title: Electrocardiographic diagnosis of myocardial infarction in patients with pacemakers.
abstract: The ECG changes of myocardial infarction during permanent or transient right ventricular pacing were studied in 32 patients with transvenous pacemakers who developed myocardial infarction. During right ventricular pacing the electrocardiogram resembled left bundle branch block in 29 patients, right bundle branch block in two, and in one patient the pattern could not be determined. Myocardial infarction induced new ECG changes during pacemaker rhythm in 20 of the 32 patients. There were only QS complexes in 5 cases, ST segment abnormalities in 4 and T wave inversions in 4, negative Q and T waves were simultaneously observed in one patient, Q wave and S-T segment changes in 3 and S-T segment change and T wave inversion in 3 patients. It is concluded that knowledge of the ECG changes induced by myocardial infarction in most patients under artificial pacing can be useful for diagnosis.
mesh_terms: D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D006327:Heart Block / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis*; D010138:Pacemaker, Artificial