detailed computational model of the canine ventricular cardiomyocyte to study the determinants of alternans in the BZ and their regulation by β-adrenergic receptor (β-AR) stimulation. The BZ model developed Ca 2+ transient alternans at slower pacing cycle lengths than the control model, suggesting that the BZ may promote spatially heterogeneous alternans formation in an infarcted heart. β-AR stimulation abolished alternans. By evaluating all combinations of downstream β-AR stimulation targets, we identified both direct (via ryanodine receptor channels) and indirect [via sarcoplasmic reticulum (SR) Ca 2+ load] modulation of SR Ca 2+ release as critical determinants of Ca 2+ transient alternans. These findings were confirmed in a human ventricular cardiomyocyte model. Cell-to-cell coupling indirectly modulated the likelihood of alternans by affecting the action potential upstroke, reducing the trigger for SR Ca 2+ release in one-dimensional strand simulations. However, β-AR stimulation inhibited alternans in both single and multicellular simulations. Taken together, these data highlight a potential antiarrhythmic role of sympathetic hyperinnervation in the BZ by reducing the likelihood of alternans and provide new insights into the underlying mechanisms controlling Ca 2+ transient and repolarization alternans. NEW & NOTEWORTHY We integrated, for the first time, postmyocardial infarction electrical and autonomic remodeling in a detailed, validated computer model of β-adrenergic stimulation in ventricular cardiomyocytes. Here, we show that β-adrenergic stimulation inhibits alternans and provide novel insights

  19. Diclofenac prolongs repolarization in ventricular muscle with impaired repolarization reserve.

    Directory of Open Access Journals (Sweden)

    Attila Kristóf

    Full Text Available BACKGROUND: The aim of the present work was to characterize the electrophysiological effects of the non-steroidal anti-inflammatory drug diclofenac and to study the possible proarrhythmic potency of the drug in ventricular muscle. METHODS: Ion currents were recorded using voltage clamp technique in canine single ventricular cells and action potentials were obtained from canine ventricular preparations using microelectrodes. The proarrhythmic potency of the drug was investigated in an anaesthetized rabbit proarrhythmia model. RESULTS: Action potentials were slightly lengthened in ventricular muscle but were shortened in Purkinje fibers by diclofenac (20 µM. The maximum upstroke velocity was decreased in both preparations. Larger repolarization prolongation was observed when repolarization reserve was impaired by previous BaCl(2 application. Diclofenac (3 mg/kg did not prolong while dofetilide (25 µg/kg significantly lengthened the QT(c interval in anaesthetized rabbits. The addition of diclofenac following reduction of repolarization reserve by dofetilide further prolonged QT(c. Diclofenac alone did not induce Torsades de Pointes ventricular tachycardia (TdP while TdP incidence following dofetilide was 20%. However, the combination of diclofenac and dofetilide significantly increased TdP incidence (62%. In single ventricular cells diclofenac (30 µM decreased the amplitude of rapid (I(Kr and slow (I(Ks delayed rectifier currents thereby attenuating repolarization reserve. L-type calcium current (I(Ca was slightly diminished, but the transient outward (I(to and inward rectifier (I(K1 potassium currents were not influenced. CONCLUSIONS: Diclofenac at therapeutic concentrations and even at high dose does not prolong repolarization markedly and does not increase the risk of arrhythmia in normal heart. However, high dose diclofenac treatment may lengthen repolarization and enhance proarrhythmic risk in hearts with reduced repolarization reserve.

  20. Cerebrovascular accidents in patients with a ventricular assist device.

    Science.gov (United States)

    Tsukui, Hiroyuki; Abla, Adib; Teuteberg, Jeffrey J; McNamara, Dennis M; Mathier, Michael A; Cadaret, Linda M; Kormos, Robert L

    2007-07-01

    A cerebrovascular accident is a devastating adverse event in a patient with a ventricular assist device. The goal was to clarify the risk factors for cerebrovascular accident. Prospectively collected data, including medical history, ventricular assist device type, white blood cell count, thrombelastogram, and infection, were reviewed retrospectively in 124 patients. Thirty-one patients (25%) had 48 cerebrovascular accidents. The mean ventricular assist device support period was 228 and 89 days in patients with and without cerebrovascular accidents, respectively (P cerebrovascular accidents occurred within 4 months after implantation. Actuarial freedom from cerebrovascular accident at 6 months was 75%, 64%, 63%, and 33% with the HeartMate device (Thoratec Corp, Pleasanton, Calif), Thoratec biventricular ventricular assist device (Thoratec Corp), Thoratec left ventricular assist device (Thoratec), and Novacor device (WorldHeart, Oakland, Calif), respectively. Twenty cerebrovascular accidents (42%) occurred in patients with infections. The mean white blood cell count at the cerebrovascular accident was greater than the normal range in patients with infection (12,900/mm3) and without infection (9500/mm3). The mean maximum amplitude of the thrombelastogram in the presence of infection (63.6 mm) was higher than that in the absence of infection (60.7 mm) (P = .0309). The risk of cerebrovascular accident increases with a longer ventricular assist device support period. Infection may activate platelet function and predispose the patient to a cerebrovascular accident. An elevation of the white blood cell count may also exacerbate the risk of cerebrovascular accident even in patients without infection. Selection of device type, prevention of infection, and meticulous control of anticoagulation are key to preventing cerebrovascular accident.

  1. Diclofenac Prolongs Repolarization in Ventricular Muscle with Impaired Repolarization Reserve

    Science.gov (United States)

    Kristóf, Attila; Husti, Zoltán; Koncz, István; Kohajda, Zsófia; Szél, Tamás; Juhász, Viktor; Biliczki, Péter; Jost, Norbert; Baczkó, István; Papp, Julius Gy; Varró, András; Virág, László

    2012-01-01

    Background The aim of the present work was to characterize the electrophysiological effects of the non-steroidal anti-inflammatory drug diclofenac and to study the possible proarrhythmic potency of the drug in ventricular muscle. Methods Ion currents were recorded using voltage clamp technique in canine single ventricular cells and action potentials were obtained from canine ventricular preparations using microelectrodes. The proarrhythmic potency of the drug was investigated in an anaesthetized rabbit proarrhythmia model. Results Action potentials were slightly lengthened in ventricular muscle but were shortened in Purkinje fibers by diclofenac (20 µM). The maximum upstroke velocity was decreased in both preparations. Larger repolarization prolongation was observed when repolarization reserve was impaired by previous BaCl2 application. Diclofenac (3 mg/kg) did not prolong while dofetilide (25 µg/kg) significantly lengthened the QTc interval in anaesthetized rabbits. The addition of diclofenac following reduction of repolarization reserve by dofetilide further prolonged QTc. Diclofenac alone did not induce Torsades de Pointes ventricular tachycardia (TdP) while TdP incidence following dofetilide was 20%. However, the combination of diclofenac and dofetilide significantly increased TdP incidence (62%). In single ventricular cells diclofenac (30 µM) decreased the amplitude of rapid (IKr) and slow (IKs) delayed rectifier currents thereby attenuating repolarization reserve. L-type calcium current (ICa) was slightly diminished, but the transient outward (Ito) and inward rectifier (IK1) potassium currents were not influenced. Conclusions Diclofenac at therapeutic concentrations and even at high dose does not prolong repolarization markedly and does not increase the risk of arrhythmia in normal heart. However, high dose diclofenac treatment may lengthen repolarization and enhance proarrhythmic risk in hearts with reduced repolarization reserve. PMID:23300901

  2. Quantitative measurement of ventricular dilatation on CT scan

    International Nuclear Information System (INIS)

    Okita, Naoshi; Mochizuki, Hiroshi; Takase, Sadao

    1985-01-01

    Cerebral atrophy might be judged from the ventricular dilatation with some indices, calculated from various ventricular width. But, there is no general agreement on what index is the most reliable. In this paper, we attempted to establish the index, easy to measure and most reliable. Our method is as follow. 1) We carried out the CT scan (EMI 1010) on 89 neurologically intact patients. Scans were parallel to orbito-meatal line (OML), and were 10 mm in thickness. On CT scan films, various width, area of anterior horns and area of bodies of lateral ventricles were measured. Measurement about the anterior horns of lateral ventricles were carried out on image the most clearly showed the foramen of Monro. And measurements about the bodies of lateral ventricles were on image, 20 mm above the image of anterior horn. Correlations of various width and areas were calculated. Then we proposed new indices with high correlations (over 0.9) with ventricular area; Anterior horn CVI (Cerebro-Ventricular Index) and Body CVI. 2) Patients with myotonic dystrophy show cerebral atrophy. We carried out the CT scan (GECT/T 8800) on 17 myotonic dystrophy patients and 30 controls. Between the two groups, age and sex were almost matched. In the two groups, we calculated our new indices as well as various indices which have been reported; Huckman number, Bifrontal CVI, Bicaudal CVI, Anterior horn index, Hirajima's index, and Cella-media index. The data were analyzed statistically. The ventricular dilatation of myotonic dystrophy patients is more definite with Anterior horn CVI, Bicaudal CVI and Body CVI (p<0.01). These indices have higher correlations with the ventricular area (about 0.9). (J.P.N.)

  3. Failure of antiarrhythmic drugs to prevent experimental reperfusion ventricular fibrillation.

    Science.gov (United States)

    Naito, M; Michelson, E L; Kmetzo, J J; Kaplinsky, E; Dreifus, L S

    1981-01-01

    Ninety-nine adult mongrel dogs underwent acute ligation of the proximal left anterior descending coronary artery. Thirty minutes later, the occlusion was released to evaluate the effectiveness of five antiarrhythmic protocols in eliminating reperfusion ventricular fibrillation. The five protocols included: protocol 1 --i.v. lidocaine, preligation and prerelease (n = 19); protocol 2 -- i.v. lidocaine, prereperfusion only (n = 22); protocol 3 -- chronic, oral, daily amiodarone for 2 weeks preligation (n = 19); protocol 4 -- i.v. procainamide, preligation and prereperfusion (n = 21); and protocol 5 -- i.v. verapamil, prereperfusion (n = 18). Each regimen was evaluated with respect to the incidence of reperfusion ventricular fibrillation in dogs that survived to reperfusion, and the results were compared to 77 control dogs that underwent identical coronary artery occlusion and release procedures without drug therapy. The incidence of reperfusion ventricular fibrillation was as follows: protocol 1 -- seven of 15 dogs (47%); protocol 2 -- six of 18 (33%); protocol 3 -- 11 of 16 dogs (69%); protocol 4 -- eight of 17 dogs (47%); and protocol 5 -- 10 of 17 dogs (59%), compared with 36 of 60 (60%) in control dogs. Using chi-square analysis, protocol 2 was beneficial (p antecedent coronary artery ligation periods, and predictive risk indexes for the occurrence of reperfusion ventricular fibrillation were developed. the Mantel-Haenszel method of statistical analysis revealed that none of these protocols resulted in a statistically significant reduction in the incidence of reperfusion ventricular fibrillation. Thus, use of these predictive indexes plus appropriate statistical methods has revealed, unexpectedly, limitations in the efficacy of a spectrum of antiarrhythmic agents in preventing reperfusion ventricular fibrillation.

  4. CT and MRI findings of 4th ventricular tumors

    International Nuclear Information System (INIS)

    Kim, Taek Geun; Ro, Hee Jeong; Byun, Jae Young; Lee, Han Jin; Chung, Myung Hee; Choi, Kyu Ho; Shinn, Kyung Sub

    1994-01-01

    The purpose of our study is to evaluate characteristic features of 4th ventricular tumors in CT and MRI. Pathologically proved 9 patients with 4th ventricular tumor were examined by CT and/or MRI. 4th ventricular tumors were ependymoma(4 cases), medulloblastoma(2 case), choroid plexus papilloma(2 cases), and oligodendroglioma(1 cases). Include in our study were only those mass lesions that were located at surgery predominantly within 4th ventricle with or without ventricular expansion. The origin of 4th ventricular tumor was the roof (ependymoma 3 cases, medulloblastoma 2 cases), the floor (ependymoma 1 cases), and the undetermined(remaining 3 case). On MRI, all tumors were hypointense except ependymoma (3 cases) showing isointensity on T1WI. All tumors were hypointense on PDWI and T2WI. On Gd-DTPA enhanced T1WI, strong enhancement was seen in all but ependymoma(1 cases) which showed mild enhancement. On CT, as compared with MR images, various density on precontrast and postcontrast images were seen. Calcification was seen in choroid plexus papilloma(1 caes) and oligodendroglioma(1 cases). Hydrocephalus is seen in all cases except ependymoma(2 cases) and oligodendroglioma(1 case). Hemorrhage within tumor was present only in ependymoma(2 cases). Cystic change or necrosis of tumor was seen in ependymoma(3 cases), choroid plexus papilloma(1 case), and oligodendroglioma(1 case). Peritumoral edema was seen in medulloblastoma(1 case). Extension through the foramen Luschka and the Megendie was seen in ependymoma (2 cases), choroid plexus(2 cases), and medulloblastoma (1 case). Seeing along the CSF pathway was seen only in ependymoma(2 case). The results od our study may suggest that specific diagnosis of 4th ventricular tumor can be suggested preoperatively by analysing the origin in 4th ventricle, difference of CT density or MRI signal intensity, presence of extension or seeding through cerebrospinal fluid of the lesion

  5. Differential diagnosis of the 4th ventricular tumors

    International Nuclear Information System (INIS)

    Lee, Sang Woo; Lee, Jong Min; Kang, Moo Song; Kim, Chul Min; Kim, Chang Soo

    1997-01-01

    To determine by analysis of MR and CT findings the points of differentiation among 4th ventricular tumors, especially the change of shape of the 4th ventricle caused by the site at which 4th ventricular tumors originate. The authors retrospectively analyzed and compared the CT(n=5) and MRI(n=12) findings of 13 pathologically proven 4th ventricular tumors comprising six medulloblastomas three ependymomas(4 cases) and three choroids plexus papillomas. On axial MRI medulloblastomas showed anterior and anterolateral CSF-clefts between the tumor mass and the 4th ventricular wall in one and five cases, respectively; on sagittal MRI, anterior beaking of the upper 4th ventricle was seen. Two ependymomas showed posterolateral CSF-cleft on axial MRI and posterior beaking of the upper 4th ventricle on sagittal MRI. Two ependymomas and all choroids plexus papillomas showed anterior, posterior and lateral CSF-clefts on axial MRI, and anterior and posterior beakings of the upper 4th ventricle on sagittal MRI. On Gd-DTPA enhanced T1WI, all medulloblastomas and ependymomas showed inhomogeneous enhancement, and all choroids plexus papillomas showed homogeneous enhancement. On CT, tow choroids plexus papillomas showed dense calcifications. The differential diagnosis of 4th ventricular tumors can be preoperatively suggested by analysis of findings such as a CSF-cleft between the tumor mass and the 4th ventricular wall on axial MR and CT images, the shape of the upper 4th ventricle on sagittal MRI, contrast enhancement pattern, necrosis and cyst, and CSF seeding

  6. Left ventricular mechanical adaptation to chronic aortic regurgitation in intact dogs

    International Nuclear Information System (INIS)

    Florenzano, F.; Glantz, S.A.

    1987-01-01

    Increased and end-diastolic wall stress has been hypothesized to stimulate left ventricular (LV) hypertrophy following volume overload. The authors instrumented intact-chest dogs with radiopaque markers in both ventricles and created volume overload by puncturing one aortic valve cusp. An x-ray system with biplane fluoroscopic and cineradiographic capabilities was used. End-diastolic stress increased immediately, then fell over 3 mo as the heart hypertrophied. End-systolic stress did not change significantly. Chamber contractility, quantified as E/sub max/, the end-systolic pressure-volume line slope, increased. E/sub max/ normalized by multiplying by LV mass increased following the lesion before but not after β-blockade with propranolol and did not change significantly over time, suggesting that chamber contractility changed because of increased mass and sympathetic tone rather than changed intrinsic muscle function. LV mass did not initially correlate with lesion size, but steady-state mass did. Over the range of lesions the authors produced, increased end-diastolic wall stress appears to stimulate hypertrophy at a fixed rate, which stops when end-diastolic wall stress has been reduced to an acceptable level

  7. Is exercise training safe and beneficial in patients receiving left ventricular assist device therapy?

    Science.gov (United States)

    Alsara, Osama; Perez-Terzic, Carmen; Squires, Ray W; Dandamudi, Sanjay; Miranda, William R; Park, Soon J; Thomas, Randal J

    2014-01-01

    Because a limited number of patients receive heart transplantation, alternative therapies, such as left ventricular assist device (LVAD) therapy, have emerged. Published studies have shown that LVAD implantation, by itself, improves exercise tolerance to the point where it is comparable to those with mild heart failure. The improvement in exercise capacity is maximally achieved 12 weeks after LVAD therapy and can continue even after explantation of the device. This effect varies, depending on the type of LVAD and exercise training. The available data in the literature on safety and benefits of exercise training in patients after LVAD implantation are limited, but the data that are available suggest that training trends to be safe and have an impact on exercise capacity in LVAD patients. Although no studies were identified on the role of cardiac rehabilitation programs in the management of LVAD patients, it appears that cardiac rehabilitation programs offer an ideal setting for the provision of supervised exercise training in this patient group.

