Heart rate adjustment of the time-voltage ST segment integral: identification of coronary disease and relation to standard and heart rate-adjusted ST segment depression criteria.
To assess the effect of heart rate adjustment of the magnitude of the ST integral (ST-HR integral) on exercise test performance, the exercise electrocardiogram (ECG) of 50 clinically normal subjects and 100 patients with known or suspected coronary artery disease was analyzed. At matched specificity of 96% with standard ECG criteria (greater than or equal to 0.1 mV of additional horizontal or downsloping ST segment depression), an unadjusted ST integral partition of 16 microV-s identified coronary disease in the 100 patients with known or suspected disease with a sensitivity of only 41%, a value significantly lower than the 59% sensitivity of standard ECG criteria (p less than 0.01) and the 65% sensitivity of an ST depression partition of 130 microV (p less than 0.001). However, test performance of the ST integral was greatly improved by simple heart rate adjustment: at a matched specificity of 96%, an ST-HR integral partition of 0.154 microV-s/beat per min identified coronary disease in the 100 patients with a sensitivity of 90%, a value significantly greater than the 59% sensitivity of standard criteria and 65% sensitivity of ST depression criteria (each p less than 0.001) and similar to the 91% sensitivity of the ST-HR index and 93% sensitivity of the ST-HR slope (each p = NS). Comparison of receiver-operating characteristic curves confirmed the superior overall test performance of the ST-HR integral relative to the ST integral and ST segment depression, and demonstrated improved performance that was comparable with that of the ST-HR index and the ST-HR slope.(ABSTRACT TRUNCATED AT 250 WORDS)
Okin
P M
PM
Department of Medicine, New York Hospital-Cornell Medical Center, New York 10021.
Bergman
G
G
Kligfield
P
P
D000328:Adult; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003327:Coronary Disease / Q000175:diagnosis* / Q000503:physiopathology; D004560:Electricity; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013997:Time Factors