ANATOMICAL FINDINGS IN PATIENTS HAVING HAD A CHRONICALLY INDWELLING CORONARY SINUS DEFIBRILLATION LEAD

The purpose of this report is to review the gross and histological car diac anatomical findings in patients with chronically indwelling coron ary sin us leads at the time of autopsy or cardiac transplantation, Tr ansvenous cardioverter defibrillators offer effective protection again st sudden death. The use of a coronary sinus electrode has been shown in some patients to decrease the defibrillation threshold. The anatomi cal consequences of chronically indwelling coronary sinus cardioversio n/defibrillation electrodes in patients having transvenous implantable cardioverter defibrillators is unknown. The hearts of seven patients with chronically indwelling coronary sinus electrodes were evaluated f ollowing autopsy (n = 2) or cardiac transplantation (n = 5). The coron ary sinus electrode in each case was a 6.5 French silicone lead with a 5-cm long defibrillation coil (Medtronic CS lead model 6933) that was positioned as distally as possible within the coronary sin us at the time of implantable cardioverfer defibrillator surgery. The seven hear ts examined were derived from patients whose age ranged between 49 and 69 (mean 56 +/- 7 years). Six had coronary artery disease and one had idiopathic dilated cardiomyopathy. The time from implant to death or cardiac transplantation was 8 +/- 6 months, range 1-18 months. In all seven patients, there was no evidence of any significant damage from t he presence of the coronary sin us lead. The only finding in each case was the scattered presence of a thin white fibrous sheath over the le ad that intermittently adhered to the coronary sinus endothelium and, in the two patients transplanted 1-3 months after implantable cardiove rter defibrillator insertion, a mild inflammation reaction adjacent to the leads in the coronary sinus endothelium. There was no evidence of coronary sinus occlusion, adjacent coronary artery injury, coronary s inus perforation, coronary sinus burn, or myocardial injury adjacent t o the lead. Cause of death was due to end-stage congestive heart failu re and thrombotic stroke, respectively, in the two patients examined a t autopsy. Coronary sinus defibrillation leads can be used safely with out harmful anatomical effect.