  8. Contribution of body surface mapping to clinical outcome after surgical ablation of postinfarction ventricular tachycardia

    NARCIS (Netherlands)

    van Dessel, Pascal F.; van Hemel, Norbert M.; Groenewegen, Arne Sippens; de Bakker, Jacques M.; Linnebank, André C.; Defauw, Jo J.

    2002-01-01

    This article investigates the influence of body surface mapping on outcome of ventricular antiarrhythmic surgery. Preoperative mapping is advocated to optimize map-guided antiarrhythmic surgery of postinfarction ventricular tachycardia. We sequentially analyzed the results of catheter activation

  9. Association of heart failure hospitalizations with combined electrocardiography and echocardiography criteria for left ventricular hypertrophy

    DEFF Research Database (Denmark)

    Gerdts, Eva; Okin, Peter M; Boman, Kurt

    2012-01-01

    The value of performing echocardiography in hypertensive patients with electrocardiographic left ventricular hypertrophy (LVH) is uncertain.......The value of performing echocardiography in hypertensive patients with electrocardiographic left ventricular hypertrophy (LVH) is uncertain....

  10. EXERCISE-INDUCED VENTRICULAR-TACHYCARDIA - A RARE MANIFESTATION OF DIGITALIS TOXICITY

    NARCIS (Netherlands)

    GOSSELINK, ATM; CRIJNS, HJGM; WIESFELD, ACP; LIE, KI

    Digitalis intoxication is one of the most common adverse drug reactions. Although some arrhythmias are seen more frequently than others, virtually any rhythm disturbance, including ventricular tachycardia, may occur. However, to our knowledge, exercise-induced ventricular tachycardia as a

  11. Ventricular dyssynchrony as a cause of structural disease in the heart of Dorper sheep

    Directory of Open Access Journals (Sweden)

    J. Ker

    2004-11-01

    Full Text Available Ventricular dyssynchrony is a disturbance of the normal, organized electromechanical coupling of the two ventricles. This condition has many causes, such as left bundle branch block, ventricular preexcitation, right ventricular pacing and right ventricular premature ventricular complexes (PVCs. Ventricular dyssynchrony has many adverse haemodynamic effects on the left ventricle and we wanted to know whether these adverse haemodynamic effects might have any structural consequences on the left ventricles of such hearts. Six healthy Dorper wethers were subjected to numerous right ventricular PVCs to induce ventricular dyssynchrony in order to determine whether any structural consequences will occur in the left ventricles of these hearts. Myocarditis in the musculature of the left ventricles of all six these hearts was seen.

  12. Prognostic value of tissue Doppler imaging for predicting ventricular arrhythmias and cardiovascular mortality in ischaemic cardiomyopathy

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Olsen, Flemming Javier; Storm, Katrine

    2016-01-01

    AIMS: Only 30% of patients receiving an implantable cardioverter defibrillator (ICD) for primary prevention receive appropriately therapy. We sought to investigate the value of tissue Doppler imaging (TDI) to predict ventricular tachycardia (VT), ventricular fibrillation (VF), and cardiovascular...

  13. Androgenic anabolic steroids also impair right ventricular function.

    Science.gov (United States)

    Kasikcioglu, Erdem; Oflaz, Huseyin; Umman, Berrin; Bugra, Zehra

    2009-05-01

    Chronic anabolic steroid use suppresses left ventricular functions. However, there is no information regarding the chronic effects of anabolic steroids on right ventricular function which also plays a key role in global cardiac function. The main objective of the present study was to investigate the effects of androgenic anabolic steroids usage among athletes on remodeling the right part of the heart. Androgenic-anabolic steroids-using bodybuilders had smaller diastolic velocities of both ventricles than drug-free bodybuilders and sedentary counterparts. This study shows that androgenic anabolic steroids-using bodybuilders exhibited depressed diastolic functions of both ventricles.

  14. Acute right ventricular dysfunction: real-time management with echocardiography.

    Science.gov (United States)

    Krishnan, Sundar; Schmidt, Gregory A

    2015-03-01

    In critically ill patients, the right ventricle is susceptible to dysfunction due to increased afterload, decreased contractility, or alterations in preload. With the increased use of point-of-care ultrasonography and a decline in the use of pulmonary artery catheters, echocardiography can be the ideal tool for evaluation and to guide hemodynamic and respiratory therapy. We review the epidemiology of right ventricular failure in critically ill patients; echocardiographic parameters for evaluating the right ventricle; and the impact of mechanical ventilation, fluid therapy, and vasoactive infusions on the right ventricle. Finally, we summarize the principles of management in the context of right ventricular dysfunction and provide recommendations for echocardiography-guided management.

  15. Exercise-Induced Ventricular Fibrillation: Seven Years Follow-Up

    Directory of Open Access Journals (Sweden)

    Gökmen Gemici

    2011-11-01

    Full Text Available We present a 7-year follow-up of a 55-year-old male who experienced ventricular fibrillation during the recovery period of exercise testing and refused implantation of an ICD. Normal left ventricular systolic function was found on echocardiographic examination, and coronary angiography revealed only a side branch disease with a vessel diameter of less than 2 millimeters. The patient was discharged on metoprolol and ASA in addition to his previous treatment with lisinopril and simvastatin. Outpatient cardiac evaluation by repeated 24-hour ECG monitorizations (Holter revealed normal findings. On follow up visits every six months for the past seven years, the patient was found to be asymptomatic.

  16. Assessment of the left ventricular function with the nuclear stethoscope

    Energy Technology Data Exchange (ETDEWEB)

    Tarkowska, A.; Adam, W.E.; Bitter, F.

    1980-08-01

    The evaluation of the left ventricular function with the Nuclear Stethoscope was performed on 27 patients with heart diseases. The reproducibility of the measurements was good. Repetitions of EF, ER and EDV estimations yielded errors of 2.63%, 1.45% and 0.31%. The comparison with the results of camera ventriculography showed a good agreement of EF, contraction velocity parameters and relaxation velocity parameters, with a cor. coeff. of greater or equal to 0.750. A particularly high correlation was found between the NS EF and NS ER (r = 0.968). It was concluded that the Nuclear Stethoscope provides a reliable evaluation of left ventricular function.

  17. Assessment of the left ventricular function with the nuclear stethoscope

    International Nuclear Information System (INIS)

    Tarkowska, A.; Adam, W.E.; Bitter, F.

    1980-01-01

    The evaluation of the left ventricular function with the Nuclear Stethoscope was performed on 27 patients with heart diseases. The reproducibility of the measurements was good. Repetitions of EF, ER and EDV estimations yielded errors of 2.63%, 1.45% and 0.31%. The comparison with the results of camera ventriculography showed a good agreement of EF, contraction velocity parameters and relaxation velocity parameters, with a cor. coeff. of greater or equal to 0.750. A particularly high correlation was found between the NS EF and NS ER (r = 0.968). It was concluded that the Nuclear Stethoscope provides a reliable evaluation of left ventricular function. (orig.) [de

  18. Simultaneous determination of left ventricular perfusion and function

    International Nuclear Information System (INIS)

    Gremillet, E.; Champailler, A.; Esquerre, J.P.; Ouhayoun, E.; Coca, F.; Furber, A.; Le Jeune, J.J.

    1997-01-01

    Myocardial perfusion scintigraphy is a very useful tool for the diagnosis and prognosis of coronary artery disease. The evaluation of left ventricular function during stress testing in also very useful to determine the prognosis of coronary artery disease. This chapter highlights three different imaging methods to assess left ventricular function and myocardial perfusion/ The first one consists of sequential dual isotope myocardial SPECT with ECG-gating. The second concerns magnetic resonance imaging and the third explores first pass exercise ventriculography and myocardial perfusion scintigraphy simultaneously evaluated by means of 99m Tc-sestamibi. (authors)

  19. Paediatric chest wall trauma causing delayed presentation of ventricular arrhythmia.

    Science.gov (United States)

    Tegethoff, Angela M; Raney, Emerald; Mendelson, Jenny; Minckler, Michael R

    2017-07-24

    This report describes a paediatric patient presenting with haemodynamically stable non-sustained ventricular tachycardia 1 day after minor blunt chest trauma. Initial laboratory studies, chest X-ray and echocardiography were normal; however, cardiac MRI revealed precordial haematoma, myocardial contusion and small pericardial effusion. Throughout her hospital course, she remained asymptomatic aside from frequent couplets and triplets of premature ventricular contractions. Ectopy was controlled with oral verapamil. This case highlights how significant cardiac injury may be missed with standard diagnostic algorithms. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Effect of food intake on left ventricular wall stress.

    Science.gov (United States)

    Gårdinger, Ylva; Hlebowicz, Joanna; Björgell, Ola; Dencker, Magnus

    2014-01-28

    Left ventricular wall stress has been investigated in a variety of populations, but the effect of food intake has not been evaluated. We assessed whether left ventricular wall stress is affected by food intake in healthy subjects. Twenty-three healthy subjects aged 25.6 ± 4.5 years were investigated. Meridional end-systolic wall stress (ESS) and circumferential end-systolic wall stress (cESS) were measured before, 30 minutes after, and 110 minutes after a standardised meal. Both ESS and cESS decreased significantly (P stress is affected by food intake in healthy subjects.

  1. Effect of food intake on left ventricular wall stress

    OpenAIRE

    Gårdinger, Ylva; Hlebowicz, Joanna; Björgell, Ola; Dencker, Magnus

    2014-01-01

    Objective: Left ventricular wall stress has been investigated in a variety of populations, but the effect of food intake has not been evaluated. We assessed whether left ventricular wall stress is affected by food intake in healthy subjects. Methods: Twenty-three healthy subjects aged 25.6 +/- 4.5 years were investigated. Meridional end-systolic wall stress (ESS) and circumferential end-systolic wall stress (cESS) were measured before, 30 minutes after, and 110 minutes after a standardised me...

  2. Epicardial deployment of right ventricular disk during perventricular device closure in a child with apical muscular ventricular septal defect

    Directory of Open Access Journals (Sweden)

    Nageswara Rao Koneti

    2013-01-01

    Full Text Available We report a successful perventricular closure of an apical muscular ventricular septal defect (mVSD by a modified technique. An eight-month-old infant, weighing 6.5 kilograms, presented with refractory heart failure. The transthoracic echocardiogram showed multiple apical mVSDs with the largest one measuring 10 mm. perventricular device closure using a 12 mm Amplatzer mVSD occluder was planned. The left ventricular disk was positioned approximating the interventricular septum; however, the right ventricular (RV disk was deployed on the free wall of the RV due to an absent apical muscular septum and a small cavity at the apex. The RV disk of the device was covered using an autologous pericardium. His heart failure improved during follow-up.

  3. IDEA: Stimulating Oral Production.

    Science.gov (United States)

    Easley, Jacob J.

    1995-01-01

    Presents daily activities that facilitate complete sentence response, promote oral production, and aid the learning of vocabulary in foreign-language classes. Because speech is the primary form of communication in the foreign-language classroom, it is important to stimulate students to converse as soon as possible. (Author/CK)

  4. stimulated BV2 Microglial

    African Journals Online (AJOL)

    2012-03-26

    Mar 26, 2012 ... 2), in LPS-stimulated BV2 microglial cells. The level of NO production was analyzed using Griess reaction. The release of PGE2 was determined using sandwich enzyme-linked immunosorbent assay. The DNA-binding activity of nuclear factor-κB (NF-κB) was measured by electrophoretic mobility shift assay ...

  5. Brain stimulation in migraine.

    Science.gov (United States)

    Brighina, Filippo; Cosentino, Giuseppe; Fierro, Brigida

    2013-01-01

    Migraine is a very prevalent disease with great individual disability and socioeconomic burden. Despite intensive research effort in recent years, the etiopathogenesis of the disease remains to be elucidated. Recently, much importance has been given to mechanisms underlying the cortical excitability that has been suggested to be dysfunctional in migraine. In recent years, noninvasive brain stimulation techniques based on magnetic fields (transcranial magnetic stimulation, TMS) and on direct electrical currents (transcranial direct current stimulation, tDCS) have been shown to be safe and effective tools to explore the issue of cortical excitability, activation, and plasticity in migraine. Moreover, TMS, repetitive TMS (rTMS), and tDCS, thanks to their ability to interfere with and/or modulate cortical activity inducing plastic, persistent effects, have been also explored as potential therapeutic approaches, opening an interesting perspective for noninvasive neurostimulation for both symptomatic and preventive treatment of migraine and other types of headache. In this chapter we critically review evidence regarding the role of noninvasive brain stimulation in the pathophysiology and treatment of migraine, delineating the advantages and limits of these techniques together with potential development and future application. © 2013 Elsevier B.V. All rights reserved.

  6. Adjustable, physiological ventricular restraint improves left ventricular mechanics and reduces dilatation in an ovine model of chronic heart failure.

    Science.gov (United States)

    Ghanta, Ravi K; Rangaraj, Aravind; Umakanthan, Ramanan; Lee, Lawrence; Laurence, Rita G; Fox, John A; Bolman, R Morton; Cohn, Lawrence H; Chen, Frederick Y

    2007-03-13

    Ventricular restraint is a nontransplantation surgical treatment for heart failure. The effect of varying restraint level on left ventricular (LV) mechanics and remodeling is not known. We hypothesized that restraint level may affect therapy efficacy. We studied the immediate effect of varying restraint levels in an ovine heart failure model. We then studied the long-term effect of restraint applied over a 2-month period. Restraint level was quantified by use of fluid-filled epicardial balloons placed around the ventricles and measurement of balloon luminal pressure at end diastole. At 4 different restraint levels (0, 3, 5, and 8 mm Hg), transmural myocardial pressure (P(tm)) and indices of myocardial oxygen consumption (MVO2) were determined in control (n=5) and ovine heart failure (n=5). Ventricular restraint therapy decreased P(tm) and MVO2, and improved mechanical efficiency. An optimal physiological restraint level of 3 mm Hg was identified to maximize improvement without an adverse affect on systemic hemodynamics. At this optimal level, end-diastolic P(tm) and MVO2 indices decreased by 27% and 20%, respectively. The serial longitudinal effects of optimized ventricular restraint were then evaluated in ovine heart failure with (n=3) and without (n=3) restraint over 2 months. Optimized ventricular restraint prevented and reversed pathological LV dilatation (130+/-22 mL to 91+/-18 mL) and improved LV ejection fraction (27+/-3% to 43+/-5%). Measured restraint level decreased over time as the LV became smaller, and reverse remodeling slowed. Ventricular restraint level affects the degree of decrease in P(tm), the degree of decrease in MVO2, and the rate of LV reverse remodeling. Periodic physiological adjustments of restraint level may be required for optimal restraint therapy efficacy.

  7. Nonischemic Left Ventricular Scar as a Substrate of Life-Threatening Ventricular Arrhythmias and Sudden Cardiac Death in Competitive Athletes.

    Science.gov (United States)

    Zorzi, Alessandro; Perazzolo Marra, Martina; Rigato, Ilaria; De Lazzari, Manuel; Susana, Angela; Niero, Alice; Pilichou, Kalliopi; Migliore, Federico; Rizzo, Stefania; Giorgi, Benedetta; De Conti, Giorgio; Sarto, Patrizio; Serratosa, Luis; Patrizi, Giampiero; De Maria, Elia; Pelliccia, Antonio; Basso, Cristina; Schiavon, Maurizio; Bauce, Barbara; Iliceto, Sabino; Thiene, Gaetano; Corrado, Domenico

    2016-07-01

    The clinical profile and arrhythmic outcome of competitive athletes with isolated nonischemic left ventricular (LV) scar as evidenced by contrast-enhanced cardiac magnetic resonance remain to be elucidated. We compared 35 athletes (80% men, age: 14-48 years) with ventricular arrhythmias and isolated LV subepicardial/midmyocardial late gadolinium enhancement (LGE) on contrast-enhanced cardiac magnetic resonance (group A) with 38 athletes with ventricular arrhythmias and no LGE (group B) and 40 healthy control athletes (group C). A stria LGE pattern with subepicardial/midmyocardial distribution, mostly involving the lateral LV wall, was found in 27 (77%) of group A versus 0 controls (group C; P<0.001), whereas a spotty pattern of LGE localized at the junction of the right ventricle to the septum was respectively observed in 11 (31%) versus 10 (25%; P=0.52). All athletes with stria pattern showed ventricular arrhythmias with a predominant right bundle branch block morphology, 13 of 27 (48%) showed ECG repolarization abnormalities, and 5 of 27 (19%) showed echocardiographic hypokinesis of the lateral LV wall. The majority of athletes with no or spotty LGE pattern had ventricular arrhythmias with a predominant left bundle branch block morphology and no ECG or echocardiographic abnormalities. During a follow-up of 38±25 months, 6 of 27 (22%) athletes with stria pattern experienced malignant arrhythmic events such as appropriate implantable cardiac defibrillator shock (n=4), sustained ventricular tachycardia (n=1), or sudden death (n=1), compared with none of athletes with no or LGE spotty pattern and controls. Isolated nonischemic LV LGE with a stria pattern may be associated with life-threatening arrhythmias and sudden death in the athlete. Because of its subepicardial/midmyocardial location, LV scar is often not detected by echocardiography. © 2016 The Authors.

  8. Associations of Blood Pressure Dipping Patterns With Left Ventricular Mass and Left Ventricular Hypertrophy in Blacks: The Jackson Heart Study.

    Science.gov (United States)

    Abdalla, Marwah; Caughey, Melissa C; Tanner, Rikki M; Booth, John N; Diaz, Keith M; Anstey, D Edmund; Sims, Mario; Ravenell, Joseph; Muntner, Paul; Viera, Anthony J; Shimbo, Daichi

    2017-04-05

    Abnormal diurnal blood pressure (BP), including nondipping patterns, assessed using ambulatory BP monitoring, have been associated with increased cardiovascular risk among white and Asian adults. We examined the associations of BP dipping patterns (dipping, nondipping, and reverse dipping) with cardiovascular target organ damage (left ventricular mass index and left ventricular hypertrophy), among participants from the Jackson Heart Study, an exclusively black population-based cohort. Analyses included 1015 participants who completed ambulatory BP monitoring and had echocardiography data from the baseline visit. Participants were categorized based on the nighttime to daytime systolic BP ratio into 3 patterns: dipping pattern (≤0.90), nondipping pattern (>0.90 to ≤1.00), and reverse dipping pattern (>1.00). The prevalence of dipping, nondipping, and reverse dipping patterns was 33.6%, 48.2%, and 18.2%, respectively. In a fully adjusted model, which included antihypertensive medication use and clinic and daytime systolic BP, the mean differences in left ventricular mass index between reverse dipping pattern versus dipping pattern was 8.3±2.1 g/m 2 ( P pattern versus dipping pattern was -1.0±1.6 g/m 2 ( P =0.536). Compared with participants with a dipping pattern, the prevalence ratio for having left ventricular hypertrophy was 1.65 (95% CI, 1.05-2.58) and 0.96 (95% CI, 0.63-1.97) for those with a reverse dipping pattern and nondipping pattern, respectively. In this population-based study of blacks, a reverse dipping pattern was associated with increased left ventricular mass index and a higher prevalence of left ventricular hypertrophy. Identification of a reverse dipping pattern on ambulatory BP monitoring may help identify black at increased risk for cardiovascular target organ damage. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  9. Arterial Ventricular Uncoupling with Age and Disease and Recoupling with Exercise

    Science.gov (United States)

    Chantler, Paul D

    2017-01-01

    The deterioration in arterial and cardiac function with aging impairs arterial ventricular coupling, an important determinant of cardiovascular performance. However, exercise training improves arterial ventricular coupling especially during exercise during the age and disease process. This review examines the concept of arterial-ventricular coupling, and how age, and disease uncouples but exercise training recouples the heart and arterial system. PMID:28072585

  10. Ventricular kinetic energy may provide a novel noninvasive way to assess ventricular performance in patients with repaired tetralogy of Fallot.

    Science.gov (United States)

    Jeong, Daniel; Anagnostopoulos, Petros V; Roldan-Alzate, Alejandro; Srinivasan, Shardha; Schiebler, Mark L; Wieben, Oliver; François, Christopher J

    2015-05-01

    Ventricular kinetic energy measurements may provide a novel imaging biomarker of declining ventricular efficiency in patients with repaired tetralogy of Fallot. Our purpose was to assess differences in ventricular kinetic energy with 4-dimensional flow magnetic resonance imaging between patients with repaired tetralogy of Fallot and healthy volunteers. Cardiac magnetic resonance, including 4-dimensional flow magnetic resonance imaging, was performed at rest in 10 subjects with repaired tetralogy of Fallot and 9 healthy volunteers using clinical 1.5T and 3T magnetic resonance imaging scanners. Right and left ventricular kinetic energy (KERV and KELV), main pulmonary artery flow (QMPA), and aortic flow (QAO) were quantified using 4-dimensional flow magnetic resonance imaging data. Right and left ventricular size and function were measured using standard cardiac magnetic resonance techniques. Differences in peak systolic KERV and KELV in addition to the QMPA/KERV and QAO/KELV ratios between groups were assessed. Kinetic energy indices were compared with conventional cardiac magnetic resonance parameters. Peak systolic KERV and KELV were higher in patients with repaired tetralogy of Fallot (6.06 ± 2.27 mJ and 3.55 ± 2.12 mJ, respectively) than in healthy volunteers (5.47 ± 2.52 mJ and 2.48 ± 0.75 mJ, respectively), but were not statistically significant (P = .65 and P = .47, respectively). The QMPA/KERV and QAO/KELV ratios were lower in patients with repaired tetralogy of Fallot (7.53 ± 5.37 mL/[cycle mJ] and 9.65 ± 6.61 mL/[cycle mJ], respectively) than in healthy volunteers (19.33 ± 18.52 mL/[cycle mJ] and 35.98 ± 7.66 mL/[cycle mJ], respectively; P tetralogy of Fallot. Quantification of ventricular kinetic energy in patients with repaired tetralogy of Fallot is a new observation. Future studies are needed to determine whether changes in ventricular kinetic energy can provide earlier evidence of ventricular dysfunction and guide future medical and

  11. Right ventricular volume and mass determined by cine magnetic resonance imaging in HIV patients with possible right ventricular dysfunction

    DEFF Research Database (Denmark)

    Kjaer, Andreas; Lebech, Anne-Mette; Gerstoft, Jan

    2006-01-01

    Impaired right ventricular (RV) function has been reported to occur in patients with HIV when studied by echocardiography. However, for accurate evaluation of RV function and morphology, first-pass radionuclide ventriculography (RNV) and cine magnetic resonance imaging (cine-MRI) are methods...... ventricular ejection fraction (RVEF). To do so, we screened patients with RNV and performed an additional cine-MRI in those with reduced RVEF determined by RNV. Ninety patients with HIV were included. To evaluate the MRI measures exactly we included 18 age- and gender-matched healthy volunteers to establish...

  12. Optimal pacing for right ventricular and biventricular devices: minimizing, maximizing, and right ventricular/left ventricular site considerations.

    Science.gov (United States)

    Gillis, Anne M

    2014-10-01

    The results from numerous clinical studies provide guidance for optimizing outcomes related to RV or biventricular pacing in the pacemaker and ICD populations. (1) Programming algorithms to minimize RV pacing is imperative in patients with dual-chamber pacemakers who have intrinsic AV conduction or intermittent AV conduction block. (2) Dual-chamber ICDs should be avoided in candidates without an indication for bradycardia pacing. (3) Alternate RV septal pacing sites may be considered at the time of pacemaker implantation. (4) Biventricular pacing may be beneficial in some patients with mild LV dysfunction. (5) LV lead placement at the site of latest LV activation is desirable. (6) Programming CRT systems to achieve biventricular/LV pacing >98.5% is important. (7) Protocols for AV and VV optimization in patients with CRT are not recommended after device implantation but may be considered for CRT nonresponders. (8) Novel algorithms to maximize the benefit of CRT are in evolution further.

  13. Optimal Implantable Cardioverter Defibrillator Programming.

    Science.gov (United States)

    Shah, Bindi K

    Optimal programming of implantable cardioverter defibrillators (ICDs) is essential to appropriately treat ventricular tachyarrhythmias and to avoid unnecessary and inappropriate shocks. There have been a series of large clinical trials evaluating tailored programming of ICDs. We reviewed the clinical trials evaluating ICD therapies and detection, and the consensus statement on ICD programming. In doing so, we found that prolonged ICD detection times, higher rate cutoffs, and antitachycardia pacing (ATP) programming decreases inappropriate and painful therapies in a primary prevention population. The use of supraventricular tachyarrhythmia discriminators can also decrease inappropriate shocks. Tailored ICD programming using the knowledge gained from recent ICD trials can decrease inappropriate and unnecessary ICD therapies and decrease mortality.

  14. Internal medicine point-of-care ultrasound assessment of left ventricular function correlates with formal echocardiography.

    Science.gov (United States)

    Johnson, Benjamin K; Tierney, David M; Rosborough, Terry K; Harris, Kevin M; Newell, Marc C

    2016-02-01

    Although focused cardiac ultrasonographic (FoCUS) examination has been evaluated in emergency departments and intensive care units with good correlation to formal echocardiography, accuracy for the assessment of left ventricular systolic function (LVSF) when performed by internal medicine physicians still needs independent evaluation. This prospective observational study in a 640-bed, academic, quaternary care center, included 178 inpatients examined by 10 internal medicine physicians who had completed our internal medicine bedside ultrasound training program. The ability to estimate LVSF with FoCUS as "normal," "mild to moderately decreased," or "severely decreased" was compared with left ventricular ejection fraction (>50%, 31-49%, and internal medicine physician-performed FoCUS and formal echocardiography for any LVSF impairment was "good/substantial" with κ = 0.77 (p Internal medicine physicians using FoCUS identify normal versus decreased LVSF with high sensitivity, specificity, and "good/substantial" interrater agreement when compared with formal echocardiography. These results support the role of cardiac FoCUS by properly trained internal medicine physicians for discriminating normal from reduced LVSF. © 2015 Wiley Periodicals, Inc.

  15. Acute Effects of Hemodialysis on Left and Right Ventricular Function: A Doppler Tissue Imaging Study

    Directory of Open Access Journals (Sweden)

    Tansel Erol

    2012-08-01

    Full Text Available Purpose: Doppler tissue imaging (DTI allows noninvasive assessment of both left ventricular (LV and right ventricular (RV function. The aim of this study was to evaluate the effect of hemodialysis (HD on LV and RV function using DTI. Method: Our study group included 30 patients on chronic HD program (mean age 45 15 years. Myocardial (Sm, Em, Am and annular velocities (Ea, Aa were measured in several cardiac territories before and after HD. Results: After HD, Ea significantly reduced from 10.8 3.4 cm/s to 9.6 2.4 cm/s (p = 0.029. Patients exhibited a lower Em following HD in all measured territories. Em/Am ratio was also reduced for each LV wall investigated after HD in all measured territories. At the RV segments, Sm, Em, and Am decreased significantly in all measured territories. Em of the anterior wall was positively related to ultrafiltration volume (r = 0.25, p = 0.006, whereas the decrease of Sm of RV basal segment correlated with a decrease of diastolic blood pressure (r = 0.23, p < 0.01. Conclusion: Our data indicate that a single HD session is associated with acute changes of systolic and diastolic parameters of LV and RV. [Cukurova Med J 2012; 37(4.000: 215-222

  16. STIMULATION TECHNOLOGIES FOR DEEP WELL COMPLETIONS

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Wolhart

    2003-06-01

    The Department of Energy (DOE) is sponsoring a Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a project to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. Phase 1 was recently completed and consisted of assessing deep gas well drilling activity (1995-2007) and an industry survey on deep gas well stimulation practices by region. Of the 29,000 oil, gas and dry holes drilled in 2002, about 300 were drilled in the deep well; 25% were dry, 50% were high temperature/high pressure completions and 25% were simply deep completions. South Texas has about 30% of these wells, Oklahoma 20%, Gulf of Mexico Shelf 15% and the Gulf Coast about 15%. The Rockies represent only 2% of deep drilling. Of the 60 operators who drill deep and HTHP wells, the top 20 drill almost 80% of the wells. Six operators drill half the U.S. deep wells. Deep drilling peaked at 425 wells in 1998 and fell to 250 in 1999. Drilling is expected to rise through 2004 after which drilling should cycle down as overall drilling declines.

  17. Heart rate turbulence and variability in patients with ventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Diego Tarricone

    2009-08-01

    Full Text Available Background: To evaluate the changes in autonomic neural control mechanisms before malignant ventricular arrhythmias, we measured heart rate variability (HRV and heart rate turbulence (HRT in patients with ventricular tachycardia or fibrillation (Group I; n=6, non sustained ventricular tachycardia (Group II; n=32, frequent premature ventricular beats (Group III; n=26 and with ICD implantation (Group IV; n=11. Methods: Time domain parameters of HRV and turbulence onset (TO and slope (TS were calculated on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0% and TS >2.5 msec/RR-I for HRT. Results: Whereas SDNN was within normal range and similar in all study groups, HRT parameters were significantly different in patients who experienced VT/VF during Holter recording. Abnormal TO and/or TS were present in 100% of Group I patients and only in about 50% of Group II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV patients and none of Group I. Conclusions: These data suggest that HRT analysis is more suitable than HRV to detect those transient alterations in autonomic control mechanisms that are likely to play a major trigger role in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7

  18. Frequency analysis of the ECG before and during ventricular fibrillation

    NARCIS (Netherlands)

    Herbschleb, J.N.; Heethaar, R.M.; Tweel, I. van der; Meijler, F.L.

    1980-01-01

    Frequency analysis of cardiac electrograms of dogs with ventricular fibrillation (VF) during complete cardiopulmonary bypass and coronary perfusion showed a power spectrum with a peak around 12 Hz and its higher harmonics, suggesting more organization than generally assumed. As a next step to see

  19. Left ventricular hypertrophy among chronic kidney disease patients ...

    African Journals Online (AJOL)

    Introduction: The presence of left ventricular hypertrophy (LVH) in patients with Chronic Kidney Disease (CKD) is associated with worsening cardiovascular outcomes. There is a dearth of data on LVH in Ghanaian CKD patients. Methods: This was a cross sectional study carried out at the Komfo Anokye Teaching Hospital ...

  20. Generalised left ventricular dysfunction after traumatic right coronary ...

    African Journals Online (AJOL)

    A patient with traumatic right coronary artery to right atrial fistula, which was repaired by direct closure and aortocoronary saphenous vein bypass grafting, is described. Cardiac catheterisation and selective cine angiocardiography were performed pre- and postoperatively, and left ventricular (LV) function was studied in ...

  1. Impact of obstructive sleep apnea and snoring on left ventricular ...

    African Journals Online (AJOL)

    Background: Systemic hypertension (HTN) and obstructive sleep apnea (OSA) are individually associated with left ventricular structural and functional adaptations. However, little is known about the impact of OSA on the left ventricle in Africans with HTN. Aim: The aim of this study is to determine the association between ...

  2. Impact of Obstructive Sleep Apnea and Snoring on Left Ventricular ...

    African Journals Online (AJOL)

    Impact of Obstructive Sleep Apnea and Snoring on Left Ventricular Mass and Diastolic Function in. Hypertensive Nigerians. Akintunde AA1,2, Kareem L1, Bakare A1, Audu M1. 1Department of Medicine, Division of Cardiology, Ladoke Akintola University of Technology Teaching Hospital, Ogbomoso,. Nigeria, 2Goshen ...

  3. Left ventricular systolic function in sickle cell anaemia: an ...

    African Journals Online (AJOL)

    Keywords: Left ventricular systolic function, sickle cell anaemia, echocardiographic evaluation, adult Nigerian patients. ..... Quadratic .505. -0.390. 12.231. 8.587 .001*. Cubic .510. -0.180. 8.264. 8.619 .001*. This relationship was further evaluated by means of scat- ter plots and subsequently by regression analysis. The.

