Non-Invasive Estimation of the Mean Right Atrial Pressure Using Sonographic Measurements of the Right Internal Jugular Vein

Abstract

Introduction Right ventricular dysfunction (RVD) is associated with increased morbidity and mortality. RVD is detected clinically by elevated JVP on physical exam, a reflection of the high mean right atrial pressure (mRAP). The sensitivity and specificity of mRAP estimation by JVP assessment is limited. Non-invasive techniques that can reliably estimate mRAP are thus useful to supplement physical exam findings. Sonographic measurement of the IVC has emerged as the most utilized non-invasive estimate of the mRAP but the IVC is visualized only 75-90% of the time. Objectives In this study, we prospectively tested the diagnostic accuracy of various static and dynamic ultrasound measurements of the right internal jugular vein (RIJV) in estimating the mRAP and compared this to mRAP measured by right heart catheterization (RHC). The best identified RIJV parameter was then compared to simultaneous measurements of IVC and JVP assessment by HF cardiologists. Methods This is a single center prospective study that enrolled patients scheduled to undergo RHC. IRB approved consents were obtained. JVP assessment was performed by a HF cardiologist, the IVC and RIJV ultrasound measures were obtained by author KH, and these were performed prior to right heart catheterization. RIJV measurements were done w/ the patient lying flat. Categorical variables were reported as percentages, mean ± standard deviation if normally distributed data, and as median ± interquartile range for non-normally distributed data. Area under the curve (AUC) of various static and dynamic RIJV measures was calculated using the receiver operator characteristic (ROC) curves. The best RIJV parameter that best estimated mRAP was then compared against IVC and JVP assessment by HF cardiologists using mRAP measured by RHC as gold standard. Results We enrolled 100 patients, 8 of whom were excluded due to incomplete data. The patients were 63.6 ± 13.8 y/o, mostly males (65%), 20% had heart transplants, and 38% were obese. The RIJV of all subjects were well visualized in all cases. Of the various static and dynamic RIJV parameters tested, the expansibility index calculated as (CSA on end-expiration- CSA with Valsalva)/CSA on end-expiration best correlated with the mRAP [AUC 0.62, 95% CI (0.49-0.74)]. In this study, the IVC max diameter was superior to HF cardiologist exam > RIJV in estimating the mRAP (Figure). The findings were similar when applied to obese patients. Conclusion While the RIJV was visualized 100% of the time, the best RIJV parameter in estimating the mean right atrial pressure was inferior to IVC max diameter and HF cardiologist JVP assessment, even in obese patients.