Can right ventricular performance be assessed by equilibrium radionuclide ventriculography

The authors have modified the gated equilibrium blood pool method to allow repeated assessment of the right ventricular ejection fraction (RVEF) and compared the results with the first-pass method in 43 patients. Good agreement was obtained between the two methods (r = 0.91, p < 0.001). In four patients the mean RVEF measured at rest was 0.44 +- 0.05 (SEM) and after exercise was 0.48 +- 0.06. After infusion of isoprenaline at 1 μg/min the mean rose to 0.64 +- 0.04 (p < 0.02) and after infusion of a new β1sympathomimetic agent, prenalterol, at doses of 1 and 2 mg it was 0.56 +- 0.02 (p < 0.02) and 0.59 +- 0.03 (p < 0.01) respectively, where the significance levels are relative to the resting values. In nine patients with good ventricular function the vasodilator nifedipine caused right and left ventricular ejection fractions to increase by the same amount; in six patients with severe impairment of left ventricular function due to ischaemic heart disease the RVEF increased from 0.58 +- 0.03 to 0.73 +- 0.03 (p < 0.01) after 2 mg of prenalterol, but the left ventricular ejection fraction increased only from 0.22 +- 0.04 to 0.26 +- 0.04. (author)