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Ventricle
Kinds of Ventricle Terms modified by Ventricle Selected AbstractsSLOW INOTROPIC RESPONSE OF INTACT LEFT VENTRICLE TO SUDDEN DILATION CRITICALLY DEPENDS ON A MYOCARDIAL DIALYSABLE FACTORCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2007Paulo JF Tucci SUMMARY 1Slow inotropic response following a sudden myocardium stretch seems to be an autocrine/paracrine mechanism the basis of which is not yet completely defined. 2We compared the canine left ventricle (LV) response to sudden dilation when the LV was supported by the arterial blood of a support dog with when it was supported by an oxygenator + haemodialyser system. 3A slow inotropic response (SIR) after dilation was seen in all six hearts supported by the donor dog, attaining 87 ± 6% of immediate increase, whereas a mere 10% SIR occurred in only one out of seven hearts maintained by the oxygenator + haemodialyser. 4These results indicate that SIR genesis involves one or more renewable components essential to the intracellular calcium gain elicited by stretch. [source] Late Presenters with Dextro-transposition of Great Arteries and Intact Ventricular Septum: To Train or Not to Train the Left Ventricle for Arterial Switch Operation?CONGENITAL HEART DISEASE, Issue 6 2009Noor Mohamed Parker MBChB ABSTRACT Objective., We report our experience in managing late presenters (older than 4 weeks) with dextro-transposition of great arteries and intact ventricular septum (d-TGA/IVS) in an effort to achieve successful arterial switch operation (ASO) in a third world setting. Design., We retrospectively reviewed the charts of all late presenters with d-TGA/IVS. Patients were divided into two groups: left ventricular training (LVT) group and non-left ventricular training (non-LVT) group. LVT group underwent pulmonary artery banding and Blalock-Taussig Shunt prior to ASO. Results., Twenty-one late presenters were included in the study. In LVT group, 11 patients with median age of 6 months (range, 1,72 months) underwent LVT. Later, 8 patients with median age of 9.25 months (range, 1.33,84 months) underwent ASO. Prior to ASO, left ventricle (LV) collapse resolved in all and left ventricle to systemic pressure (LV/SP) ratio was 0.81 (range, 0.76,0.95) in 4 patients. Two patients who had LVT for ,14 days required postoperative extracorporeal membrane oxygenation (ECMO) support due to LV dysfunction. Seven patients survived to discharge. In non-LVT group, 10 patients with median age of 2.5 months (range, 1,98 months) underwent ASO. Five patients had LV collapse, and median LV/SP ratio was 0.67 (range, 0.56,1.19) in 5 patients. Seven patients needed ECMO support. Seven patients survived to discharge. Conclusion., Late presenters with d-TGA/IVS, who have LV collapse on echocardiography and/or a LV/SP ratio <0.67 on cardiac catheterization, should be subjected to LVT preferably for duration of longer than 14 days in order to avoid potential ECMO use. [source] Acute Adaptation to Volume Unloading of the Functional Single Ventricle in Children Undergoing Bidirectional Glenn AnastomosisCONGENITAL HEART DISEASE, Issue 2 2009Catherine Ikemba MD ABSTRACT Objective., Volume unloading of the functional single ventricle after a bidirectional Glenn anastomosis (BDG) prior to 1 year of age leads to improved global ventricular function as measured by the myocardial performance index (MPI), a Doppler-derived measurement of combined systolic and diastolic ventricular function. Systolic function remains unchanged after BDG according to previous studies; however, acute changes in global and diastolic function have not been previously investigated in this cohort. Our objective was to assess the short-term effects of the BDG on global ventricular function in patients with a functional single ventricle. Design., Echocardiograms to obtain MPI, isovolumic contraction time, and isovolumic relaxation time were performed at four time periods: in the operating room, in the operating room prior to BDG, shortly after separation from cardiopulmonary bypass, less than 24 hours postoperatively, and either prior to hospital discharge or at the first clinic follow-up visit. Results., Twenty-six patients were enrolled. There was significant ventricular dysfunction noted shortly after separation from cardiopulmonary bypass, median MPI 0.63 (0.39,0.81), that persisted in the short term postoperatively median MPI 0.50 (0.40,0.63). Isovolumic contraction time did not change, however, isovolumic relaxation time was significantly prolonged following BDG. Conclusion., In the postoperative patient after BDG, systolic function is preserved; however, there is evidence of diastolic and global ventricular dysfunction, at least in the short term. [source] Single Left Ventricle and PheochromocytomaCONGENITAL HEART DISEASE, Issue 5 2008Yat W. Cheung MD ABSTRACT We report a patient born with a Holmes heart who was later diagnosed with pheochromocytoma in her teenage years. A review of the literature showed only two such cases reported. The findings of these two rare conditions simultaneously in several individuals is suggestive of an association. [source] Stent Dilatation of a Right Ventricle to Pulmonary Artery Conduit in a Postoperative Patient with Hypoplastic Left Heart SyndromeCONGENITAL HEART DISEASE, Issue 