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Ventricular Arrhythmias (ventricular + arrhythmias)
Kinds of Ventricular Arrhythmias Selected AbstractsPerioperative Ventricular Arrhythmias in Patients Undergoing Partial Left VentriculectomyJOURNAL OF CARDIAC SURGERY, Issue 2 2001Toshimi Ujiie M.D. Background: Although incidence of ventricular arrhythmias after partial left ventriculectomy (PLV) has been reported, there are no studies comparing incidence before and after PLV. Although operative scars may give rise to arrhythmias, improved energetic efficiency after PLV may decrease their incidence. Methods: Pre- and postoperative ventricular arrhythmias were monitored by Holter ECG and analyzed in 17 patients undergoing PLV in Curitiba, Brazil. Results: Although total 24-hour heart beat (THB) increased significantly (p = 0.018), ventricular premature contractions (VPCs) decreased markedly (p = 0.036), excluding one patient dying in low cardiac output (LOS) who had terminal arrhythmias increased multifold. In the remaining 16 patients, VPC pairs were also reduced significantly on the average (p = 0.038). In contrast, ventricular tachycardia (VT; more than three consecutive VPCs) disappeared in five patients, decreased in two patients, and newly occurred in four patients, with five patients showing no change; one of them developed a prolonged VT, successfully reversed by external cardioversion. Conclusions: Despite notable significant increase in THB immediately after PLV, PVC and PVC pairs were significantly decreased in contrast to VT, which disappeared in some patients and newly occurred in other patients, remaining constant on the average. Sustained VT occurring in a patient with all other arrhythmias suppressed may suggest a unique electrophysiological substrate, may justify prophylactic use of amiodarone or an implantable cardioverter-defibrillator, and may underscore the importance of further and extended studies. [source] Calcium Channel Antagonism Reduces Exercise-Induced Ventricular Arrhythmias in Catecholaminergic Polymorphic Ventricular Tachycardia Patients with RyR2 MutationsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2005HEIKKI SWAN M.D. Introduction: Recently, gain-of-function mutations of cardiac ryanodine receptor RyR2 gene have been identified as a cause of familial or catecholaminergic polymorphic ventricular tachycardia. We examined the influence of the calcium channel blockers, verapamil and magnesium, on exercise-induced ventricular arrhythmias in patients with RyR2 mutations. Methods and Results: Six molecularly defined catecholaminergic polymorphic ventricular tachycardia patients, all carrying a RyR2 mutation and on ,-adrenergic blocker therapy, underwent exercise stress test four times: at baseline, after verapamil and magnesium sulphate infusions, and finally, without interventions. The number of isolated and successive premature ventricular complexes during exercise ranged from 40 to 374 beats (mean 165 beats) at baseline, and was reduced during verapamil by 76 ± 17% (P < 0.05). Premature ventricular complexes appeared later and at higher heart rate during verapamil than at baseline (119 ± 21 vs. 127 ± 27 min,1, P < 0.05). Magnesium did not inhibit the arrhythmias. Results in the fourth exercise stress test without interventions were similar to those in the first baseline study. Conclusions: This study provides the first in vivo demonstration that a calcium channel antagonist, verapamil, can suppress premature ventricular complexes and nonsustained ventricular salvoes in catecholaminergic polymorphic ventricular tachycardia caused by RyR2 mutations. Modifying the abnormal calcium handling by calcium antagonists might have therapeutic value. [source] Analysis of the Pattern of Initiation of Sustained Ventricular Arrhythmias in Patients with Implantable DefibrillatorsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2000ERIC TAYLOR M.D. Initiation of Sustained Ventricular Arrhythmias. Introduction: The purpose of this study was to analyze the pattern of initiation of sustained ventricular arrhythmias in patients with varying types of underlying structural heart disease. Methods and Results: The study group consisted of 90 patients with an implantable cardioverter defibrillator. Cardiovascular diagnoses included coronary artery disease in 64 patients (71%). The patients were divided into four groups based on the type and severity of structural heart disease. Two hundred sixty episodes of sustained ventricular arrhythmias were analyzed. The mean coupling interval of the initiating heat of all ventricular arrhythmias was 523 ± 171 msec. The coupling interval of the initiating beat was longer in patients with impaired ventricular function, particularly those with nonischemic dilated cardiomyopathy. The prematurity index was similar regardless of the type of underlying structural heart disease. However, the prematurity index was shorter in patients with polymorphic ventricular tachycardia (VT) compared to those with monomorphic VT. A pause was observed more commonly before the onset of polymorphic VT/ventricular fibrillation than sustained monomorphic VT. Two hundred twenty-two (85%) of the arrhythmia episodes were initiated by a late-coupled premature beat, 33 (13%) were initiated by an early-coupled premature beat, and 5 episodes (2%) were initiated with a short-long-short sequence. The patttern of initiation of the ventricular arrhythmias was similar in all patient groups and for both monomorphic and polymorphic tachycardias. Conclusion: These findings demonstrate that sustained ventricular arrhythmias typically are