Cardiac evaluation from radioisotope dynamics.

Abstract

Summary A method for radioisotope angiocardiography using the scintillation camera and a quantitative television data system for rapid data recording and readout is described. This essentially noninvasive, risk-free, outpatient procedure, which can be repeated at frequent intervals, shows promise of being a significant supplement to conventional x-ray angiocardiography. By precise area-of-interest masking and the use of fast-response counting-rate recording, a stroke-by-stroke reading of the left ventricular ejection fraction is obtained. Cardiac output is determined from the same record. In the absence of valvular insufficiency, end-diastolic volume is computed from these numbers. Comparison of this value with end-diastolic volume determined from area of measurements of the pictures provides an estimate of the degree of regurgitation when present. Direct comparison of this technique with standard contrast angiocardiography has been made in 16 patients with confirmatory results which are presented. Clinical application has already demonstrated the ability of isotope cardiography to provide a large amount of information not obtainable by other simple techniques. It is likely that this method will also prove useful in situations requiring serial study such as the management of intensive-care cardiac patients.