Sinus pause in association with Lyme carditis.

Lyme disease is the most prevalent tick-borne disease in the United States. It is caused by the spirochete Borrelia burgdorferi. Cardiac involvement is seen in 4% to 10% of patients with Lyme disease.

Extreme externalisation of a Riata defibrillator lead conductor cable with prolapse into the left pulmonary artery.

The Riata family of defibrillator leads (St. Jude Medical, Sylmar, CA) has been recalled because of externalisation of conductor cables and increased electrical failure. We describe the case of a man with an incidental finding of extreme externalisation of a conductor from the right ventricular defibrillator lead (Riata family) with prolapse into the left pulmonary artery.

High-sensitivity C-reactive protein as a predictor of atrial fibrillation recurrence after primary circumferential pulmonary vein isolation.

Background: Atrial fibrillation (AF) recurrence after circumferential pulmonary vein isolation (CPVI) is difficult to predict. Inflammation is associated with the development of AF. Inflammatory markers, such as high sensitivity C-reactive protein (hsCRP), are related to AF development via atrial remodeling.

Measuring the complexity of atrial fibrillation electrograms.

Introduction: Complex fractionated atrial electrograms (CFAE) have been identified as targets for atrial fibrillation (AF) ablation. Robust automatic algorithms to objectively classify these signals would be useful. The aim of this study was to evaluate Shannon's entropy (ShEn) and the Kolmogorov-Smirnov (K-S) test as a measure of signal complexity and to compare these measures with fractional intervals (FI) in distinguishing CFAE from non-CFAE signals.

Spatiotemporal characterization of atrial activation in persistent human atrial fibrillation: multisite electrogram analysis and surface electrocardiographic correlations--a pilot study.

Background: The mechanisms of persistent human atrial fibrillation (AF) are not well understood.

Objective: The purpose of this study was to examine whether left atrial (LA) drivers are present in persistent AF by performing a comprehensive evaluation of atrial activation frequency and organization using multisite atrial recordings and correlating the findings with atrial waveform frequency and organization on surface ECG.

Methods: Nine patients undergoing catheter ablation for persistent AF were studied.

New simplified technique for 3D mapping and ablation of right ventricular outflow tract tachycardia.

Objective: To evaluate the safety and efficacy of using a circular multielectrode catheter for mapping and ablation of ventricular tachycardia (VT) or premature ventricular complexes (PVCs) from the right ventricular outflow tract (RVOT).

Background: Three-dimensional (3D) mapping systems are commonly used for mapping and ablation of RVOT VT and PVCs. Newer catheters that are circular with multiple electrodes, such as the Lasso catheter, are capable of simultaneously recording from multiple points within a circumferential plane.

Radiofrequency ablation of atrial flutter: a randomized controlled study of two anatomic approaches.

Atrial flutter often results from a macroreentrant circuit that uses anatomic structures within the right atrium as its borders. RF ablation at the site of an obligatory isthmus can eliminate the atrial flutter circuit. The aim of this study was to compare two approaches to atrial flutter ablation: the septal (septal aspect of the tricuspid valve annulus to coronary sinus ostium and Eustachian ridge) approach versus the posterior (inferior vena cava to tricuspid valve annulus) approach.

In vitro performance characteristics of reused ablation catheters.

Background: Prior studies have found that there is a widespread practice of catheter reprocessing in cardiac electrophysiology laboratories. Effects of reprocessing of ablation catheters on temperature sensing and mechanical deflection are not fully known.

Methods: Twenty-four new and used ablation catheters were studied.

Clinical and electrophysiologic characteristics of left septal atrial tachycardia.

Objectives: It was the purpose of this study to define the electrophysiologic (EP) identity of left septal atrial tachycardia (AT).

Background: The clinical and EP characteristics of this particular type of arrhythmia have not been fully described.

Methods: A total of 120 patients with AT underwent invasive EP evaluation.