initiated by late-coupled ventricular premature depolarizations, regardless of the type or severity of underlying structural heart disease or resultant arrhythmia. [source] Temporal Variability of Ventricular Arrhythmias in Boxer Dogs with Arrhythmogenic Right Ventricular CardiomyopathyJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2009B.A. Scansen Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is prevalent in the Boxer. There is little information on the temporal variability of ventricular arrhythmias within affected dogs. Objective: To evaluate ambulatory electrocardiograms (AECG) from Boxers with ARVC for hourly variation in premature ventricular complexes (PVC) and heart rate (HR). Animals: One hundred and sixty-two Boxer dogs with ARVC. Methods: Retrospective, observational study of 1,181 AECGs collected from Boxer dogs at The Ohio State University from 1997 to 2004 was evaluated. The proportion of depolarizations that were PVCs was compared across each hour of the day, during six 4-hour periods of day, to the time after AECG application, and to the maximum and minimum HR. Results: A lower proportion of PVCs was noted during early morning (midnight to 0400 hours) as compared with the morning (0800,1200 hours) and late (1600,2000 hours) afternoon (P= .012). There was no increase in PVC proportion in the 1st hour after AECG application as compared with all other hours of the day (P= .06). There was poor correlation between maximum (,= 0.19) and minimum (,= 0.12) HR and PVC proportion. Conclusions and Clinical Importance: The likelihood of PVC occurrence in Boxer dogs with ARVC was relatively constant throughout the day, although slightly greater during the hours of 0800,1200 and 1600,2000. A biologically important correlation with HR was not apparent. The role of autonomic activity in the modulation of electrical instability in the Boxer with ARVC requires further study. [source] Toxicity in Doberman Pinchers with Ventricular Arrhythmias Treated with Amiodarone (1996,2005)JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2009M.S. Kraus Background: Asymptomatic Doberman Pinschers with dilated cardiomyopathy (DCM) often die suddenly owing to ventricular tachycardia that degenerates into ventricular fibrillation. A safe and effective antiarrhythmic drug treatment is needed. This will require a large, well-controlled, prospective study. Hypothesis: Amiodarone toxicity is common in Dobermans with occult DCM and ventricular tachyarrhythmias refractory to antiarrhythmia therapy. Infrequent monitoring of hepatic function is inadequate. Frequent monitoring may be useful to determine dogs in which the dosage should be decreased or the drug withdrawn. Methods: Medical records from the University of Georgia and Cornell University were searched for Doberman Pinschers diagnosed with preclinical DCM that received amiodarone for severe ventricular arrhythmias refractory to other antiarrhythmic agents. Echocardiographic data, Holter recording data, hepatic enzyme serum activity, and serum amiodarone concentrations were recorded. The presence of clinical signs of toxicity was recorded. Serum amiodarone concentrations were obtained in some dogs. Results: Reversible toxicity was identified in 10 of 22 (45%) dogs. Conclusion and Clinical Importance: Adverse effects from amiodarone were common and were, in part, dosage related. Patients should be monitored for signs of toxicity and liver enzyme activity should be measured at least monthly. [source] Heart Rate Turbulence Impairment and Ventricular Arrhythmias in Patients with Systemic SclerosisPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2010PIOTR BIENIAS M.D., Ph.D. Background:,Arrhythmias, conduction disturbances, and cardiac autonomic nervous system dysfunction are the most frequent cardiovascular complications in systemic sclerosis (scleroderma). The aim of the study was to assess heart rate turbulence (HRT) in systemic sclerosis patients and to identify the relationship between HRT and occurrence of arrhythmias. Methods:,Forty-five patients with scleroderma (aged 54.6 ± 14.7 years) and 30 healthy sex- and age-matched subjects were examined. In addition to routine studies, 24-hour Holter monitoring with assessment of HRT was performed. Results:,As compared to controls, HRT was significantly impaired in systemic sclerosis patients. Abnormal HRT defined as turbulence onset (TO) ,0.0% and/or turbulence slope (TS) ,2.5 ms/RR (ms/RR interval) was found in 19 (42%) scleroderma patients and in no members of the control group. Serious ventricular arrhythmias Lown class IV (VA-LownIV), for example, couplets and/or nonsustained ventricular tachycardias, were observed in 16 (36%) scleroderma patients. The median value of TS was significantly lower in systemic sclerosis patients with VA-LownIV than in patients without VA-LownIV (3.68 vs 7.00 ms/RR, P = 0.02). The area under curve of ROC analysis for prediction of VA-LownIV was 0.72 (95% confidence interval [CI] 0.56,0.87) and revealed that TS <9.0 ms/RR was associated with VA-Lown IV occurrence, with sensitivity of 93.7% and specificity of 44.8%. Univariate and multivariate analyses confirmed that lower values of TS were associated with VA-LownIV occurrence (odds ratio 1.52, 95% CI 1.09,2.12, P = 0.01). Conclusions:,Patients with systemic sclerosis are characterized by significant HRT impairment. Assessment of HRT and especially TS is useful in the identification of patients at risk for ventricular arrhythmias. (PACE 2010; 920,928) [source] Suboptimal Glycemic Control, Independently of QT Interval Duration, Is Associated with Increased Risk of Ventricular