  4. Aspects of surgery for congenital ventricular septal defect

    NARCIS (Netherlands)

    G. Bol-Raap (Goris)

    2007-01-01

    textabstractIn chapter 1, an outline of the thesis is given. This thesis focuses on aspects of surgical closure of a congenital ventricular septal defect. In Chapter 2, the accuracy and the potential of 3-D echocardiography in the preoperative assessment of a congenital VSD were evaluated. 3-D

  5. Right ventricular function assessment in single LAD lesion patients ...

    African Journals Online (AJOL)

    Rania Gaber

    2015-10-09

    Oct 9, 2015 ... Doppler method in patients with single LAD lesion. Methods: The patient group was ... Results: The right ventricular tissue Doppler parameters (Sm, E, A, E/A ratio, IVA, E/E00) of the patients group were significantly .... cardial interaction effect of tethered LV anterior myocardium. Mittal et al. reported that Left ...

  6. Gender specific pattern of left ventricular cardiac adaptation to ...

    African Journals Online (AJOL)

    Background: Cardiac adaptation to hypertension and obesity may be related to many factors such as race, gender and haemodynamic status. Some gender specific associations with left ventricular structure and function have been described among Caucasians. Objectives: To describe the sex specific pattern of left ...

  7. Left ventricular hypertrophy in renal failure review | Arodiwe ...

    African Journals Online (AJOL)

    Renal failure is becoming increasingly common in our enironment. Advances in management like availability of dialysis and transplantation is prolonging the live of patients. As a consequence complication are increasingly being encountered. Cardiovascular complication is one of the commonest; and left ventricular ...

  8. Changes in Left Ventricular Diastolic Function During Hemodialysis Sessions

    NARCIS (Netherlands)

    Assa, Solmaz; Hummel, Yoran M.; Voors, Adriaan A.; Kuipers, Johanna; Groen, Henk; de Jong, Paul E.; Westerhuis, Ralf; Franssen, Casper F. M.

    Background: Left ventricular diastolic dysfunction is common in hemodialysis patients and is associated with worse outcome. Previous studies have shown that diastolic function worsens from pre- to post-dialysis session, but this has not been studied during hemodialysis. We studied the evolution of

  9. Left ventricular cardiac myxoma and sudden death in a dog

    NARCIS (Netherlands)

    de Nijs, M.I.; Vink, Aryan; Bergmann, W.; Szatmári, V.

    2016-01-01

    Background: Myxoma is a very rare benign cardiac tumor in dogs. This is the first description of a cardiac myxoma originating from the left ventricular outflow tract, presumably causing sudden death. Case presentation: A previously healthy 12-year-old male West Highland white terrier was found dead

  10. Left ventricular cardiac myxoma and sudden death in a dog

    NARCIS (Netherlands)

    de Nijs, Maria Irene; Vink, Aryan; Bergmann, Wilhelmina; Szatmári, Viktor

    2016-01-01

    BACKGROUND: Myxoma is a very rare benign cardiac tumor in dogs. This is the first description of a cardiac myxoma originating from the left ventricular outflow tract, presumably causing sudden death. CASE PRESENTATION: A previously healthy 12-year-old male West Highland white terrier was found dead

  11. Normalised radionuclide measures of left ventricular diastolic function

    International Nuclear Information System (INIS)

    Lee, K.J.; Southee, A.E.; Bautovich, G.J.; Freedman, B.; McLaughlin, A.F.; Rossleigh, M.A.; Hutton, B.F.; Morris, J.G.; Royal Prince Alfred Hospital, Sydney

    1989-01-01

    Abnormal left ventricular diastolic function is being increasingly recognised in patients with clinical heart failure and normal systolic function. A simple routine radionuclide measure of diastolic function would therefore be useful. To establish, the relationship of peak diastolic filling rate (normalized for either end diastolic volume, stroke volume, or peak systolic emptying rate), and heart rate, age, and left ventricular ejection fraction was studied in 64 subjects with normal cardiovascular systems using routine gated heart pool studies. The peak filling rate when normalized to end diastolic volume correlated significantly with heart rate, age and left ventricular ejection fraction, whereas normalization to stroke volume correlated significantly to heart rate and age but not to left ventricular ejection fraction. Peak filling rate normalized for peak systolic emptying rate correlated with age only. Multiple regression equations were determined for each of the normalized peak filling rates in order to establish normal ranges for each parameter. When using peak filling rate normalized for end diastolic volume or stroke volume, appropriate allowance must be made for heart rate, age and ejection fraction. Peak filling rate normalized to peak ejection rate is a heart rate independent parameter which allows the performance of the patient's ventricle in diastole to be compared with its systolic function. It may be used in patients with normal systolic function to serially follow diastolic function, or if age corrected to screen for diastolic dysfunction. (orig.)

  12. Synthetic Marijuana Induced Acute Nonischemic Left Ventricular Dysfunction.

    Science.gov (United States)

    Elsheshtawy, Moustafa; Sriganesh, Priatharsini; Virparia, Vasudev; Patel, Falgun; Khanna, Ashok

    2016-01-01

    Synthetic marijuana is an uptrending designer drug currently widely spread in the US. We report a case of acute deterioration of nonischemic left ventricular dysfunction after exposure to synthetic marijuana. This case illustrates the importance of history taking in cardiac patients and identifies a negative cardiovascular effect of synthetic marijuana known as K2, not yet well detected by urine toxicology screening tools.

  13. Synthetic Marijuana Induced Acute Nonischemic Left Ventricular Dysfunction

    OpenAIRE

    Moustafa Elsheshtawy; Priatharsini Sriganesh; Vasudev Virparia; Falgun Patel; Ashok Khanna

    2016-01-01

    Synthetic marijuana is an uptrending designer drug currently widely spread in the US. We report a case of acute deterioration of nonischemic left ventricular dysfunction after exposure to synthetic marijuana. This case illustrates the importance of history taking in cardiac patients and identifies a negative cardiovascular effect of synthetic marijuana known as K2, not yet well detected by urine toxicology screening tools.

  14. Measurement of right ventricular volumes using 131I-MAA

    International Nuclear Information System (INIS)

    Sekimoto, T.; Grover, R.F.

    1975-01-01

    A method is presented for determining the right ventricular residual ratio, that is, the ratio of the end-systolic volume to the end-diastolic volume during each cardiac cycle. 131 I-MAA was injected as a bolus into the right ventricle, and the ratio of isotope remaining in the chamber during the succeeding cardiac cycles was determined with a collimated scintillation counter placed over the right ventricle. Since the counter detected the radioactivity from the entire right ventricular cavity, potential errors from incomplete mixing were minimized. The washout curve from the ventricle was distorted somewhat by the accumulation of isotope in intervening lung tissue. This distortion was eliminated by subtracting the build-up curve of radioactivity in the lung recorded simultaneously with a second scintillation counter positioned over the lateral chest wall. In 14 dogs anesthetized with chloralose, the right ventricular residual ratio was relatively constant at 40.4 +- 3.1 per cent. Duplicate measurements differed by less than 3 percent indicating the good reproducibility of the method. Right ventricular stroke volume was determined from cardiac output (dye dilution) and heart rate. With this and the simultaneously determined residual ratio ( 131 I-MAA), end-diastolic volume could be calculated. Stroke volume and stroke work were highly correlated with end-diastolic volume, in keeping with the Frank-Starling mechanism. (U.S.)

  15. Quinidine-induced ventricular flutter and fibrillation without digitalis therapy

    NARCIS (Netherlands)

    Koster, R. W.; Wellens, H. J.

    1976-01-01

    Three cases are described with documented ventricular flutter and fibrillation during quinidine medication without concomitant digitalis therapy. In all three patients the arrhythmia developed while they were receiving moderate doses of quinidine. Although no changes in QRS width were observed after

  16. Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology.

    Directory of Open Access Journals (Sweden)

    Shankarjee Krishnamoorthi

    Full Text Available We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

  17. Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology.

    Science.gov (United States)

    Krishnamoorthi, Shankarjee; Perotti, Luigi E; Borgstrom, Nils P; Ajijola, Olujimi A; Frid, Anna; Ponnaluri, Aditya V; Weiss, James N; Qu, Zhilin; Klug, William S; Ennis, Daniel B; Garfinkel, Alan

    2014-01-01

    We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG) and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

  18. Phase image characterization of ventricular contraction in left anterior hemiblock

    International Nuclear Information System (INIS)

    Ono, Akifumi; Mizuno, Haruyoshi; Tahara, Yorio; Ishikawa, Kyozo

    1991-01-01

    We investigated whether or not left anterior hemiblock is present in patients with left axis deviation using first-harmonic Fourier analysis of gated blood-pool images. Gated blood-pool images were taken in 50 patients without contraction abnormality. They included 14 normal subjects, 8 patients with right bundle branch block (RBBB), 20 with left axis deviation (LAD) and 8 with both RBBB and LAD (RBBB+LAD). ECG gated blood-pool scans were acquired in the anterior and 'best septal' left anterior oblique projections. First, the phase images were displayed cinematically as a continuous-loop movie. Next, for quantitative analysis of the phase image, the whole left ventricular and left ventricular high lateral regions of interest were drawn. The 'regional phase shift' (RPS) was then defined as {RPS=A-a} where 'A' is the mean value of the whole left ventricular phase angles and 'a' is that of phase angles in the high lateral region. The left ventricular phase changes and the RPSs in the RBBB and LAD groups were similar to those in the normal group. In the RBBB+LAD group, the latest phase changes occurred in the high anterolateral region. The RPSs of this group were significantly lower than those in the other 3 groups (p<0.01). These data suggest that left anterior hemiblock might coexist with RBBB in patients with RBBB+LAD, whereas left anterior hemiblock might not exist in the majority of patients with LAD alone. (author)

  19. Gender specific pattern of left ventricular cardiac adaptation to ...

    African Journals Online (AJOL)

    EB

    2013-09-03

    Sep 3, 2013 ... Some gender specific associations with left ventricular structure and function have been described ... used for analysis. ... risk due to LVH and that cardiac adaptation to ... had history taking, physical examination and ..... between the gender specific differences in cardiac ... A metaanalysis of individual.

  20. Evolution and development of ventricular septation in the amniote heart

    NARCIS (Netherlands)

    Poelmann, Robert E.; Gittenberger-de Groot, Adriana C.; Vicente-Steijn, Rebecca; Wisse, Lambertus J.; Bartelings, Margot M.; Everts, Sonja; Hoppenbrouwers, Tamara; Kruithof, Boudewijn P. T.; Jensen, Bjarke; de Bruin, Paul W.; Hirasawa, Tatsuya; Kuratani, Shigeru; Vonk, Freek; van de Put, Jeanne M. M. S.; de Bakker, Merijn A.; Richardson, Michael K.

    2014-01-01

    During cardiogenesis the epicardium, covering the surface of the myocardial tube, has been ascribed several functions essential for normal heart development of vertebrates from lampreys to mammals. We investigated a novel function of the epicardium in ventricular development in species with partial

  1. Relationship between obesity and left ventricular hypertrophy in children

    Directory of Open Access Journals (Sweden)

    Johnny Rompis

    2016-10-01

    Full Text Available Background Obesity is a chronic metabolic disorder associated with cardiovascular disease (CVD increasing morbidity-mortality rates. It is apparent that a variety of adaptations/alterations in cardiac structure and function occurs as excessive adipose tissue accumulates. This leads to a decrease in diastolic compliance, eventually resulting in an increase in left ventricular filling pressure and left ventricular enlargement. Objective To evaluate left ventricular hypertrophy (LVH among  obese using electrocardiographic (ECG criteria. Methods A cross-sectional study was conducted on 74 children aged 10-15 years from February 2009 to October 2009. The subjects were divided into obese and control groups. Physical examination and standard 12 lead electrocardiography (ECG were done in both groups. Results Of 37 obese children, LVH were featured in 3 subjects, while in control group, only 1 child had LVH (P= 0.304. We found that mean RV6 in obese and control group were 9.8446 (SD 3.5854 and 11.9662 (SD 3.2857, respectively (P=0.005. As an additional findings, we found that birth weight was related to obesity in children. Conclusion There is no relation between obesity and left ventricular using ECG criteria in obese children aged 10-15 years.

  2. Normalleft ventricular function does not protect against propafenone ...

    African Journals Online (AJOL)

    propafenone-induced incessant ventricular tachycardia. R. N. SCOTT MILLAR, J. B. LAWRENSON, D. A. MILNE. Abstract Propafenone is a class Ic anti-arrhythmic agent with mild B-blocking properties which has re- ..... Coplen SE, Antman EM, Berlin JA, Hewitt P, Chalmers TC. Efficacy and safery of quinidine therapy for ...

  3. Arrhythmogenic right ventricular cardiomyopathy in a patient with schizophrenia

    OpenAIRE

    Kawasaki, Kenta; Miyaji, Kotaro; Kodera, Satoshi; Suzuki, Yoshio; Kanda, Junji; Ikeda, Masayuki

    2015-01-01

    Key Clinical Message People with schizophrenia are at greater risk of cardiovascular morbidity and mortality than the general population. Arrhythmogenic right ventricular cardiomyopathy is a recognized cause of sudden cardiac death in young people. This report discusses the necessity for close cardiac evaluation to reduce incidence of sudden death in people with schizophrenia.

  4. Pneumatic distension of ventricular mural architecture validated histologically

    Energy Technology Data Exchange (ETDEWEB)

    Burg, M.C.; Heindel, W. [University Hospital Muenster (Germany). Dept. of Clinical Radiology; Lunkenheimer, P. [University Hospital Muenster (Germany). Dept. of Experimental Thoraco-vascular Surgery; Niederer, P. [ETH and University of Zuerich (Switzerland). Inst. for Biomedical Engineering; Brune, C. [Twente Univ. (Netherlands). Dept. of Applied Mathematics; Redmann, K. [University Hospital Muenster (Germany). Center for Reproductive Medicine and Andrology; Smerup, M. [Aarhus University Hospital (Denmark). Dept. of Cardiothoracic and Vascular Surgery; Spiegel, U.; Becker, F. [University Hospital Muenster (Germany). Dept. Surgical Research; Maintz, D. [University Hospital Muenster (Germany). Dept. of Clinical Radiology; Cologne Univ. (Germany). Dept. of Radiology; Anderson, R.H. [Newcastle Univ., London (United Kingdom). Inst. of Genetic Medicine

    2016-11-15

    There are ongoing arguments as to how cardiomyocytes are aggregated together within the ventricular walls. We used pneumatic distension through the coronary arteries to exaggerate the gaps between the aggregated cardiomyocytes, analyzing the pattern revealed using computed tomography, and validating our findings by histology. We distended 10 porcine hearts, arresting 4 in diastole by infusion of cardioplegic solutions, and 4 in systole by injection of barium chloride. Mural architecture was revealed by computed tomography, measuring also the angulations of the long chains of cardiomyocytes. We prepared the remaining 2 hearts for histology by perfusion with formaldehyde. Increasing pressures of pneumatic distension elongated the ventricular walls, but produced insignificant changes in mural thickness. The distension exaggerated the spaces between the aggregated cardiomyocytes, compartmenting the walls into epicardial, central, and endocardial regions, with a feathered arrangement of transitions between them. Marked variation was noted in the thicknesses of the parts in the different ventricular segments, with no visible anatomical boundaries between them. Measurements of angulations revealed intruding and extruding populations of cardiomyocytes that deviated from a surface-parallel alignment. Scrolling through the stacks of tomographic images revealed marked spiraling of the aggregated cardiomyocytes when traced from base to apex. Our findings call into question the current assumption that cardiomyocytes are uniformly aggregated together in a tangential fashion. There is marked heterogeneity in the architecture of the different ventricular segments, with the aggregated units never extending in a fully transmural fashion.

  5. Acquired ventricular septal defect: A rare sequel of blunt chest ...

    African Journals Online (AJOL)

    Ventricular septal defect (VSD) is the most common congenital cardiac lesion encountered worldwide. Only very rarely is it acquired, and causation through blunt injury in a child is extremely rare. A previously healthy 7‑year‑old boy suffered blunt chest trauma while at play. He presented 11 days later with features of acute ...

  6. Pneumatic distension of ventricular mural architecture validated histologically

    International Nuclear Information System (INIS)

    Burg, M.C.; Heindel, W.; Lunkenheimer, P.; Niederer, P.; Brune, C.; Redmann, K.; Smerup, M.; Spiegel, U.; Becker, F.; Maintz, D.; Cologne Univ.; Anderson, R.H.

