Critical appraisal of exercise variables: a treadmill study.
BACKGROUND
New criteria for diagnosing ischemic response to treadmill exercise testing (TET) have continuously been proposed. Simultaneous comparison of test performances according to these criteria is likely contributory to interpreting TET and needs to be updated time after time. This study was conducted to accomplish this end.


METHODS
A comparison of test performances of various TET variables for a cohort of 107 clinical normals and 139 angiographic patients with normal resting electrocardiograms was performed. Angiographic references included enumeration of diseased coronary vessels, Gensini's and Duke's coronary scores, left ventricular wall motion score and ejection fraction at rest.


RESULTS
The ST-segment-related variables (depression, integral, and heart-rate-adjusted slope or index) outdid non-ST-segment variables (changes in R amplitude, the Athens QRS score, peak exercise blood pressure increment and recovery pressure ratios; most P < 0.05) in diagnosing coronary artery disease. Among them the heart-rate-adjusted ST-segment depression performed still better. This trend was not evident in identifying left main and three-vessel disease. However, correlation to the coronary scores favored the ST-segment-related criteria (r = 0.18-0.39, P < 0.05 to P < 0.001 versus r = 0.05-0.23, NS to P < 0.01) for evaluating severity of coronary artery disease.


CONCLUSIONS
For patients with normal resting electrocardiograms, the adjustment of ST-segment depression for heart rate is valuable for evaluating coronary artery disease.
Hsu
T S
TS
First Cardiovascular Division, Chang Gung Memorial Hospital, Taipei, Taiwan, Republic of China.
Lee
C P
CP
Chern
M S
MS
Cheng
N J
NJ
D006328:Cardiac Catheterization; D016022:Case-Control Studies; D015331:Cohort Studies; D017023:Coronary Angiography; D004562:Electrocardiography; D005080:Exercise Test / Q000706:statistics & numerical data; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis*; D012372:ROC Curve