A Case of Reversible Atrioventricular Block Potentially Associated with Atenolol-Induced Hyperkalemia

Potassium is an extracellular ion that plays an important role in the electrophysiological function of the heart. Any change in the extracellular concentration of potassium can have a marked impression upon cardiac electrophysiology. Underlying kidney disease, certain medical conditions, dietary indiscretions, and medications can precipitate hyperkalemia. Drug-induced hyperkalemia is one of the most important causes of increased serum potassium in everyday clinical practice. Hyperkalemia can lead to various life-threatening dysrhythmias and if left untreated, it will ultimately cause ventricular arrhythmias and asystole. This case report describes an end-stage renal disease (ESRD) patient taking atenolol who presented with hyperkalemia and type II second degree atrioventricular (AV) block. He presented with hyperkalemia when atenolol was introduced and normalized when atenolol was discontinued. The heart block completely resolved after treatment of hyperkalemia.