Right ventricular function at rest and during submaximal exercise assessed by 81Krm equilibrium ventriculography in normal subjects.

81Krm equilibrium ventriculography was used to study right ventricular function in 37 healthy male volunteers. 'Anatomical' lung subtraction using 99Tcm lung perfusion scintigraphy was compared with conventional background correction in the calculation of resting right ventricular ejection fraction (RVEF). Resting RVEF was significantly greater following 'anatomical' lung subtraction than that using background correction (0.59 +/- 0.06 versus 0.55 +/- 0.05). The exercise response of the normal right ventricle was defined in 23 subjects during exercise. Right ventricular ejection fraction showed a progressive increase during graded submaximal exercise (0.55 +/- 0.05 at rest, 0.60 +/- 0.05 at 50 W and 0.66 +/- 0.05 at 100 W). Right heart 81Krm equilibrium ventriculography is well suited to the evaluation of right ventricular function at rest and during exercise. The absolute value of RVEF will however be dependent upon the method of image analysis.