Assessment of right ventricular diastolic filling in patients with coronary artery disease

To assess right ventricular (RV) diastolic filling in coronary artery disease (CAD), with special reference to the involved lesions of the coronary arteries and left ventricular (LV) systolic function, gated radionuclide ventriculography was performed at rest in 106 patients with single-vessel CAD. Based on the site of coronary arterial involvement, patients were classified into three groups: left anterior descending CAD, right CAD, and left circumflex CAD. Patients in each group were further subdivided according to normal or decreased LV ejection fraction, resulting in six groups. Seventeen normal subjects were examined as a control group. Time-activity and its first-derivative curves were computed for the right and left ventricles. RV systolic function was normally preserved in all six groups, even when LV systolic function was damaged severely. The ratio of peak RV filling rate to peak RV ejection rate was significantly decreased in all six groups compared with that in control subjects, indicating that RV filling was impaired in patients with CAD. The ratio was below the lower limit of normal in 14 (23%) of 62 patients with normal LV systolic function and in 13 (30%) of 44 patients with impaired LV systolic function. None of the control subjects showed a decreased ratio of peak RV filling rate to peak RV ejection rate. Thus, in patients with CAD, RV filling is impaired, which may be independent of the site of coronary arterial involvement and of the LV or RV systolic function.