RESUMO
PURPOSE: To determine the usefulness of an ambulatory electrocardiographic monitoring system, in identifying atherosclerotic coronary artery disease among symptomatic and asymptomatic patients, through a comparison of ST-segment depression with angiographic findings. METHODS: Fifty patients, 48 men, with the mean age 49 +/- 13 years (range 20 to 73), presenting ST-segment depression, were submitted to coronary angiography, complemented by echocardiogram and exercise testing, when the angiography was considered normal. According to the symptoms patients were divided into three groups: I--asymptomatic (16-32%); II--atypical chest pain (15-30%); and III--angina (19-38%). The Cardiac Care Units (Compass TM) system was used for the ambulatory electrocardiographic monitoring. RESULTS: Twenty-four patients (48%) had significant atherosclerotic coronary artery disease documented angiographically. Twenty-six patients (52%) had normal coronary arteries by angiography: 18 (36%), presented some pathology demonstrated by echocardiographic studies (left ventricle hypertrophy, mitral valve prolapse, non-obstructive septal hypertrophy, dilated cardiomyopathy). Eight patients (16%) had normal echocardiograms, and in (6%) the exercise test was positive and in the other 5 (6%) negative. One of those patients (2%), with negative exercise test, had a myocardial bridge over the anterior descending branch of the left coronary artery, 2 patients (4%) presented symptomatic episodes of ST depression, and 2 other patients (4%) were asymptomatic. CONCLUSION: A comparison of the ST depression analysed in real time during ambulatory electrocardiographic monitoring with the cinecoronarographic findings showed a poor correlation of the two methods in identifying atherosclerotic coronary disease. The ischemic depressions of ST-segment were associated to obstructive lesions or slow flow in the coronary arteries in only 48% of the cases studied.
