title: The value of sum of ST segment depression in 12-lead electrocardiogram in relation to change in heart rate during exercise to predict the extent of coronary artery disease.
abstract: The present study was planned to investigate whether the sum of ST segment depression in 12-lead electrocardiogram (sigma STD) in relation to change in heart rate (delta HR) during exercise, sigma STD/delta HR index, could be utilized to predict the extent of underlying coronary artery disease. Two hundred and twenty-six consecutive patients were included in this study, 191 men and 35 women, aged 28-74 years (mean 56). Patients were classified into two groups. Group I consisted of 165 patients with either no coronary disease, single or double vessel disease. Group II included 61 patients with triple vessel or left main stem stenosis. It was found that the sigma STD/delta HR index at 25 mm. beat-1 X min. 10(2) provided the best separation between Groups I and II patients. All but 3 of the 61 patients in Group II had a sigma STD/delta HR index greater than 25. In contrast, all but 4 of the 165 patients in Group I had an index less than 25. The sensitivity, specificity and positive predictive value in the identification of Group II patients by using the index were 95%, 98% and 94% respectively. Utilization of ST segment depression of greater than or equal to 2 mm in a VF alone as a test criterion for the recognition of Group II patients had a low sensitivity (41%), specificity (88%) and positive predictive value (56%).(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis*; D004562:Electrocardiography / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis