EXTERNAL CARDIAC MASSAGE has wide application in the treatment of cardiac arrest. Though complications have been reported to accompany this maneuver,1-4it is unquestionably a valuable resuscitative measure. Nevertheless, the case reported below suggests there are certain situations where closed-chest cardiac massage might well be hazardous. Report of a Case A 22-year-old mentally retarded woman was first admitted to North Carolina Memorial Hospital in 1955 with the diagnosis of rheumatic heart disease, mitral-valve insufficiency, and subacute bacterial endocarditis secondary to infection with α-hemolytic streptococci. At that time, her electrocardiogram showed frequent premature ventricular contractions with runs of bigeminal rhythm. She responded well to therapy and was discharged on a regimen of prophylactic penicillin and digitalis. Her second admission was in 1961 for sterilization by abdominal hysterectomy. Her preoperative and postoperative course was complicated by ventricular arrhythmia, necessitating a prolonged hospitalization. In April 1962, prior to her third admission, she