Estimation of Right Atrial Pressure Using a Portable Handheld Ultrasound Device

Abstract

BackgroundHandheld ultrasound devices are increasingly used by clinicians for their ease of use and portability. Their utility for estimating right atrial pressure (RAP) is poorly described. MethodsThis prospective study enrolled 50 consecutive patients presenting for outpatient right heart catheterization (RHC). A handheld ultrasound device was used to measure inferior vena cava size and collapsibility and estimate RAP to be 3, 8, or 15 mmHg according to American Society of Echocardiography recommendations for cardiac chamber quantification. Invasive pressure measurements were then performed using RHC. Spearman's correlation and linear regression analysis were used to evaluate the association between estimated RAP using ultrasound and invasive RAP. ResultsFifty patients were enrolled (mean age 68 ± 8 years). Estimated RAP by ultrasound was significantly associated with invasive RAP (r 0.80; R2 0.63; 95% confidence interval, 0.61-0.96; P < .001). The correlation was stronger when RHC was indicated for evaluation of heart failure (r 0.88; P < .001) compared with other indications (r 0.69; P < .001). An estimated RAP of 3, 8, and 15 mmHg by ultrasound had a sensitivity and specificity of predicting an invasive RAP of 0-5, 6-10, and > 10 mmHg of 88% and 76%, 56% and 88%, and 81% and 97%, respectively, with overall accuracy of 80%, 76%, and 92%, respectively. Estimated RAP also correlated with invasive pulmonary capillary wedge pressure (r 0.64; R2 0.41; 95% confidence interval, 0.26-0.54; P < .001). ConclusionsHandheld ultrasonography is a useful tool that can accurately estimate RAP at the bedside.