[Cardiorenal syndrome: causes, diagnosis and treatment of congestive nephropathy].

Congestive nephropathy (CN) is an entity of the cardiorenal syndrome that essentially arises from venous congestion and neurohormonal activation. The most common underlying causes include heart failure, pulmonary arterial hypertension, isolated tricuspid valve insufficiency and congenital heart defects. Currently, there are no universally accepted diagnostic criteria; however, the most suitable method appears to be the recording of intrarenal venous blood flow using Doppler sonography. A distinction can be made between continuous venous flow (no congestion) and discontinuous flow patterns, categorized as pulsatile (mild), biphasic (moderate) and monophasic (severe congestion). The venous impedance index (VII) and the renal venous stasis index (RVSI) are additional Doppler sonographic criteria for detecting CN. Evidence supports the efficacy of loop diuretics and/or the administration of sodium-glucose cotransporter 2 (SGLT2) inhibitors in the management of venous congestion.