ICD malfunction caused by excessive defibrillation charge time.

A 71-year-old man with a history of myocardial infarction and syncopal ventricular tachycardia received an ICD. Progressively, increased defibrillation charge times of the ICD were observed. During a fast ventricular tachycardia, the patient collapsed. The underlying malfunction could be documented by ICD telemetric interrogation. An excessive charge time was recorded causing subsequent delayed therapy. The ICD was considered potentially ineffective and required a generator exchange. This case report underlines the possible factors affecting the ICD charge times. Excessive charge time must be considered as a rare, or underestimated, cause of ICD malfunction, requiring generator replacement.