    2016-01-01

    There are ongoing arguments as to how cardiomyocytes are aggregated together within the ventricular walls. We used pneumatic distension through the coronary arteries to exaggerate the gaps between the aggregated cardiomyocytes, analyzing the pattern revealed using computed tomography, and validating our findings by histology. We distended 10 porcine hearts, arresting 4 in diastole by infusion of cardioplegic solutions, and 4 in systole by injection of barium chloride. Mural architecture was revealed by computed tomography, measuring also the angulations of the long chains of cardiomyocytes. We prepared the remaining 2 hearts for histology by perfusion with formaldehyde. Increasing pressures of pneumatic distension elongated the ventricular walls, but produced insignificant changes in mural thickness. The distension exaggerated the spaces between the aggregated cardiomyocytes, compartmenting the walls into epicardial, central, and endocardial regions, with a feathered arrangement of transitions between them. Marked variation was noted in the thicknesses of the parts in the different ventricular segments, with no visible anatomical boundaries between them. Measurements of angulations revealed intruding and extruding populations of cardiomyocytes that deviated from a surface-parallel alignment. Scrolling through the stacks of tomographic images revealed marked spiraling of the aggregated cardiomyocytes when traced from base to apex. Our findings call into question the current assumption that cardiomyocytes are uniformly aggregated together in a tangential fashion. There is marked heterogeneity in the architecture of the different ventricular segments, with the aggregated units never extending in a fully transmural fashion.

  7. Quantitative assessment of regional left ventricular motion using endocardial landmarks

    NARCIS (Netherlands)

    C.J. Slager (Cornelis); T.E.H. Hooghoudt (Ton); P.W.J.C. Serruys (Patrick); J.C.H. Schuurbiers (Johan); J.H.C. Reiber (Johan); G.T. Meester (Geert); P.D. Verdouw (Pieter); P.G. Hugenholtz (Paul)

    1986-01-01

    textabstractIn this study the hypothesis is tested that the motion pattern of small anatomic landmarks, recognizable at the left ventricular endocardial border in the contrast angiocardiogram, reflects the motion of the endocardial wall. To verify this, minute metal markers were inserted in the

  8. Congenital bicuspid stenosis with left ventricular hypoplasia in a kitten.

    Science.gov (United States)

    van Nie, C J; van Messel, M A; Straatman, T J

    1980-01-15

    Congenital bicuspid stenosis with left ventricular hypoplasia was diagnosed in a kitten. Clinical weakness, dyspnoea and marked cardiomegaly (X rays) were related to postmortem findings. The cardiomegaly had resulted from an enlargement of the left auricular appendage. It is supposed the cardiomegaly developed after the closing of the foramen ovale.

  9. Dangers of collapsible ventricular drainage systems. Technical note.

    Science.gov (United States)

    Kaye, A H; Wallace, D

    1982-02-01

    Ventricular drainage systems employing a collapsible plastic bag for fluid collection were postulated to cause an increasing back-pressure produced in part by the elasticity of the bag. This postulate was shown to be correct in an experimental situation. There was a logarithmic rise in cerebrospinal fluid pressure as the bag filled. By increasing the size of the bag, the problem was overcome.

  10. A compartmentalized mathematical model of the β1-adrenergic signaling system in mouse ventricular myocytes.

    Directory of Open Access Journals (Sweden)

    Vladimir E Bondarenko

    Full Text Available The β1-adrenergic signaling system plays an important role in the functioning of cardiac cells. Experimental data shows that the activation of this system produces inotropy, lusitropy, and chronotropy in the heart, such as increased magnitude and relaxation rates of [Ca(2+]i transients and contraction force, and increased heart rhythm. However, excessive stimulation of β1-adrenergic receptors leads to heart dysfunction and heart failure. In this paper, a comprehensive, experimentally based mathematical model of the β1-adrenergic signaling system for mouse ventricular myocytes is developed, which includes major subcellular functional compartments (caveolae, extracaveolae, and cytosol. The model describes biochemical reactions that occur during stimulation of β1-adrenoceptors, changes in ionic currents, and modifications of Ca(2+ handling system. Simulations describe the dynamics of major signaling molecules, such as cyclic AMP and protein kinase A, in different subcellular compartments; the effects of inhibition of phosphodiesterases on cAMP production; kinetics and magnitudes of phosphorylation of ion channels, transporters, and Ca(2+ handling proteins; modifications of action potential shape and duration; magnitudes and relaxation rates of [Ca(2+]i transients; changes in intracellular and transmembrane Ca(2+ fluxes; and [Na(+]i fluxes and dynamics. The model elucidates complex interactions of ionic currents upon activation of β1-adrenoceptors at different stimulation frequencies, which ultimately lead to a relatively modest increase in action potential duration and significant increase in [Ca(2+]i transients. In particular, the model includes two subpopulations of the L-type Ca(2+ channels, in caveolae and extracaveolae compartments, and their effects on the action potential and [Ca(2+]i transients are investigated. The presented model can be used by researchers for the interpretation of experimental data and for the developments of

  11. Ventricular fibrillation cardiac arrest produces a chronic striatal hyperdopaminergic state that is worsened by methylphenidate treatment.

    Science.gov (United States)

    Nora, Gerald J; Harun, Rashed; Fine, David F; Hutchison, Daniel; Grobart, Adam C; Stezoski, Jason P; Munoz, Miranda J; Kochanek, Patrick M; Leak, Rehana K; Drabek, Tomas; Wagner, Amy K

    2017-07-01

    Cardiac arrest survival rates have improved with modern resuscitation techniques, but many survivors experience impairments associated with hypoxic-ischemic brain injury (HIBI). Currently, little is understood about chronic changes in striatal dopamine (DA) systems after HIBI. Given the common empiric clinical use of DA enhancing agents in neurorehabilitation, investigation evaluating dopaminergic alterations after cardiac arrest (CA) is necessary to optimize rehabilitation approaches. We hypothesized that striatal DA neurotransmission would be altered chronically after ventricular fibrillation cardiac arrest (VF-CA). Fast-scan cyclic voltammetry was used with median forebrain bundle (MFB) maximal electrical stimulations (60Hz, 10s) in rats to characterize presynaptic components of DA neurotransmission in the dorsal striatum (D-Str) and nucleus accumbens 14 days after a 5-min VF-CA when compared to Sham or Naïve. VF-CA increased D-Str-evoked overflow [DA], total [DA] released, and initial DA release rate versus controls, despite also increasing maximal velocity of DA reuptake (V max ). Methylphenidate (10 mg/kg), a DA transporter inhibitor, was administered to VF-CA and Shams after establishing a baseline, pre-drug 60 Hz, 5 s stimulation response. Methylphenidate increased initial evoked overflow [DA] more-so in VF-CA versus Sham and reduced D-Str V max in VF-CA but not Shams; these findings are consistent with upregulated striatal DA transporter in VF-CA versus Sham. Our work demonstrates that 5-min VF-CA increases electrically stimulated DA release with concomitant upregulation of DA reuptake 2 weeks after brief VF-CA insult. Future work should elucidate how CA insult duration, time after insult, and insult type influence striatal DA neurotransmission and related cognitive and motor functions. © 2017 International Society for Neurochemistry.

  12. Bioelectronic block of paravertebral sympathetic nerves mitigates post-myocardial infarction ventricular arrhythmias.

    Science.gov (United States)

    Chui, Ray W; Buckley, Una; Rajendran, Pradeep S; Vrabec, Tina; Shivkumar, Kalyanam; Ardell, Jeffrey L

    2017-11-01

    Autonomic dysfunction contributes to induction of ventricular tachyarrhythmia (VT). To determine the efficacy of charge-balanced direct current (CBDC), applied to the T1-T2 segment of the paravertebral sympathetic chain, on VT inducibility post-myocardial infarction (MI). In a porcine model, CBDC was applied in acute animals (n = 7) to optimize stimulation parameters for sympathetic blockade and in chronic MI animals (n = 7) to evaluate the potential for VTs. Chronic MI was induced by microsphere embolization of the left anterior descending coronary artery. At termination, in anesthetized animals and following thoracotomy, an epicardial sock array was placed over both ventricles and a quadripolar carousel electrode positioned underlying the right T1-T2 paravertebral chain. In acute animals, the efficacy of CBDC carousel (CBDCC) block was assessed by evaluating cardiac function during T2 paravertebral ganglion stimulation with and without CBDCC. In chronic MI animals, VT inducibility was assessed by extrasystolic (S1-S2) stimulations at baseline and under >66% CBDCC blockade of T2-evoked sympathoexcitation. CBDCC demonstrated a current-dependent and reversible block without impacting basal cardiac function. VT was induced at baseline in all chronic MI animals. One animal died after baseline induction. Of the 6 remaining animals, only 1 was reinducible with simultaneous CBDCC application (P block of the T1-T2 paravertebral chain with CBDCC reduced VT in a chronic MI model. CBDCC prolonged VERP, without altering baseline cardiac function, resulting in improved electrical stability. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  13. Lead reduces tension development and the myosin ATPase activity of the rat right ventricular myocardium

    Directory of Open Access Journals (Sweden)

    D.V. Vassallo

    2008-09-01

    Full Text Available Lead (Pb2+ poisoning causes hypertension, but little is known regarding its acute effects on cardiac contractility. To evaluate these effects, force was measured in right ventricular strips that were contracting isometrically in 45 male Wistar rats (250-300 g before and after the addition of increasing concentrations of lead acetate (3, 7, 10, 30, 70, 100, and 300 µM to the bath. Changes in rate of stimulation (0.1-1.5 Hz, relative potentiation after pauses of 15, 30, and 60 s, effect of Ca2+ concentration (0.62, 1.25, and 2.5 mM, and the effect of isoproterenol (20 ng/mL were determined before and after the addition of 100 µM Pb2+. Effects on contractile proteins were evaluated after caffeine treatment using tetanic stimulation (10 Hz and measuring the activity of the myosin ATPase. Pb2+ produced concentration-dependent force reduction, significant at concentrations greater than 30 µM. The force developed in response to increasing rates of stimulation became smaller at 0.5 and 0.8 Hz. Relative potentiation increased after 100 µM Pb2+ treatment. Extracellular Ca2+ increment and isoproterenol administration increased force development but after 100 µM Pb2+ treatment the force was significantly reduced suggesting an effect of the metal on the sarcolemmal Ca2+ influx. Concentration of 100 µM Pb2+ also reduced the peak and plateau force of tetanic contractions and reduced the activity of the myosin ATPase. Results showed that acute Pb2+ administration, although not affecting the sarcoplasmic reticulum activity, produces a concentration-dependent negative inotropic effect and reduces myosin ATPase activity. Results suggest that acute lead administration reduced myocardial contractility by reducing sarcolemmal calcium influx and the myosin ATPase activity. These results also suggest that lead exposure is hazardous and has toxicological consequences affecting cardiac muscle.

  14. The antiarrhythmic effect of vagal stimulation after acute coronary occlusion: Role of the heart rate.

    Science.gov (United States)

    Manati, Waheed; Pineau, Julien; Doñate Puertas, Rosa; Morel, Elodie; Quadiri, Timour; Bui-Xuan, Bernard; Chevalier, Philippe

    2018-01-03

    Strong evidence suggests a causal link between autonomic disturbances and ventricular arrhythmias. However, the mechanisms underlying the antiarrhythmic effect of vagal stimulation are poorly understood. The vagal antiarrhythmic effect might be modulated by a decrease in heart rate. the proximal anterior interventricular artery was occluded in 16 pigs by clamping under general anaesthesia. Group 1: heart rates remained spontaneous (n = 6; 12 occlusions); Group 2: heart rates were fixed at 190 beats per minute (bpm) with atrial electrical stimulation (n = 10; 20 occlusions). Each pig received two occlusions, 30 min apart, one without and one with vagal stimulation (10 Hz, 2 ms, 5-20 mA). The antiarrhythmic effect of vagal activation was defined as the time to the appearance of ventricular fibrillation (VF) after occlusion. In Group 1, vagal stimulation triggered a significant decrease in basal heart rate (132 ± 4 vs. 110 ± 17 bpm, p coronary occlusion (1102 ± 85 vs. 925 ± 41 s, p acute coronary occlusion.

  15. The Effectiveness of Three Reading Approaches and an Oral Language Stimulation Program with Disadvantaged Children in the Primary Grades: A Final Report After Two Years of the Cooperative Reading Project.

    Science.gov (United States)

    Dunn, Lloyd M.; And Others

    The Cooperative Reading Project's purpose was to examine the relative effectiveness of three approaches to the teaching of beginning reading and the effectiveness of oral stimulation. This monograph reports the results of the last year of the project. The experimental reading treatments were: (1) the Initial Teaching Alphabet (ITA), (2) the Words…

  16. A modified Glenn shunt reduces right ventricular stroke work during left ventricular assist device therapy.

    Science.gov (United States)

    Schiller, Petter; Vikholm, Per; Hellgren, Laila

    2016-03-01

    Right ventricular (RV) failure is a major cause of morbidity and mortality after left ventricular assist device (LVAD) placement and remains hard to predict. We hypothesized that partial surgical exclusion of the RV with a modified Glenn shunt during LVAD treatment would reduce RV stroke work. An LVAD was implanted in eight pigs and a modified Glenn shunt was constructed. A conductance pressure-volume catheter was placed in the right ventricle through the apex. Haemodynamic data and pressure-volume loops were obtained at the following time periods: (i) baseline, (ii) open shunt, (iii) LVAD with closed shunt and (iii) LVAD and open shunt. During LVAD therapy, the right atrial (RA) pressure increased from 9 mmHg (9-9) to 15 mmHg (12-15), P = 0.01. RV stroke volume increased from 30 ml (29-40) to 51 ml (42-53), P work increased to 708 mmHg ml (654-1193) from 535 mmHg ml (424-717), P = 0.04, compared with baseline. During LVAD therapy in combination with a Glenn shunt, the RA pressure decreased from 15 mmHg (12-15) to 10 mmHg (7-11) when compared with LVAD therapy only, P = 0.01. A decrease in RV stroke work from 708 mmHg ml (654-1193) to 465 mmHg ml (366-711), P = 0.04, was seen when the LVAD was combined with a shunt, not significantly different from the baseline value (535 mmHg ml). The developed pressure in the right ventricle decreased from 29 mmHg (26-32) to 21 mmHg (20-24), P work during the use of the shunt with LVAD treatment. A modified Glenn shunt reduced RV volumes, RV stroke work and RA pressure during LVAD therapy in an experimental model of heart failure in pigs. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  17. [Transcranial magnetic stimulation and motor cortex stimulation in neuropathic pain].

    Science.gov (United States)

    Mylius, V; Ayache, S S; Teepker, M; Kappus, C; Kolodziej, M; Rosenow, F; Nimsky, C; Oertel, W H; Lefaucheur, J P

    2012-12-01

    Non-invasive and invasive cortical stimulation allows the modulation of therapy-refractory neuropathic pain. High-frequency repetitive transcranial magnetic stimulation (rTMS) of the contralateral motor cortex yields therapeutic effects at short-term and predicts the benefits of epidural motor cortex stimulation (MCS). The present article summarizes the findings on application, mechanisms and therapeutic effects of cortical stimulation in neuropathic pain.

  18. Evaluation of left ventricular volume by MRI using modified Simpson's rule method

    International Nuclear Information System (INIS)

    Okamura, Masahiro; Kondo, Takeshi; Anno, Naoko

    1990-01-01

    The conventional contrast left ventriculogrpahy (LVG) has been the gold standard for estimating left ventricular volume (LVV), but it is an invasive technique, and volume overload must be caused by contrast medium. the true left ventricular (LV) long axis may not be obtained by LVG in routine right anterior oblique (RAO) projection. MRI, on the other hand, is noninvasive, does not require contrast medium, and permits to obtain the true LV long axis sections. Thus, MRI seems the ideal technique for estimating LVV. To estimate LVV, we have developed the on-line programs for calculating LVV by single-plane (SMS) or biplane modified Simpson's rule method (BMS), and have applied these programs to the water in the bottle with the elliptic short axis plane, normal volunteer and patients with various heart diseases. In the water phantom, the water volume calculated by the BMS was more accurate than the SMS. In nine normal volunteers, multiple LV short axis sections in each end-systole and end-diastole were obtained by ECG-gated spin echo MRI, LVV as standard was calculated by true Simpson's rule method (TS) on these images. Then both vertical and horizontal LV long axis sections were also obtained by ECG-gated field echo (FE) rephasing cine MRI, LVV was calculated by the BMS or SMS on these images. The BMS or SMS significantly correlated (r=0.974, r=0.927, 0.947) with TS for estimating LVV, respectively. In 20 patients with various heart diseases, both vertical and horizontal LV long axis sections were obtained by FE cine MRI. LVV (r=0.907 and r=0.901) and EF (r=0.822 and r=0.938) calculated by the SMS on the vertical or horizontal LV long axis sections significantly correlated with the conventional RAO-LVG, respectively. In conclusion, the MRI using our on-line programs would be clinically useful for estimating LVV and EF. (author)

  19. Assessment of left ventricular function and volumes by myocardial perfusion scintigraphy - comparison of two algorithms

    International Nuclear Information System (INIS)

    Zajic, T.; Fischer, R.; Brink, I.; Moser, E.; Krause, T.; Saurbier, B.

