The present study was undertaken in order to evaluate the usefulness and safety of low-dose dobutamine echocardiography (LED) performed within 48 hours of an anterior acute myocardial infarction (AMI) to identify the extent of viable and irreversible damaged myocardium. Moreover, early LED was compared with predischarge LED and rest-redistribution thallium-SPECT. Ten consecutive patients admitted to the Intensive Coronary Care Unit for a first Q-wave anterior AMI entered the study. All the patients were treated with thrombolytic therapy. Coronary angiography was performed in all the patients within 8 days of admission. LED (5 and 10 γ/kg/min infusion rates with 5 min steps) was performed within 48 hours of hospital admission and at predischarge. In all the patients a rest-redistribution thailium-SPECT myocardial scintigraphy was performed before hospital discharge. Finally, a rest echocardiogram was performed at 3 months from hospital discharge. At cardiac catheterization, 5 patients had one-vessel disease, 3 had two-vessel disease and 2 had three-vessel disease; 9 patients had a significant residual stenosis of the infarct-related artery (left anterior descending artery in all the cases) and in one patient a total occlusion was observed. Coronary revascularization was performed in 5 patients (coronary angioplasty in 3 and aortocoronary bypass in 2). At the 3-month follow-up, 45% of early dyssynergic segments improved, 61% of which were already spontaneously improved at predischarge, whilst 31% of predischarge dyssynergic segments improved. Sensitivity and specificity for wall motion improvement at follow-up were 73 and 87% for early LED and 86 and 69% for predischarge LED. Rest-redistribution thallium-SPECT showed sensitivity and specificity values of 91 and 35%. The agreement for viability detection between early and predischarge LED and rest-redistribution thallium was 58 and 70%, respectively. Our results indicate that LED can be safely performed within 48 hours of an anterior AMI and that it appears to be a quite good predictor of late outcome of regional ventricular function. When compared to LED, rest-redistribution thallium-SPECT overestimates myocardial viability, being a less specific predictor of myocardial functional recovery.
|Number of pages||5|
|Publication status||Published - 1997|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Radiology Nuclear Medicine and imaging