Accuracy of Low Dose Dobutamine Echocardiography in Detection of Myocardial Viability Experience of Menofia University

Background: The identification of severely dysfunctional but viable myocardium is of particular importance for the selection of patients with depressed left ventricular function who will benefit from coronary revascularization. Assessment of inotropic reserve with dobutamine has recently been used for this purpose. Aim of the Study: Detecting the accuracy of low-dose dobutamine echocardiography (DSE) for the identification of viable myocardium in patients with previous myocardial infarction. Patients and Methods: Resting and low-dose dobutamine (7.5pig/kg/min) echocardiography (R and DSE) and resting post-revascularization echocardiography (PRecho) (3 months later) were prospectively studied in 33 patients with previous myocardial infarction and severely depressed regional function. Revascularization had been done either by CABG or PTCA for all patients. Wall motion assessment was done using 4 point score with 1 normal and 4 dyskinetic and viable tissue was diagnosed by presence of contractile response (CR) during LDD infusion in echocardiography using 17 segment model. Results: Out of the 561 myocardial segments resting echo (R) revealed 367 segments with normal wall motion (NWM), 109 hypokinetic with (CR) in 83, 52 akinetic with (CR) in 24, 33 dyskinetic with CR in 3. Post-revascularization echo, revealed 476 segments with NWM, 26 hypo, 28 ak., and 30 dyskinetic. Compared to PR DSE., degree of matching was 85.6%. Sensitivity and specificity for detection of viability was 79.6% and 100% respectively. Conclusion: DSE can be used accurately for detection of clinical viability and predicting early functional recovery post-revascularization.