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Supraventricular Arrhythmias (supraventricular + arrhythmias)
Selected AbstractsSupraventricular Arrhythmias in Children and Young Adults with Implantable Cardioverter DefibrillatorsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2001BARRY A. LOVE M.D. SVT in Pediatric ICD Recipients.Introduction: Rapidly conducted supraventricular tachycardias (SVTs) can lead to inappropriate device therapy in implantable cardioverter defibrillator (ICD) patients. We sought to determine the incidence of SVTs and the occurrence of inappropriate ICD therapy due to SVT in a pediatric and young adult population. Methods and Results: We undertook a retrospective review of clinical course, Holter monitoring, and ICD interrogations of patients receiving ICD follow-up at our institution between March 1992 and December 1999. Of 81 new ICD implantations, 54 eligible patients (median age 16.5 years, range 1 to 48) were identified. Implantation indications included syncope and/or spontaneous/inducible ventricular arrhythmia with congenital heart disease (30), long QT syndrome (9), structurally normal heart (ventricular tachycardia/ventricular fibrillation [VT/VF]) (7), and cardiomyopathies (7). Sixteen patients (30%) received a dual-chamber ICD. SVT was recognized in 16 patients, with 12 of 16 having inducible or spontaneous atrial tachycardias. Eighteen patients (33%) received , 1 appropriate shock(s) for VT/VF; 8 patients (15%) received inappropriate therapy for SVT. Therapies were altered after an inappropriate shock by increasing the detection time or rate and/or increasing beta-blocker dosage. No single-chamber ICD was initially programmed with detection enhancements, such as sudden onset, rate stability, or QRS discriminators. Only one dual-chamber defibrillator was programmed with an atrial discrimination algorithm. Appropriate ICD therapy was not withheld due to detection parameters or SVT discrimination programming. Conclusion: SVT in children and young adults with ICDs is common. Inappropriate shocks due to SVT can be curtailed even without dual-chamber devices or specific SVT discrimination algorithms. [source] 25 Years of Insights into the Mechanisms of Supraventricular ArrhythmiasPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2003NASPE HISTORY SERIES The introduction of programmed electrical stimulation of the heart and intracardiac activation mapping 35 years ago made it possible to study the site of origin or pathway of a supraventricular tachycardia and to gain insight into the tachycardic mechanism. Information from these studies has been the basis for the development of new therapies, like arrhythmia surgery, antitachycardia pacing, and catheter ablation. The correlation of intracardiac findings with the 12-lead ECG during the tachycardia resulted in the recognition of characteristic ECG patterns for the different types of supraventricular tachycardias. Currently, gross localization of the site of origin of the arrhythmia is based on the 12-lead ECG during the arrhythmia with fine tuning using intracardiac activation mapping and pacing. These developments during the past 3 decades make accurate arrhythmia diagnosis possible and allow us to offer curative therapies to many of patients suffering from a supraventricular tachycardia. (PACE 2003; 26:1916,1922) [source] Evaluation of the Relationship between Atrial Septal Aneurysm and Cardiac Arrhythmias via P-Wave Dispersion and Signal-Averaged P-Wave DurationANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2010Onur Sinan Deveci M.D. Objective: The aim of the study was to investigate the relationship between atrial septal aneurysms (ASAs) and cardiac arrhythmias via signal-averaged P-wave duration (SAPWD) and P-wave dispersion (Pd). Methods: Sixty-six patients with ASA served as the study group (group 1; 28 men and 38 women; mean age, 34 ± 10 years) and 62 healthy volunteers served as the control group (group 2; 29 men and 33 women; mean age, 31 ± 8 years) in the current study. ASAs were diagnosed by transthoracic echocardiography based on the criteria of a minimal aneurysmal base of ,15 mm; and an excursion of ,10 mm. All subjects were evaluated by 24-hour Holter monitoring, 12 lead body surface electrocardiogram for P-wave analysis, and signal-averaged electrocardiogram for P-wave duration (PWD). Results: There was no significant difference between the study and control groups in terms of age, gender, left atrium diameter, and left ventricular ejection fraction. Supraventricular arrhythmias (SVAs) were detected in 29 patients with ASA (43.9%) and 5 controls (8.1%; P < 0.001). The mean Pd in patients