[Usefulness of dobutamine in producing myocardial ischemia. Comparison with ergometry]

Fifty six patients were studied while in the Coronary Care Unit: 17 with unstable angina and 39 with acute myocardial infarction. All patients underwent dobutamine stress testing (doses of 5, 10, 15 and 20 micrograms/kg/min every 5 min) and exercise testing (modified protocol to finish at an energy expenditure of approximately 5 METS): 4-5 days after the last crisis of angina or 6-8 days after the onset of noncomplicated acute myocardial infarction. The heart rate increased from 72 +/- 10 to 104 +/- 12 beat/min with dobutamine (p = 0.00001) and from 84 +/- 11 to 118 +/- 15 beat/min with exercise testing (p = 0.00001). The systolic blood pressure increased from 116 +/- 9 to 138 +/- 11 mmHg with dobutamine (p = 0.00001) and from 117 +/- 8 to 156 +/- 7 mmHg with exercise testing (p = 0.00001). Due to different reasons 33 patients did not finish the exercise protocol, while only 8 patients did not finish the dobutamine testing. The ST segment wast elevated in 22 cases with dobutamine and in 9 cases with exercise, eight of them coinciding in both tests. The ST segment was depressed in 36 cases with dobutamine and in 21 cases with exercise, 20 of them coinciding in both tests. Angina was present in 11 cases with dobutamine and in four exercise, three of them coinciding. If the unfinished tests or those with angina or ST segment depression are considered abnormal, there were 40 abnormal tests with dobutamine and 38 with exercise, 32 of them coinciding.(ABSTRACT TRUNCATED AT 250 WORDS)