Persistent ST-segment elevation in patients with anterior myocardial infarctions. Evaluation by exercise electrocardiography, echocardiography and Holter monitoring.
One hundred and seventy patients who suffered an acute myocardial infarction (MI) were followed up at 3-monthly intervals by a full clinical evaluation, exercise electrocardiography and ambulatory Holter monitoring. Fifty-eight patients (34%) had anterior MIs, and of these 23 (40%) had persistent ST-segment elevation over the infarct zone, reflected by leads presenting with Q-S configuration. Fifteen (65,2%) of the latter demonstrated further ST-segment elevation during exercise. They were further investigated by cross-sectional echocardiography. Left ventricular (LV) dysfunction was diagnosed in 87% of patients with persistent ST-segment elevation, and in 93% of the patients with additional exercise-induced ST-segment elevation. Organized thrombi occurred in 2 patients (8,7%) and 1 experienced a transient ischaemic attack. Ventricular arrhythmias occurred frequently (ventricular ectopy--91,3%, ventricular tachycardia--17,4%, and couplets--47,8%). Death occurred in 3 patients (13,1%) and 1 patient (4,3%) had a second MI over a mean follow-up period of 83,6 months. This study suggests that persistent ST-segment elevation on the resting ECG of patients with anterior MIs is a reliable indicator of LV wall motion abnormalities, and that this correlation further increases if it is associated with exercise-induced ST-segment elevation. Furthermore, the role of echocardiography as a diagnostic tool in evaluating LV function is stressed. The prognosis of patients with post-infarction LV dysfunction is notably poor and may be the result of frequent complex ventricular arrhythmias.
D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D004452:Echocardiography; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D012189:Retrospective Studies