Arrhythmogenic cardiomyopathy (AC) is a rare heart muscle disease with a genetic background and autosomal dominant mode of transmission. The clinical manifestation is characterized by ventricular arrhythmias (VA), heart failure (HF) and the risk of sudden cardiac death (SCD). Pregnancy in young female patients with AC represents a challenging condition for the life and family planning of young affected women.
View Article and Find Full Text PDFIntroduction: The antihistaminic antazoline (ANT) was reported to be highly effective and safe for rapid conversion of atrial fibrillation (AF). We therefore analyzed underlying mechanisms in an experimental whole-heart model.
Methods And Results: Isolated and retrogradely perfused rabbit hearts underwent a standardized protocol employing atrial burst pacing-induced AF in five of 20 hearts under baseline conditions (seven episodes).
In several case reports proarrhythmic effects of citalopram and escitalopram have been reported. Systematic analyses on prorarrhythmic effects of these drugs are not yet available. The aim of the present study was to investigate if application of citalopram, escitalopram or haloperidol provokes polymorphic ventricular tachycardia in a sensitive model of proarrhythmia.
View Article and Find Full Text PDFIn several case reports a prolongation of the QT-interval and even proarrhythmic effects of fluconazole and voriconazole were reported. The aim of the present study was to investigate if application of fluconazole or voriconazole has the potential to provoke polymorphic ventricular tachycardia in a sensitive model of proarrhythmia. In female rabbits, fluconazole (10, 30 and 50 µM, n=6) and voriconazole (10, 30 and 50 µM, n=6) were infused after obtaining baseline data.
View Article and Find Full Text PDFObjective: Catheter-based modulation of the slow pathway is the first-line therapy of atrioventricular nodal reentrant tachycardia (AVNRT), the most common supraventricular tachycardia (SVT). In patients with a typical history, in whom AVNRT is not inducible during an electrophysiological study, the current guidelines allow consideration of empirical slow pathway modulation (ESPM) under the precondition that both, dual nodal pathway physiology (DNPP) and an ECG documentation compatible with AVNRT exist. This recommendation is based on small series.
View Article and Find Full Text PDFAims: Interaction between dronedarone and digitalis has been discussed as a possible cause for increased mortality in the presence of dronedarone observed in the PALLAS trial. The aim of this study was to assess possible proarrhythmic effects of dronedarone in combination with digitalis in an experimental whole heart model.
Methods And Results: Twenty-six female rabbits underwent chronic oral treatment with dronedarone (50 mg/kg/day for 6 weeks).
Background: The present ESC guidelines on atrial fibrillation have introduced vernakalant (VER) for pharmacologic cardioversion of atrial fibrillation. The aim of the present study was to investigate possible proarrhythmic effects of vernakalant in an experimental model of heart failure (HF).
Methods And Results: In 12 female rabbits, HF was induced with the use of 4 weeks of rapid ventricular pacing.
Aim: The most recent European Society of Cardiology (ESC) update on atrial fibrillation has introduced vernakalant (VER) for pharmacological cardioversion of atrial fibrillation. The aim of the present study was to investigate the safety profile of VER in a sensitive model of proarrhythmia.
Methods And Results: In 36 Langendorff-perfused rabbit hearts, VER (10, 30 µM, n = 12); ranolazine (RAN, 10, 30 µM, n = 12), or sotalol (SOT, 50; 100 µM, n = 12) were infused after obtaining baseline data.
Owing to increased life expectancy, patients with grown-up congenital heart disease nowadays present various types of arrhythmias. We report treatment of a 27-year-old patient with tricuspid and pulmonary atresia who was referred to our department with symptomatic tachycardia. During electrophysiologic study, a diagnosis of typical AV-nodal re-entrant tachycardia was made, and he was successfully treated despite the described anatomic malformation.
View Article and Find Full Text PDFAims: Phased radiofrequency (RF) ablation for atrial fibrillation is associated with an increased number of silent cerebral lesions on magnetic resonance imaging and cerebral microembolic signals (MESs) on transcranial Doppler ultrasound imaging compared with irrigated RF. The increased rate of embolic events may be due to a specific electrical interference of ablation electrodes attributed to the catheter design. The purpose of this study was to elucidate the effect of deactivating the culprit electrodes on cerebral MESs.
View Article and Find Full Text PDFHerzschrittmacherther Elektrophysiol
June 2013
Early repolarization, involving infero-lateral ST segment elevation and prominent J waves at the QRS-ST junction has been considered a normal ECG variant for more than 80 years. More recent studies suggest that this phenomenon is not as benign as earlier believed and may represent a risk for subsequent ventricular fibrillation in patients with and without structural heart disease. However, based on current data it seems unjustified to consider these often accidental ECG findings a marker for high risk of sudden cardiac death.
View Article and Find Full Text PDFBackground: Ranolazine is evaluated for antiarrhythmic therapy of atrial fibrillation (AF). The electrophysiologic mechanisms of ranolazine in combination with class III drugs were studied in an isolated whole-heart model of stretch-related AF.
