Azimilide reduces emergency department visits and hospitalizations in patients with an implantable cardioverter-defibrillator in a placebo-controlled clinical trial.

Objectives: The goal of this study was to determine whether azimilide, as compared with placebo, will reduce the number of emergency department (ED) visits and hospitalizations caused by arrhythmias or cardiac events in patients with an implantable cardioverter-defibrillator (ICD).

Background: Patients with an ICD may require ED visits and hospitalizations because of arrhythmias, which trigger ICD therapies. The effect of adjunctive antiarrhythmic therapy on these outcomes is not known.

Cellular properties of C-terminal KCNH2 long QT syndrome mutations: description and divergence from clinical phenotypes.

Background: C-terminal KCNH2 mutations are commonly associated with a more benign clinical presentation, but mutations localized in close proximity may exhibit different clinical and biophysical phenotypes. The value of detailed cellular characterization of such mutant channels in vitro has not been studied with respect to clinical risk stratification of affected patients.

Objective: The purpose of this study was to study the cellular properties and clinical presentation of C-terminal KCNH2 missense mutations localized in close proximity.

Rhythm control versus rate control for atrial fibrillation and heart failure.

Background: It is common practice to restore and maintain sinus rhythm in patients with atrial fibrillation and heart failure. This approach is based in part on data indicating that atrial fibrillation is a predictor of death in patients with heart failure and suggesting that the suppression of atrial fibrillation may favorably affect the outcome. However, the benefits and risks of this approach have not been adequately studied.

Risk factor assessment: defining populations and individuals at risk.

This article summarizes the current knowledge on risk stratification in patients who have structural heart disease, notably coronary artery disease and nonischemic cardiomyopathy. Although other types of structural heart disease and inherited ion channel abnormalities are also associated with a risk of SCD, the risk stratification strategies and data in these entities are diverse and beyond the scope of this article.

Characterization of human cardiac Kv1.5 inhibition by the novel atrial-selective antiarrhythmic compound AVE1231.

Objective: Atrial-selective drug therapy represents a novel therapeutic approach for atrial fibrillation management. The aim of the present study was to investigate the mechanism of hKv1.5 channel inhibition by the atrial-selective compound AVE1231.

Quantitative analysis of the duration of slow conduction in the reentrant circuit of ventricular tachycardia after myocardial infarction.

Background: Few data are available to define the circuits in ventricular tachycardia (VT) after myocardial infarction and the conduction time (CT) through the zone of slow conduction (SCZ). This study assessed the CT of the SCZ and identified different reentrant circuits.

Methods: During VTs, concealed entrainment (CE) was attempted.

Heart rate turbulence and other autonomic risk markers for arrhythmia risk stratification in dilated cardiomyopathy.

Background: Noninvasive arrhythmia risk stratification in patients with nonischemic dilated cardiomyopathy (DCM) using autonomic markers have yielded disappointing results. Heart rate turbulence is a new method to assess cardiac autonomic function.

Aim: The aim of the study was to compare the predictive value of heart rate turbulence with those of conventional autonomic risk markers for ventricular tachyarrhythmic events in patients with DCM.

Risks and benefits of oral anticoagulation compared with clopidogrel plus aspirin in patients with atrial fibrillation according to stroke risk: the atrial fibrillation clopidogrel trial with irbesartan for prevention of vascular events (ACTIVE-W).

Background And Purpose: In ACTIVE-W, oral anticoagulation (OAC) was more efficacious than combined clopidogrel plus aspirin (C+A) in preventing vascular events in patients with atrial fibrillation. However, because OAC carries important bleeding complications, risk stratification schemes have been devised to identify patients for whom the absolute benefits of OAC exceed its risks.

Methods: Participants were risk-stratified with the widely-used CHADS(2) scheme.

Biventricular pacing does not affect microvolt T-wave alternans in heart failure patients.

Background: Microvolt T-wave alternans (MTWA) is a valuable tool for stratification of patients at risk for sudden death and has recently been approved for this purpose by Medicare. Although right atrial (RA) pacing has been applied for MTWA testing, the effects of other pacing modalities on MTWA have not been systematically studied. Accordingly, it is unknown whether biventricular (BiV) pacing might influence MTWA test results.

Coronary sinus side branches for cardiac resynchronization therapy: prospective evaluation of availability, implant success, and procedural determinants.

Introduction: There are only sparse data concerning individual coronary side branch (CS-SB) anatomy with respect to LV lead implantation for cardiac resynchronization therapy (CRT).

Methods: In patients (pts) undergoing CRT device implantation, a detailed venogram was obtained, and the CS-SB of first, second, third, and fourth choices for CS-lead implantation was defined. Study endpoints included successful LV lead implantation in the first choice CS-SB, number of CS-SB potentially available, implantation success in selected CS-SB, procedural variables, and 6-month response to CRT.

