Improved detection of coronary artery disease by exercise electrocardiography with the use of right precordial leads

Background Exercise electrocardiography is an imperfect test for the detect ion of coronary artery disease. We attempted to improve the diagnostic accu racy of exercise testing as a noninvasive method for the detection of coron ary artery disease by using a combination of the left and right precordial leads. Methods We studied 245 patients (218 men and 27 women) ranging from 32 to 7 4 years of age (mean [+/-SD], 52 +/- 8) who underwent treadmill exercise te sting, thallium-201 scintigraphy, and coronary arteriography. During exerci se testing, each patient had one electrocardiogram recorded with the standa rd 12 leads and 3 right precordial leads (V3R, V4R, and V5R), with the resu lts for each set of leads recorded and analyzed separately. Results On the basis of coronary arteriography, 34 patients had normal coro nary arteries, 85 had single-vessel disease, 84 had two-vessel disease, and 42 had three-vessel disease. The sensitivities of the standard 12-lead exe rcise electrocardiogram, exercise electrocardiography incorporating right p recordial leads, and thallium-201 scintigraphy were 52 percent, 89 percent, and 87 percent, respectively, for the detection of single-vessel disease; 71 percent, 94 percent, and 96 percent for the detection of two-vessel dise ase; 83 percent, 95 percent, and 98 percent for the detection of three-vess el disease; and 66 per cent, 92 percent, and 93 percent for the detection o f any coronary artery disease. The specificities of the three methods for t he detection of any coronary artery disease were 88 percent, 88 percent, an d 82 percent, respectively. Conclusions Use of right precordial leads along with the standard six left precordial leads during exercise electrocardiography greatly improves the s ensitivity of exercise testing for the diagnosis of coronary artery disease . (N Engl J Med 1999;340:340-5.) (C) 1999, Massachusetts Medical Society.