2 2008Rowan Walsh MD ABSTRACT A 10-day-old child with hypoplastic left heart syndrome (HLHS) underwent first-stage palliation for HLHS, Norwood procedure with a Sano modification, i.e., placement of a right ventricular to pulmonary artery (RV-PA) conduit. The patient developed progressively worsening systemic oxygen desaturation in the immediate postoperative period. Stenosis of the proximal RV-PA conduit was diagnosed by echocardiography. In the catheterization laboratory stent placement in the conduit was performed. This resulted in increased systemic oxygen saturation. The patient was eventually discharged from the hospital with adequate oxygen saturations. [source] Device Closure of a Secundum Atrial Septal Defect in a 4-Month-Old Infant with a Marginal Left Ventricle Following Coarctation RepairCONGENITAL HEART DISEASE, Issue 6 2007Emilie Jean-St-Michel BSc ABSTRACT A male infant presented at birth with severe coarctation of the aorta and marginal left ventricular and mitral valve dimensions associated with a large secundum atrial septal defect. Following successful arch repair, the left ventricle remained small with preferential left-to-right atrial shunting and a dilated right ventricle. Clinically, the infant continued with tachypnea, poor feeding, and failure to thrive. At 4 months of age, the defect was closed with an Amplatzer Atrial Septal Occluder which resulted in immediate left ventricular cavity enlargement and clinical improvement. [source] Fontan Operation and the Single VentricleCONGENITAL HEART DISEASE, Issue 1 2007Jamil A. AboulHosn MD ABSTRACT The Fontan operation has gone through multiple incarnations since Fontan and Baudet's initial description in 1971. Through the medical dossier of a patient with a single ventricle, we plot the history of medical, surgical, and percutaneous interventions over the past 40 years, specifically focusing on the Fontan procedure, its development, indications, sequelae, and complications. Cardiac computed tomography with angiography is highlighted as a noninvasive imaging tool for the evaluation of the complex Fontan circulation. [source] Large Apical Muscular Ventricular Septal Defect: Asymptomatic due to Anomalous Muscle Bundles in the Right VentricleCONGENITAL HEART DISEASE, Issue 1 2007Anant Khositseth MD ABSTRACT This case report demonstrated an apical muscular ventricular septal defect (VSD) that was a large defect but behaved like a small defect because of the restrictive flow across the anomalous muscle bundles in the right ventricular (RV) apex. The anomalous muscle bundles separated the RV sinus into two parts: the RV apex connecting with the left ventricle through the apical muscular VSD on one side, and the rest of the RV sinus connecting with RV inflow and RV outflow on the other side. These findings explained why the 11-year-old girl in this study remained asymptomatic without evidence of volume load. Thus far, it was not necessary to close her defect because of the hemodynamic insignificance. [source] Baseline Echocardiographic Predictors of Dynamic Intraventricular Obstruction of the Left Ventricle during Dobutamine Stress EchocardiogramECHOCARDIOGRAPHY, Issue 10 2009Edmundo Jose Nassri Cāmara M.D., Ph.D. Background: Intraventricular obstruction (IVO) during dobutamine stress echocardiogram (DSE) may be associated with or reproduce symptoms. Predictors of IVO are not well established. Methods: 149 patients were studied at rest and during DSE. The normal range of the left ventricular outflow tract (LVOT) velocities was investigated in 68 healthy patients. Results: 19 patients (13%) developed IVO (peak LVOT velocity > 271 cm/sec). A significant linear correlation was observed between peak LVOT velocity during DSE and the following rest parameters: LV end-diastolic dimension (r =,0.20, P = 0.018), LV end-systolic dimension (r =, 0.27, P = 0.001), relative wall thickness (r = 0.23, P = 0.006), shortening fraction (r = 0.24, P = 0.004), LVOT diameter (r =, 0.20, P = 0.023) and LVOT velocity (r = 0.29, P < 0.0001). Only relative wall thickness (P = 0.012) and LVOT diameter (P = 0.027) were independent predictors of IVO. As a dichotomous variable, a relative wall thickness ,0.44 was the only independent predictor of IVO (OR 5.7, 95% CI 1.6,20, P = 0.006), with sensitivity, specificity, negative predictive value, and positive predictive value of 77%, 62%, 95%, and 21%, respectively, and global accuracy of 63% (area under the ROC curve = 0.7). IVO was significantly associated with general cardiovascular symptoms (P = 0.0006) and with chest pain (P = 0.008). Conclusions: Relative wall thickness and LVOT diameter were independent predictors of obstruction. As a dichotomous variable, a relative wall thickness , 0.44 was the only independent predictor of dynamic IVO. [source] Rupture of a Right Sinus of Valsalva Aneurysm into the Right Ventricle During Vaginal Delivery: A Case ReportECHOCARDIOGRAPHY, Issue 10 2005F.E.S.C., Josip Vincelj M.D., Ph.D. A case is reported of a right sinus of Valsalva aneurysm rupture into the right ventricle during vaginal delivery in a 34-year-old healthy woman in her third pregnancy. Pregnancy was carried to term and a healthy baby was delivered vaginally. On day 7 following vaginal delivery she was admitted to hospital for dyspnea and cough, with clinical