with ASA was significantly longer compared to the control group (14.1 ± 8 ms vs 7.0 ± 2.9 ms; P < 0.001). Similarly, the mean SAPWD in group 1 was significantly longer compared to group 2 (127.4 ± 17.6 ms vs 99.8 ± 12.3 ms; P < 0.001). Conclusion: Prolonged SAPWD and Pd were determined to indicate electrical disturbances in the atrial myocardium, and predict the increase in the prevalence of SVA in patients with ASA. Ann Noninvasive Electrocardiol 2010;15(2):157,164 [source] Potent Antiarrhythmic Effects of Chronic Amiodarone in Canine Pulmonary Vein Sleeve PreparationsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2009SERGE SICOURI M.D. Objectives: To examine the effects of chronic amiodarone on the electrophysiology of canine pulmonary vein (PV) sleeve preparations and left ventricular wedge preparation. Background: Amiodarone is commonly used for the treatment of ventricular and supraventricular arrhythmias. Ectopic activity arising from the PV plays a prominent role in the development of atrial fibrillation (AF). Methods: Standard microelectrode techniques were used to evaluate the electrophysiological characteristics of superfused PV sleeve (left superior or inferior) and arterially perfused left ventricular (LV) wedge preparations isolated from untreated and chronic amiodarone-treated dogs (amiodarone, 40 mg/kg daily for 6 weeks). Results: In PV sleeves, chronic amiodarone (n = 6) induced a significant increase in action potential duration at 90% repolarization (APD90) and a significant use-dependent reduction in Vmax leading to 1:1 activation failure at long cycle lengths (basic cycle length of 124 ± 15 ms in control vs 420 ± 320 ms after chronic amiodarone [P < 0.01]). Diastolic threshold of excitation increased from 0.3 ± 0.2 to 1.8 ± 0.7 mA (P < 0.01). Delayed and late phase 3 early afterdepolarizations and triggered activity could be induced in PV sleeve preparations using acetylcholine (ACh, 1 ,M), high calcium ([Ca2+]o= 5.4 mM), isoproterenol (Iso, 1 ,M), or their combination in 6 of 6 untreated PV sleeves, but in only 1 of 5 chronic amiodarone-treated PV sleeve preparations. Vmax, conduction velocity, and 1:1 activation failure were much more affected in PV sleeves versus LV wedge preparations isolated from amiodarone-treated animals. Conclusions: The results point to potent effects of chronic amiodarone to preferentially suppress arrhythmogenic substrates and triggers arising from the PV sleeves of the dog. [source] Cigarette Smoking and the Risk of Supraventricular and Ventricular Tachyarrhythmias in High-Risk Cardiac Patients with Implantable Cardioverter DefibrillatorsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2006ILAN GOLDENBERG M.D. Introduction: Nicotine elevates serum catecholamine concentration and is therefore potentially arrhythmogenic. However, the effect of cigarette smoking on arrhythmic risk in coronary heart disease patients is not well established. Methods and Results: The risk of appropriate and inappropriate defibrillator therapy by smoking status was analyzed in 717 patients who received an implantable cardioverter defibrillator (ICD) in the Multicenter Automatic Defibrillator Implantation Trial-II. Compared with patients who had quit smoking before study entry (past smokers) and patients who had never smoked (never smokers), patients who continued smoking (current smokers) were significantly younger and generally had more favorable baseline clinical characteristics. Despite this, the adjusted hazard ratio (HR) for appropriate ICD therapy for fast ventricular tachycardia (at heart rates ,180 b.p.m) or ventricular fibrillation was highest among current smokers (HR = 2.11 [95% CI 1.11,3.99]) and intermediate among past smokers (HR = 1.57 [95% CI 0.95,2.58]), as compared with never smokers (P for trend = 0.02). Current smokers also exhibited a higher risk of inappropriate ICD shocks (HR = 2.93 [95% CI 1.30,6.63]) than past (HR = 1.91 [95% CI 0.97,3.77]) and never smokers (P for trend = 0.008). Conclusions: In patients with ischemic left ventricular dysfunction, continued cigarette smoking is associated with a significant increase in the risk of life-threatening ventricular tachyarrhythmias and inappropriate ICD shocks induced by rapid supraventricular arrhythmias. Our findings stress the importance of complete smoking cessation in this high-risk population. [source] Pharmacotherapy Review: Calcium Channel BlockersJOURNAL OF CLINICAL HYPERTENSION, Issue 1 2006Domenic A. Sica MD As a drug class, calcium channel blockers encompass a heterogeneous group of compounds with distinctive structures and pharmacologic characteristics. These agents are widely used