Syncope caused by iatrogenic hyperkalemia.

Symptomatic bradycardia in the emergency department may have several causes (excessive vagal tone, drug toxicity, acute myocardial ischemia, sick sinus syndrome, heart block, and electrolyte imbalance); among these, hyperkalemia may develop as a complication of chronic medical treatment with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and must be considered in the early approach to the bradyarrhythmic patient with possible electrocardiographic signs of hyperkalemia. We report a case of an 87-year-old woman with a clinical history of chronic angiotensin-receptor blocker consumption that led her to dangerous bradyarrhythmia, cardiogenic syncope, and risk of sudden cardiac death.