Doppler-Derived Intrarenal Venous Flow Mirrors Right-Sided Heart Hemodynamics in Patients With Cardiovascular Disease

BACKGROUND: Interruption in Doppler intrarenal venous flow (IRVF) has been used in assessing renal congestion and in the prediction of prognosis of cardiovascular diseases. However, there is a paucity of pathophysiological knowledge, so we aimed to clarify the determinants of IRVF interruption. METHODS AND RESULTS: Intrarenal Doppler studies were performed within 24 h before right-side catheterization studies. The interruption in IRVF in 73 patients was divided into a continuous pattern, and 4 discontinuous types based on the timing of interruption. Type 1, with an interruption in early systole, was associated with a-wave elevation of right atrial pressure (RAP). Type 2, with an interruption in early diastole, was associated with v-wave elevation, tricuspid regurgitation (TR), and right ventricular dysfunction. Both Type 1 and 2 were observed even in the normal range of mean RAP. Type 3, with an interruption throughout systole, was observed in advanced right heart failure patients with markedly elevated RAP, particularly elevated x-descend and atrial fibrillation. Finally, Type 4, with limited flow at systole, was observed in 2 of the patients with pulmonary arterial hypertension. CONCLUSIONS: IRVF interruption was closely related to RAP elevation at each specific point of the cardiac cycle rather than to mean RAP levels, suggesting that the characteristics of IRVF mirror right-sided heart hemodynamics, not mean RAP.