ACCURACY OF DOBUTAMINE STRESS ECHOCARDIOGRAPHY FOR THE DIAGNOSIS OF CORONARY-ARTERY STENOSIS IN PATIENTS WITH MYOCARDIAL-INFARCTION - THE IMPACT OF EXTENT AND SEVERITY OF LEFT-VENTRICULAR DYSFUNCTION

Objectives-To assess the value of dobutamine stress echocardiography ( DSE) in the prediction of the extent and location of coronary artery s tenosis in symptomatic patients with old myocardial infarction and to study the impact of the severity of resting wall motion abnormalities (WMA) on the diagnostic accuracy of the test. Patients-One hundred and thirty two symptomatic patients with old myocardial infarction. Metho ds-DSE (up to 40 mu g/kg/min, with atropine up to 1 mg) was performed in all patients. Ischaemia was defined as new or worsened WMA. For eac h coronary artery, regional wall motion in the corresponding territory was classified as normal, mildly, moderately, or severely impaired ac cording to the wall motion score index. Significant coronary stenosis was defined as greater than or equal to 50% diameter stenosis. Results -A positive DSE for ischaemia occurred in 87 of 111 patients with and three of 21 patients without coronary artery stenosis (sensitivity = 7 8%; CI 71 to 86, specificity = 86%; CI 79 to 92, accuracy = 80%; CI 73 to 87). The accuracy for the diagnosis of individual coronary stenosi s was 69% in the presence ofnormal wall motion and 74%, 74%, and 61% r espectively when there was mild, moderate, and severe WMA in the corre sponding territories (P = NS). The sensitivity was higher in presence of mild or moderate WMA (73%) than with normal wall motion (53%) or se vere WMA (56%, P < 0.05 in both). In territories subtended by a stenot ic artery, the regional wall motion score index was not different with or without ischaemia. Conclusion-DSE had a good overall accuracy for the diagnosis of coronary artery stenosis in symptomatic patients with old myocardial infarction. The presence of resting WMA did not limit DSE as a method of eliciting myocardial ischaemia and diagnosing signi ficant coronary artery stenosis in patients with old myocardial infarc tions.