Advantages and disadvantages of dobutamine stress echocardiography compared with treadmill exercise electrocardiography in detecting ischemia

We compared the effectiveness and practicability of dobutamine stress echocardiography (DSE) and treadmill exercise electrocardiographic testing (TMT) for detecting coronary artery disease. Ninety-six patients (mean age 58.8 +/- 9.0 years) who presented for coronary angiography underwent both DSE and symptom-limited TMT. Two-dimensional echocardiography was performed to detect ischemia-induced wall motion abnormalities during incremental dobutamine infusion (5-40 mu g/kg per min administered in 5 min steps). The sensitivity of detecting ischemia was 63% for TMT and 79% for DSE (p < 0.05); the specificity was 61% for TMT and 88% for DSE (p < 0.05). The accuracy of TMT was 63% and of DSE 82% (p < 0.01). In patients in whom both tests gave true-positive results, the maximum ST depression was evaluated during DSE and TMT (n = 31). The ST segment depressions detected by DSE were significantly smaller than those detected by TMT (0.04 +/- 0.04 mV vs 0.17 +/- 0.07 mV, p < 0.01), and 10 patients had no evidence of ST segment depression despite the presence of new wall motion abnormalities. DSE took significantly longer to perform than TMT (26.0 +/- 5.0 min vs 5.5 +/- 2.0 min, p < 0.01). Thus, DSE is more sensitive, specific and accurate than TMT in detecting coronary artery disease and can detect ischemia at an earlier stage. However, it takes longer to perform than TMT and thus may be less suitable for routine clinical use.