signs of severe heart failure. The diagnosis of the right sinus of Valsalva aneurysm rupture into the right ventricle was established by transthoracic and transesophageal echocardiography. Clinical recognition and early echocardiographic diagnosis followed by immediate surgical repair proved lifesaving in our patient. (ECHOCARDIOGRAPHY, Volume 22, November 2005) [source] Left Ventricle and Left Atrium Remodeling after Mitral Valve Replacement in Case of Mixed Mitral Valve Disease of Rheumatic OriginJOURNAL OF CARDIAC SURGERY, Issue 4 2010n Ender Topal M.D. Methods: Thirty consecutive elective patients with MVR for mixed mitral disease of rheumatic origin formed the study group. Of these, 21 (70%) were women and the mean age was 37 years. Transthoracic echocardiography was performed prior to surgery, at three-month follow-up, and at three-year follow-up except for the latest nine patients. Results: The mean duration of follow-up was 3.6 ± 1.8 years. MVR surgery improved the functional class (mean New York Heart Association [NYHA] class) at three-year follow-up (p = 0.008). LV end-diastolic diameter and LA sizes decreased after MVR. Total chordal preservation causes better outcome, regarding to LV ejection fraction (LVEF) and NYHA functional class of patients. Preoperative high NYHA class, low LVEF, and high LV end-systolic diameter (LVESd) resulted with postoperative LV dysfunction (p were < 0.001, < 0.001, and 0.006, respectively). Conclusion: In patients with mixed mitral valve disease, MVR enhanced LV and LA remodeling resulting in better NYHA function. Preoperative NYHA, LVEF, and LVESd were significant predictors of postoperative LV function. (J Card Surg 2010;25:367-372) [source] Timing of Depolarization and Contraction in the Paced Canine Left Ventricle:JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2003Experiment, Model Introduction: For efficient pump function, contraction of the heart should be as synchronous as possible. Ventricular pacing induces asynchrony of depolarization and contraction. The degree of asynchrony depends on the position of the pacing electrode. The aim of this study was to extend an existing numerical model of electromechanics in the left ventricle (LV) to the application of ventricular pacing. With the model, the relation between pacing site and patterns of depolarization and contraction was investigated. Methods and Results: The LV was approximated by a thick-walled ellipsoid with a realistic myofiber orientation. Propagation of the depolarization wave was described by the eikonal-diffusion equation, in which five parameters play a role: myocardial and subendocardial velocity of wave propagation along the myofiber cm and ce; myocardial and subendocardial anisotropy am and ae; and parameter k, describing the influence of wave curvature on wave velocity. Parameters cm, ae, and k were taken from literature. Parameters am and ce were estimated by fitting the model to experimental data, obtained by pacing the canine left ventricular free wall (LVFW). The best fit was found with cm= 0.75 m/s, ce= 1.3 m/s, am= 2.5, ae= 1.5, and k= 2.1 × 10,4 m2/s. With these parameter settings, for right ventricular apex (RVA) pacing, the depolarization times were realistically simulated as also shown by the wavefronts and the time needed to activate the LVFW. The moment of depolarization was used to initiate myofiber contraction in a model of LV mechanics. For both pacing situations, mid-wall circumferential strains and onset of myofiber shortening were obtained. Conclusion: With a relatively simple model setup, simulated depolarization timing patterns agreed with measurements for pacing at the LVFW and RVA in an LV. Myocardial cross-fiber wave velocity is estimated to be 0.40 times the velocity along the myofiber direction (0.75 m/s). Subendocardial wave velocity is about 1.7 times faster than in the rest of the myocardium, but about 3 times slower than as found in Purkinje fibers. Furthermore, model and experiment agreed in the following respects. (1) Ventricular pacing decreased both systolic pressure and ejection fraction relative to natural sinus rhythm. (2) In early depolarized regions, early shortening was observed in the isovolumic contraction phase; in late depolarized regions, myofibers were stretched in this phase. Maps showing timing of onset of shortening were similar to previously measured maps in which wave velocity of contraction appeared similar to that of depolarization. (J Cardiovasc Electrophysiol, Vol. 14, pp. S188-S195, October 2003, Suppl.) [source] Role of Structural Complexities of Septal Tissue in Maintaining Ventricular Fibrillation in Isolated, Perfused Canine VentricleJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2001TAKANORI IKEDA M.D. Tissue Structure and VF.Introduction: It is unclear how the patterns of wavelet propagation during ventricular fibrillation (VF) vary between structurally different tissues. We hypothesized that the structural complexities of septal tissue influence the maintenance of reentrant wavelets in the ventricle. Methods and Results: Endocardial activation patterns during VF were analyzed in the isolated, perfused canine right ventricular (RV) free wall (n = 9), interventricular septum (n = 5), and left ventricular (LV) free wall (n = 6) using a computerized mapping system (2-mm