Permanent and Transient Electrophysiological Effects During Cardiac Cryoablation Documented by Optical Activation Mapping and Thermal Imaging.

Objective: Cardiac catheter cryoablation is a safer alternative to radiofrequency ablation for arrhythmia treatment, but electrophysiological (EP) effects during and after freezing are not adequately characterized. The goal of this study was to determine transient and permanent temperature induced EP effects, during and after localized tissue freezing.

Methods: Conduction in right (RV) and left ventricles (LV) was studied by optical activation mapping during and after cryoablation in paced, isolated Langendorff-perfused porcine hearts.

Spinal cord stimulation protects against atrial fibrillation induced by tachypacing.

Background: Spinal cord stimulation (SCS) has been shown to modulate atrial electrophysiology and confer protection against ischemia and ventricular arrhythmias in animal models.

Objective: To determine whether SCS reduces the susceptibility to atrial fibrillation (AF) induced by tachypacing (TP).

Methods: In 21 canines, upper thoracic SCS systems and custom cardiac pacing systems were implanted.

Spatiotemporal electrophysiological changes in a murine ablation model.

Aims: High recurrence rates after complex radiofrequency ablation procedures, such as for atrial fibrillation, remain a major clinical problem. Local electrophysiological changes that occur following cardiac ablation therapy are incompletely described in the literature. The purpose of this study was to determine whether alterations in conduction velocity, action potential duration (APD), and effective refractory period resolve dynamically following cardiac ablation.

Notch signaling regulates murine atrioventricular conduction and the formation of accessory pathways.

Ventricular preexcitation, which characterizes Wolff-Parkinson-White syndrome, is caused by the presence of accessory pathways that can rapidly conduct electrical impulses from atria to ventricles, without the intrinsic delay characteristic of the atrioventricular (AV) node. Preexcitation is associated with an increased risk of tachyarrhythmia, palpitations, syncope, and sudden death. Although the pathology and electrophysiology of preexcitation syndromes are well characterized, the developmental mechanisms are poorly understood, and few animal models that faithfully recapitulate the human disorder have been described.