TEMPORARY ATRIAL ELECTRODE FOR THE TREATMENT OF SUPRAVENTRICULAR TACHYCARDIA AFTER CARDIAC OPERATIONS

Background. Supraventricular tachycardia is a common postoperative com plication early after cardiac operations. A temporary atrial patch ele ctrode for low-energy atrial defibrillation was developed in 1992 and subsequently tested. Methods. The electrode first was tested and remov ed intraoperatively during open heart operations in 10 patients (phase I). After the intraoperative testing, the temporary atrial patch elec trode was implanted in 20 patients for postoperative termination of sp ontaneous episodes of supraventricular tachycardia (phase II). When su praventricular tachycardia occurred, biphasic shocks (1.2 to 5 J) were applied and the aerial defibrillation thresholds were measured. Resul ts. In phase I, the mean intraoperative atrial defibrillation threshol d was 1.6 +/- 1.4 J, with a mean shock impedance of 64 +/- 7.3 Omega. In phase II, 6 of 20 patients (30%) had 7 episodes of aerial fibrillat ion (n = 6) and atrial flutter (n = 1) after operation. In 5 patients, the supraventricular tachycardia could be converted to a sinus (n = 5 ) or normofrequent atrioventricular rhythm (n = 1). The mean postopera tive defibrillation threshold was 2.7 +/- 2.1 J, with a mean shock imp edance of 50.2 +/- 6.8 Omega. Conclusions. The temporary aerial patch electrode allows low-energy defibrillation of episodes of atrial fibri llation. It may serve as apr alternative therapeutic option for the tr eatment of supraventricular tachycardia. (C) 1998 by The Society of Th oracic Surgeons.