A Novel method for estimating right atrial pressure with point-of-care ultrasound (POCUS)

Current noninvasive estimation of right atrial pressure (RAP) by either bedside jugular venous pressure (JVP) exam or inferior vena cava (IVC) measurement during a formal echocardiogram offer imprecise estimates of actual RAP. We enrolled 41 patients in a prospective, blinded study to validate a novel point-of-care ultrasound method to estimate RAP. Two subjects were excluded and 39 were included in the final analysis. The ultrasound estimate of RAP (RAPU) was compared to the RAP measurement during right heart catheterization (RAPi) both as measured and corrected for the mid-AP diameter. The correlation coefficient between RAPi and corrected RAPU measurements was +0.72, regression R2 0.52, bias -0.60 mmHg (95% confidence interval [CI], -1.60 to +0.39 mmHg) with the limits of agreement -5.56 to +7.24 mmHg, and 3 mmHg accuracy of 26 (67%). Similarly, for the uncorrected RAPU measurement, the correlation coefficient was +0.75, regression R2 0.56, bias -0.49 mmHg (95% CI, -1.42 to +0.43 mmHg) with the limits of agreement -5.56 to +7.24 mmHg, and 3 mmHg accuracy of 29 (74%). This simple bedside evaluation of right atrial depth and the right jugular vein correlates with actual right atrial pressure better than traditional IVC parameters, and can accurately estimate RAP within 3mmHg in most patients.