[Significance of repetitive ventricular extrasystoles in the acute phase of myocardial infarction]

Abstract

Ventricular extrasystoles were analysed by a computerised monitor in 144 patients during the first three days of myocardial infarction. The patients had been hospitalised within 6 hours (77% of cases) and within 12 hours (92% of cases) of onset of symptoms. The patients were divided into 4 groups: Group A (46 cases) without repetitive ventricular extrasystoles; Group B (37 cases) with repetitive ventricular extrasystoles but without frequent isolated extrasystoles; Group C (25 patients) with repetitive ventricular extrasystoles and frequent isolated extrasystoles but without polymorphism or R on T phenomenon; and Group D (36 patients) with repetitive extrasystoles, frequent isolated polymorphic extrasystoles and/or R on T phenomenon. The size of infarction, as judged by peak CPK values, was smaller in Group A than in the other groups but was not significantly different in Groups B, C and D. The incidence of cardiac failure was comparable in Groups A and B and in Groups C and D, and was higher in the latter two groups than in A and B. The cardiothoracic ratio on admission was increased more often in Group D than in the other groups. Therefore, repetitive ventricular extrasystoles are the result of large infarcts. Their association with frequent isolated ventricular extrasystoles is a sign of insufficiency of the remaining myocardium. Patients with pre-existing poor myocardial function develop polymorphism and R on T phenomenon, signs which are associated with a particularly poor prognosis (hospital mortality: 42%). On the other hand, patients in Group B appeared to have satisfactory myocardial function despite the size of their infarcts, and the mortality, nil in this group, was less than in patients without arrhythmias.