Stress Echocardiography Using Adenosine Combined with Nitroglycerin- Dobutamine in the Detection of Viable Myocardium in Patients with Previous Myocardial Infarction:

The aim of this study was to assess the value of adenosine (A) and the combination of nitroglycerin (N) with dobutamine (D) stress echocardiography (SE) in the identification of viable myocardium. The clinical and electrocardiographic (ECG) effects of both tests were also evaluated.Fifty-two coronary artery disease patients, aged 56.4 ±8 years, with left ventricular dysfunction due to a previous myocardial infarction (mean ejection fraction: 49 ±8%) were included in the study. Cardiac catheterization was performed in all patients before A (140 μg/kg/minute for five minutes) and the combination of N with D (5-10 μg/kg/minute) stress echocardiography. On the echocardiogram, the left ventricle was divided into 16 segments and wall motion was graded semiquantitatively from 1 (normal) to 4 (dyskinesia). The echocardiographic index was also estimated. A segment was considered viable during A infusion when resting asynergy showed deterioration of one grade or more. In contrast, segmental viability was considered...