Arrhythmias in a High-Risk PopulationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2006CAROL CHEN-SCARABELLI Background: Although cardiovascular disease is the leading cause of mortality in diabetic patients, little is known about the impact of glycemic control on ventricular tachycardia (VT). Objective: To investigate whether hemoglobin A1c (HbA1c) is associated with increased incidence of VT. Methods: A retrospective study of 336 implantable cardioverter-defibrillator patients (both diabetes mellitus (DM) and non-DM) was conducted. Results: HbA1c levels between 8% and 10% had a significant association with spontaneous VT, but not with QT/QTc. Conclusions: Glycemic index is a significant predictor of spontaneous VT, independently of QT interval. Optimal glycemic control may help reduce occurrence of VT and sudden cardiac death in high-risk DM patients. [source] Ventricular Dyssynchrony and Risk Markers of Ventricular Arrhythmias in Nonischemic Dilated Cardiomyopathy:PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1p2 2003A Study with Phase Analysis of Angioscintigraphy FAUCHIER, L.,et al.: Ventricular Dyssynchrony and Risk Markers of Ventricular Arrhythmias in Nonischemic Dilated Cardiomyopathy: A Study with Phase Analysis of Angioscintigraphy.Biventricular pacing is a new form of treatment for patients with dilated cardiomyopathy and ventricular dyssynchrony. Limited information is available regarding the relationship between ventricular dyssynchrony and risk markers of ventricular arrhythmias in idiopathic dilated cardiomyopathy (IDC). In 103 patients with IDC, Fourier phase analysis of both ventricles was performed from equilibrium radionuclide angiography (ERNA). The difference between the mean phase of the LV and RV was a measure of interventricular dyssynchrony, and the standard deviations of the mean phases in each ventricle measured intraventricular dyssynchrony. There were no significant differences in inter- and intraventricular dyssynchrony between patients with versus without histories of sustained VT or VF, nonsustained VT, abnormal signal-averaged ECG, or induced sustained monomorphic VT. Dyssynchrony was not related to decreased heart rate variability (HRV). LV and interventricular dyssynchrony were weakly related to QT duration and QT dispersion. During a follow-up of27 ± 23 months, 21 patients had major adverse cardiac events (MACE), including 7 cardiac deaths, 11 progression of heart failure leading to cardiac transplantation, and 3 sustained VT/VF. The only independent predictors of MACE were an increased standard deviation of LV mean phase (P = 0.003), a decreased HRV (standard deviation of normal-to-normal intervals, P = 0.004), and histories of previous VT/VF (P = 0.03) or nonsustained VT (P = 0.04). In conclusion, left intraventricular dyssynchrony evaluated with ERNA was an independent predictor of MACE in IDC and was not related to usual risk markers of ventricular arrhythmias. This may have implications for resynchronization therapy and/or the use of implantable cardioverter defibrillators in IDC. (PACE 2003; 26[Pt. II]:352,356) [source] T-Wave Alternans and Ventricular Arrhythmias in Athletes: Usefulness of Follow-up UpdatesANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 1 2009F.E.S.C., Giuseppe Inama M.D. No abstract is available for this article. [source] Adenosine-Induced Ventricular Arrhythmias in Patients with Supraventricular TachycardiasANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 4 2008Cagatay Ertan M.D. Background: Adenosine is widely used for the diagnosis and the termination of supraventricular arrhythmias. There are many case reports and few series about the proarrhythmic potential of adenosine. We sought to evaluate the proarrhythmic potential of adenosine used to terminate the supraventricular arrhythmias. Methods: The records of all patients that received adenosine for the termination of supraventricular tachycardia were reviewed retrospectively and those with a continuous electrocardiographic (ECG) recording during adenosine administration were included to the study. Results: Our search identified 52 supraventricular episodes of 46 patients with a continuous ECG recording during adenosine administration. Following adenosine administration, premature ventricular contraction (PVC) or ventricular tachycardia (VT) developed in 22 (47.8%) patients and in 26 (50%) tachycardia episodes. No patient had a sustained VT. Nonsustained VT developed in eight (17.4%) patients. All VT episodes were polymorphic, short, and self-terminating. When the basal and demographic properties of patients with PVC or VT and those without PVT or VT were compared, there was no significant difference. Conclusions: Adenosine is a quite safe and effective drug for the termination of narrow QRS complex tachycardia but it often induces nonsustained VT or PVC that are clinically insignificant in the absence of other accompanying heart disease. [source] Usefulness of Nonlinear Analysis of ECG Signals for Prediction of Inducibility of Sustained Ventricular Tachycardia by Programmed Ventricular Stimulation in Patients with Complex Spontaneous Ventricular ArrhythmiasANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2008Ornella Durin M.D. Introduction: The aim of our study was to assess the effectiveness of the nonlinear analysis (NLA) of ECG in predicting the results of invasive electrophysiologic study (EPS) in patients with ventricular arrhythmias. Methods: We evaluated 25 patients with history of cardiac arrest, syncope, sustained, or nonsustained ventricular tachycardia (VT). All patients underwent