Methods And Results: Thirty rabbits were fed with amiodarone (50 mg/kg/day, n = 10), dronedarone (50 mg/kg/day, n = 10), or placebo (n = 10) for 6 weeks.
Objectives: The purpose of this study was to evaluate clinical and electrophysiologic characteristics of AT in patients after surgical ASD repair as well as outcome after ablation.
Background: Atrial tachycardias (AT) are a common complication after surgical closure of an atrial septal defect (ASD).
Methods: From a prospective ablation database we analyzed data of patients with a history of ASD repair who presented to our institution for AT ablation.
Background: Symptomatic, premature ventricular contractions (PVCs) frequently originate in the right ventricular outflow tract, less frequently in the left ventricular outflow tract, aortic root, or mitral annulus (MA). Little is known about the patient population presenting with MA PVC and/or ventricular tachycardia (VT).
Objective: To characterize the subgroup of ventricular arrhythmias arising from the MA.
Aims: In several clinical and pre-clinical studies, application of ranolazine (RAN) led to suppression of atrial fibrillation (AF). The aim of the present study was to investigate whether RAN can suppress AF in an experimental rabbit whole heart model, in which acute haemodynamic changes trigger AF. Ranolazine was compared with flecainide and sotalol as established antiarrhythmic agents.
View Article and Find Full Text PDFBackground: Ranolazine inhibits late Na(+) and K(+) currents. Earlier studies have reported an antiarrhythmic effect. The aim of the present study was to understand whether ranolazine could still preserve its antiarrhythmic properties in the settings of chronic heart failure (CHF).
View Article and Find Full Text PDFAims: Ranolazine (RAN) was reported to be effective and safe in converting atrial fibrillation (AF) to sinus rhythm by administration of a single dose ('pill in the pocket') to patients with structural heart disease. This study examines the underlying mechanisms for the antiarrhythmic benefit of RAN application in chronic heart failure (CHF).
Methods And Results: In 10 female rabbits, CHF was induced by rapid ventricular pacing, leading to a significant decrease in ejection fraction in the presence of a dilated left ventricle and atrial enlargement.
Background: Ranolazine exhibits a synergistic effect in combination with class III drugs to suppress atrial fibrillation.
Objective: To investigate whether a combination therapy affects repolarization and provokes ventricular tachyarrhythmias (VT) in a sensitive model of proarrhythmia.
Methods: Thirty-seven rabbits were assigned to 3 groups and fed with amiodarone (50 mg/kg/d; n = 10) or dronedarone (50 mg/kg/d; n = 10) over a period of 6 weeks.
Background: The risk of developing a stroke or systemic embolus due to a left atrial (LA) thrombus in patients with atrial fibrillation (AF) and/or atrial flutter (AFL) is estimated by the CHADS(2) score and more recently the CHA(2)DS(2)-VASc score. We aimed to further characterize AF/AFL patients who were found to have a LA thrombus on a transesophageal echocardiogram (TEE).
Methods And Results: Of 3,165 TEE between 2005 and 2011 for a broad spectrum of indications, we detected 65 AF patients with LA thrombus (2 %).
Background: Antral pulmonary vein isolation (PVI) for treatment of atrial fibrillation may induce left atrial tachycardias (ATs).
Objective: To determine the prevalence, time course of occurrence, mechanisms, and correlation with the electrocardiogram as well as the outcome of ablation of these tachycardias.
Methods And Results: Out of the 839 patients who underwent circumferential antral radiofrequency PVI guided by a circumferential pulmonary vein catheter at our institution between February 2005 and April 2011, 35 patients (4%) developed AT during follow-up.
Pharmacologic modification of cellular calcium handling recently moved into focus as an alternative for prevention and treatment of ventricular tachyarrhythmias. Calcium overload and spontaneous calcium release from the sarcoplasmatic reticulum are regarded as possible initiations of early and delayed afterdepolarization thereby triggering ventricular arrhythmias. In chronic heart failure, calcium overload is more likely to occur compared with healthy hearts, which is one explantation for the increased vulnerability in this condition.
View Article and Find Full Text PDFThe cardiac Na(+)/Ca(2+) exchanger (NCX) generates an inward electrical current during SR-Ca(2+) release, thus possibly promoting afterdepolarizations of the action potential (AP). We used transgenic mice 12.5 weeks or younger with cardiomyocyte-directed overexpression of NCX (NCX-Tg) to study the proarrhythmic potential and mechanisms of enhanced NCX activity.
View Article and Find Full Text PDFBackground: Electrophysiologic characteristics, mapping strategies, and acute success rates of radiofrequency catheter ablation of atriofascicular accessory pathways are well described. However, data on long-term prognosis and predictors for freedom from arrhythmias are lacking.
Objective: To report our 20-year single-center experience on ablation of atriofascicular fibers.
Background: Molecular remodeling in heart failure includes slowing of repolarization, leading to proarrhythmia.
Objective: To evaluate the effects of Na(+)/Ca(2+) exchanger (NCX) inhibition on repolarization as a novel antiarrhythmic concept in chronic heart failure (CHF).
Methods And Results: CHF was induced by rapid ventricular pacing in rabbits.