Limitations of 24 hour ambulatory electrocardiographic recording in predicting coronary events after acute myocardial infarction

Abstract

Twenty-four hour Holter electrocardiographic tape recordings were made in 200 survivors of an acute myocardial infarction 1 to 7 days after discharge from the hospital. Patients taking beta adrenergic blocking or antiarrhythmic drugs were excluded. Eighty-nine percent of the patients participated after completion of the Holter tape recording in an ongoing 1:1 placebo-controlled intervention study with a cardioselective beta adrenergic blocking drug. The incidence and grade of ventricular premature complexes in the standard electrocardiogram and Holter tape recording were correlated with subsequent coronary events: sudden death, fatal recurrent myocardial infarction and uncomplicated recurrent myocardial infarction during the 1st year after the myocardial infarction. Frequent, multiform and repetitive ventricular premature complexes were found in 81 percent of the patients. The occurrence of ventricular premature complexes in the standard electrocardiogram showed a positive correlation with repetitive forms during Holter tape recording. Although more coronary events occurred in the patients with more severe forms of ventricular premature complexes, a statistically significant correlation could not be demonstrated because of the relatively small number of patients studied. It is concluded that a greater proportion of patients than hitherto suspected have severe forms of ventricular premature complexes on 24 hour Holler tape recording 1 to 7 days after hospital discharge. Even if a correlation could be demonstrated between ventricular premature complexes and subsequent coronary events the incidence of this rhythm disturbance is so great that the clinical usefulness of this finding may be limited.