resolution) with 120-msec consecutive windows. Each tissue sample was cut progressively to reduce the tissue mass until the VF was terminated. More wavelets were seen in the septa than in the RV and LV free walls at baseline (P = 0.004), and VF in the septa displayed a shorter cycle length than in the RV and LV free walls (P = 0.017). As the tissue mass decreased, VF became successively more organized in all regions: the number of wavelets decreased and the cycle length of VF lengthened. Single and "figure-of-eight" stationary, reentrant wavelets often were mapped after tissue mass reduction in the RV free walls and rarely in the LV free walls, but they were not observed in the septa. Less critical mass was required to maintain VF in the septa than in the RV and LV free walls (P = 0.0006). Gross anatomic and histologic examinations indicated that the tissue structure of the septa is more complex than that of the RV and LV free walls. Conclusion: VF activation patterns with progressive reduction of tissue mass differ for the septum and the ventricular free walls. The structural complexities of the septal tissue influence the maintenance of fibrillation in the ventricle. [source] Independent Autonomic Modulation of Sinus Node and Ventricular Myocardium in Healthy Young Men During SleepJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2000PETER KOWALLIK M.D. Autonomic Modulation of Sinus Node and Ventricle. Introduction. The aim of this study was to investigate whether autonomic modulation of ventricular repolarization may spontaneousiy differ from that of the sinoatrial node. Methods and Results. Onset of P waves. QRS complexes, and the apex and end of T waves were detected heat to heat in high-resolution ECGs from nine healthy young men during the night. There were time-dependent fluctuations in the QT/RR slopes of consecutive 5-minute segments that could not he explained by the mean RR cycle length of the respective segment. Because the variahility found in QT intervals could not be explained hy either possible effects of rate dependence or hysteresis, autonomic effects were obvious. Power speetral analysis was performed for consecutive 5-minute segments of PP and QT techograms. In a given subject. trends in the time course of low-frequency (LF) and high-frequency (HF) power in PP and QT often were similar, but they were quite different at other times. The mean LF/HF ratio for QTend (0.75 ± 0.1) was different from that of PP (1.8 ± 0.2; P = 0.002), indicating differences in sympathovagal balance at the different anatomic sites. Furthermore, at a given mean heart rate, averaged QT intervals were different on a time scale of several minutes to hours. The QT/RR slope of 5-minute segments correlated significantly with the HF power of QT variability but not with that of PP variability, indicating effects of the autonomic nervous system on ventricular action potential restitution. Conclusion. These differences demonstrate that changes in sinus node automaticity are not necessarily indicative of the autonomic control of ventricular myocardium. (J Cardiavasc Electrophysiol, Vol. II, pp. 1063-1070. October 2000) [source] Double Chambered Right Ventricle in 9 CatsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2007H. Koffas Background: Double-chambered right ventricle (DCRV) is a frequently recognized cardiac congenital abnormality in humans. It has been described in dogs and in 1 cat. However systemic description of clinical and echocardiographic features of the disease in cats is currently lacking from the veterinary literature. Animals: Nine cats with DCRV are described. Results: The cats ranged from 4 months to 10 years of age. Eight cats at presentation were asymptomatic and 1 cat had chylothorax. In all cases echocardiography revealed abnormal fibromuscular bundles obstructing the mid-right ventricle, dividing the chamber into 2 compartments. The proximal right ventricular compartment was markedly hypertrophied, and right atrial dilation was usually present. The mean pressure gradient measured across the stenotic area was 130 ± 50 mm Hg. Concurrent abnormalities included a ventricular septal defect (n = 2); aortic malalignment, aortic insufficiency (n = 1); and congenital peritoneal-pericardial diaphragmatic hernia (n = 1). Two cats had systolic anterior motion of the mitral valve, one of which had concurrent left ventricular hypertrophy. Five cats have remained asymptomatic for a median period of 3.6 years (range, 3.3,5 years) and 3 cats have developed clinical signs associated with congestive heart failure (at 2, 3.3, and 9 years). One cat showed progressive lethargy and exercise intolerance and underwent partial ventriculectomy at the age of 2 years. This cat died during the operation with electromechanical dissociation. Conclusions: DCRV is a congenital cardiac abnormality that may be more common than previously recognized. [source] A Shock Lead Intentionally Placed in the Left VentriclePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2009KARIN KRAAIER M.D. The implantable cardioverter defibrillator is effective in reducing sudden cardiac death in high-risk patients. The implantation procedure is usually simple; however, in those patients who have congenital heart disease (CHD) placement of leads can be a challenge. In this report we present a patient with CHD where due to the complex cardiac anatomy it was decided to place the shock lead in the left ventricle. [source] Diagnosis and Management of Inadvertently Placed Pacing and ICD Leads in the Left Ventricle: A Multicenter Experience and Review of the LiteraturePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2000BERRY M. VAN GELDER Three patients from different centers with pacemaker or ICD leads endocardially implanted in the left ventricle are described. All leads, two ventricular pacing leads and one ICD lead, were inserted through a patent foramen ovale or an atrial septum defect. The diagnosis was made 9 months. 