Scintigraphic evaluation of left ventricular function.

Scintigraphic studies, performed with a scintillation camera and a small computer, can provide information concerning total and regional left ventricular function (Table 1). Of the two types of studies (first-pass and gated blood pool) the gated blood study is more appropriate for studies of regional function than is the first-pass method. Ejection fraction, an index of global ventricular function, is measureable from first-pass or gated blood pool studies. Gated blood pool studies allow visual assessment of net ventricular function as well as the local functional status of the myocardium. Multiple gated blood pool studies allow computation of ventricular volume curves, from which ejection fraction and ejection rate may be determined. There are several areas of application for these relatively inexpensive and virtually noninvasive studies. In patients with recent myocardial infarction, visual assessment of regional ventricular wall motion and quantitative measurement of ejection fraction provide additional prognostic information, especially when measured serially. In patients with coronary artery disease, the development of regional ventricular wall motion abnormalities may indicate local myocardial ischemia. Consequently, scintigraphic imaging may add significantly to the usefulness of exercise stress testing.