Abstract
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.
