Long-term outcome with the automatic implantable cardioverter-defibrillator

AbstractThe automatic implantable cardioverter-defibrillator was implanted in 270 patients because of life-threatening arrhythmias over a 7 year period. There was a history of sustained ventricular tachycardia or fibrillation, or both, in 96% of these patients, 80% had one or more prior cardiac arrests and 78% had coronary artery disease as their underlying diagnosis. The average ejection fraction was 34%, and 96% of these patients had had an average of 3.4 antiarrhythmic drug failures per patient before defibrillator implantation. There were four perioperative deaths and eight patients had generator infection or generator erosion, or both, during the perioperative period or during long-term follow-up. Concomitant antiarrhythmic drug therapy was given to 69% of patients.Shocks from the device were given to 58% of patients, and 20% received “problematic” shocks. The device was removed from 16 patients during long-term follow-up for a variety of reasons. There were 7 sudden cardiac deaths and 30 nonsudden cardiac deaths, 18 of which were secondary to congestive heart failure. The actuarial incidence of sudden death, total cardiac death and total mortality from all causes was 1%, 7% and 8%, respectively, at 1 year, and 4%, 24% and 26% at 5 years.The automatic implantable cardioverter-defibrillator nearly eliminates sudden death over a long-term follow-up period in a high risk group of patients. It has an acceptable rate of complications or problems, or both, and most late deaths in these patients are nonsudden and of cardiovascular origin

Transvenous catheter ablation of extranodal accessory pathways

AbstractTwelve patients with an accessory pathway and recurrent symptomatic reciprocating tachycardia or atrial fibrillation, or both, underwent attempted transvenous catheter ablation of the accessory pathway. In one patient with a small right coronary artery, the pathway was along the right free wall. In 11 patients, the pathway was located at or within 15 mm of the coronary sinus os. For these patients, a quadripolar electrode catheter was placed in the coronary sinus and positioned, if possible, so that the proximal pair of electrodes straddled the pathway. For those patients with a pathway > 5 mm within the coronary sinus, the most proximal electrode was placed at the os. This proximal pair of electrodes was connected to the cathodal output of a defibrillator with an anterior chest wall patch serving as the current sink. Two shocks were then delivered for a cumulative energy of 500 to 600 J (stored energy).Among the eight patients with a pathway at or within 5 mm of the coronary sinus os, conduction over the pathway was abolished in five and modified in one. Among the four patients with a pathway farther from the os (10 to 15 mm) and along the right free wall, pathway conduction was modified only in two. Rupture of the coronary sinus did not occur in any patient. There were no serious complications. Minor damage surrounding the area of ablation was seen at the time of surgical division of the accessory pathway in two of five patients with unsuccessful ablation who subsequently underwent surgery.Transvenous catheter ablation of accessory pathways appears to be a safe and reasonably effective alternative to surgery for those patients with a pathway at or near the coronary sinus os, but not for those with a pathway farther from the septum. Although subsequent intraoperative mapping was more difficult because of the loss of large, discrete atrial electrograms, surgical division was successful in all five patients after unsuccessful catheter ablation