Life-threatening hyperkalemia in severe heart failure.

The therapeutic course of patients with severe heart failure can be complicated by disturbances in potassium homeostasis. Although hypokalemia in more prevalent, hyperkalemia may occur. Among 730 consecutive patients admitted to the hospital because of heart failure, nine episodes of acute, life-threatening hyperkalemia (mean serum potassium level: 7.2 +/- 0.5 mEq/L) were diagnosed in six patients (0.8%) with severe chronic heart failure during maintenance oral potassium therapy and exacerbation of heart failure and/or after additional oral doses had been administered for correction of hypokalemia. Of nine hyperkalemic episodes observed, one was fatal, seven episodes were successfully treated, and one resolved spontaneously. Only one patient was receiving an angiotensin-converting enzyme inhibitor. An awareness of this complication and the clinical setting in which it is likely to occur could lead to earlier recognition and successful management.