Relation between admission time, haemodynamic measurements, and prognosis in acute myocardial infarction.

Abstract

SUMMARY Pulmonary arterial end-diastolic pressure, cardiac index, and stroke work index were measured via a thermistor-tipped balloon catheter and monitored for 51±51 hours in 226 patients admitted with an acute myocardial infarction (184 survivors and 42 non-survivors). Mortality was related to time of admission after onset of symptoms of infarction. Of 69 patients in group A 13 died in hospital (18 8%) one to four hours after onset; in group B (five to eight hours after onset) eight of 71 patients (11%) died five to eight hours after onset; four of 26 patients in group C (15%) died nine to 12 hours after onset; 15 of 42 patients (36%) in group D died 13 to 24 hours after onset; and two of 18 patients in group E died (11%) more than 24 hours after onset. Irrespective of admission time, haemodynamic findings in survivors were significantly better than in non-survivors. During the first eight to 12 hours after onset of infarction cardiac index and stroke work index were normal or above normal, with raised left ventricular filling pressures. In patients admitted later, this compensatory mechanism had often collapsed. Where pump failure with subnormal cardiac index and stroke work index were present mortality was increased. All four patients dying from acute myocardial rupture had significantly higher values of cardiac index and stroke work index and lower values of pulmonary artery end-diastolic pressure compared with those dying from other causes.Although the initial haemodynamic values give some prognostic information, longitudinal analysis provides insight into the evolving myocardial disturbance and compensatory mechanisms. If the initial values of pulmonary artery end-diastolic pressure and cardiac and stroke work indices remain normal or become stable after a transient disturbance in the acute phase, prognosis is good. If, however, these values deteriorate or remain abnormal, prognosis is poor. Typically such patients have suffered large infarctions with a tendency to expansion. If the haemodynamic situation during the first 24 hours after onset of infarction remains stable for 12 to 15 hours, haemodynamic monitoring may be stopped; the chance of relapse in such patients was found to be below 10%. Late deterioration, usually manifest by further pain or by electrocardiographic or enzyme changes, should be an indication to restart haemodynamic monitoring so that treatment can be chosen and adjusted optimally. These haemodynamic measurements in patients treated traditionally with vasodilators, positive inotropic agents, and fluid will form the basis for comparison of measurements in patients who are now treated within the first eight hours with selective intracoronary thrombolysis and, if possible, with adjacent intracoronary balloon dilatation of the underlying coronary artery stenosis.

Predictors and importance of congestive heart failure in patients with acute inferior myocardial infarction

“…Previous studies have shown that patients with congestive heart failure complicating acute myocardial infarction have poor prognosis [5][6][7][8][9]. Even in the thrombolytic era, left ventricular dysfunction remains the single most important predictor of mortality following acute myocardial infarction [10,11].…”

Left Ventricular Failure Complicating Acute Myocardial Infarction - Problems and Potential of Nonthrombolytic Therapy

“…1) and longer term ( fig. 2) mortality risk is concentrated in those with haemodynamic evidence of heart fail ure [3][4][5][6][7][8]. For these reasons the treatment of left ventricular failure complicating acute myocardial infarction demands urgent atten tion and aggressive correction.…”