A Novel Method for Estimating Right Atrial Pressure With Point-of-Care Ultrasound

Abstract

Background Current noninvasive estimation of right atrial pressure (RAP) by either bedside jugular venous pressure exam or inferior vena cava measurement during a comprehensive echocardiogram offers imprecise estimates of actual RAP. Methods We enrolled 41 patients in a prospective, blinded study to validate a novel point-of-care ultrasound method using direct right atrial depth (RAD) measurement and jugular venous ultrasound to estimate RAP. Two subjects were excluded, and 39 were included in the final analysis. A parasternal long-axis view was obtained, and the depth of the noncoronary cusp attachment to the posterior left ventricular outflow tract was recorded as the RAD. This was added to an estimate of the jugular venous pressure obtained during a jugular vein ultrasound to calculate an estimated RAP (RAP US ). The RAP US was compared to the RAP measurement during right heart catheterization (RAP cath ) both as measured and as corrected for where the catheter was zeroed. Results The correlation coefficient between RAP cath and RAP US was +0.75; regression R 2 , 0.56; and bias, –0.49 mm Hg (95% CI, −1.42 to +0.43 mm Hg), with the limits of agreement −5.56 to +7.24 mm Hg and accuracy of 3 mm Hg or less in 29 (74%) of the subjects. For the RAP US corrected for the catheter zero point, the correlation coefficient between RAP cath and RAP US was +0.72; regression R 2 , 0.52; and bias, –0.60 mm Hg (95% CI, −1.60 to +0.39 mm Hg), with the limits of agreement −5.56 to +7.24 mm Hg and accuracy of 3 mm Hg or less in 26 (67%) of the subjects. Conclusion This simple ultrasound evaluation of RAD and the right jugular vein correlates well with actual RAP and can accurately estimate RAP within 3 mm Hg in most patients. This has the potential to improve our bedside volume status exam, as well as improve the accuracy of RAP estimation during comprehensive echocardiogram.

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