Left atrial isolation: new technique for the treatment of supraventricular arrhythmias.

TLDR

Refractory ectopic supraventricular tachycardia originating in the left atrium is traditionally treated with cryoablation of the His bundle and implantation of a permanent ventricular pacemaker. The study aimed to develop a method to electrically isolate the left atrium, eliminating the need for an artificial pacemaker. In ten anesthetized dogs, a left atriotomy was extended across the mitral annulus and posteriorly to the interatrial septum, and the interatrial fibers near the coronary sinus were cryoablated at –60 °C for 2 min under cardiopulmonary bypass. All animals remained in normal sinus rhythm, and pacing of the left atrium did not alter the rhythm or rate of the rest of the heart; loss of the left atrial kick had minimal hemodynamic impact, indicating the technique is a viable alternative to current surgical management.

Abstract

Surgical management of refractory ectopic supraventricular tachycardia arising in the left atrium requires cryoablation of the bundle of His and insertion of a permanent ventricular pacemaker. This study was designed to develop a technique to isolate the left atrium electrically from the remainder of the heart, so that an artificial pacemaking system would be unnecessary. Ten adult dogs were subjected to cardiopulmonary bypass and a standard left atriotomy was extended anteriorly across the mitral valve anulus between the right and left fibrous trigones. Posteriorly, the atriotomy was extended across the mitral valve anulus just to the left of the posterior crux and interatrial septum. The muscular interatrial fibers accompanying the coronary sinus were cryoablated at -60 degrees C for 2 minutes. Postoperatively, all animals remained in normal sinus rhythm. Rapid left atrial pacing did not affect the rate or rhythm of the remainder of the heart. Preliminary hemodynamic measurements suggest that loss of the synchronous left atrial "kick" does not significantly affect left ventricular preload, afterload, or cardiac output. This technique offers an alternative to the current surgical approach for management of refractory ectopic supraventricular tachycardia arising in the left atrium.