Repeated 1 hour electrocardiographic monitoring of survivors of myocardial infarction at 6 month intervals: Arrhythmia detection and relation to prognosis

In a study of the relation between ventricular premature beats and sudden death among 1,739 male survivors of myocardial infarction enrolled in the Health Insurance Plan of Greater New York (HIP), patients underwent 1 hour of electrocardiographic monitoring at a baseline examination. During follow-up periods of up to 5 1/2 years, survivors underwent repeated monitoring at 6 month intervals for a maximum of four monitorings. At each monitoring a constant proportion of the men—25 percent—showed complex ventricular premature beats (runs of two or more, R on T phenomenon, bigeminal or multiform beats) during the hour. In comparison with men free of such arrhythmia, those demonstrating these complex forms in a given hour were three times as likely to show such beats in a subsequent monitoring hour. The mortality risk over 3 1/2 years after each of the four monitoring observations was in all cases elevated among men with complex ventricular premature beats. The risk of sudden death over this period was 6 percent for men without and 13 to 17 percent for men with such complexes. A study of the 1,445 men who underwent monitoring both at baseline examination and 6 months later identified the presence of runs of ventricular premature beats in either observation as a particularly important harbinger of sudden death.