Clinical results with nonthoracotomy ICD systems.

The results of two separate US Food and Drug Administration clinical trials that involved endocardial and epicardial leads were compared with regard to patient demographics, detection and conversion characteristics, and subsequent clinical course including long-term survival experience. The patient groups, although not strictly contemporaneous, were sufficiently similar to allow meaningful comparisons. There were no significant differences in detection of induced arrhythmias and ability to convert them. The surgical mortality, infection rate, and incidence of other morbid complications were lower in patients who had received endocardial leads; however, the differences did not reach statistical significance. Survivals through 1 year of follow-up were uniformly high. These results suggest that the performance of the endocardial lead system is comparable to existing epicardial leads in similar patient populations.