14 months, and 16 years, respectively, after implantation. All patients had right bundle branch block configuration during ventricular pacing. Chest X ray was suggestive of a left-sided positioned lead except in the ICD patient. Diagnosis was confirmed with echocardiography in all patients. One patient with a ventricular pacing lead presented with a transient ischcmic attack at 1-month postimplantation. During surgical repair of the atrial septum defect 14 months later, the lead was extracted and thrombus was attached to the lead despite therapy with aspirin. The other patients were asymptomatic without anticoagulation (9 months and 16 years after implant). No thrombus was present on the ICD lead at the time of the cardiac transplantation in one patient. We reviewed 27 patients with permanent leads described in the literature. Ten patients experienced thromboembolic complications, including three of ten patients on antiplatelet therapy. The lead was removed in six patients, anticoagulation with warfarin was effective for secondary prevention in the four remaining patients. In the asymptomatic patients, the lead was removed in five patients. In the remaining patients, 1 patient was on warfarin, 2 were on antiplatelet therapy, and in 3 patients the medication was unknown. After malposition was diagnosed, three additional patients were treated with warfarin. In conclusion, if timely removal of a malpositioned lead in the left ventricle is not preformed, lifelong anticoagulation with warfarin can be recommended as the first choice therapy and lead extraction reserved in case of failure or during concomitant surgery. [source] Regional Analysis of the Ependyma of the Third Ventricle of Rat by Light and Electron MicroscopyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2008T. C. Mathew Summary Ependymal lining of cerebral ventricles lies at the interface between the ventricular cavities and the brain parenchyma. Ependymal cells are involved in various functions within the brain and play a major role in the production of the chemical principals of the cerebrospinal fluid. Histological studies on the regional variation of the third ventricular ependyma and the subependyma of adult rats were carried out by light and electron microscopic methods. For light microscopic analysis, methacrylate sections were used. In addition to the routine haematoxylin and eosin (H and E) staining for histological studies, the sections were stained with toluidine blue, cresyl violet and periodic acid Schiff's reagent (PAS). A regional analysis of the ependyma of the third ventricle showed that in most regions the ependyma was monolayered. The sidewalls and floor of the ventral portion of the third ventricle showed a multilayered ependyma. For descriptive purposes at the light microscopic level, the ependymal cells were classified, based on the cell shape (flat, cuboidal or columnar), presence or absence of cilia and the number of cytoplasmic granules present in the cells. Studies of transmission electron microscope have shown that these granules represent the cell organelles of the ependyma. The subependyma also showed a regional morphological variation, and, in most instances, contained glial and neuronal elements. In regions of specific brain nuclei, neurons were the major cell type of the subependyma. PAS staining did not show any positive granules in the ependymal cytosol. Characteristic supraependymal elements were present at the ependymal surface of the third ventricle. [source] Dynamic Electromechanical Remodeling of the Left VentricleANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 1 2008Arthur J. Moss M.D. No abstract is available for this article. [source] Heterogeneity Of The Properties Of INa in Epicardial And Endocardial Cells Of Rat VentricleCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 3 2002Bonny N Honen SUMMARY 1. Ventricular INa heterogeneity was investigated in adult rat hearts. Differences in transient outward potassium current (Ito) were used to confirm isolation of subepicardial and subendocardial cells. Mean peak Ito was 6.0 ± 0.7 and 1.6 ± 0.45 pA/pF in epicardial and endocardial cells, respectively (P < < 0.01). 2. Maximum sodium conductance was smaller in subendocardial cells compared with subepicardial cells (2.39 ± 0.11 vs 2.78 ± 0.12 nS/pF, respectively; n = 17 for both; 0.01 < P < 0.05) and 50% activation occurred at a slightly more negative potential (,47.6 ± 0.8 vs,44.9 ± 0.9 mV, respectively; n = 10 for both; 0.01 < P < 0.05). 3. The potential for 50% inactivation was not significantly different in subepicardial compared with subendocardial cells (72.2 ± 1.0 vs 72.8 ± 2.2 mV, respectively; n = 17 for both; NS). 