From July 1984 to December 1987, intra-aortic balloon pumping (IABP) was attempted percutaneously to 22 patients at the ages of 37-78 with cardiogenic shock or medically refractory heart failure complicating acute myocardial infarction (CS/MRHF-AMI). There was only one failure because of severe bilateral iliofemoral atherosclerosis. Of the 21 patients undergoing IABP, 17 were in cardiogenic shock and 13 of them showed reversal of shock syndrome after 10 to 48 hours of IABP. Cardiac index increased from 1.91 +/- 0.43 to 2.45 +/- 0.43 L/min/M2 (P less than 0.005), spontaneous systolic arterial pressure rose from 79 +/- 10 to 114 +/- 19 mmHg (P = 0.0001), heart rate dropped from 111 +/- 26 to 85 +/- 13 beats/min (P = 0.0001), pulmonary artery wedge pressure decreased from 29 +/- 5 to 16 +/- 3 mmHg (P = 0.0001), and urine output increased from 7 +/- 10 to 79 +/- 22 ml/h (P = 0.0001). Twelve patients, including 4 shock-free, were subsequently weaned from balloon assistance. Of these patients, 8 (5 shock and 3 nonshock) were discharged from the hospital and followed-up for a mean period of 23 months (4 to 38 months). Of the surviving patients, 4 underwent surgical reperfusion and/or infarctectomy during balloon support (n = 1) or after weaning from IABP (n = 3). All of the 10 patients who underwent coronary angiogram were found a severe left anterior descending artery lesion. The main complication was leg ischemia, which was observed in 7 patients: 3 needed removal or replacement of balloon catheter and one required surgical removal of the thrombus.(ABSTRACT TRUNCATED AT 250 WORDS)