Organ cross talk in the critically ill: the heart and kidney

Heart failure results in significant morbidity and mortality in the United States. Chronic heart failure is often complicated by renal insufficiency. Further, acute decompensated heart failure is often complicated by worsening renal function or the development of diuretic resistance. Heart failure complicated by renal dysfunction has a significantly worse prognosis. The pathophysiology underlying this so-called cardiorenal syndrome (CRS) is unclear. It likely involves a combination of maladaptive neurohormonal activation and renal homeostatic mechanisms. The treatment (including recombinant B-type natriuretic peptide, ultrafiltration, continuous furosemide infusions and vasopressin antagonists) has thus far been marginally successful at best. Further research into the mechanism and treatment of CRS is required.