Search

71 of 840 patients admitted to an intensive care unit (I.C.U.) between 1970 and 1974 because of acute myocardial infarction were aged over 80 years. Age was thus an important determinant of infarction and the death-rate rose steeply with age, the hospital death-rate being 61% in those over 80 but only 8.4% in those under 50 years. The high incidence and severity of haemodynamic complications (pulmonary oedema, generalized heart failure, cardiogenic shock) were the main cause of the high death-rate. Supraventricular arrhythmias (atrial flutter and fibrillation) were frequent. Early treatment in an I.C.U. improved prognosis even in the elderly patient, by control of conduction disturbances and other arrhythmias but also by early recognition and treatment of haemodynamic complications.

Among 909 patients with acute myocardial inarction treated in an intensive care unit between 1970 and 1974, atrial flutter and (or) fibrillation occurred in 124 (13.6%). The incidence of these arrhythmias rose with increasing age and predominantly in paroxysmal form (78%). The clinic mortality of patients with arrhythmias was 42%, while in the remaining 785 it was only 26% (P less than 0.001). Patients with atrial fibrillation and (or) flutter had a higher mean age, more frequently cardiac failure (P less than 0.001) - especially in the prognostically unfavourable severe forms with pulmonary oedema (P less than 0.05) and combined right and left heart failure (P less than 0.001) - and other disorders of impulse conduction or formation and chronic arterial hypertension (P less than 0.01).

In 301 patients admitted to an intensive-care unit because of acute myocardial infarction a prognostic analysis was undertaken, based on 21 parameters (history, condition on admission, laboratory results) and related to ultimate outcome. Although some parameters were singly of prognostic value, discrimination analysis markedly improved predictive value. A prognostic index was constructed from seven easily available parameters: age, pulmonary congestion, leucocytosis, peripheral vasoconstriction, systolic blood pressure, site of infarct and hypertension. For those in a low-risk class (index less than 60, death-rate up to 5%), duration of stay in the intensive-care unit may be shortened and rehabilitation measures accelerated. Those at moderate risk (index 60-90, death-rate up to 25%) require careful monitoring. The highest risk classes (index 90-120, death-rate up to 90%; and index more than 120, death-rate more than 90%) require specially intensive and long-term monitoring, and various procedures for assisted circulation and possible cardiacsurgical intervention should be considered from the outset.