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 cardiac anatomical findings in patients with chronically indwelling coronary sinus leads at the time of autopsy or cardiac transplantation. Transvenous cardioverter defibrillators offer effective protection against sudden death. The use of a coronary sinus electrode has been shown in some patients to decrease the defibrillation threshold. The anatomical consequences of chronically indwelling coronary sinus cardioversion/defibrillation electrodes in patients having transvenous implantable cardioverter defibrillators is unknown. The hearts of seven patients with chronically indwelling coronary sinus electrodes were evaluated following autopsy (n = 2) or cardiac transplantation (n = 5). The coronary 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 sinus at the time of implantable cardioverter defibrillator surgery. The seven hearts 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 the presence of the coronary sinus lead. The only finding in each case was the scattered presence of a thin white fibrous sheath over the lead that intermittently adhered to the coronary sinus endothelium and, in the two patients transplanted 1-3 months after implantable cardioverter 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 sinus perforation, coronary sinus burn, or myocardial injury adjacent to the lead. Cause of death was due to end-stage congestive heart failure and thrombotic stroke, respectively, in the two patients examined at autopsy. Coronary sinus defibrillation leads can be used safely without harmful anatomical effect.