The hot can: ICD failure presenting as severe shoulder pain

We describe a patient whose presentation of ICD generator failure was excru ciating shoulder pain lasting 3 hours. This painful episode prompted evalua tion and subsequent generator replacement. Destructive analysis of the expl anted device revealed a short circuit of three battery filter capacitors, w hich resulted in the battery "dumping" its full energy very rapidly, since the impedance across the battery terminal was < 1 ohm. The duration of the painful episode was equal to the estimated ICD battery life under this low impedance condition.