electrophysiologic study (EPS) and nonlinear analysis (NLA) of ECG. The study group was compared with a control group of 25 healthy subjects, in order to define the normal range of NLA. ECG was processed in order to obtain numerical values, which were analyzed by nonlinear mathematical functions. Patients were classified through the application of a clustering procedure to the whole set of functions, and the correlation between the results of nonlinear analysis of ECG and EPS was tested. Results: NLA assigned all patients with negative EPS to the same class of healthy subjects, whereas the patients in whom VT was inducible had been correctly and clearly isolated into a separate cluster. In our study, the result of NLA with application of the clustering technique was significantly correlated to that of EPS (P < 0.001), and was able to predict the result of EPS, with a negative predictive value of 100% and a positive predictive value of 100%. Conclusions: NLA can predict the results of EPS with good negative and positive predictive value. However, further studies are needed in order to verify the usefulness of this noninvasive tool for sudden death risk stratification in patients with ventricular arrhythmias. [source] TASER X26 Discharges in Swine Produce Potentially Fatal Ventricular ArrhythmiasACADEMIC EMERGENCY MEDICINE, Issue 1 2008Robert J. Walter PhD Abstract Objectives:, Data from the authors and others suggest that TASER X26 stun devices can acutely alter cardiac function in swine. The authors hypothesized that TASER discharges degrade cardiac performance through a mechanism not involving concurrent acidosis. Methods:, Using an Institutional Animal Care and Use Committee (IACUC)-approved protocol, Yorkshire pigs (25,71 kg) were anesthetized, paralyzed with succinylcholine (SCh; 2 mg/kg), and then exposed to two 40-second discharges from a TASER X26 with a transcardiac vector. Vital signs, blood chemistry, and electrolyte levels were obtained before exposure and periodically for 48 hours postdischarge. Electrocardiograms and echocardiography (echo) were performed before, during, and after the discharges. p-Values < 0.05 were considered significant. Results:, Electrocardiograms were unreadable during the discharges due to electrical interference, but echo images showed unmistakably that cardiac rhythm was captured immediately at a rate of 301 ± 18 beats/min (n = 8) in all animals tested. Capture continued for the duration of the discharge and in one animal degenerated into fatal ventricular fibrillation (VF). In the remaining animals, ventricular tachycardia (VT) occurred postdischarge for 1,17 seconds, whereupon sinus rhythm was regained spontaneously. Blood chemistry values and vital signs were minimally altered postdischarge and no significant acidosis was seen. Conclusions:, Extreme acid,base disturbances usually seen after lengthy TASER discharges were absent with SCh, but TASER X26 discharges immediately and invariably produced myocardial capture. This usually reverted spontaneously to sinus rhythm postdischarge, but fatal VF was seen in one animal. Thus, in the absence of systemic acidosis, lengthy transcardiac TASER X26 discharges (2 × 40 seconds) captured myocardial rhythm, potentially resulting in VT or VF in swine. [source] Coronary Slow Flow Phenomenon and Risk for Sudden Cardiac Death Due to Ventricular Arrhythmias: A Case Report and Review of LiteratureCLINICAL CARDIOLOGY, Issue 8 2008Dr. Shoaib Saya Abstract We report a case of coronary slow flow phenomenon (CSFP) in a patient who underwent coronary angiography due to anginal chest pain and recurrent syncope with complete normalization of flow after intracoronary adenosine. He was noted to have multiple episodes of nonsustained ventricular tachycardia on holter monitor and increased QTc dispersion on surface electrocardiogram (EKG). He responded very well to oral dipyridamole therapy with complete resolution of his symptoms and no episodes of ventricular tachycardia on the event recorder at 3 months. We review the diagnosis and clinical features of CSFP and its association with increased QTc dispersion and the role of oral dipyridamole therapy in this condition. Copyright © 2007 Wiley Periodicals, Inc. [source] Benefit of Pacing and Beta-Blockers in Idiopathic Repetitive Polymorphic Ventricular TachycardiaJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2001NICASIO PÉREZ-CASTELLANO M.D. Pacing and Beta-Blockers in Repetitive Polymorphic VT. An 18-year-old woman presented with recurrent exercise-induced syncopal episodes and severe systolic dysfunction. ECG monitoring disclosed repetitive polymorphic ventricular complexes, paroxysms of bidirectional ventricular tachycardia, and nonsustained bursts of slow polymorphic ventricular tachycardia that increased in length and rate during exercise. Ventricular arrhythmias were refractory to medical treatment, which included verapamil and beta-blockers. Addition of permanent atrial pacing to beta-blocker therapy suppressed the arrhythmias and reversed systolic impairment in the following months. [source] Characterization of the Electroanatomic Substrate for Monomorphic Ventricular Tachycardia in Patients with Nonischemic CardiomyopathyPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2002HENRY H. HSIA HSIA, H.H., et al.: Characterization of the Electroanatomic Substrate for Monomorphic Ventricular Tachycardia in Patients with Nonischemic Cardiomyopathy. Ventricular arrhythmias are common in the setting of nonischemic cardiomyopathy. The etiology for the cardiomyopathy is frequently not identified and the label of "idiopathic" is applied. Interstitial