Precordial mapping of ST-segment elevation and Q waves following anterior myocardial infarction. The effects of established beta-blocking drugs.
The electrocardiographic (ECG) signs of ST-segment elevation and the development of Q was using 72-lead precordial surface mapping, and the release of creatine kinase (CK) activity has been studied in 47 patients with uncomplicated anterior myocardial infarction. These findings were compared with a further nine patients who had acute myocardial infarction but were receiving long-term beta-blocking drugs. It was found that ST-segment elevation and Q waves had rapidly changing and different natural histories and that beta-blocking drugs altered the natural history of ST-segment changes but had no effect on the pattern and time course for the loss of electrically active myocardium. There was a close relationship between the precordial area of ST-segment elevation at 2--3 h and the final development of Q waves in the patients with uncomplicated anterior myocardial infarction. No similar relationship could be found in those on beta-blocking drugs. The pattern of changes in plasma CK and its MB isoenzymes activity were similar for both groups. The relationship between early ST-segment elevation and the final area of Q waves may prove useful in clinical practice. This may not apply where beta-blocking drugs are commenced before the initial recording of ST-segment elevation.
D000208:Acute Disease; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000097:blood; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy*
D000319:Adrenergic beta-Antagonists; D007527:Isoenzymes; D003402:Creatine Kinase