Ventricular fibrillation (VF) is the primary mechanism of cardiac arrest in the vast majority of sudden death patients. Whether similar modes and mechanisms of death can be generalized to denervated hearts in orthotopic heart transplantation (OHT) patients is unknown.

The purpose of this study was to determine the mode and mechanisms of death in patients who have undergone cardiac transplantation.

We analyzed the outcomes of 628 patients who underwent OHT between January 1994 and December 2004. The mode of death was classified as either sudden death (SD) or non-sudden death (NSD). The first documented rhythm taken at the time of arrest was also reviewed to determine the mechanism of cardiac arrest.

During a mean follow-up of 76 months, 194 patients died. Of these, the mode of death could be determined in 116 patients (60%). Forty-one patients (35%) died of SD, and 75 patients (65%) died of NSD. The first documented rhythm of death was available in 91 patients (26 SD and 65 NSD). The terminal rhythms in patients who died suddenly were: asystole (34%), pulseless electrical activity (PEA) (20%), and VF (10%). In NSD patients, the terminal rhythms were asystole (73%), followed by VF (7%), and PEA (7%), P < .001 compared with SD patients.

SD represented the mode of death in 35% of OHT patients. The main mechanisms underlying SD in this population were asystole and PEA, suggesting that denervation of the donor heart, among other post-transplantation changes, may alter susceptibility to VF.