fibrosis with conduction system involvement and associated left bundle branch block characterizes the disease process in some patients and the mechanism for monomorphic ventricular tachycardia is commonly bundle branch reentry. However, most patients with nonischemic cardiomyopathy have VT due to myocardial reentry and demonstrate marked myocardial fibrosis and electrogram abnormalities. Although patient specific, the overall distribution of electroanatomic abnormalities appears to be equal on the endocardium and epicardium. The extent of electrogram abnormalities appears to parallel arrhythmia presentation and/or inducibility. Patients with sustained uniform morphology VT have the most extensive endocardial and epicardial electrogram abnormalities. Magnetic electroanatomic voltage mapping provides a powerful tool to characterize the location and extent of the arrhythmia substrate. Basal left ventricular myocardial involvement, as indexed by the location of contiguous electrogram abnormalities, is common in patients with sustained VT and left ventricular cardiomyopathy. The relatively equal distribution of electrogram abnormalities on the endocardium and epicardium, and the results of mapping and ablation attempts, suggest that critical parts of the reentrant circuit may be epicardial. Unique features of the electroanatomic substrate associated with cardiomyopathy due to Chagas' disease, sarcoidosis, and arrhythmogenic right ventricular dysplasia are also discussed. [source] Ventricular arrhythmias: A general cardiologist's assessment of therapies in 2005CLINICAL CARDIOLOGY, Issue 7 2005C. Richard Conti M.D., M.A.C.C. Editor-in-Chief No abstract is available for this article. [source] The Spectrum of Long-term Electrophysiologic Abnormalities in Patients with Univentricular HeartsCONGENITAL HEART DISEASE, Issue 5 2009Kathryn K. Collins MD ABSTRACT Patients with univentricular hearts experience a wide range of electrophysiolgic abnormalities which tend to develop years after cardiovascular surgical interventions. Intra-atrial reentrant tachycardia (atrial flutter) in the Fontan population is the most common arrhythmia and, as such, has the largest body of literature addressing its cause and treatment. However, sinus node dysfunction, other atrial arrhythmias, ventricular arrhythmias, and cardiac dysynchrony also occur in this patient population. The purpose of this article is to review the prevalence, mechanisms, and treatment of these electrophysiologic abnormalities within the single ventricle and Fontan patient. [source] Aortic Valve Sclerosis: Is It a Cardiovascular Risk Factor or a Cardiac Disease Marker?ECHOCARDIOGRAPHY, Issue 3 2007F.I.S.C.U., Pasquale Palmiero M.D. Background: Aortic valve sclerosis, without stenosis, has been associated with an increased cardiovascular mortality and morbidity due to myocardial infarction. However, it is unclear whether it is a cardiovascular risk factor or a cardiac disease marker. The goal of our study is to evaluate the difference in the prevalence of cardiovascular disease and risk factors among patients with or without aortic sclerosis. Methods: This observational study compared a group of 142 consecutive subjects with aortic valve sclerosis, assigned as group S, with a group of 101 subjects without aortic sclerosis, assigned as group C. Patients with bicuspid aortic valves and those with antegrade Doppler velocity across aortic valve leaflets exceeding 2.0 m/sec were excluded. Results: Mean ages of groups S and C were 71 ± 8, and 68.8 ± 6 years, respectively (P value = not significant). The prevalence of smoking, diabetes, hypercholesterolemia, hypertension, pulse pressure, left ventricular diastolic dysfunction, atrial fibrillation, and stroke was not significantly different between the two groups. However, there was a significantly higher prevalence of left ventricular hypertrophy (P = 0.05), ventricular arrhythmias (P = 0.02), myocardial infarction (P = 0.04), and systolic heart failure (P = 0.04) in aortic sclerosis group. Conclusions: Aortic sclerosis is associated with a higher prevalence of left ventricular hypertrophy, ventricular arrhythmias, myocardial infarction, and systolic heart failure, while the prevalence of cardiovascular risk factors is not different between aortic sclerosis patients and controls. Hence, aortic sclerosis represents a cardiac disease marker useful for early identification of high-risk patients beyond cardiovascular risk factors rate. [source] Noncompaction of the Ventricular Myocardium: Report of Two Cases With Bicuspid Aortic Valve Demonstrating Poor Prognosis and With Prominent Right Ventricular InvolvementECHOCARDIOGRAPHY, Issue 4 2003Yuksel Cavusoglu Noncompaction of the ventricular myocardium is a rare, unclassified cardiomyopathy due to an arrest of myocardial morphogenesis. The characteristic echocardiographic findings consist of multiple, prominent myocardial trabeculations and deep intertrabecular spaces communicating with the left ventricular (LV) cavity. The disease typically involves the LV myocardium, but right ventricular (RV) involvement is not uncommon. The clinical manifestations include heart failure (HF) signs, ventricular arrhythmias and cardioembolic events. Noncompacted myocardium may occur as an isolated cardiac lesion, as well as it can be in association with congenital anomalies. We describe two illustrative cases of noncompaction of the ventricular myocardium, a 19-year-old male with bicuspid aortic valve and progressive worsening of HF, and a 61-year-old male with marked RV involvement in addition to LV apical involvement, both with the