Among the quantitative parameters of left ventricular function derived from radionuclide angiographic studies, the change is ejection fraction from rest to exercise has been considered the most important. Recently other parameters derivable from the cardiac LV time activity curve have also been shown to differ between normal and coronary artery disease patients. These parameters have usually been considered to be of marginal clinical utility because when taken alone they frequently possess poor sensitivity/specificity for the detection of CAD. We postulate, however, that, taken together, they might be used in concert to increase the ability of radionuclide angiography to distinguish normal subjects from those with CAD. Multiple regression models we used to discriminate CAD subjects from normal subjects. The normal group consists of both normal volunteers and subjects with chest pain but normal coronary arteries. This allowed a comparison between these two supposedly normal groups- a comparison which indicated that these supposedly normal individuals differ signficantly from the asymptomatic normal volunteers. In addition, it was found that the multiple regression model which used only resting parameters gave a sensitivity/specificity relationship not significantly different from the exercise ejection fraction response. This finding is important because it indicates that under some circumstances, signficant diagnostic information may be obtained at rest alone, without the need for exercise. Other of the multiple regression models are now being analyzed, and the results prepared for publication.
