Predictive value of dobutamine radionuclide ventriculography in detection of functional improvement after acute anterior wall infarction and thrombolytic therapy.

Background: Prolonged postischemic ventricular dysfunction (stunned myocardium) may prevent the assessment of myocardial salvage early after thrombolysis. Dobutamine in conjunction with radionuclide ventriculography has been proposed for the early assessment of myocardial viability and prediction of functional recovery.

Hypothesis: This study was designed to investigate the effects of low-dose dobutamine infusion on early global and regional function of reperfused myocardium after acute anterior wall myocardial infarction (MI). In particular, our purpose was to examine whether this response can predict late recovery of left ventricular function and correlate with the reperfused status (patency of infarct-related artery).

Methods: In all, 29 consecutive patients with first uncomplicated anterior wall MI, and who had received thrombolytic therapy, underwent radionuclide ventriculography at rest and 2 min after each dose increment of dobutamine infusion (5-15 micrograms/kg/min) on the third day after the infarction, at discharge, and at 3 months' follow-up. Global and regional ejection fraction were calculated at each stage. Four patients with complications were dropped from the study. A significant response to dobutamine was defined as an increase of at least > or = 7% in global or regional ejection fraction at the infarct zones.

Results: Of the 25 patients, 18 (72%) fulfilled these criteria. Of these, 10 patients (56%) had a significant improvement in global or regional ejection fraction at discharge and 13 patients (72%) at 3-month follow-up. The overall sensitivity of the dobutamine test in predicting left ventricular improvement was 100% at discharge and 93% at 3-month follow-up. However, the positive and negative predictive values were 56 and 100% at discharge and 72 and 86%, respectively, at 3-month follow-up.

Conclusion: Low-dose dobutamine radionuclide ventriculography is a safe and useful test for assessing myocardial viability and may predict late functional improvement in patients with anterior wall MI.