    2001-01-01

    Aim: Left ventricular volume and function can be computed from gated SPECT myocardial perfusion imaging using emory cardiac toolbox (ECT) or gated SPECT quantification (GS-Quant). The aim of this study was to compare both programs with respect to their practical application, stability and precision on heart-models as well as in clinical use. Methods: The volumes of five cardiac models were calculated by ECT and GS-Quant. 48 patients (13 female, 35 male) underwent a one day stress-rest protocol and gated SPECT. From these 96 gated SPECT images, left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) were estimated by ECT and GS-Quant. For 42 patients LVEF was also determined by echocardiography. Results: For the cardiac models the computed volumes showed high correlation with the model-volumes as well as high correlation between ECT and GS-Quant (r ≥0.99). Both programs underestimated the volume by approximately 20-30% independent of the ventricle-size. Calculating LVEF, EDV and ESV, GS-Quant and ECT correlated well to each other and to the LVEF estimated by echocardiography (r ≥0.86). LVEF values determined with ECT were about 10% higher than values determined with GS-Quant or echocardiography. The incorrect surfaces calculated by the automatic algorithm of GS-Quant for three examinations could not be corrected manually. 34 of the ECT studies were optimized by the operator. Conclusion: GS-Quant and ECT are two reliable programs in estimating LVEF. Both seem to underestimate the cardiac volume. In practical application GS-Quant was faster and easier to use. ECT allows the user to define the contour of the ventricle and thus is less susceptible to artifacts. (orig.) [de

  20. Angiographic differentiation of type of ventricular septal defects

    International Nuclear Information System (INIS)

    Cheon, Mal Soon; Park, Hee Young; Kim, Yang Sook

    1989-01-01

    Defects of the ventricular septum are the commonest type of congenital cardiac malformations. A classification with axial angiography of the subtypes of ventricular septal defects is proposed on the study of 126 patients with defects of the ventricular septum. The results were as follows: 1. The incidence of the ventricular septal defects was 39.6% of congenital heart malformation. 2. The sex distribution of cases were 70 males and 56 females, the age ranged from 13 months to 26 years. 3. Angiographic features seen by axial angiography were as follows: a. Perimembranous defects as seen on long axial view of left ventriculogram were in continuity wity aortic valve. The relation of the defect to the tricuspid valve allows distinction of the extension of the preimembranous defect toward inlet, trabecular, or infundibular zones. This relation was determined angiographically, using the course of the contrast medium from the left ventricle through the ventricular septal defect, opacifying the right ventricle. In inlet excavation, the shunted blood opacified the recess between septal leaflet of tricuspid valve and interventricular septum in early phase, in infundibular excavation, opacified the recess between anterior leaflet of tricuspid valve and anterior free wall of right ventricle and in trabecular excavation, the shunted blood traversed anterior portion of tricuspid valve ring, opacified trabecular portion of right ventricle. b. Muscular defects were separated from the semilunar and atrioventricular valves. c, Subarterial defects were related to both semilunar valves, and they were best demonstrated on the elongated right anterior oblique view of the left ventriculogram. d. Total infundibular defects were profiled in right anterior oblique 30 and long axial view, subaortic in location in both views

  1. Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension

    International Nuclear Information System (INIS)

    Sultana, R.; Sultana, N.; Rashid, A.; Rasheed, S.Z.; Ahmed, M.; Ishaq, M.; Samad, A.

    2010-01-01

    Background: Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. Objective was to investigate the prevalence of cardiac arrhythmias and LVH in systemic hypertension. Methods: In all subjects blood pressure was measured, electrocardiography and echocardiography was done. Holter monitoring and exercise test perform in certain cases. There were 500 hypertensive patients, 156 (31.2%) men and 344 (69%) women >30 years of age in the study. Among them 177 (35.4%) were diabetic, 224 (45%) were dyslipidemia, 188 (37.6%) were smokers, and 14 (3%) had homocysteinemia. Mean systolic BP (SBP) was 180 +- 20 mm Hg and diastolic BP (DBP) was 95 +- 12 in male and female patients. Left ventricular mass index (LVMI) was 119.2 +- 30 2 2gm/m in male while 103 +- 22 gm/m in female patients. Palpitation was seen in 126 (25%) male and 299 (59.8%) female patients. Atrial fibrillation was noted in 108 (21.6%) male and 125 (25%) female patients, 30 (6%) male and 82 (16.4%) female patients had atrial flutter. Ventricular tachycardia was noted in 37 (7.4%) male and 59 (11.8%) female patients. Holter monitoring showed significant premature ventricular contractions (PVC'S) in 109 (21.8%) male and 128 (25.69%) female patients while Holter showed atrial arrhythmias (APC'S) in 89 (17.8%) males and 119 (23.8%) females. Angiography findings diagnosed coronary artery disease in 119 (23.8%) with CAD male and 225 (45%) without CAD while 47 (9.4%) females presented with CAD and 109 (21.8%) without CAD. Conclusion: A significant association has been demonstrated between hypertension and arrhythmias. Diastolic dysfunction of the left ventricle, left atrial size and function, as well as LVH have been suggested as the underlying risk factors for supraventricular, ventricular arrhythmias and sudden death in hypertensives with LVH. (author)

  2. Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Sultana, R; Sultana, N; Rashid, A; Rasheed, S Z; Ahmed, M; Ishaq, M; Samad, A [Karachi Institute of Heart Diseases, Karachi (Pakistan)

    2010-10-15

    Background: Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. Objective was to investigate the prevalence of cardiac arrhythmias and LVH in systemic hypertension. Methods: In all subjects blood pressure was measured, electrocardiography and echocardiography was done. Holter monitoring and exercise test perform in certain cases. There were 500 hypertensive patients, 156 (31.2%) men and 344 (69%) women >30 years of age in the study. Among them 177 (35.4%) were diabetic, 224 (45%) were dyslipidemia, 188 (37.6%) were smokers, and 14 (3%) had homocysteinemia. Mean systolic BP (SBP) was 180 +- 20 mm Hg and diastolic BP (DBP) was 95 +- 12 in male and female patients. Left ventricular mass index (LVMI) was 119.2 +- 30 2 2gm/m in male while 103 +- 22 gm/m in female patients. Palpitation was seen in 126 (25%) male and 299 (59.8%) female patients. Atrial fibrillation was noted in 108 (21.6%) male and 125 (25%) female patients, 30 (6%) male and 82 (16.4%) female patients had atrial flutter. Ventricular tachycardia was noted in 37 (7.4%) male and 59 (11.8%) female patients. Holter monitoring showed significant premature ventricular contractions (PVC'S) in 109 (21.8%) male and 128 (25.69%) female patients while Holter showed atrial arrhythmias (APC'S) in 89 (17.8%) males and 119 (23.8%) females. Angiography findings diagnosed coronary artery disease in 119 (23.8%) with CAD male and 225 (45%) without CAD while 47 (9.4%) females presented with CAD and 109 (21.8%) without CAD. Conclusion: A significant association has been demonstrated between hypertension and arrhythmias. Diastolic dysfunction of the left ventricle, left atrial size and function, as well as LVH have been suggested as the underlying risk factors for supraventricular, ventricular arrhythmias and sudden death in hypertensives with LVH. (author)

  3. Grating stimulated echo

    International Nuclear Information System (INIS)

    Dubetsky, B.; Berman, P.R.; Sleator, T.

    1992-01-01

    A theory of a grating simulated echo (GTE) is developed. The GSE involves the sequential excitation of atoms by two counterpropagating traveling waves, a standing wave, and a third traveling wave. It is shown that the echo signal is very sensitive to small changes in atomic velocity, much more sensitive than the normal stimulated echo. Use of the GSE as a collisional probe or accelerometer is discussed

  4. Thyroid Stimulating Hormone Receptor

    Directory of Open Access Journals (Sweden)

    Murat Tuncel

    2017-02-01

    Full Text Available Thyroid stimulating hormone receptor (TSHR plays a pivotal role in thyroid hormone metabolism. It is a major controller of thyroid cell function and growth. Mutations in TSHR may lead to several thyroid diseases, most commonly hyperthyroidism. Although its genetic and epigenetic alterations do not directly lead to carcinogenesis, it has a crucial role in tumor growth, which is initiated by several oncogenes. This article will provide a brief review of TSHR and related diseases.

  5. Left ventricular pressure and volume data acquisition and analysis using LabVIEW.

    Science.gov (United States)

    Cassidy, S C; Teitel, D F

    1997-03-01

    To automate analysis of left ventricular pressure-volume data, we used LabVIEW to create applications that digitize and display data recorded from conductance and manometric catheters. Applications separate data into cardiac cycles, calculate parallel conductance, and calculate indices of left ventricular function, including end-systolic elastance, preload-recruitable stroke work, stroke volume, ejection fraction, stroke work, maximum and minimum derivative of ventricular pressure, heart rate, indices of relaxation, peak filling rate, and ventricular chamber stiffness. Pressure-volume loops can be graphically displayed. These analyses are exported to a text-file. These applications have simplified and automated the process of evaluating ventricular function.

  6. [Ventricular tachycardia in a patient with rate-responsive cardiac pacemaker].

    Science.gov (United States)

    Himbert, C; Lascault, G; Tonet, J; Coutte, R; Busquet, P; Frank, R; Grosgogeat, Y

    1992-11-01

    The authors report a case of syncopal ventricular tachycardia in a patient with a respiratory-dependent rate responsive pacemaker, followed-up for valvular heart disease with severe left ventricular dysfunction and sustained atrial and ventricular arrhythmias. The introduction of low dose betablocker therapy with reinforcement of the treatment of cardiac failure controlled the ventricular arrhythmia, after suppression of the data responsive function had been shown to be ineffective. The authors discuss the role of the rate responsive function in the triggering of the ventricular tachycardias.

  7. LEFT VENTRICULAR ROTATION, TWIST AND UNTWIST: PHYSIOLOGICAL ROLE AND CLINICAL RELEVANCE

    Directory of Open Access Journals (Sweden)

    E. N. Pavlyukova

    2015-09-01

    Full Text Available The helical ventricular myocardial band of Torrent-Guasp is a new concept, which provides strong grounds for reconciliation of some important aspects in cardiovascular medicine. Oblique fiber orientation provides left ventricular rotation, which in addition to radial thickening and longitudinal shortening, is predicted as an essential component of the effective left ventricular pumping. Left ventricular rotation can be measured in clinical practice noninvasively using echocardiography and this provides new opportunities for the assessment of different aspects of left ventricular mechanical function.

  8. Independence of intrapericardial right and left ventricular performance in septic pulmonary hypertension

    International Nuclear Information System (INIS)

    Boeck, J.C.; Eichstaedt, H.; Barker, B.C.; Lewis, F.R.; Lim, A.D.; Pollycove, M.

    1990-01-01

    To study the effect of septic pulmonary hypertension on right/left ventricular intrapericardial interactions thirteen trauma patients, seven septic and six nonseptic controls, were compared. Ventricular volumes were derived from firstpass or gated equilibrium radionuclide angiocardiography, and related to body surface area. Systemic and pulmonary pressures were measured invasively. Pulmonary arterial pressure was significantly increased in the sepsis group. Although right ventricular end-diastolic volumes were higher in sepsis, left ventricular end-diastolic volumes were not decreased. In terms of intrapericardial right/left ventricular interactions these results indicate that the right and left ventricles operate independently in septic pulmonary hypertension. (orig.) [de

  9. The management of ventricular dysrhythmia in aconite poisoning.

    Science.gov (United States)

    Coulson, James M; Caparrotta, Thomas M; Thompson, John P

    2017-06-01

    Aconite poisoning is relatively rare but is frequently complicated by ventricular dysrhythmias, which may be fatal. Molecular basis of aconite alkaloid ventricular arrhythmogenicity: Aconite exerts its toxic effects due to the presence of an admixture of alkaloids present in all parts of the plant. The major target of these aconite alkaloids is the fast voltage-gates sodium channel, where they cause persistent activation. This blockade of the channel in the activated state promotes automaticity within the ventricular myocardium and the generation of ventricular arrhythmias. Aconitine-induced arrhythmias: Aconite alkaloids are known to cause many different types of disturbance of heart rhythm. However, this focused review specifically looks at ventricular rhythm disturbances, namely ventricular ectopy, ventricular tachycardia, torsades des pointes and ventricular fibrillation. The objective of this review was to identify the outcome of anti-dysrhythmic strategies from animal studies and case reports in humans in order to guide the management of ventricular dysrhythmias in aconite poisoning in humans. A review of the literature in English was conducted in PubMed and Google Scholar from 1966 to July 2016 using the search terms "aconite/aconitine"; "aconite/aconitine + poisoning" and "aconite/aconitine + dysrhythmia". 168 human case-reports and case-series were identified by these searches, of which 103 were rejected if exposure to aconite did not result in ventricular dysrhythmias, if it was uncertain as to whether aconite had been ingested, if other agents were co-ingested, if there was insufficient information to determine the type of treatments administered or if there was insufficient information to determine outcome. Thus, 65 case reports of probable aconite poisoning that resulted in ventricular dysrhythmias were identified. Toxicokinetic data in aconite poisoning: Data were only available in three papers; the presence of ventricular rhythm disturbances

  10. Delayed recovery of right ventricular systolic function after repair of long-standing tricuspid regurgitation associated with severe right ventricular failure.

    Science.gov (United States)

    Kim, Jong Hun; Kim, Kyung Hwa; Choi, Jong Bum; Kuh, Ja Hong

    2016-03-01

    After tricuspid valve surgery for long-standing tricuspid regurgitation associated with right ventricular failure, reverse remodelling of the enlarged right ventricle, including recovery of right ventricular systolic function, is unpredictable. We present the case of a 31-year old man with early reduction of dilated right ventricular dimensions and delayed recovery of impaired right ventricular systolic function after valve repair for traumatic tricuspid regurgitation lasting 16 years. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  11. Stenting of right ventricular outflow tract in Tetralogy of Fallot with subarterial ventricular septal defect: A word of caution

    Directory of Open Access Journals (Sweden)

    Jonathan Lee

    2017-01-01

    Full Text Available We report a case of Tetralogy of Fallot with severe cyanosis who underwent a successful right ventricular outflow tract stenting. Follow-up echocardiography revealed moderate aortic regurgitation due to the impingement of the stent on the aortic valve. The patient underwent successful surgical correction at which time the stent was removed completely with a resolution of the aortic regurgitation.

  12. Flecainide reduces ventricular arrhythmias via a mechanism that differs from that of β-blockers in catecholaminergic polymorphic ventricular tachycardia

    Directory of Open Access Journals (Sweden)

    Kenichi Dochi

    2013-10-01

    Conclusion: Flecainide effectively reduced ventricular arrhythmias via a mechanism that differs from that of β-blockers in genotype-positive patients with CPVT. The specific effects of flecainide may be critical in the improvement noted in the patients' ability to perform daily activities.

  13. Interdependence of right ventricular systolic function and left ventricular filling and its association with outcome for patients with pulmonary hypertension.

    Science.gov (United States)

    Motoji, Yoshiki; Tanaka, Hidekazu; Fukuda, Yuko; Sano, Hiroyuki; Ryo, Keiko; Imanishi, Junichi; Miyoshi, Tatsuya; Sawa, Takuma; Mochizuki, Yasuhide; Matsumoto, Kensuke; Emoto, Noriaki; Hirata, Ken-ichi

    2015-04-01

    Although impaired right ventricular (RV) performance has been associated with adverse outcomes for pulmonary hypertension (PH) patients, the relationship between bi-ventricular interdependence and outcomes is not yet fully understood. We studied 96 PH patients. RV systolic function was assessed by means of RV free-wall longitudinal speckle-tracking strain (RV-free), and left ventricular (LV) filling as early diastolic transmitral flow velocity (TMF-E). RV-free ≤19 % and TMF-E functional class IV and brain natriuretic peptide >150 pg/dl (χ(2) = 1.2) was improved by the addition of RV-free (χ(2) = 5.5, p = 0.04) as well as of TMF-E (χ(2) = 11.5, p = 0.01). In conclusions, RV systolic function was shown to correlate significantly with LV filling in PH patients. In addition, not only assessment of RV systolic function, but also of a combined bi-ventricular parameter comprising RV systolic function and LV filling may well have clinical implications for more successful management of PH patients.

