Low dose dobutamine echocardiography is more predictive of reversible dysfunction after acute myocardial infarction than resting single photon emission computed tomographic thallium-201 scintigraphy.

To directly compare dobutamine echocardiography and resting single photon emission computed tomographic (SPECT) thallium-201 (Tl-201) scintigraphy for the detection of reversible dysfunction, 64 patients underwent dobutomine echocardiography (baseline, low dose 5 and 10 mg/kg/min, and peak dose), rest Tl-201 scintigraphy (3 mCi - 15 minute and 3- to 4-hour SPECT imaging), and coronary angiography during the first week after acute myocardial infarction. Follow-up echocardiography was performed 4 to 8 weeks after discharge. Wall thickening improved at follow-up in 52% (207 of 399) of the dysfunctional segments. By receiver operating characteristic analysis, biphasic responses and sustained improvement during dobutamine echocardiography were more accurate (p < 0.01) than Tl-201 uptake by SPECT scintigraphy for reversible dysfunction. The greater accuracy of dobutamine echocardiography resulted from higher accuracy in akinetic segments, Q wave infarction, and multivessel coronary artery disease. In conclusion, dobutamine echocardiography was more accurate than resting SPECT Tl-201 scintigraphy for reversible dysfunction after acute myocardial infarction.

Detection of coronary artery disease with upright bicycle exercise echocardiography.

This study examined the advantages and limitations of upright bicycle exercise echocardiography in the evaluation of a large series of patients with known or suspected coronary artery disease. The study population consisted of 309 patients (231 men, mean age 57 +/- 11 years) who underwent exercise echocardiography within 8.5 +/- 16.1 days of coronary angiography. All stress electrocardiographic, echocardiographic, and angiographic data were reinterpreted in a blinded manner by the investigators. No patient was excluded because of poor echocardiographic image quality. Wall motion was analyzed at baseline, peak exercise, and immediately after exercise with a 16-segment model, and a regional wall motion score index was calculated at each stage. Abnormalities were ascribed to the distribution of the three coronary arteries and correlated with qualitative angiography. There were 126 patients with wall motion abnormalities at rest and 211 (75%) with coronary artery disease. The stress electrocardiogram (ECG) was negative in 61, positive in 144, and nondiagnostic in 104, yielding a sensitivity of 40% and a specificity of 89%. Echocardiography was normal in 76 of 98 patients without coronary disease (78% specificity) and abnormal in 193 of 211 patients with disease (91% sensitivity). Sensitivity was higher among patients with multivessel disease compared with those with single vessel disease (95% versus 86%, respectively, p = 0.03). Among patients with normal wall motion at rest (n = 183), sensitivity was 83% and specificity was 84%. Of the 104 patients with a nondiagnostic stress ECG, echocardiography correctly identified 95% of those with coronary disease and 75% of those without disease. Among 82 patients with a wall motion abnormality at rest, an additional exercise-induced wall motion abnormality developed in 32 of 46 patients (70%) with multivessel disease and seven of 32 (22%) with single-vessel disease. Overall, echocardiography detected 258 of 392 (66%) individual coronary lesions. Accuracy was higher for lesions in the left anterior descending and right coronary arteries (both 79%) compared with the left circumflex artery (36%, p < 0.001). In conclusion, upright bicycle exercise echocardiography is an accurate technique for the evaluation of patients with known or suspected coronary artery disease and is especially valuable in patients with a nondiagnostic stress ECG. The test provides supplemental information on the extent and location of coronary lesions and is useful in patients with and without prior myocardial infarction.