Diuretics play a central role in HF treatment, particularly during episodes of acute decompensation. Furosemide is the prototype of loop diuretics, acting through the inhibition of the Na+K+2Cl- pump at the thick ascending limb of the Henle loop. According to international registries, almost all patients receive a loop diuretic during a hospital stay for acute decompensated HF and the majority are discharged taking a "maintenance dose". Despite the undeniable beneficial hemodynamic effects of improvement of peripheral and central congestion, the net clinical effect of the chronic use of diuretics on HF prognosis is controversial.