  14. Ventricular premature contraction in hypertrophic cardiomyopathy and essential hypertension with left ventricular hypertrophy

    International Nuclear Information System (INIS)

    Kobiki, Naoki

    1989-01-01

    In order to investigate the relationship of different morbid states of the hypertrophied myocardium to the appearance of ventricular premature contraction (VPC), we compared the VPC findings from Holter ECG with those of UCG and stress thallium-201 myocardial SPECT scintigraphy (stress scinti) in 31 patients with hypertrophic cardiomyopathy (HCM) and 20 with essential hypertension (HT). The HCM patients consisted of 21 with asymmetric hypertrophy (ASH), 3 with symmetric hypertrophy (SH), and 7 with apical hypertrophy (APH). We recognized positive findings on the stress scinti such as fixed perfusion defect (FD) or reversible perfusion defect (RD) in 11 patients (ASH 10, APH 1) out of 31 patients with HCM (35%). Positive findings were observed in only one patient out of 20 with HT (5%). We recognized a high grade VPC (grade 4a and 4b of Lown's criteria) in 8 of 11 scinti positive patients with HCM (ASH 7, APH 1)(73%), while high grade VPC appeared in 5 (all of them are ASH) out of 20 scinti negative patients with HCM (25%). Therefore, these findings suggest that high grade VPCs in HCM occur in relation to a myocardial perfusion defect. (author)

  15. Synchronous intra-myocardial ventricular pacing without crossing the tricuspid valve or entering the coronary sinus

    Energy Technology Data Exchange (ETDEWEB)

    Konecny, Tomas; DeSimone, Christopher V.; Friedman, Paul A.; Bruce, Charles [Department of Medicine, Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States); Asirvatham, Samuel J., E-mail: asirvatham.samuel@mayo.edu [Department of Medicine, Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States); Department of Pediatric and Adolescent Medicine, Pediatric Cardiology, Mayo Clinic, Rochester, MN (United States)

    2013-05-15

    Ventricular pacing is most commonly performed at the right ventricular (RV) apex. This is not without risk as placement requires crossing the tricuspid valve (TV) and may cause valvular dysfunction and dyssynchronous activation of the ventricles. The fact that the tricuspid valve lies more apically than the mitral valve allows for the possibility of pacing the ventricles from the right atrium (RA) via the “atrio-ventricular septum” without crossing the TV or entering the coronary sinus (CS). In order to mitigate far field activation inherent to current pacing technology, we constructed a novel lead in which the cathode and anode are both intra-myocardial. We demonstrate safety and efficacy of this novel lead for ventricular pacing at the atrio-ventricular septum in canines, including improved synchronous activation of both ventricles, improved differentiation in ventricular versus atrial sensing, while providing reliable ventricular capture, opening novel and a potentially safer alternative to human cardiac resynchronization therapy.

  16. Impact of hypertension on left ventricular structure in patients with asymptomatic aortic valve stenosis (a SEAS substudy)

    DEFF Research Database (Denmark)

    Rieck, Ashild E; Cramariuc, Dana; Staal, Eva M

    2010-01-01

    Both hypertension and aortic valve stenosis induce left ventricular hypertrophy. However, less is known about the influence of concomitant hypertension on left ventricular structure in patients with aortic valve stenosis.......Both hypertension and aortic valve stenosis induce left ventricular hypertrophy. However, less is known about the influence of concomitant hypertension on left ventricular structure in patients with aortic valve stenosis....

  17. An angiographic study of left- and right-ventricular function in patients with alcoholic heart and dilatation cardiomyopathy

    International Nuclear Information System (INIS)

    Savchenko, A.P.; Samko, A.N.; Smetnev, A.S.; Grudtsyn, G.V.

    1986-01-01

    An angiographic study of left- and right-ventricular function in 57 patients with alcoholic heart and dilatation cardiomyopathy demonstrated preclinical disorders of left-ventricular myocardial contractility and more marked right-ventricular changes in patients with second-stage chronic alcoholism. In cases of dilatation cardiomyopathy, left-ventricular dysfunction was predominant, while right-venricular changes were less pronouced

  18. Low intensity transcranial electric stimulation

    DEFF Research Database (Denmark)

    Antal, Andrea; Alekseichuk, I; Bikson, M

    2017-01-01

    Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears...

  19. Cardiac pacing in heart failure patients with left bundle branch block: impact of pacing site for optimizing left ventricular resynchronization.

    Science.gov (United States)

    Pappone, C; Rosanio, S; Oreto, G; Tocchi, M; Gulletta, S; Salvati, A; Dicandia, C; Santinelli, V; Mazzone, P; Veglia, F; Ding, J; Sallusti, L; Spinelli, J; Vicedomini, G

    2000-07-01

    Acute left ventricular pacing has been associated with hemodynamic improvement in patients with congestive heart failure and wide QRS complex. We hypothesized that pacing two left ventricular sites simultaneously would produce faster activation and better systolic function than single-site pacing. We selected 14 heart failure patients (NYHA functional class III or IV) in normal sinus rhythm with left bundle branch block and QRS > 150 ms. An 8F dual micromanometer catheter was placed in the aorta for measuring +dP/dt (mmHg/s), aortic pulse pressure (mmHg), and end-diastolic pressure (mmHg). Pacing leads were positioned via coronary veins at the posterior base and lateral wall. Patients were acutely paced VDD at the posterior base, lateral wall, and both sites (dual-site) with 5 atrioventricular delays (from 8 ms to PR -30 ms). Pacing sequences were executed in randomized order using a custom external computer (FlexStim, Guidant CRM). Dual-site pacing increased peak +dP/dt significantly more than posterior base and lateral wall pacing. Dual-site and posterior base pacing raised aortic pulse pressure significantly more than lateral wall pacing. Dual-site pacing shortened QRS duration by 22 %, whereas posterior base and lateral wall pacing increased it by 2 and 12%, respectively (p = 0.006). In heart failure patients with left bundle branch block, dual-site pacing improves systolic function more than single-site stimulation. Improved ventricular activation synchrony, expressed by paced QRS narrowing, may account for the additional benefit of dual- vs single-site pacing in enhancing contractility. This novel approach deserves consideration for future heart failure pacing studies.

  20. Variability of insulin-stimulated myocardial glucose uptake in healthy elderly subjects

    DEFF Research Database (Denmark)

    Kofoed, Klaus F; Hove, Jens D; Freiberg, Jacob

    2002-01-01

    The aim of this study was to assess regional and global variability of insulin-stimulated myocardial glucose uptake in healthy elderly subjects and to evaluate potentially responsible factors. Twenty men with a mean age of 64 years, no history of cardiovascular disease, and normal blood pressure...... rest and hyperaemic blood flow during dipyridamole infusion were measured with nitrogen-13 ammonia and positron emission tomography in 16 left ventricular myocardial segments. Intra-individual and inter-individual variability of insulin-stimulated myocardial glucose uptake [relative dispersion...... = (standard deviation/mean)] was 13% and 29% respectively. Although inter-individual variability of glucose uptake and blood flow at rest was of the same magnitude, no correlation was found between these measures. Regional and global insulin-stimulated myocardial glucose uptake correlated linearly with whole...

  1. Spinal Cord Stimulation

    DEFF Research Database (Denmark)

    Meier, Kaare

    2014-01-01

    Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain that is refractory to other treatment. Originally described by Shealy et al. in 1967(1), it is used to treat a range of conditions such as complex regional pain syndrome (CRPS I)(2), angina pectoris(3), radicular...... pain after failed back surgery syndrome (FBSS)(4), pain due to peripheral nerve injury, stump pain(5), peripheral vascular disease(6) and diabetic neuropathy(7,8); whereas phantom pain(9), postherpetic neuralgia(10), chronic visceral pain(11), and pain after partial spinal cord injury(12) remain more...

  2. Transient left ventricular apical ballooning and exercise induced hypertension during treadmill exercise testing: is there a common hypersympathetic mechanism?

    Directory of Open Access Journals (Sweden)

    Oh Jae K

    2008-07-01

    Full Text Available Abstract Objective To describe two cases of Takotsubo like myocardial contractile pattern during exercise stress test secondary to hypertensive response. Background Treadmill exercise testing is known to cause sympathetic stimulation, leading to increased levels of catecholamine, resulting in alteration in vascular tone. Hypertensive response during exercise testing can cause abnormal consequences, resulting in false positive results. Cases We present the cases of two patients experiencing apical and basal akinesis during exercise stress echocardiography, in whom normal wall motion response was observed on subsequent pharmacologic stress testing. The first patient developed transient left ventricular (LV apical akinesis during exercise stress echocardiography. Due to high suspicion that this abnormality might be secondary to hypertensive response, pharmacologic stress testing was performed after three days, which was completely normal and showed no such wall motion abnormality. Qualitative assessment of myocardial perfusion using contrast was also performed, which showed good myocardial blood flow, indicating low probability for significant obstructive coronary artery disease. The second patient developed LV basal akinesis as a result of hypertensive response during exercise testing. Coronary angiogram was not performed in either patient due to low suspicion for coronary artery disease, and subsequently negative stress studies. Results Transient stress induced cardiomyopathy can develop secondary to hypertensive response during exercise stress testing. Conclusion These cases provide supporting evidence to the hyper-sympathetic theory of left ventricular ballooning syndrome.

  3. Effects of Navigated Repetitive Transcranial Magnetic Stimulation After Stroke.

    Science.gov (United States)

    Chervyakov, Alexander V; Poydasheva, Alexandra G; Lyukmanov, Roman H; Suponeva, Natalia A; Chernikova, Ludmila A; Piradov, Michael A; Ustinova, Ksenia I

    2018-03-01

    The purpose of this study was to test the effects of navigated repetitive transcranial magnetic stimulation, delivered in different modes, on motor impairments and functional limitations after stroke. The study sample included 42 patients (58.5 ± 10.7 years; 26 males) who experienced a single unilateral stroke (1-12 months previously) in the area of the middle cerebral artery. Patients completed a course of conventional rehabilitation, together with 10 sessions of navigated repetitive transcranial magnetic stimulation or sham stimulation. Stimulation was scheduled five times a week over two consecutive weeks in an inpatient clinical setting. Patients were randomly assigned to one of four groups and received sham stimulation (n = 10), low-frequency (1-Hz) stimulation of the nonaffected hemisphere (n = 11), high-frequency (10-Hz) stimulation of the affected hemisphere (n = 13), or sequential combination of low- and high-frequency stimulations (n = 8). Participants were evaluated before and after stimulation with clinical tests, including the arm and hand section of the Fugl-Meyer Assessment Scale, modified Ashworth Scale of Muscle Spasticity, and Barthel Index of Activities of Daily Living. Participants in the three groups receiving navigated repetitive transcranial magnetic stimulation showed improvements in arm and hand functions on the Fugl-Meyer Stroke Assessment Scale. Ashworth Scale of Muscle Spasticity and Barthel Index scores were significantly reduced in groups receiving low- or high-frequency stimulation alone. Including navigated repetitive transcranial magnetic stimulation in a conventional rehabilitation program positively influenced motor and functional recovery in study participants, demonstrating the clinical potential of the method. The results of this study will be used for designing a large-scale clinical trial.

  4. Neural stem cell heterogeneity through time and space in the ventricular-subventricular zone.

    Science.gov (United States)

    Rushing, Gabrielle; Ihrie, Rebecca A

    2016-08-01

    The origin and classification of neural stem cells (NSCs) has been a subject of intense investigation for the past two decades. Efforts to categorize NSCs based on their location, function and expression have established that these cells are a heterogeneous pool in both the embryonic and adult brain. The discovery and additional characterization of adult NSCs has introduced the possibility of using these cells as a source for neuronal and glial replacement following injury or disease. To understand how one could manipulate NSC developmental programs for therapeutic use, additional work is needed to elucidate how NSCs are programmed and how signals during development are interpreted to determine cell fate. This review describes the identification, classification and characterization of NSCs within the large neurogenic niche of the ventricular-subventricular zone (V-SVZ). A literature search was conducted using Pubmed including the keywords "ventricular-subventricular zone," "neural stem cell," "heterogeneity," "identity" and/or "single cell" to find relevant manuscripts to include within the review. A special focus was placed on more recent findings using single-cell level analyses on neural stem cells within their niche(s). This review discusses over 20 research articles detailing findings on V-SVZ NSC heterogeneity, over 25 articles describing fate determinants of NSCs, and focuses on 8 recent publications using distinct single-cell analyses of neural stem cells including flow cytometry and RNA-seq. Additionally, over 60 manuscripts highlighting the markers expressed on cells within the NSC lineage are included in a chart divided by cell type. Investigation of NSC heterogeneity and fate decisions is ongoing. Thus far, much research has been conducted in mice however, findings in human and other mammalian species are also discussed here. Implications of NSC heterogeneity established in the embryo for the properties of NSCs in the adult brain are explored, including

  5. The Assessment of Left Ventricular Time-Varying Radius Using Tissue Doppler Imaging

    Directory of Open Access Journals (Sweden)

    Fardin Mirbolouk

    2012-03-01

    Full Text Available Background: Left ventricular twist/torsion is believed to be a sensitive indicator of systolic and diastolic performance. To obtain circumferential rotation using tissue Doppler imaging, we need to estimate the time-varying radius of the left ventricle throughout the cardiac cycle to convert the tangential velocity into angular velocity. Objectives: The aim of this study was to investigate accuracy of measured LV radius using tissue Doppler imaging throughout the cardiac cycle compared to two-dimensional (2D imaging. Methods: A total of 35 subjects (47±12 years old underwent transthoracic echocardiographic standard examinations. Left ventricular radius during complete cardiac cycle measured using tissue Doppler and 2D-imaging at basal and apical short axis levels. For this reason, the 2D-images and velocity-time data derived and transferred to a personal computer for off-line analysis. 2D image frames analyzed via a program written in the MATLAB software. Velocity-time data from anteroseptal at basal level (or anterior wall at apical level and posterior walls transferred to a spreadsheet Excel program for the radius calculations. Linear correlation and Bland-Altman analysis were calculated to assess the relationships and agreements between the tissue Doppler and 2D-measured radii throughout the cardiac cycle. Results: There was significant correlation between tissue Doppler and 2D-measured radii and the Pearson correlation coefficients were 0.84 to 0.97 (P<0.05. Bland-Altman analysis by constructing the 95% limits of agreement showed that the good agreements existed between the two methods. Conclusion: It can be concluded from our experience that the tissue Doppler imaging can reasonably estimate radius of the left ventricle throughout the cardiac cycle.

  6. 2D-speckle tracking right ventricular strain to assess right ventricular systolic function in systolic heart failure. Analysis of the right ventricular free and posterolateral walls.

