Table 1.

Classification of cardio-renal syndrome (CRS)

Typology of CRS	Description
Type 1	Rapid worsening of cardiac function influences renal function leading to an acute kidney injury
Type 2	Chronically abnormal heart function exerts chronic deleterious effects on renal function
Type 3	Sudden worsening of renal function that leads to acute cardiac injury
Type 4	Chronic primary renal disease that may result in the course of time in chronic heart damage
Type 5	Cardiac dysfunction in conjunction with renal dysfunction due to a chronic systemic disease

From Ronco et al.²