Heparin-induced life-threatening hyperkalemia.

Hyperkalemia may occur in many clinical settings and lead to serious events. Heparin-induced hyperkalemia is presumably less well recognized than other untoward effects of heparin treatment and more frequent than commonly perceived. To draw attention to this clinically relevant occurrence, we report 2 cases of life-threatening bradyarrhythmia associated with heparin prescription. Heparin-induced hyperkalemia is mediated by an enzymatic block in the synthesis of aldosterone; however, in most cases severe hyperkalemia occurs in the presence of additional factors influencing potassium homeostasis. Patients treated with heparin should be stratified and adequately monitored according to the outlined risk profile.