    Science.gov (United States)

    Mouton, Stéphanie; Ridon, Héléne; Fertin, Marie; Pentiah, Anju Duva; Goémine, Céline; Petyt, Grégory; Lamblin, Nicolas; Coisne, Augustin; Foucher-Hossein, Claude; Montaigne, David; de Groote, Pascal

    2017-10-15

    Right ventricular (RV) systolic function is a powerful prognostic factor in patients with systolic heart failure. The accurate estimation of RV function remains difficult. The aim of the study was to determine the diagnostic accuracy of 2D-speckle tracking RV strain in patients with systolic heart failure, analyzing both free and posterolateral walls. Seventy-six patients with dilated cardiopathy (left ventricular end-diastolic volume≥75ml/m 2 ) and left ventricular ejection fraction≤45% had an analysis of the RV strain. Feasibility, reproducibility and diagnostic accuracy of RV strain were analyzed and compared to other echocardiographic parameters of RV function. RV dysfunction was defined as a RV ejection fraction≤40% measured by radionuclide angiography. RV strain feasibility was 93.9% for the free-wall and 79.8% for the posterolateral wall. RV strain reproducibility was good (intra-observer and inter-observer bias and limits of agreement of 0.16±1.2% [-2.2-2.5] and 0.84±2.4 [-5.5-3.8], respectively). Patients with left heart failure have a RV systolic dysfunction that can be unmasked by advanced echocardiographic imaging: mean RV strain was -21±5.7% in patients without RV dysfunction and -15.8±5.1% in patients with RV dysfunction (p=0.0001). Mean RV strain showed the highest diagnostic accuracy to predict depressed RVEF (area under the curve (AUC) 0.75) with moderate sensitivity (60.5%) but high specificity (87.5%) using a cutoff value of -16%. RV strain seems to be a promising and more efficient measure than previous RV echocardiographic parameters for the diagnosis of RV systolic dysfunction. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Quantitative Assessment of Left Ventricular Function and Myocardial Mass: A Comparison of Coronary CT Angiography with Cardiac MRI and Echocardiography

    International Nuclear Information System (INIS)

    Kara, Bedia; Nayman, Alaaddin; Guler, Ibrahim; Gul, Enes Elvin; Koplay, Mustafa; Paksoy, Yahya

    2016-01-01

    The purpose of this study was to compare the left ventricular parameters obtained from multi-detector row computed tomography (MDCT) studies with two-dimensional echocardiography (2DE), and magnetic resonance imaging (MRI), which is accepted as the gold standard in the evaluation of left ventricular functions. The study also aimed to evaluate whether or not there is a relationship between the MR-Argus and CMR tools software programs which are used in post-process calculations of data obtained by MRI. Forty patients with an average age of 51.4±14.9 years who had been scanned with cardiac MDCT were evaluated with cardiac MRI and 2DE. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), cardiac output (CO), and myocardial mass values calculated by MDCT, MRI, and 2DE were compared with each other. Two different MR software programs were used to compare left ventricular functions. The CMR tools LV tutorials method is accepted as the gold standard because it can be used in three-dimensional functional evaluation. The Pearson Correlation and Bland-Altman analysis were performed to compare the results from the two MR methods (MR-Argus and CMR tools) and the results from both the MDCT and the 2DE with the CMR tools results. Strong positive correlations for EF values were found between the MDCT and CMR tools (r=0.702 p<0.001), and between the MR-Argus and CMR tools (r=0.746 p<0.001). The correlation between the 2DE and CMR tools (r=0.449 p<0.004), however, was only moderate. Similar results were obtained for the other parameters. The strongest correlation for ESV, EDV, and EF was between the two MR software programs. The correlation coefficient between the MDCT and CMR tools is close to the correlation coefficient between the two software programs. While the correlation between 2DE and CMR tools was satisfactory for ESV, EDV, and CO values, it was at a moderate level for the other parameters. Left ventricular functional analysis

  8. Left Ventricular Assist Devices: The Adolescence of a Disruptive Technology.

    Science.gov (United States)

    Pinney, Sean P

    2015-10-01

    Clinical outcomes for patients with advanced heart failure receiving left ventricular assist devices are driven by appropriate patient selection, refined surgical technique, and coordinated medical care. Perhaps even more important is innovative pump design. The introduction and widespread adoption of continuous-flow ventricular assist devices has led to a paradigm shift within the field of mechanical circulatory support, making the promise of lifetime device therapy closer to reality. The disruption caused by this new technology, on the one hand, produced meaningful improvements in patient survival and quality of life, but also introduced new clinical challenges, such as bleeding, pump thrombosis, and acquired valvular heart disease. Further evolution within this field will require financial investment to sustain innovation leading to a fully implantable, durable, and cost-effective pump for a larger segment of patients with advanced heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Allowable variance set on left ventricular function parameter

    International Nuclear Information System (INIS)

    Zhou Li'na; Qi Zhongzhi; Zeng Yu; Ou Xiaohong; Li Lin

    2010-01-01

    Purpose: To evaluate the influence of allowable Variance settings on left ventricular function parameter of the arrhythmia patients during gated myocardial perfusion imaging. Method: 42 patients with evident arrhythmia underwent myocardial perfusion SPECT, 3 different allowable variance with 20%, 60%, 100% would be set before acquisition for every patients,and they will be acquired simultaneously. After reconstruction by Astonish, end-diastole volume(EDV) and end-systolic volume (ESV) and left ventricular ejection fraction (LVEF) would be computed with Quantitative Gated SPECT(QGS). Using SPSS software EDV, ESV, EF values of analysis of variance. Result: there is no statistical difference between three groups. Conclusion: arrhythmia patients undergo Gated myocardial perfusion imaging, Allowable Variance settings on EDV, ESV, EF value does not have a statistical meaning. (authors)

  10. The effects of stress on left ventricular ejection fraction

    International Nuclear Information System (INIS)

    Kiess, M.C.; Dimsdale, J.E.; Moore, R.H.; Liu, P.; Newell, J.; Barlai-Kovach, M.; Boucher, C.A.; Strauss, H.W.; Massachusetts General Hospital, Boston; Massachusetts General Hospital, Boston

    1988-01-01

    The left ventricular ejection fraction (EF) was studied in 17 healthy volunteers with a new ambulatory left ventricular function monitor. Heart rate, EF, and blood pressure measurements were made during rest, a psychiatric stress interview, cold exposure, exercise, and eating. An increase in EF was seen during emotional stress (from 0.45±0.09 to 0.51±0.13, P<0.001). This increase was comparable to that observed during exercise (0.52±0.14) and eating (0.52±0.10, P<0.001). In contrast, cold exposure caused a decrease in EF (0.43±0.13, P<0.05). These observations demonstrate the powerful hemodynamic consequences of common behaviors as well as the utility and feasability of studying such behavioral factors in ambulatory subjects. (orig.)

  11. Left ventricular pseudoaneurysm versus aneurysm a diagnosis dilemma

    Directory of Open Access Journals (Sweden)

    Samarjit Bisoyi

    2016-01-01

    Full Text Available Free wall rupture of the left ventricle (LV is a rare but life-threatening complication of acute myocardial infaction. Very rarely such rupture may be contained by the adhering pericardium creating a pseudoaneurysm. This condition warrants for an emergency surgery. Left ventricular aneurysm is the discrete thinning of the ventricular wall (<5 mm with akinetic or dyskinetic wall motion causing an out-pouching of the ventricle. Given the propensity for pseudoaneurysms to rupture leading to cardiac tamponade, shock, and death, compared with a more benign natural history for true aneurysms, accurate diagnosis of these conditions is important. True aneurysm, usually, calls for an elective surgery. Clinically differentiating the two conditions remains a challenge. We report the case of a patient with LV pseudoaneurysm, initially diagnosed as true aneurysm at our institution. We have attempted to review the existing literature and discussed the characteristic findings of each entity.

  12. Radionuclide determination of right and left ventricular stroke volumes

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wei Feng; Roubin, G S; Choong, C Y.P.; Harris, P J; Flether, P J; Kelly, D T; Uren, R F; Hutton, B F

    1985-03-01

    The relationship between radionuclide and thermodilution measurement of stroke volumes (SV) was investigated in 30 patients without valvular regurgitation or intracardiac shunt (group A) at rest and during exercise. Both attenuated radionuclide right ventricular (RV) and left ventricular (LV) SV measurements correlated well with the SV determined by the thermodilution method (r = 0.87 and r = 0.93, all P < 0.001). The reliability of the radionuclide method to estimate SV was evaluated prospectively in two additional groups of patients. In 11 patients without valvular regurgitation or intracardiac shunt (group B) the radionuclide RVSV and LVSV closely approximated to thermodilution SV at rest and during exercise. In 15 patients with aortic regurgitation (group C) the radionuclide stroke volume ratio correlated well with the angiographic regurgitant fraction. Thus, both RVSV and LVSV and the severity of aortic regurgitation can be reliably measured with gated radionuclide ventriculography.

  13. Dynamic Changes in Sarcoplasmic Reticulum Structure in Ventricular Myocytes

    Directory of Open Access Journals (Sweden)

    Amanda L. Vega

    2011-01-01

    sarcoplasmic reticulum (SR and the sarcolemma where Ca2+ release is activated. Here, we tested the hypothesis that the SR is a structurally inert organelle in ventricular myocytes. Our data suggest that rather than being static, the SR undergoes frequent dynamic structural changes. SR boutons expressing functional ryanodine receptors moved throughout the cell, approaching or moving away from the sarcolemma of ventricular myocytes. These changes in SR structure occurred in the absence of changes in [Ca2+] during EC coupling. Microtubules and the molecular motors dynein and kinesin 1(Kif5b were important regulators of SR motility. These findings support a model in which the SR is a motile organelle capable of molecular motor protein-driven structural changes.

  14. Mutations in calmodulin cause ventricular tachycardia and sudden cardiac death

    DEFF Research Database (Denmark)

    Nyegaard, Mette; Overgaard, Michael Toft; Sondergaard, M.T.

    2012-01-01

    a substantial part of sudden cardiac deaths in young individuals. Mutations in RYR2, encoding the cardiac sarcoplasmic calcium channel, have been identified as causative in approximately half of all dominantly inherited CPVT cases. Applying a genome-wide linkage analysis in a large Swedish family with a severe......Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a devastating inherited disorder characterized by episodic syncope and/or sudden cardiac arrest during exercise or acute emotion in individuals without structural cardiac abnormalities. Although rare, CPVT is suspected to cause...... calmodulin-binding-domain peptide at low calcium concentrations. We conclude that calmodulin mutations can cause severe cardiac arrhythmia and that the calmodulin genes are candidates for genetic screening of individual cases and families with idiopathic ventricular tachycardia and unexplained sudden cardiac...

  15. Right Ventricular Involvement in either Anterior or Inferior Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Firoozeh Abtahi

    2016-06-01

    Full Text Available Background: Unlike left ventricular function, less attention has been paid to Right Ventricular (RV function after Myocardial Infarction (MI. Objectives: The current study aimed to compare RV function in patients with inferior and anterior MI. Patients and Methods: During the study period, 60 patients consecutively presented to the Emergency Department with chest pain were divided into two groups based on their electrocardiographic findings. Accordingly, 25 patients had inferior MI (IMI group and 35 ones had anterior MI (AMI group. Echocardiography was performed 48 hours after starting the standard therapy. Conventional echocardiographic parameters and Tissue Doppler Imaging (TDI measurements were acquired from the standard views. Student t-test and the chi-square test were respectively used for comparisons of the normally distributed continuous and categorical variables in the two groups. Besides, P < 0.05 was considered to be statistically significant.

  16. Spontaneous haemorrhage and rupture of third ventricular colloid cyst.

    LENUS (Irish Health Repository)

    Ogbodo, Elisha

    2012-01-01

    Acute bleeding within a colloid cyst of the third ventricle represents a rare event causing sudden increase in the cyst volume that may lead to acute hydrocephalus and rapid neurological deterioration. We report a case of spontaneous rupture of haemorrhagic third ventricular colloid cyst and its management. A 77-year-old ex-smoker presented with unsteady gait, incontinence and gradually worsening confusion over a 3-week period. Brain CT scan findings were highly suggestive of a third ventricular colloid cyst with intraventricular rupture. He underwent cyst excision and histopathology, which confirmed the radiological diagnosis with evidence of haemorrhage within the cyst. A ventriculo peritoneal shunt was performed for delayed hydrocephalus. Surgical management of these patients must include emergency ventriculostomy followed by prompt surgical removal of the haemorrhagic cyst.

  17. Assessment of right ventricular function using gated blood pool single photon emission computed tomography in inferior myocardial infarction with or without hemodynamically significant right ventricular infarction

    International Nuclear Information System (INIS)

    Takahashi, Masaharu

    1992-01-01

    Right ventricular function was assessed using gated blood pool single photon emission computed tomography (GSPECT) in 10 normal subjects and 14 patients with inferior myocardial infarction. Three-dimensional backbround subtraction was achieved by applying an optimal cut off level. The patient group consisted of 6 patients with definite hemodynamic abnormalities indicative of right ventricular infarction (RVI) and 8 other patients with significant obstructive lesion at the proximal portion of right coronary artery without obvious hemodynamic signs of RVI. Right ventricular regional wall motion abnormalities were demonstrated on GSPECT functional images and the indices of right ventricular function (i.e the right ventricular ejection fraction (RVEF), the right ventricular peak ejection rate (RVPER) and the right ventricular peak filling rate (RVPFR)) were significantly reduced in the patient group, not only in the patients with definite RVI but also in those without hemodynamic signs of RVI, even in the absence of definite hemodynamic signs, when the proximal portion of right coronary artery is obstructed. It is concluded that GSPECT is reliable for the assessment of right ventricular function and regional wall motion, and is also useful for the diagnosis of RVI. (author)

  18. Evaluation of the accuracy of ventricular volume measurement by ultrafast CT

    International Nuclear Information System (INIS)

    Cui Wei; Dai Ruping; Guo Yuyin

    1997-01-01

    The authors evaluated the accuracy of ventricular volume measured by ultrafast CT (UFCT); and (2) compared the value of ventricular volume derived from long- and short-axis view. Fourteen human left ventricular casts and 15 right ventricular casts were scanned by Imatron C-150 scanner along both the long- and short-axis. The scan protocol was similar to that used in vivo. Eight 7 mm-thick slices were obtained from each cast for both long- and short-axis views. Ventricular volume was determined by the modified Simpson's rule provided by Inamtron Inc. The actual volumes of the ventricular casts were determined by the amount of water displacement by the cast. The actual volumes for left and right ventricles were 55.57 +- 28.91 ml and 64.23 +- 24.51 ml, respectively, the left and right ventricular volumes determined by UFCT were 66.50 +- 33.04 ml and 76.47 +-28.70 ml from long-axis view, and 60.36 +- 29.90 ml and 75.36 +- 28.73 ml from short-axis view, respectively. The measurements by UFCT were significantly greater than the actual volumes of the casts, both for the left and right ventricles (P 0.990). Both left and right ventricular volumes can be determined by UFCT with identical accuracy for both long- and short-axis views in calculating ventricular volume; however, overestimation of ventricular volume by UFCT should be noted

  19. Right ventricular systolic and diastolic function at rest in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Caglar, N.M.; Araki, Haruo; Taira, Yuji; Fukuyama, Takaya; Nakamura, Motoomi

    1985-01-01

    Right ventricular systolic and diastolic function was studied in patients with ischemic heart disease using equilibrium radionuclide ventriculography. In patients with inferior myocardial infarction and proximal right coronary lesions, the right ventricular ejection fraction (0.43+-0.06, n=10, mean+-SD) and peak filling rate (1.7+-0.4 EDV/sec) were lower than normals (0.57+-0.07 and 2.7+-0.4 EDV/sec, n=10, p<0.001, respectively). In these patients, the right ventricular time to peak filling rate was longer than in normals (225+-36 msec vs 136+-45 msec, p<0.001), while the left ventricular ejection fraction remained normal. In patients with inferior myocardial infarction and distal right coronary lesions, the right ventricular ejection fraction, peak filling rate and time to peak filling rate were not different from those in normals. Even in patients with proximal right coronary lesions, the right ventricular ejection fraction was normal unless they had an inferior myocardial infarction. A decreased left ventricular ejection fraction and abnormal motion of the ventricular septum did not affect the right ventricular ejection fraction. The present results suggest that patients with an inferior myocardial infarction and proximal right coronary lesion often develop right ventricular systolic and diastolic dysfunction. (author)

  20. Value of the radiological study of the thorax for diagnosing left ventricular dysfunction in Chagas' disease

    Directory of Open Access Journals (Sweden)

    Perez Amanda Arantes

    2003-01-01

    Full Text Available OBJECTIVE: To determine the value of the radiological study of the thorax for diagnosing left ventricular dilation and left ventricular systolic dysfunction in patients with Chagas' disease. METHODS: A cross-sectional study of 166 consecutive patients with Chagas' disease and no other associated diseases. The patients underwent cardiac assessment with chest radiography and Doppler echocardiography. Sensitivity, specificity, and positive and negative predictive values of chest radiography were calculated to detect left ventricular dysfunction and the accuracy of the cardiothoracic ratio in the diagnosis of left ventricular dysfunction with the area below the ROC curve. The cardiothoracic ratio was correlated with the left ventricular ejection fraction and the left ventricular diastolic diameter. RESULTS: The abnormal chest radiogram had a sensitivity of 50%, specificity of 80.5%, and positive and negative predictive values of 51.2% and 79.8%, respectively, in the diagnosis of left ventricular dysfunction. The cardiothoracic ratio showed a weak correlation with left ventricular ejection fraction (r=-0.23 and left ventricular diastolic diameter (r=0.30. The area calculated under the ROC curve was 0.734. CONCLUSION: The radiological study of the thorax is not an accurate indicator of left ventricular dysfunction; its use as a screening method to initially approach the patient with Chagas' disease should be reevaluated.