Claus Schmitt

Do Current Dual Chamber Cardioverter Defibrillators Have Advantages Over Conventional Single Chamber Cardioverter Defibrillators in Reducing Inappropriate Therapies? A Randomized, Prospective Study

Dual Chamber vs Single Chamber Cardioverter Defibrillators. Introduction: Supraventricular tachyarrhythmias are the main cause of inappropriate therapies in patients with conventional single chamber implantable cardioverter defibrillators (VVI‐ICD). It was anticipated that dual chamber cardioverter defibrillators (DDD‐ICD), with their capacity to analyze atrial and ventricular rhythm, could substantially reduce inappropriate therapies.

Does electrogram guided substrate ablation add to the success of pulmonary vein isolation in patients with paroxysmal atrial fibrillation? A prospective, randomized study.

Introduction: Pulmonary vein isolation (PVI) is an established treatment for paroxysmal atrial fibrillation (AF). The ablation of complex fractionated atrial electrograms (CFAE) has emerged as a novel treatment approach. We sought to evaluate the additional effect of CFAE ablation to PVI in paroxysmal AF.

Prospective Randomized Comparison of Closed Cooled-Tip versus 8-mm-Tip Catheters for Radiofrequency Ablation of Typical Atrial Flutter

Cooled‐Tip vs 8‐mm‐Tip Ablation of Atrial Flutter. Introduction: Cooled‐tip and 8‐mm‐tip catheters have been found to be more effective than conventional 4‐mm‐tip catheters for radiofrequency (RF) ablation of common atrial flutter. The aim of this study was to compare the efficacy and safety of cooled‐tip and 8‐mm‐tip catheters for flutter ablation in a randomized, prospective study.

Radiofrequency ablation of complex fractionated atrial electrograms (CFAE): preferential sites of acute termination and regularization in paroxysmal and persistent atrial fibrillation.

Introduction: Complex fractionated atrial electrograms (CFAE) have been described as a new target for ablation of atrial fibrillation (AF). This prospective study evaluates the acute effects of CFAE ablation in patients with paroxysmal or persistent AF and analyzes the preferential anatomic sites where these effects occur.

Differential Effect of β-Adrenergic Stimulation on the Frequency-Dependent Electrophysiologic Actions of the New Class III Antiarrhythmics Dofetilide, Ambasilide, and Chromanol 293.

Class III Antiarrhythmics and β‐Adrenergic Stimulation. Introduction: Blockade of the rapid delayed rectifier potassium current (IKr) as an important mechanism for current Class III antiarrhythmics is less effective in action potential prolongation during β‐adrenergic activation. We hypothesized that blockade of the increased slow IK (IKs) current during β‐adrenergic stimulation could improve action potential prolongation and tested this hypothesis by comparison of three different IK blockers: dofetilide, a selective blocker of IKr; ambasilide, a nonselective blocker of IK; and chromanol 293B, a selective blocker of IKs.

The Modified Anterior Line: An Alternative Linear Lesion in Perimitral Flutter

Modified Anterior Line for Perimitral Flutter. Introduction: Ablation of left atrial flutter (LAF) is often limited by the need for technically demanding linear lesions. We evaluated the safety and efficacy of a new modified anterior line (MAL), connecting the anterior/anterolateral mitral annulus with the left superior pulmonary vein for ablation of perimitral flutter.

Delineation of intra-atrial reentrant tachycardia circuits after mustard operation for transposition of the great arteries using biatrial electroanatomic mapping and entrainment mapping

Introduction: Intra‐atrial reentrant tachycardia (IART) circuits after Mustard operation remain incompletely understood due to the complex atrial anatomy after extensive surgical procedures. The aim of this study was to delineate IART circuits and their relations to the individual anatomic boundaries in Mustard patients.

Complex Fractionated Atrial Electrogram or Linear Ablation in Patients with Persistent Atrial Fibrillation—A Prospective Randomized Study

Background: Catheter ablation of complex fractionated atrial electrograms (CFAE) for persistent atrial fibrillation (AF) is a promising treatment strategy. We tested the hypothesis that CFAE ablation is superior to linear ablation in patients with persistent or long‐standing persistent AF.

Acute and Late Outcomes of Transcatheter Aortic Valve Implantation (TAVI) for the Treatment of Severe Symptomatic Aortic Stenosis in Patients at High- and Low-Surgical Risk

BACKGROUNDnThis prospective study examines the impact of EuroSCORE and transfemoral (TF) or transapical (TA) delivery approach on mortality at 30 days and 1 year in patients with severe aortic stenosis implanted with either the Edwards SAPIEN Transcatheter Heart Valve (THV) or Medtronic CoreValve.nnnMETHODS AND RESULTSnTAVI was successfully performed in 293 (97.7%) of 300 patients (TF: 174, TA: 126, mean EuroSCORE 24.0). The mortality at 30 days and after 1 year was 6.0% and 17.3%. Mortality depends significantly on the logistic EuroSCORE with a 30-day odds ratio (OR) of 1.92 (95% CI 1.41 to 2.62, P < 0.001) and after 1 year of 1.67 (95% CI 1.34 to 2.08, P < 0.001). Mortality in patients with a logistic EuroSCORE <15 (n = 113) or ≥15 (n = 187) at 30 days was 0.9% versus 9.1% and after 1 year 7.1% versus 23.5% demonstrating significantly less mortality (P < 0.001) in patients with lower logistic EuroSCOREs. In this specific setup of our center there was no significant difference (P = 0.553) in mortality regarding the technical approach for TA (4.0% and 15.9%) and for TF (7.5% and 18.4%). Severe cardiac complications occurred in 20 patients (6.7%) with a 30-day mortality of 45.0%.nnnCONCLUSIONnThe mortality in patients undergoing TAVI correlates significantly with the logistic EuroSCORE. Patients with a logistic EuroSCORE <15 can be implanted, with a low 30-day mortality and good long-term outcome over 1 year.

Altered Transient Outward Current in Human Atrial Myocytes of Patients with Reduced Left Ventricular Function

Ito1 in Human Atrium and Heart Failure. Introduction: Electrophysicologic remodeling is involved in the self‐perpetuation of atrial fibrillation. To define whether differences in atrial electrophysiology already are present in patients with increased susceptibility for atrial fibrillation, we compared patients in sinus rhythm with and without heart failure.