[The nephrologist and the role of ultrasound imaging in the diagnosis of cardiorenal syndrome].

The term cardiorenal syndrome (CRS) refers to multiple possible clinicopathological correlations between heart and kidney failure. The most recent classification recognizes five types of CRS: types I and II originate from heart failure (acute and chronic, respectively), type III and IV from kidney failure (again acute and chronic), while type V originates from a range of systemic diseases. Echocardiography and renal ultrasound are important means to arrive at a correct diagnosis. Basic echocardiography (defined by some as "echocardioscopy") allows the assessment of the left and right ventricles (diastolic and systolic function), atrial size, pulmonary circulation markers such as systolic pulmonary arterial pressure (PAPs) and tricuspid annular plane excursion (TAPSE), pericardial effusions, valve dysfunctions, and volume repletion. Renal ultrasound is of help in distinguishing between chronic and acute renal failure (kidney volume, parenchymal thickness, echogenicity) and excluding obstructive kidney disease.