typical clinical and echocardiographic features of the disease. (ECHOCARDIOGRAPHY, Volume 20, May 2003) [source] A new approach to long QT syndrome mutation detection by Sequenom MassARRAY® systemELECTROPHORESIS, Issue 10 2010Catarina Allegue Abstract Congenital long QT syndrome is an inherited cardiac disorder characterized by a prolonged QT interval and polymorphic ventricular arrhythmias that could result in recurrent syncope, seizures or sudden death as the most dramatic event. Until now QT interval mutations have been described in 12 genes, where the majority of mutations reside in three genes KCNQ1, KCNH2, and SCN5A. Diagnosis and prognosis are directly related with the gene and mutation involved. We have developed a diagnostic approach for long QT syndrome and Brugada syndrome based on published mutations and Sequenom MassArray® system. Three diagnostic tests have been developed, oriented to each of the three most prevalent genes in the long QT syndrome. A total of 433 mutations are analyzed in 38 multiplex reactions, allowing their detection in about 48,h. Tests were validated on 502 samples from individuals with different clinical conditions and family history. The average call rates obtained for each of the tests were 93, 83, and 73% in KCNQ1, KCNH2, and SCNA, respectively. Sequenom MassARRAY mutation detection is a reliable, highly flexible, and cost-efficient alternative to conventional methods for genetic testing in long QT syndrome and Brugada syndrome, facilitating flexible upgrades of the version of the test presented here with the inclusion of new mutations. [source] Increased QT variability in young asymptomatic patients with ,-thalassemia majorEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 4 2007Damiano Magrě Abstract Background:, Despite recent progress in iron chelation therapy, sudden cardiac death due to malignant ventricular arrhythmias remains a vexing, clinical problem in patients with ,-thalassemia major (TM). In this study we assessed whether the major indices of QT variability, emerging tools for risk stratification of sudden cardiac death, differ in young asymptomatic patients with TM and healthy persons. Methods: Thirty patients with TM and 30 healthy control subjects underwent a 5-min electrocardiography recording to calculate the following variables: QT variance (QTv), QTv normalized for mean QT (QTVN) and QT variability index (QTVI). All subjects also underwent a two-dimensional and Doppler echocardiography study and magnetic resonance imaging (MRI) to determine cardiac and hepatic T2* values. Results: No differences were observed in clinical and conventional echo-Doppler findings in healthy control subjects and patients with TM whereas QTv, QTVN and QTVI values were significantly higher in patients than those in controls (QTv, P < 0.001; QTVN, P < 0.05 and QTVI, P < 0.001) and cardiac T2* and hepatic MRI T2* values were significantly lower in patients with TM (P < 0.001). The indices of temporal QT variability correlated significantly with MRI data. Conclusions: Young asymptomatic patients with TM have increased cardiac repolarization variability as assessed by QT variability indices, probably due to cardiac iron deposition. These easily assessed, non-invasive markers could be used to identify increased myocardial repolarization lability early in asymptomatic patients with TM. [source] Correlation of ,-skeletal actin expression, ventricular fibrosis and heart function with the degree of pressure overload cardiac hypertrophy in ratsEXPERIMENTAL PHYSIOLOGY, Issue 3 2006Donatella Stilli We have analysed alterations of ,-skeletal actin expression and volume fraction of fibrosis in the ventricular myocardium and their functional counterpart in terms of arrhythmogenesis and haemodynamic variables, in rats with different degrees of compensated cardiac hypertrophy induced by infra-renal abdominal aortic coarctation. The following coarctation calibres were used: 1.3 (AC1.3 group), 0.7 (AC0.7) and 0.4 mm (AC0.4); age-matched rats were used as controls (C group). One month after surgery, spontaneous and sympathetic-induced ventricular arrhythmias were telemetrically recorded from conscious freely moving animals, and invasive haemodynamic measurements were performed in anaesthetized animals. After killing, subgroups of AC and C rats were used to evaluate in the left ventricle the expression and spatial distribution of ,-skeletal actin and the amount of perivascular and interstitial fibrosis. As compared with C, all AC groups exhibited higher values of systolic pressure, ventricular weight and ventricular wall thickness. AC0.7 and AC0.4 rats also showed a larger amount of fibrosis and upregulation of ,-skeletal actin expression associated with a higher vulnerability to ventricular arrhythmias (AC0.7 and AC0.4) and enhanced myocardial contractility (AC0.4). Our results illustrate the progressive changes in the extracellular matrix features accompanying early ventricular remodelling in response to different degrees of pressure overload that may be involved in the development of cardiac electrical instability. We also demonstrate for the first time a linear correlation between an increase in ,-skeletal actin expression and the degree of compensated cardiac hypertrophy, possibly acting as an early compensatory mechanism to maintain normal mechanical performance. [source] Effect of Cl, channel blockers on aconitine-induced arrhythmias in rat heartEXPERIMENTAL PHYSIOLOGY, Issue 6 2005Shi-Sheng Zhou The effects of Cl, channel blockers 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) and niflumic acid (NFA) on aconitine-induced