Morphologic effects of defibrillation: a preliminary report.

A 72-yr-old man receiving more than 300 separate DC countershocks in 2 wk exhibited morphologic heart changes, including areas of coagulation necrosis in the subepicardium and areas of frank hemorrhage. In other sites the myocytes were pathologically contracted, a finding previously demonstrated in experimental animals as a result of defibrillation but not seen in man. We suggest that these changes may occur more often than has been previously supposed and thus may be of clinical importance.