Efficacy of adenosine two-dimensional echocardiography in the diagnosis of viable myocardium. Comparison with thallium scintigraphy

The aim of this study was to assess the feasibility, safety and diagnostic accuracy of two-dimensional echocardiography performed during adenosine infusion (140 μg/Kg/min for 6 min) in recognizing segments of viable myocardium as assessed by thallium-201 scintigraphy (exercise-redistribution-reinjection protocol). For this purpose, 27 patients (25 males and 2 females, mean age 54 ± 6 years) with previous myocardial infarction, angiographically proven coronary artery disease and mild left ventricular systolic dysfunction (election fraction 35-45%) performed adenosine two-dimensional echocardiography and thallium-201 scintigraphy within 7 days in the absence of effective treatment. A 22 segment model of the left ventricle was used for both techniques. A score index ranging from 1 (normokinesia) to 4 (dyskinesia) was used for two-dimensional echocardiography. In the 102 segments identified as a-dyskinetic at rest echocardiography, 40 were classified as viable during echo-adenosine (improvement of ≤ 1 grade at peak hyperkinesia) and 62 necrotic. A concordance of 97.5% was found between the two diagnostic techniques in the former segments and of 82% in the latter. Our results indicate that iv adenosine infusion combined with two-dimensional echocardiography imaging can safely be used for the diagnosis of viable myocardium and may represent a useful alternative to thallium-201 scintigraphy in evaluating patients to be addressed to revascularization procedures.