Diagnostic Methods Coronary Artery Disease

Patients with clinically significant coronary artery disease often have normal resting electrocardiograms. Clinical and experimental studies have shown that body surface potential maps provide improved recognition of some disease states and more regionally selective information than standard electrocardiograms. Body surface maps were recorded at rest from 41 symptomatic patients with angiographically documented coronary artery disease and normal electrocardiograms. Patient maps were statistically compared with maps recorded from 644 normal subjects with the use of previously reported data representation technique. By this technique, maps from patients with symptomatic coronary artery disease and normal electrocardiograms were separated from maps of normal subjects with a sensitivity and specificity greater than 94%. The majority of discriminating information was present in the QRS interval. Fifteen of the 41 symptomatic patients had documented single-vessel coronary disease and their maps were separately compared with normal maps. Average maps from each of three patient groups with single-vessel disease contained abnormal patterns during the QRS interval that were unique to the vessel affected. In comparison with an average map from normal subjects, the average map from the group with left anterior descending coronary disease showed lower potentials over the anterior and inferolateral thorax during the early to mid QRS interval, the average map from the circumflex disease group showed decreased potentials around the entire inferior thorax in the mid to late QRS interval, and the average map from the right coronary disease group showed decreased potentials over the right anterior thorax during the mid to late QRS interval. Multivariate statistical analysis of body surface maps detected resting, regional electrophysiologic abnormalities associated with coronary artery disease and maps may have utility in diagnosis of coronary artery disease in patients with normal electrocardiograms. Circulation 76, No. 6, 1290-1297, 1987. PATIENTS with clinically significant coronary artery disease often have a normal resting electrocardiogram. Previous studies have shown 25% to 50% of patients with a history of chest pain due to documented coronary artery disease have normal resting electrocardiograms when they are pain free. 1-3 These studies included patients with both single and multivessel disease. Other studies have shown that in patients with coronary artery disease and no history of infarction, the most common electrocardiographic abnormalities From the Nora Eccles Harrison Cardiovascular Research and Training Institute and The Department of Medicine, University of Utah School of Medicine, Salt Lake City. Supported by Program Project grant HL13480 and research grant HL35204 from the National Heart, Lung, and Blood Institute, and awards from the Nora Eccles Treadwell Foundation and the Richard A. and Nora Eccles Harrison Cardiovascular Research Fund. Address for correspondence: Larry S. Green, M.D., Nora Eccles Harrison Cardiovascular Research and Training Institute, Building 100, University of Utah, Salt Lake City, UT 84112. Received May 1, 1987; revision accepted Aug. 20, 1987. 1290 are nonspecific and occur during the ST-T interval.4 Compared with the 12-lead electrocardiogram, body surface potential mapping provides enhanced sensitivity to individual cardiac regions and improved electrocardiologic recognition of some disease states.5 8 Previous studies have shown that patients with coronary artery disease and normal electrocardiograms can be discriminated from normal subjects with the use of body surface potential maps.1'These studies relied primarily on analysis of the ST-T interval, a portion of the electrocardiogram affected by a variety of nonpathologic factors. The study reported here was undertaken to determine whether the added information content of resting body surface potential maps of the entire QRST interval could be used to detect the presence and location of documented coronary artery disease in symptomatic patients with normal resting electrocardiograms. CIRCULATION by gest on M ay 4, 2017 http://ciajournals.org/ D ow nladed from DIAGNOSTIC METHODS-CORONARY ARTERY DISEASE