Jugular Venous Flow Velocity Pattern Application to Bedside Recognition of Jugular Venous Pulse Contour and Right Heart Hemodynamics

Abstract

Jugular venous flow velocity patterns and their variations reflect right heart hemodynamics and its derangement irrespective of underlying etiology. Since jugular venous flow velocity peaks correspond to the descents in the right atrial pressure pulse, the observations on jugular venous flows are valuable to bedside assessment of jugular venous pulse contour and right heart function. In normal adults, systolic flow (Sf) and the corresponding X' descent caused by the descent of the base is dominant. Although the smaller diastolic flow (Df) is recordable, the corresponding Y descent is not usually seen. Double descents in the jugular venous pulse whether X' > Y, X' = Y or X' < Y, generally arise either because the X' descent is decreased or the Y descent is exaggerated or both, similar to the corresponding flow velocity peaks. Decreased Sf (X' descent) usually reflects decreased right ventricular (RV) contraction as in RV failure in pulmonary hypertension, post-cardiac surgery RV damage and RV infarction. Sf and X' descent diminish in atrial fibrillation due to the loss of the Starling effect of the atrial contraction and rarely in severe mitral regurgitation due to a Bemheim effect on the interatrial septum. The Df (Y descent) gets exaggerated when there is increased V wave pressure- head with no restriction to ventricular filling during the rapid filling phase of diastole as may be seen with high sympathetic tone, hypervolemia, extra source of venous return as in atrial septal defect, pericardial effusion with some restriction, constrictive pericarditis, pulmonary hypertension with elevated RV diastolic pressure, RV infarct and cardiomyopathy. The exaggerated Df and Y descent with normal V wave pressure in post-cardiac surgery patients is explainable by the decreased right atrial capacitance function. In pulmonary hypertension, the jugular venous flow velocity pattern progresses from a compensated state reflected by Sf dominance (X' > Y) to equal Sf and Df (X' = Y) with rising RV pre-A wave pressure, to dominant Df (X' < Y) with onset of RV failure, and eventually to Df alone (single Y descent) with significant RV decompensation. In the absence of pulmonary hypertension, equal Sf and Df (X' = Y) indicates increased V wave pressure with no restriction to rapid filling (except in post-cardiac surgery patients), whereas the dominant Df pattern (X' < Y) indicates decreased RV function. Thus, an understanding of the jugular venous flow velocity pattern is directly applicable to bedside assessment of jugular venous pulse contour and right heart function.