in the treatment of hypertension, chronic coronary ischemia, and/or supraventricular arrhythmias. Much of the early debate alluding to increased cardiovascular risk associated with calcium channel blocker use has been silenced by an array of outcomes trials that show these drugs to be both safe and effective in reducing hard cardiovascular end points. The most common side effects associated with calcium channel blockers are vasodilatory in nature and include a non-volume-dependent form of peripheral edema, flushing, and headache. Despite the sometimes discomforting side effects seen with calcium channel blocker therapy, their robust blood pressure-lowering effect makes them an important component of most multidrug regimens used for blood pressure control. [source] Alcohol Intake is Significantly Associated with Atrial Flutter in Patients under 60 Years of Age and a Shorter Right Atrial Effective Refractory PeriodPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2008GREGORY M. MARCUS M.D. Background: Although evidence suggests that alcohol is associated with atrial fibrillation (AF), the association between alcohol and atrial flutter (AFL) has not been examined. The mechanism connecting alcohol and atrial arrhythmias is unknown. Methods: Alcohol intake was determined in 195 consecutive patients with AF and AFL. Control subjects included patients with other supraventricular arrhythmias (n = 132) and healthy subjects (n = 54). Because of important competing risk factors for atrial arrhythmias in the elderly, stratification by age was performed. In a subset, atrial effective refractory periods (AERPs) were obtained from the high right atrium and proximal and distal coronary sinus. Results: AF and AFL patients were significantly more likely to be daily alcohol drinkers (27% vs 14% of controls, P = 0.001). In multivariable analysis, AFL patients , 60 years of age were significantly more likely to be daily drinkers than to drink no alcohol compared to controls (odds ratio 17, 95% confidence interval 1.6,192.0, P = 0.019). Progressively more frequent alcohol intake was significantly associated with a progressively greater odds of AFL in patients , 60 years of age (P = 0.045). Neither AF subjects of any age nor AFL subjects > 60 years of age exhibited significant associations with alcohol after multivariable adjustment. Right AERPs shortened significantly with increasing amounts of alcohol intake (P = 0.025), whereas left AERPs were not associated with alcohol intake. Conclusions: Alcohol intake is positively associated with AFL in younger patients. The mechanism may be related to a shortening of the right AERP. [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] Right ventricular involvement in hypertrophic cardiomyopathy: A case report and literature reviewCLINICAL CARDIOLOGY, Issue 1 2001Dariush Mozaffarian M.D. Abstract Although hypertrophic cardiomyopathy (HCM) is classically considered a disease of the left ventricle, right ventricular (RV) abnormalities have also been reported. However, involvement of the right ventricle in HCM has not been extensively characterized. The literature regarding prevalence, genetics, patterns of involvement, histologic findings, symptoms, diagnosis, and treatment of RV abnormalities in HCM is reviewed. To highlight the salient points, a case is presented of apical HCM with significant RV involvement, with an RV outflow tract gradient and near obliteration of the RV cavity, in the absence of a left intraventricular gradient. Right ventricular involvement in HCM appears to be as heterogeneous as that of the left ventricle. The spectrum extends from mild concentric hypertrophy to more unusual severe, obstructive disease. While in some cases the extent of RV involvement correlates with left ventricular (LV) involvement, predominant RV disease can be seen as well. While the genetics of RV involvement have not been well characterized, histologic findings appear to be similar to those in the left ventricle, suggesting similar pathogenesis. Significant RV involvement may result in RV outflow obstruction and/or reduced RV diastolic filling, with potentially increased incidence of severe dyspnea, supraventricular arrhythmias, and pulmonary thromboembolism. The optimal treatment for patients with significant RV disease is unknown. Medical and surgical therapies have been attempted with variable success; experience with newer techniques such as percutaneous catheter ablation has not been reported. Further characterization of RV involvement in HCM is necessary to elucidate more clearly the clinical features and optimal treatments of this manifestation of HCM. [source] | ||||||||||