4. Persistent sodium current density appeared smaller in subendocardial (n = 19) compared with subepicardial (n = 11) cells (at a test potential of ,25 mV current, density was 0.118 ± 0.041 vs 0.144 ± 0.085 pA/pF, respectively), although this was not statistically significant due to large variability between cells. 5. Mathematical modelling of the cardiac action potential indicated that the combined effects of differences in current density and voltage dependence of sodium currents are unlikely to contribute to ventricular action potential heterogeneity between epicardial and endocardial cells. [source] Phenotyping the Right Ventricle in Patients with Pulmonary HypertensionCLINICAL AND TRANSLATIONAL SCIENCE, Issue 4 2009M.S., Marc A. Simon M.D. Abstract Right ventricular (RV) failure is associated with poor outcomes in pulmonary hypertension (PH). We sought to phenotype the RV in PH patients with compensated and decompensated RV function by quantifying regional and global RV structural and functional changes. Twenty-two patients (age 51 ± 11, 14 females, mean pulmonary artery (PA) pressure range 13,79 mmHg) underwent right heart catheterization, echocardiography, and ECG-gated multislice computed tomography of the chest. Patients were divided into three groups: Normal, PH with hemodynamically compensated, and decompensated RV function (PH-C and PH-D, respectively). RV wall thickness (WT) was measured at end-diastole (ED) and end-systole (ES) in three regions: infundibulum, lateral free wall, and inferior free wall. Globally, RV volumes progressively increased from Normal to PH-C to PH-D and RV ejection fraction decreased. Regionally, WT increased and fractional wall thickening (FWT) decreased in a spatially heterogeneous manner. Infundibular wall stress was elevated and FWT was lower regardless of the status of global RV function. In PH, there are significant phenotypic abnormalities in the RV even in the absence of overt hemodynamic RV decompensation. Regional changes in RV structure and function may be early markers of patients at risk for developing RV failure. [source] Risk of Heart Failure Due to a Combination of Mild Mitral Regurgitation and Impaired Distensibility of the Left Ventricle in Patients with Old Myocardial InfarctionCLINICAL CARDIOLOGY, Issue 12 2008Shu Inami MD Abstract Background Ischemic mitral regurgitation (MR) is a serious complication after myocardial infarction, and the incidence of heart failure (HF) increases as the severity of MR increases. However, little is known about the relationship between mild MR and HF in the patients with old myocardial infarction (OMI) and a normal ejection fraction (EF). Hypothesis We hypothesized that a combination of mild MR and impaired distensibility of the left ventricle may increase the risk of diastolic HF in the patients with OMI and a normal EF. Methods The relationship between HF and mild MR was retrospectively investigated in 62 patients with OMI and EF of > 50% on echocardiography. Results Of the 62 patients, 47 (76%) did not have HF and 15 (24%) had HF. There was a significant difference in the incidence of mild MR between the patients with and without HF (p < 0.0001): of the 47 patients without HF, mild MR was detected in 19, but all 15 patients with HF had mild MR. However, there were no significant differences in age, gender, infarct sites, diseased coronary vessels, peak CK level, and observation period between the 2 groups. An increased E-wave and the ratio of the E-wave to the A-wave (E/A), a reduction of the E-wave deceleration time, and an increased brain natriuretic peptide (BNP) level were significantly noted in HF patients with mild MR compared with patients without HF. Conclusions Even a mild MR may cause diastolic HF in patients with impaired distensibility of the left ventricle due to ischemic heart disease. Copyright © 2008 Wiley Periodicals, Inc. [source] Regional Differences in Arrhythmogenic Aftereffects of High Intensity DC Stimulation in the VentriclesPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2000ITSUO KODAMA Regional differences of the aftereffects of high intensity DC stimulation were investigated in isolated rabbit hearts stained with a voltage-sensitive dye (di-4-ANEPPS). Optical action potential signals were recorded from the epicardial surface of the right and left ventricular free wall (RVep, LVep) and from the right endocardial surface of the interventricular septum (IVS). Ten-millisecond monophasic DC stimulation (S2, 20,120 V) was applied to the signal recording spots during the early plateau phase of the action potential induced by basic stimuli (S1, 2.5 Hz). There was a linear relationship between S2 voltage and the S2 field intentisy (FI). S2 caused postshock additional depolarization. giving rise to a prolongation of the shocked action potential. With S2, 40 V (FI ,,20 V/cm), terminal repolarization of action potential was inhibited, and subsequent postshock S1 action potentials for 1,5 minutes were characterized by a decrease in the maximum diastolic potential and a decrease in the amplitude and a slowing of their upstroke phase. The higher the S2 voltage, the larger the aftereffects. The changes in postshock action potential configuration in RVep were significantly greater than those observed in LVep and IVS when