Repetitive short time-constant capacitive shocks significantly increased myocardial lesion volume (195, 480, and 595 mm3 for 1, 2, and 3 shocks) without compromising safety.
Does an increasing number of short time-constant capacitive shocks increase myocardial lesion volume in a canine ventricular myocardium model?
Repetitive short time-constant capacitive direct current shocks can produce larger, clinically useful myocardial lesions without the adverse hemodynamic effects associated with single high-energy shocks.
Arching and barotrauma, seen with high energy DC catheter ablation, are responsible for diffuse cardiac damage and coronary sinus rupture. In six anesthetized dogs, we investigated the effects of an increasing number of short time-constant capacitive shocks on the volume of myocardial damage. Each dog received capacitive shocks of 2 J/kg at 3 sites in the left ventricle. One shock was delivered in 2 dogs, 2 shocks were delivered in 2 dogs and 3 shocks were delivered in 2 dogs. Shock delivery was not accompanied by hemodynamic collapse, sustained ventricular tachycardia or ventricular fibrillation. The dogs were sacrificed at 60 minutes. Mean (SEM) lesion volumes were 195 (39) mm3, 480 (41) mm3, and 595 (110) mm3, respectively. Despite variability in individual volume of damage, there was a significant increase in lesion volume with an increasing number of shocks. There was no evidence of perforation or tamponade. Increasing myocardial damage can be produced using repetitive capacitive shocks. Delivery of 2 shocks produces clinically useful lesions without the adverse effects associated with single high energy shocks. Repetitive capacitive shocks offer a method of increasing lesion volume without increasing energy and thereby without compromising safety.
Watanabe et al. (Wed,) conducted a other in Catheter ablation of ventricular myocardium (n=6). Repetitive short time-constant capacitive shocks vs. Single shock was evaluated on Volume of myocardial damage (lesion volume). Repetitive short time-constant capacitive shocks significantly increased myocardial lesion volume (195, 480, and 595 mm3 for 1, 2, and 3 shocks) without compromising safety.