[Hemodynamic measurements by Doppler echocardiography]

This paper discusses the measurement of cardiac output and pulmonary artery pressures by Doppler echocardiography. Blood flow may be measured through the aortic valve, the left ventricle and the mitral and pulmonary valves. In each case certain conditions for the validity of calculations must be respected. These measurements contribute to the evaluation of valvular stenosis and regurgitation, intracardiac shunts and cardiac function. Pulmonary artery pressures may be estimated from Doppler signals of tricuspid and pulmonary regurgitation, from the morphology of systolic pulmonary blood flow and from the duration of the right ventricular isovolumic relaxation period. They provide important information for the evaluation of many cardiac and pulmonary diseases.