arrhythmias were investigated. Left ventricular pressure and electrocardiogram were monitored in Langendorff-perfused rat hearts. Whole-cell patch-clamp and current-clamp techniques were used to measure sodium current (INa) and action potential (AP), respectively, in single rat cardiac ventricular myocytes. Addition of the Na+ channel agonist aconitine (0.1 ,m) to the perfusion solution produced polymorphic ventricular arrhythmias with a latent period of 25.5 ± 6.3 s. NPPB could reverse aconitine-induced arrhythmias. A similar effect was observed by using NFA. NPPB and NFA reversibly depressed the upstroke of the AP in a dose-dependent manner with IC50 values of ,12.3 and ,73.1 ,m, respectively, without significantly affecting the resting potential of rat ventricular myocytes. Both Cl, channel blockers inhibited INa and induced a leftward shift of the steady-state inactivation of INa. In conclusion, the results of this study demonstrate that NPPB as well as NFA can suppress aconitine-induced arrhythmias in rat hearts mainly by inhibiting cardiac INa. [source] Optimal boundary control of cardiac alternansINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 2 2009Stevan Dubljevic Abstract Alternation of normal electrical activity in the myocardium is believed to be linked to the onset of life-threatening ventricular arrhythmias and sudden cardiac death. In this paper, a spatially uniform unstable steady state of small amplitude of alternans described by parabolic partial differential equations (PDEs) is stabilized by boundary optimal control methods. A finite dimensional linear quadratic regulator (LQR) is utilized in both a full-state-feedback control structure and in a compensator design with the Luenberger observer, and it achieves global stabilization in a finite size tissue cable length. The ability to realize such control algorithm is analyzed based on the structure of the amplitude of alternans equation and the control methodology applied. Copyright © 2008 John Wiley & Sons, Ltd. [source] A case of fatal caffeine poisoningACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010T. RUDOLPH Caffeine is a natural alkaloid methylxanthine that is found in various plants such as coffee or tea. Symptoms of a severe overdose may present with hypokalemia, hyponatremia, ventricular arrhythmias, hypertension followed by hypotension, respiratory failure, seizures, rhabdomyolysis, ventricular fibrillation and finally circulatory collapse. A 21-year-old woman called for the ambulance herself soon after the ingestion of about 10,000 mg of caffeine. At the arrival of the ambulance, the patient went into cardiac arrest almost immediately. After a total resuscitation period of 34 min including seven counter-shocks and 2 mg epinephrine, the patient was stable enough to be transferred to the hospital. The patient soon went into VF again and received two more counter-shocks and 1 mg epinephrine and finally an intravenous bolus dose of 300 mg amiodarone. The initial arterial blood gas showed pH at 6.47, lactate at 33 mmol/l and potassium level at 2.3 mmol/l. Unfortunately, no blood samples for caffeine analysis were taken. Three days after hospital admission, the patient developed myoclonus, which did not respond to medical treatment. Excessive intake of caffeine may produce arrhythmias and pronounced hypokalemia and ensuing ventricular fibrillation. In case of counter-shock-resistant VF, it can be necessary to give an early loading dose of amiodarone. Furthermore, it may be beneficial to replace the potassium as early as possible. Epinephrine and buffer solutions used during resuscitation may further decrease blood potassium levels and should be administrated cautiously. Epinephrine can be replaced by other vasopressor drugs, such as vasopressin without effects on ,-receptors. [source] Predictors of Early Outcome After Coronary Artery Surgery in Patients with Severe Left Ventricular DysfunctionJOURNAL OF CARDIAC SURGERY, Issue 2 2003Naresh Trehan The present study was undertaken to identify the prognostic factors in such patients. Methods: We analyzed the data of 176 consecutive patients (161 men, 15 women), aged 29 to 88 years (mean 58.43), with a left ventricular ejection fraction (LVEF) <30% who underwent isolated coronary artery bypass grafting. The LVEF ranged from 15% to 30% (mean 27.18%). Preoperatively, 33% had angina, 19.9% had recent myocardial infarction, and 21.6% had congestive heart failure. The mean number of grafts was 2.5/patient. The intra-aortic balloon was used prophylactically in 20.5% of patients and therapeutically in 4.0% of patients. Results: The hospital mortality was 2.3%. The complications occurred as follows: perioperative myocardial infarction in two (1.1%), intractable ventricular arrhythmias in two (1.1%), prolonged ventilation in four (2.3%) and peritoneal dialysis in 1 (0.6%). The mean ICU and hospital stay were2.46 ± 0.76and7.57 ± 2.24days, respectively. The predictors of survival on univariate analysis were New York Heart Association (NYHA) class(x2 = 14.458, p < 0.001), recent myocardial infarction(x2 = 5.852, p = 0.016), congestive heart failure (CHF)(x2 = 5.526, p = 0.019), and left ventricular end-systolic volume index (LVESVI)(x2 = 25.833, p < 0.001). However, on multivariate analysis, left ventricular end-systolic volume index was the only independent left ventricular function measurement predictive of survival(x2 = 10.228, p = 0.001). Conclusion: Left ventricular end-systolic volume index is the most important predictor of survival after coronary artery bypass surgery in patients with severe myocardial dysfunction.