Differentiation of papillary muscle from fascicular and mitral annular ventricular arrhythmias in patients with and without structural heart disease.

Background: Idiopathic left ventricular arrhythmias (VAs) and those caused by structural heart disease can originate from the papillary muscles, fascicles, and mitral annulus. Differentiation of these arrhythmias can be challenging because they present with a right bundle branch block morphology by electrocardiography. We sought to identify clinical, electrocardiographic, and electrophysiological features that distinguish these left VAs in patients with and without structural heart disease.

Improved conduction and increased cell retention in healed MI using mesenchymal stem cells suspended in alginate hydrogel.

Introduction: Mesenchymal stem cells (MSCs) have been associated with reduced arrhythmias; however, the mechanism of this action is unknown. In addition, limited retention and survival of MSCs can significantly reduce efficacy. We hypothesized that MSCs can improve impulse conduction and that alginate hydrogel will enhance retention of MSCs in a model of healed myocardial infarction (MI).

Complications from catheter ablation of atrial fibrillation: impact of current and emerging ablation technologies.

Catheter ablation has emerged as an important therapy for atrial fibrillation. The past decade has seen tremendous growth in the use of this technology, as well as the use of novel sources and methods of energy delivery. As the volume and complexity of catheter ablation procedures for atrial fibrillation have increased, our understanding of the range of procedural complications has also grown.

Optical mapping of cryoinjured rat myocardium grafted with mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have been shown to improve cardiac electrophysiology when administered in the setting of acute myocardial infarction. However, the electrophysiological phenotype of MSCs in situ is not clear. We hypothesize that MSCs delivered intramyocardially to cryoinjured myocardium can engraft, but will not actively generate, action potentials.