Acute severe cardiac failure complicating myocardial infarction. Experience with 100 patients referred for consideration of mechanical left ventricular assistance.

Abstract

One hundred patients were referred with suspected acute cardiacfailurefollowing acute myocardial infarction. The diagnosis was confirmed in 72: 3I of these patients underwent elective medical treatment, with 2 survivors (6%); 4V were accepted for counterpulsation, but 9 died before this could be initiated and another 2 died shortly after vain attempts to pass the balloon catheter were abandoned; 30 patients underwent counterpulsation with 14 hospital survivors (47%). Survivor status was usually good. Results of counterpulsation were better in patients who were not shocked (with 5/5 survivors) than in those who were in shock (with 9 of 25 survivors). Results support the view that counterpulsation (alone or combined with corrective surgery) may play an important role in the complications of myocardial infarction provided intervention is early.

Arterial counterpulsation in severe refractory heart failure complicating acute myocardial infarction.

“…Results at this stage were dismal (O'Rourke et al, 1975). We attributed these poor results to the unrealistically strict definition of shock, to the delays incurred in preliminary assessment, and to the trauma of cardiac diagnostic and surgical procedures.…”

“…Our present procedure requires (1) a diagnosis of definite acute myocardial infarction by WHO criteria (WHO, 1970), (2) definite evidence of acute severe heart failure by clinical and radiological criteria (WHO, 1970), or (if such signs are equivocal) an increase in pulmonary artery pressure above 16 mmHg wedge or 20 mmHg mean, and (3) absent or completely unsatisfactory response to medical treatment over at least a 2-hour period, such treatment to include oxygen by mask, relief of pain, adequate diuretics (the minimum dose of frusemide was 80 mg by intravenous injection), and correction of haemodynamically significant arrhythmias. The MIRU definition of cardiogenic shock (Dunkman et al, 1972;Sanders et al, 1972;O'Rourke et al, 1975) was modified by (a) foregoing the requirement of pulmonary and systemic catheterisation before counterpulsation if clinical signs of cardiac failure were unequivocal and if indirect pressure in the brachial artery was less than 100 mmHg systolic and (b) allowing urine output up to 25 ml/hour with diuretic therapy. All other aspects of the 'MIRU definition' (Dunkman et al, 1972) were retained.…”

“…The procedure requires that counterpulsation be continued until maximal clinical improvement has been attained and maintained for at least 3 days. At this stage (usually after 7 to 10 days), a trial of weaning is performed (O'Rourke et al, 1975). If deterioration occurs, counterpulsation is continued for a further 4 to 7 days and the trial repeated.…”

“…Predicted survival rate for patients with shock was < 10 per cent (Wan et al, 1971;O'Rourke et al, 1975;O'Rourke, 1977) and for patients without shock was < 50 per cent from Peel et al (1962) and Norris et al (1969) indices (Table 2). Of the first 200 patients referred to us for consideration of counterpulsation, 39 met the criteria but did not proceed to counterpulsation.…”

“…These patients were accepted from a group of over 300 referred for consideration of mechanical heart assistance (O'Rourke et al, 1975(O'Rourke et al, , 1976.…”