Continuous - wave Doppler echocardiographic detection of pulmonary regurgitation and its application to noninvasive estimation

Continuous-wave Doppler echocardiography was used to estimate pulmonary artery pressures by measuring pulmonary regurgitant flow velocity in 21 patients with pulmonary hypertension (mean pulmonary artery pressure 20 mm Hg) and 24 patients without pulmonary hypertension. The pulmonary regurgitant flow velocity patterns, characterized by a rapid rise in flow velocity immediately after closure of the pulmonary valve and a gradual deceleration until the next pulmonary valve opening, were successfully obtained in 18 of the 21 patients with pulmonary hypertension and in 13 of the 24 patients without pulmonary hypertension. As pulmonary artery pressure increased, pulmonary regurgitant flow velocity became higher; the pulmonary artery-to-right ventricular pressure gradient in diastole (PG) was estimated from the pulmonary regurgitant flow velocity (V) by means of the simplified Bernoulli equation (PG = 4V2). The Doppler-determined pressure gradient at enddiastole correlated well with the catheter measurement of the pressure gradient at end-diastole (r = .94, SEE = 3 mm Hg) and with pulmonary artery end-diastolic pressure (r = .92, SEE = 4 mm Hg). The peak of Doppler-determined pressure gradient during diastole correlated well with mean pulmonary artery pressure (r = .92, SEE = 5 mm Hg). Thus continuous-wave Doppler echocardiography was useful for noninvasive estimation of pulmonary artery pressures. Circulation 74, No. 3, 484-492, 1986. PULMONARY HYPERTENSION can be assessed to some extent from abnormal findings in electrocardiograms,' phonocardiograms, 2, 3 chest roentgenograms,4 and echocardiograms5`7; however, none of these methods provides a quantitative estimate of pulmonary artery pressure. Recently, several investigators8"12 have used pulsed Doppler echocardiography to measure the flow velocity in the right ventricular outflow tract or pulmonary artery and have found that Doppler measurements of right ventricular systolic time intervals8 9 and flow velocity pattern 1-2 correlate well with pulmonary artery pressures. Continuous-wave Doppler echocardiography may provide another accurate method for the noninvasive estimation of pulmonary artery pressures because the From the Cardiovascular Division, Osaka Police Hospital, and the First Department of Medicine, Osaka University School of Medicine, Osaka, Japan. Address for correspondence: Akira Kitabatake, M.D., The First Department of Medicine, Osaka University School of Medicine, 1-1-50 Fukushima, Fukushima-ku, Osaka 553, Japan. Received Feb. 12, 1986; revision accepted May 8, 1986. 484 pressure gradient across a regurgitant valve can be estimated accurately by measuring the high flow velocity of the regurgitant jet with continous-wave Doppler echocardiography and by applying the simplified Bernoulli equation.'3"15 Recently, Hatle and Angelsen`9 indicated that measurement of pulmonary regurgitant flow by continuous-wave Doppler echocardiography had a potential for estimating pulmonary artery-to-right ventricular pressure gradient. Thus, in the presence of pulmonary regurgitation, continuouswave Doppler echocardiography might be useful for estimating not only the pulmonary artery-to-right ventricular pressure gradient but also pulmonary artery pressures. Waggoner et al.20 reported that the incidence of pulmonary regurgitation was greater in patients with pulmonary hypertension than in patients without pulmonary hypertension. Yock et al.2' observed that pulmonary regurgitation could be detected even in normal adults at an incidence of 40% by continuous-wave Doppler echocardiography. More recently, Takao et al.22 indicated that pulmonary regurgiCIRCULATION by gest on Sptem er 6, 2017 http://ciajournals.org/ D ow nladed from DIAGNOSTIC METHODS-DOPPLER ECHOCARDIOGRAPHY tation, even though it might be physiologic and trivial, could be detected with pulsed Doppler echocardiography at a high incidence in healthy subjects. Thus a method for estimating pulmonary artery pressures based on Doppler-detected pulmonary regurgitation might have wide applicability. The purposes of this study were to examine the detection rate of pulmonary regurgitation with continuous-wave Doppler echocardiography and to estimate pulmonary artery pressures by analyzing the flow velocity patterns of pulmonary regurgitation.