Atrial-selective approaches for the treatment of atrial fibrillation.

Atrial-selective pharmacologic approaches represent promising novel therapeutic options for the treatment of atrial fibrillation (AF). Medical treatment for AF is still more widely applied than interventional therapies but is hampered by several important weaknesses. Besides limited clinical efficacy (cardioversion success and sinus-rhythm maintenance), side effects like ventricular proarrhythmia and negative inotropy are important limitations to present class I and III drug therapy.

Refinement of CARTO-guided substrate modification in patients with ventricular tachycardia after myocardial infarction.

Background: Substrate modification guided by CARTO system has been introduced to facilitate linear ablation of ventricular tachycardia (VT) after myocardial infarction (MI). However, there is no commonly accepted standard approach available for drawing these ablation lines. Therefore, the aim of the present study was to practically refine this time consuming procedure.

Upgrading to biventricular pacing/defibrillation systems in right ventricular paced congestive heart failure patients: prospective assessment of procedural parameters and response rate.

Aims: Cardiac resynchronization therapy (CRT) is indicated in patients with heart failure and bundle branch block. It is less clear whether this includes patients with pre-existing right ventricular pacemaker/defibrillator systems, particularly with respect to implantation success and clinical benefit.

Methods And Results: In consecutive patients scheduled for CRT, we prospectively compared implantation success, procedural parameters, and clinical response in 'de novo' vs.

Incidence of stroke in paroxysmal versus sustained atrial fibrillation in patients taking oral anticoagulation or combined antiplatelet therapy: an ACTIVE W Substudy.

Objectives: Our goal was to determine the risk of stroke or non-cerebral embolism associated with paroxysmal compared with sustained atrial fibrillation (AF).

Background: The risk of stroke and non-cerebral embolism and the efficacy of oral anticoagulation (OAC) in paroxysmal AF as compared with sustained AF are not precisely known.

Methods: The ACTIVE W (Atrial Fibrillation Clopidogrel Trial With Irbesartan for Prevention of Vascular Events) was a trial comparing OAC to combined antiplatelet therapy with aspirin and clopidogrel for prevention of vascular events in 6,706 AF patients.

Rationale and design of ATHENA: A placebo-controlled, double-blind, parallel arm Trial to assess the efficacy of dronedarone 400 mg bid for the prevention of cardiovascular Hospitalization or death from any cause in patiENts with Atrial fibrillation/atrial flutter.

Background: Atrial fibrillation (AF) is the most commonly encountered clinical arrhythmia, predominantly affecting elderly patients. There is a continued need for new antiarrhythmic drugs to treat the ever-increasing number of patients with this arrhythmia. Dronedarone is a new antiarrhythmic compound currently being developed for treatment of AF.

Outcome parameters for trials in atrial fibrillation: recommendations from a consensus conference organized by the German Atrial Fibrillation Competence NETwork and the European Heart Rhythm Association.

Atrial fibrillation (AF), the most common atrial arrhythmia, has a complex aetiology and causes relevant morbidity and mortality due to different mechanisms, including but not limited to stroke, heart failure, and tachy- or bradyarrhythmia. Current therapeutic options (rate control, rhythm control, antithrombotic therapy, 'upstream therapy') only prevent a part of this burden of disease. New treatment modalities are therefore currently under evaluation in clinical trials.

Outcome parameters for trials in atrial fibrillation: executive summary.

Atrial fibrillation (AF), the most common atrial arrhythmia, has a complex aetiology and causes relevant morbidity and mortality due to different mechanisms, including but not limited to stroke, heart failure, and tachy- or bradyarrhythmia. Current therapeutic options (rate control, rhythm control, antithrombotic therapy, 'upstream therapy') only prevent a part of this burden of disease. Several new treatment modalities are therefore under evaluation in controlled trials.

Dronedarone for maintenance of sinus rhythm in atrial fibrillation or flutter.

Background: Amiodarone is effective in maintaining sinus rhythm in atrial fibrillation but is associated with potentially serious toxic effects. Dronedarone is a new antiarrhythmic agent pharmacologically related to amiodarone but developed to reduce the risk of side effects.

Methods: In two identical multicenter, double-blind, randomized trials, one conducted in Europe (ClinicalTrials.

Novel anti-arrhythmic drugs for atrial fibrillation management.

Atrial fibrillation (AF) is a highly prevalent arrhythmia and responsible for significant morbidity, mortality and health care cost. Considerable work has been performed to improve medical options but treatment success still remains suboptimal. The use of conventional anti-arrhythmic agents has been limited by potentially fatal ventricular proarrhythmia.