COMPARISON OF THE DIAGNOSTIC POTENTIAL OF 4 ECHOCARDIOGRAPHIC STRESS TESTS SHORTLY AFTER ACUTE MYOCARDIAL-INFARCTION - SUBMAXIMAL EXERCISE,TRANSESOPHAGEAL ATRIAL-PACING, DIPYRIDAMOLE, AND DOBUTAMINE-ATROPINE

This study assessed and compared the diagnostic potential of submaxima l exercise, transesophageal atrial pacing, dipyridamole, and dobutamin e-atropine stress echocardiography tests shortly after acute myocardia l infarction. In 121 study patients, 325 digital echocardiographic str ess tests were attempted 10 to 11 days after acute myocardial infarcti on: 83 submaximal exercise tests, 121 high-dose dipyridamole echocardi ography tests (DET), 69 transesophageal atrial pacing tests (<150 beat s/min), and 52 dobutamine tests, starting at 10 mu g/kg per minute, in creasing stepwise to 40 mu g/kg/min, and coadministering atropine in 1 2 patients (dobutamine-atropine stress echocardiography [DASE]). Resul ts were correlated to a coronary artery diameter stenosis greater than or equal to 50% as determined by quantitative angiography. Feasibilit y to perform submaximal exercise echocardiography, atrial pacing echoc ardiography, DET, and DASE was 89%, 52%, 98%, and 88%, respectively. A trial pacing was not tolerated by 18 patients and refused by 6 (9%). S evere but not life-threatening side effects were hypotension in DET (2 %) and tachyarrhythmias in DASE (6%). Test positivity in multivessel d isease with submaximal exercise, DET, and DASE was 55%, 93%, and 90%, respectively, and in 1-vessel disease 47%, 65%, 71%, and for atrial pa cing, 82%, respectively. We conclude that submaximal exercise has limi ted sensitivity and atrial pacing limited feasibility. The pharmacolog ic stressors provide a useful, safe diagnostic approach: DET with slig htly lower sensitivity in 1-vessel disease and DASE with insignificant ly less feasibility.