(J Card Surg 2003;18:101-106) [source] Perioperative Ventricular Arrhythmias in Patients Undergoing Partial Left VentriculectomyJOURNAL OF CARDIAC SURGERY, Issue 2 2001Toshimi Ujiie M.D. Background: Although incidence of ventricular arrhythmias after partial left ventriculectomy (PLV) has been reported, there are no studies comparing incidence before and after PLV. Although operative scars may give rise to arrhythmias, improved energetic efficiency after PLV may decrease their incidence. Methods: Pre- and postoperative ventricular arrhythmias were monitored by Holter ECG and analyzed in 17 patients undergoing PLV in Curitiba, Brazil. Results: Although total 24-hour heart beat (THB) increased significantly (p = 0.018), ventricular premature contractions (VPCs) decreased markedly (p = 0.036), excluding one patient dying in low cardiac output (LOS) who had terminal arrhythmias increased multifold. In the remaining 16 patients, VPC pairs were also reduced significantly on the average (p = 0.038). In contrast, ventricular tachycardia (VT; more than three consecutive VPCs) disappeared in five patients, decreased in two patients, and newly occurred in four patients, with five patients showing no change; one of them developed a prolonged VT, successfully reversed by external cardioversion. Conclusions: Despite notable significant increase in THB immediately after PLV, PVC and PVC pairs were significantly decreased in contrast to VT, which disappeared in some patients and newly occurred in other patients, remaining constant on the average. Sustained VT occurring in a patient with all other arrhythmias suppressed may suggest a unique electrophysiological substrate, may justify prophylactic use of amiodarone or an implantable cardioverter-defibrillator, and may underscore the importance of further and extended studies. [source] Idiopathic Left Ventricular Arrhythmias Originating Adjacent to the Left Aortic Sinus of Valsalva: Electrophysiological Rationale for the Surface ElectrocardiogramJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2 2010TAKUMI YAMADA M.D. IVT Arising Adjacent to the Left Sinus of Valsalva.Background: Idiopathic ventricular arrhythmias (VAs) may be amenable to catheter ablation within or adjacent to the left sinus of Valsalva (LSOV). However, features that discriminate these sites have not been defined. The purpose of this study was to determine the electrocardiographic and electrophysiological features of VAs originating within or adjacent to the LSOV. Methods and Results: We studied 48 consecutive patients undergoing successful catheter ablation of idiopathic VAs originating from the left coronary cusp (LCC, n = 29), aortomitral continuity (AMC, n = 10) and great cardiac vein or anterior interventricular cardiac vein (Epi, n = 9). A small r wave, or rarely an R wave, was typically observed in lead I during the VAs and pacing in these regions. An S wave in lead V5 or V6 occurred significantly more often during both the VAs and pacing from the AMC than during that from the LCC and Epi (p < 0.05 to 0.0001). For discriminating whether VA origins can be ablated endocardially or epicardially, the maximum deflection index (MDI = the shortest time to the maximum deflection in any precordial lead/QRS duration) was reliable for VAs arising from the AMC (100%), but was less reliable for LCC (73%) and Epi (67%) VAs. In 3 (33%) of the Epi VAs, the site of an excellent pace map was located transmurally opposite to the successful ablation site (LCC = 1 and AMC = 2). Conclusions: The MDI has limited value for discriminating endocardial from epicardial VA origins in sites adjacent to the LSOV probably due to preferential conduction, intramural VA origins or myocardium in contact with the LCC. (J Cardiovasc Electrophysiol, Vol. 21, pp. 170-176, February 2010) [source] Cardiac Calsequestrin: The New Kid on the Block in ArrhythmiasJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2009NAGESH CHOPRA M.D. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited disease characterized by physical or emotional stress-induced ventricular arrhythmias in the absence of any structural heart disease or QT prolongation. Thus far, mutations in genes encoding the sarcoplasmic reticulum Ca2+ release channel (RYR2) and the sarcoplasmic reticulum Ca2+ binding protein cardiac calsequestrin (CASQ2) have been identified in CPVT patients. Here, we review the role of cardiac calsequestrin in health and disease, with a particular focus on how calsequestrin deficiency can cause arrhythmia susceptibility. Clinical implications and a promising new drug therapy for CPVT are discussed. [source] Malignant Ventricular Arrhythmia in a Case of Adult Onset of Spinal Muscular Atrophy (Kugelberg,Welander Disease)JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2009MARKUS ROOS M.D. We present a case of a 43-year-old male patient with adult onset of spinal muscular atrophy (SMA). The patient first came to our attention with atrioventricular (AV) block. A dual-chamber pacemaker (DDD-PM) was implanted. Four years later, the PM data log showed occurrence of frequent episodes of nonsustained ventricular tachycardia (NSVT). The episodes progressed in duration and frequency. An electrophysiological study revealed prolonged His-ventricular (HV) interval duration and induction of sustained ventricular tachycardia. The patient was successfully upgraded to a prophylactic dual-chamber cardioverter defibrillator. Our case is the first description of a patient with adult-onset SMA (Kugelberg,Welander disease [KWD]) and malignant ventricular arrhythmias. [source] | ||||||||||||||||||||||||||||||||||