Evaluation of myocardial viability in coronary artery disease by isosorbide dinitrate and dobutamine using the ECG gated blood pool scintigraphy

ECG-gated blood pool imaging with combined isosorbide dinitrate (ISDN) and dobutamine (DOB) was performed in 15 patients with ischemic heart disease to examine its ability to evaluate myocardial viability. The findings were compared with those of exercise thallium-201 imaging. Left ventricular ejection fraction (LVEF) increased by the administration of both ISDN and DOB in the group showing positive redistribution on thallium imaging. Among 7 patients with left ventricular wall motion abnormality (LVWMA) on gated blood pool imaging, six patients had improvement in LVWMA by giving both ISDN and DOB. In 3 of the 4 patients showing LVWMA on gated blood pool imaging and negative redistribution on thallium imaging, an improvement in LVWMA was observed on ISDN and DOB gated blood pool imaging. In 4 patients, gated blood pool imaging failed to reveal LVWMA as detected on left ventriculography. The results indicate the potential use of ISDN and DOB gated blood pool imaging and the limitation of exercise thallium-201 myocardial imaging and modified LAO view of gated blood pool imaging in the evaluation of myocardial viability. (Namekawa, K)