compared at the same levels of S2 intensity. In RVep, 12 of 20 shocks of 120 V resulted in a prolonged refractoriness to S1 (> 1 s), and the arrest was often followed by oscillation of membrane potential. Ventricular tachycardia or fibrillation ensued from the oscillation in five cases. No such long arrest or serious arrhythmias were elicited in LVep and IVS. These results suggest that RVep is more susceptible than LVep and IVS for arrhythmogenic aftereffects of high intensity DC stimulation. [source] Pycnogenol increases the probability of the contraction state in chick embryonic cardiomyocytes, indicating inotropic effectsPHYTOTHERAPY RESEARCH, Issue 2 2007Noboru Hasegawa Abstract The influence of pycnogenol on the probability of contraction was studied in chick cardiomyocytes. Ventricles from 9,11 day chicken embryos were cultured. After 10,11 days in culture, stable spontaneous contractions were recorded and the contraction kinetics analysed. Isoproterenol and pycnogenol increased the probability of the contraction state. After pretreatment with the , -receptor antagonist, propranolol reduced the isoproterenol- and pycnogenol-increased probability of contraction state. These data suggested that pycnogenol has inotropic effects via stimulation of , -receptor mediated activity. Copyright © 2006 John Wiley & Sons, Ltd. [source] Motion visualization of human left ventricle with a time-varying deformable model for cardiac diagnosisCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 2 2001Soo-Mi Choi Abstract We present a time-varying deformable model to visualize and analyze the motion of the left ventricle from a time series of 3-D images. The model is composed of a non-rigid body that deforms around a reference shape obtained from the previous time step. At each time step, the position and orientation of the left ventricle are extracted from the feature points of images. This information gives the position and orientation of the coordinate system attached to the non-rigid body. To compute a dense non-rigid motion field over the entire endocardial wall of the left ventricle, we introduce a 3-D blob finite element and Galerkin interpolants based on 3-D Gaussian, and use a physically based finite element method and a modal analysis. Then, cinematic attributes are visualized in pseudo colors on the reconstructed surface in order to help medical doctors in their interpretation of the data. Using the presented model, we estimate clinically useful quantitative parameters such as regional wall motion and ejection fraction. Experimental results are shown in a time series of X-ray angiographic images. Copyright ©2001 John Wiley & Sons, Ltd. [source] Myocardial growth before and after birth: clinical implications,ACTA PAEDIATRICA, Issue 2 2000AM Rudolph Perinatal changes in myocardial growth have recently evoked considerable interest with regard to cardiac chamber development with congenital cardiac lesions and to myocardial development in preterm infants. It is suggested that cardiac chamber development is influenced by blood flow. Experimental pulmonary stenosis in fetal lambs may induce either greatly reduced or markedly increased right ventricular volume. Ventricular enlargement appears to be associated with a large ventricular volume load resulting from tricuspid valve regurgitation. A small competent tricuspid valve is associated with reduced flow through the ventricle due to outflow obstruction and a small right ventricle. Postnatal growth of the ventricles in congenital heart disease is discussed. Increase in myocardial mass prenatally is achieved by hyperplasia, both during normal development and when myocardial mass is increased by right ventricular outflow obstruction. Postnatally, increases in myocardial mass with normal growth, as well as with ventricular outflow obstruction, are largely due to hypertrophy of myocytes. Myocardial capillary numbers do not increase in proportion with myocyte numbers in ventricular myocardium in association with outflow obstruction. The postnatal effects of these changes in congenital heart lesions are considered. Studies in fetal lambs suggest that the late gestational increase in blood cortisol concentrations is responsible for the change in the pattern of myocardial growth after birth. The concern is raised that prenatal exposure of the premature infant to glucocorticoids, administered to the mother to attempt to prevent hyaline membrane disease in the infant, may inhibit myocyte proliferation and result in a heart with fewer than normal myocytes. This would necessitate that each myocyte would have to hypertrophy abnormally to achieve a normal cardiac mass postnatally. [source] Downregulation of oxytocin receptors in right ventricle of rats with monocrotaline-induced pulmonary hypertensionACTA PHYSIOLOGICA, Issue 2 2010T. L. Broderick Abstract Aim:, Pulmonary hypertension (PH) in the rat leads to right ventricular (RV) hypertrophy, inflammation and increased natriuretic peptide (NP) levels in plasma and RV. Because the release of nitric oxide (NO) and atrial natriuretic peptide (ANP) is a function of the oxytocin receptor (OTR), we examined the effect of PH on gene and protein expression of OTR, NP (A, atrial; B, brain) and receptors (NPRs), nitric oxide synthases (NOS), interleukin (IL)-1,, IL-6 and tumour necrosis