Radionuclide left ventricular ejection fraction: a comparison of three methods

SUMMARY Three commercially available computer programs (a semiautomatic method, a manual method, and a regional method) were used to calculate left ventricular ejection fraction from the equilibrium multiple gated radionuclide ventriculograms obtained from 24 normal male subjects and 20 men with heart failure. In the normal subjects the ejection fraction values calculated by each method were significantly different (mean (SD) difference between semiautomatic and man-ual 3 3 (5 8); between semiautomatic and regional 12 0 (6 3); and between manual and regional 8 7 (6 9)). In the patients with heart failure the ejection fraction values calculated by the semi-automatic method differed significantly from those calculated by the manual and regional meth-ods (mean (SD) difference between semiautomatic and manual 3-4 (4 7); between semiautomatic and regional 4 9 (4-9); and between manual and regional 1-5 (6-2)). The ejection fraction values obtained by the semiautomatic method were generally higher and more consistent than those derived from the manual and regional methods. An ejection fraction of> 50 % with the semi-automatic method would be regarded as normal but if the same normal range was applied to the regional method nine (38%) of the 24 normal subjects would appear to have an abnormal left ventricular function