The effect of acute hypoxia on right ventricular function in healthy adults

Right ventricular ejection fraction and right ventricular volumes were derived in 12 healthy male subjects using krypton-81m equilibrium radionuclide ventriculography whilst subjects breathed 30% (high inspired oxygen) and then 8-12% oxygen in nitrogen mixture (hypoxia). 'Physiological' tricuspid valve regurgitation was identified in 7 of the subjects by Doppler echocardiography, and right ventricular peak systolic pressure was estimated during high inspired oxygen and during hypoxia. Mean right ventricular peak systolic pressure was 24.1 +/- 3.3 mmHg during high inspired oxygen and increased to 41.3 +/- 8.4 mmHg during hypoxia (P less than 0.01). Mean right ventricular ejection fraction was 0.612 +/- 0.075 during high inspired oxygen and was unchanged at 0.590 +/- 0.073 during hypoxia. There was no significant change in right ventricular end-diastolic volume or stroke volume in response to hypoxia. The systolic performance of the normal right ventricle is well-maintained during an acute rise in afterload induced by hypoxia.