factor-, in the hypertrophied RV in a model of PH. Methods:, RV hypertrophy was induced in male Sprague,Dawley rats with monocrotaline (MCT; 60 mg kg,1) and was confirmed by the presence of an increased RV weight and RV-to-[left ventricle (LV) and septum] ratio. Results:, In the RV of MCT-treated rats, a ,40% reduction in OTR mRNA and protein was observed compared with the RV of control rats. This reduction was associated with increased transcripts of ANP and BNP in both ventricles and a corresponding increase in NP receptor mRNA expression for receptors A, B and C. Protein expression of inducible NOS was increased in the RV, whereas endothelial NOS transcripts were increased only in the LV of MCT-treated rats. In the RV of MCT-treated rats, downregulation of OTR was also associated with increased mRNA expression of IL-1, and IL-6. Conclusion:, Our results show that downregulation of the OTR in the RV of MCT-treated rats is associated with increased expression of NP and their receptors as well as IL-1, and IL-6. This reduction in OTR in RV myocardium may have an impact on cardiac function in the MCT-induced model of PH. [source] Second lineage of heart forming region provides new understanding of conotruncal heart defectsCONGENITAL ANOMALIES, Issue 1 2010Yuji Nakajima ABSTRACT Abnormal heart development causes various congenital heart defects. Recent cardiovascular biology studies have elucidated the morphological mechanisms involved in normal and abnormal heart development. The primitive heart tube originates from the lateral-most part of the heart forming mesoderm and mainly gives rise to the left ventricle. Then, during the cardiac looping, the outflow tract is elongated by the addition of cardiogenic cells from the both pharyngeal and splanchnic mesoderm (corresponding to anterior and secondary heart field, respectively), which originate from the mediocaudal region of the heart forming mesoderm and are later located anteriorly (rostrally) to the dorsal region of the heart tube. Therefore, the heart progenitors that contribute to the outflow tract region are distinct from those that form the left ventricle. The knowledge that there are two different lineages of heart progenitors in the four-chambered heart provides new understanding of the morphological and molecular etiology of conotruncal heart defects. [source] Understanding heart development and congenital heart defects through developmental biology: A segmental approachCONGENITAL ANOMALIES, Issue 4 2005Masahide Sakabe ABSTRACT The heart is the first organ to form and function during development. In the pregastrula chick embryo, cells contributing to the heart are found in the postero-lateral epiblast. During the pregastrula stages, interaction between the posterior epiblast and hypoblast is required for the anterior lateral plate mesoderm (ALM) to form, from which the heart will later develop. This tissue interaction is replaced by an Activin-like signal in culture. During gastrulation, the ALM is committed to the heart lineage by endoderm-secreted BMP and subsequently differentiates into cardiomyocyte. The right and left precardiac mesoderms migrate toward the ventral midline to form the beating primitive heart tube. Then, the heart tube generates a right-side bend, and the d-loop and presumptive heart segments begin to appear segmentally: outflow tract (OT), right ventricle, left ventricle, atrioventricular (AV) canal, atrium and sinus venosus. T-box transcription factors are involved in the formation of the heart segments: Tbx5 identifies the left ventricle and Tbx20 the right ventricle. After the formation of the heart segments, endothelial cells in the OT and AV regions transform into mesenchyme and generate valvuloseptal endocardial cushion tissue. This phenomenon is called endocardial EMT (epithelial-mesenchymal transformation) and is regulated mainly by BMP and TGF,. Finally, heart septa that have developed in the OT, ventricle, AV canal and atrium come into alignment and fuse, resulting in the completion of the four-chambered heart. Altered development seen in the cardiogenetic process is involved in the pathogenesis of congenital heart defects. Therefore, understanding the molecular nature regulating the ,nodal point' during heart development is important in order to understand the etiology of congenital heart defects, as well as normal heart development. [source] Single Coronary Artery with Right Ventricular Fistula: Case Report and Literature ReviewCONGENITAL HEART DISEASE, Issue 1 2010Yoichiro Ishii MD ABSTRACT We report a rare case of a 6-year-old boy who was diagnosed with coronary artery fistulae communicating with the right ventricle and a left single coronary artery. Preoperative angiography showed a dilated and tortuous single coronary artery draining into the right ventricle. Two coronary artery fistulae draining into the right ventricle were detected at operation and both of these were ligated. Postoperative angiography showed that the single coronary artery diameter was almost normalized, although the vessel was still slightly tortuous. His clinical course was uneventful. In this report, we summarize cases of coronary artery fistula with single coronary artery that have been reported in the literature as well as our case. [source] | |||||||||||||||||||||||||||||||||||||