Echocardiographic evaluation of pulmonary hypertension by oxygen inhalation method.

The ratio of the right ventricular preejection period to the right ventricular ejection time was calculated from the echocardiogram of the pulmonic valve before and after inhalation of a high concentration of oxygen in pulmonary hypertensive patients. The results showed that this non-invasive method could differentiate pulmonary vascular disease from non-pulmonary vascular disease and hence useful for evaluating the change of the pulmonary vascular bed in the pulmonary hypertensive patients.