Gated cardiac blood-pool scan: Use in patients with coronary heart disease

Abstract

M EASUREMENT of ventricular function by calculating ejection fraction or regional myocardial wall motion can provide an objective assessment of the severity of myocardial damage due to ischemic heart disease. Cardiac catheterization and contrast angiography are usually required to obtain the information necessary to determine ejection fraction and regional myocardial wall motion. The risks and expense of these procedures make them unsuitable for recording these important parameters repeatedly over time or for obtaining this information in patients with chronic disease, such as hypertension, many of whom may not be sick enough to otherwise warrant this procedure. The importance of these measurements has led to the development of several noninvasive approaches for the determination of ejection fraction and regional wall motion. The gated cardiac blood-pool scan is a noninvasive scintiphotographic technique that records the regional distribution of a blood-pool tracer in the heart at end-systole and enddiastole. These data are then used to calculate left ventricular ejection fraction and regional myocardial wall motion. Since the examination is noninvasive and poses no risk other than the small radiation burden incurred from the radioactive material,* the gated scan is well suited to serve as both a screening test and for recording repeated measurements in the same patient. The equipment required to perform a gated blood-pool scan is: a scintillation camera with a