Reproducibility of ejection fraction and ventricular volume by gated radionuclide angiography after myocardial infarction.

To validate the repeated use of radionuclide equilibrium angiography for determining left ventricular (LV) ejection fraction (EF) and end-diastolic and end-systolic volumes (EDV and ESV), 25 patients were studied on an hourly basis an average of 9.1 days after acute myocardial infarction. Data were processed with a semi-automatic computer program which develops an averaged-volume curve from an assigned LV region-of-interest. LV EDV and ESV were derived from a previously described method which correlates well with contrast angiography (r = 0.977, y = 0.0255x - 0.121). Comparison between initial and subsequent equilibrium EF and between initial and subsequent volumes showed excellent correlation. Excluding three anginal episodes, the EF variation between studies averaged 0.03 +/- 0.02.