Noninvasive assessment of pulmonary hypertension from right ventricular isovolumic contraction time

In order to assess a noninvasive method of predicting pulmonary arterial pressure in adults, right ventricular systolic time intervals were determined with echocardiography simultaneously with pulmonary arterial end-diastolic pressure measurements. Right ventricular isovolumic contraction time was measured from echographic recordings of the tricuspid and pulmonary valves. Although this interval was found to increase as pulmonary arterial pressure increased, the method cannot be used to predict quantitatively the level of pulmonary arterial pressure in adults. However, an echocardiographically determined right ventricular contraction time of less than 25 ms suggests a normal pulmonary arterial pressure. In patients with pulmonary parenchymal diseases, echograms of the tricuspid and pulmonary valves are only rarely of such quality as to permit accurate delineation of the valvular events required for these measurements.