FEASIBILITY OF GENERATING HEMODYNAMIC PRESSURE CURVES FROM NONINVASIVE DOPPLER-ECHOCARDIOGRAPHIC SIGNALS

Objectives. This study was designed to determine the feasibility of Do ppler generation of accurate, complete right ventricular and pulmonary artery pressure curves in patients with Doppler-measurable tricuspid and pulmonary regurgitation. Background. Doppler-derived flow velociti es have been used to assess right ventricular systolic pressure; pulmo nary artery systolic, diastolic and mean pressures, and left ventricul ar systolic and diastolic pressures. Instantaneous gradient across any area of discrete narrowing is accurately derived using the simplified Bernoulli equation (4V(2)). Invasive catheterization is currently the only means of generating intracardiac pressure curves. Noninvasively derived pressure curves using Doppler echocardiography would be a cons iderable advance in the assessment of normal and pathologic cardiac he modynamics. Methods. Right ventricular and pulmonary artery pressure c urves were generated in 18 of 22 patients with measurable tricuspid an d pulmonary valve regurgitation using superimposition of Doppler-measu red tricuspid and pulmonary valve blood flow velocities on an assumed right atrial pressure. Doppler-measured right ventricular and pulmonar y artery pressure curves were compared with simultaneous catheterizati on-measured curves. Results. Doppler-derived pulmonary artery systolic pressure (Doppler PAP) correlated with simultaneous catheter-measured pulmonary artery pressure (Cath PAP) by the equation Doppler PAP = 0. 92(Cath PAP) + 4.5, r = 0.98. Other Doppler-derived pressure measureme nts that correlated at near identity with the characterization-measure d corresponding measurement include Doppler-derived pulmonary artery m ean pressure (Doppler mean PAP) [Doppler mean PAP = 0.85(Cath mean PAP ) + 2.6, r = 0.97], and Doppler-derived right ventricular pressure (Do ppler RVP) [Doppler RVP 0.84(Cath measured RVP) + 7.9, r = 0.98]. Dopp ler-derived pulmonary artery diastolic pressure (Doppler PAP diast) di d not correspond as well in this study [Doppler PAP diast = 0.45(Cath PAP diast) + 6.6, r = 0.83]. Conclusions. Clinically usable right vent ricular and pulmonary artery pressure curves can be derived by superim posing Doppler-measured tricuspid and pulmonary valve blood flow veloc ities in patients with tricuspid and pulmonary valve regurgitation.