VALUE OF THE ELECTROCARDIOGRAM IN DIAGNOSING THE NUMBER OF SEVERELY NARROWED CORONARY-ARTERIES IN REST ANGINA-PECTORIS

The aim of this study was to assess the value of the electrocardiogram recorded during chest pain for identifying high-risk patients with 3- vessel or left main stem coronary artery disease (CAD). Therefore, the number of leads with abnormal ST segments, the amount of ST-segment d eviation, and specific combinations of leads with abnormal ST segments were correlated with the number of coronary arteries with proximal na rrowing of >70%. Electrocardiograms recorded during chest pain were co mpared with one from a symptom-free episode. In this retrospective ana lysis, 113 consecutive patients were included. One-vessel CAD was pres ent in 47 patients, 2-vessel CAD in 22, 3-vessel CAD in 24 and left ma in CAD in 20. Stratification was performed according to the presence o f an old myocardial infarction. The number of leads with ST-segment de viations, and the amount of ST-segment deviation in the electrocardiog ram obtained during chest pain at rest showed a positive correlation w ith the number of diseased coronary arteries. These findings were more marked when the absolute shifts from baseline were considered, becaus e ST-segment abnormalities could be present also in the electrocardiog ram obtained during the symptom-free episode. Left main and 3-vessel C AD showed a frequent combination of leads with abnormal ST segments: S T-segment depression in leads I, II and V4-V6, and ST-segment elevatio n in lead aVR. The negative predictive and positive accuracy of this p attern were 78 and 62%, respectively. When the total amount of ST-segm ent changes was >12 mm, the positive predictive accuracy for 3-vessel or left main stem CAD increased to 86%. The findings show that the ele ctrocardiogram during chest pain at rest is of great value in diagnosi ng the number of diseased coronary arteries in patients with rest angi na.