[Effect of chronic pressure and volume stress on the function of the right ventricle]

Biplane right ventricular angiography was performed in 36 patients with chronic pressure overload of the right ventricle; 12 patients additionally had tricuspid insufficiency (TI). There were 4 subgroups: patients with systolic pulmonary artery pressure less than or equal to 40 mm Hg without (group I, n = 10) and with TI (group II, n = 6), as well as patients with systolic pulmonary artery pressure greater than 40 mm Hg without (group III, n = 14) and with TI (group IV, n = 6). Compared with the normal volumes of groups I and III, a significant increase in end-diastolic right ventricular volumes (p less than 0.01) was found in groups II and IV with 112.2 +/- 22.3 ml/m2 and 116.3 +/- 27.4 ml/m2, respectively. In both groups II and IV end-systolic volumes were also significantly increased, with 51.0 +/- 10.3 ml/m2 in group II and 49.7 +/- 11.3 ml/m2 in group IV. Right ventricular ejection fraction was 53.8 +/- 11.9% in group II, 57.3 +/- 8.5% in group III and 57.8 +/- 7.3% in group IV. There was no significant difference between the ejection fraction of these groups in comparison to the normal ejection fraction of group I with 63.4 +/- 10.9%. The results suggest that the right ventricle can compensate for moderate chronic pressure and volume overload using the Frank-Starling mechanism. Overall right ventricular dysfunction is not determined primarily by the loading conditions alone. Local myocardial and septal involvement is suspected to be an important determinant of right ventricular function.