Doppler Estimation of Pulmonary Diastolic Pressure
Abstract & Commentary
Synopsis: Estimation of PADP by the new TR jet velocity method is reliable over a wide range of pressures in patients with heart failure.
Source: Lanzarini L, et al. Am Heart J. 2002;144:1087.
Doppler echocardiographic techniques for estimating pulmonary artery (PA) systolic pressure (SP) and diastolic pressure (DP) using tricuspid (TR) and pulmonic valve (PV) regurgitation (PR), jet velocity and estimation of right atrial pressure (RAP) usually by inspection of the size and dynamics of the inferior vena cava (IVC) have been well described. A new technique based upon the TR jet velocity alone has been studied in a small number of subjects. Lanzarini and associates sought to verify the accuracy of this approach in a larger group of patients undergoing right heart catheterization for evaluation of heart failure. In 86 stable patients who were potential heart transplant recipients, right heart catheterization and echo Doppler were performed within 24 hours of each other. PASP was estimated using the peak TR jet velocity-derived pressure difference plus estimated RAP via IVC inspection. PADP was estimated in the standard way using PR jet-derived end-diastolic pressure difference plus RAP (PADP-PR). Since PADP = RVSP at the time of PV opening, the time from the ECG QRS wave onset to the onset of PA flow can be superimposed on the continuous wave Doppler recording of the TR jet and the resulting pressure value calculated (PADP-TR). PADP-PR and PADP-TR were then compared to the invasive measure.
Catheter-measured PASP ranged from 8 to 119 mm Hg, PADP from 1 to 59 mm Hg, and RAP from -5 to 20 mm Hg. The Jin concordance correlation coefficient and Bland Altman paired differences analysis were used to determine the accuracy of each noninvasive estimate to the corresponding invasive measure. There was good agreement with PASP and PADP-TR, but agreement was poor with PADP-PR and RAP. Lanzarini et al concluded that estimation of PADP by the new TR jet velocity method is reliable over a wide range of pressures in patients with heart failure.
The noninvasive estimation of both systolic and diastolic pulmonary pressures provides more information of value to the management of patients with heart failure and pulmonary hypertension. For example, elevated systolic pressure with normal or low diastolic pressures suggests volume overload pulmonary hypertension rather than left heart failure or pulmonary vascular disease. The derivation of both pressures largely from the TR jet velocity is advantageous since it is often obtainable even in patients with poor images, especially if contrast enhancement is used. In this study, TR jet velocity was obtainable in 87% of the patients, RAP in 77%, and PR in 76%. However, TR velocity at the time of PV opening (PADP-TR) was obtained in 93%, PASP was estimated in 84%, and PADP-PR in 89%. Thus, there is a clear acquisition advantage to TR jet-based methods.
Since PASP and PADP-PR both require estimation of RAP, which was poorly estimated, why was PASP accurate and PADP-PR not? Perhaps because RAP is numerically a larger fraction of the PADP-PR calculation. Also, PR jets are difficult to record, which may have contributed to the inaccuracy of methods based upon it. TR jets can be difficult to record also, but often the early part of the jet is better seen than the peak as was demonstrated in this study.
Interestingly, the range of the catheter RAP values was -5 to 20 mm Hg, whereas, RAP estimated by the IVC method was 5 to 25 mm Hg. Clearly, estimation of RAP continues to be a problem, especially at the low end, which explains why PASP estimates of 40 mm Hg can be observed in normal subjects. Thus, the PADP estimate from the TR jet, which does not use RAP, should have superior accuracy as was shown in this study.
The strengths of this study include the large population with a wide range of right heart pressures. Weaknesses include the up to 24-hour time difference between the invasive and noninvasive measurements and the lack of contrast use, which may have increased the success of recording TR jet velocity. Finally, Lanzarini et al recommend that this new technique for estimating PADP be incorporated into the standard echo Doppler report.
Doppler echocardiographic techniques for estimating pulmonary artery (PA) systolic pressure (SP) and diastolic pressure (DP) using tricuspid (TR) and pulmonic valve (PV) regurgitation (PR), jet velocity and estimation of right atrial pressure (RAP) usually by inspection of the size and dynamics of the inferior vena cava (IVC) have been well described.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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