Occurrence and regression of initial and terminal notching of the QRS complex in the electrocardiograms of patients with acute myocardial infarction.

The occurrence of initial and terminal notching in the QRS complex of the electrocardiogram was studied in a series of 158 male patients surviving acute myocardial infarction during hospital admission and at follow-up examinations 6-8 weeks, 5 and 12 months after the infarction. In 115 men with their first myocardial infarction signifiant initial notching was found in the acute stage in 30% and significant terminal notching in 32%. One year later these percentages were 14 and 9, respectively. In patients with reinfarction the prevalence of notching was even higher. Inital notches were most often associated with anterior and terminal notches with inferoposterio infarction.