Complete Atrioventricular Block Due to Severe Hyperkalemia in a Hemodialysis Patient: Successful Management with Temporary Transvenous Pacing.

Abstract

Severe hyperkalemia is a potentially fatal electrolyte disturbance that can produce a broad spectrum of cardiac conduction abnormalities. Although electrocardiographic changes classically follow a predictable progression, advanced atrioventricular block is an uncommon and often overlooked manifestation. We report the case of a 70-year-old woman with end-stage renal disease on maintenance hemodialysis who presented with altered mental status, profound bradycardia, and hypotension. Initial electrocardiography demonstrated complete atrioventricular block with a ventricular escape rhythm of 15-20 beats per minute. Laboratory evaluation confirmed severe hyperkalemia with a serum potassium level of 8.5 mmol/L. Despite prompt initiation of standard medical therapy, including intravenous calcium gluconate, insulin with glucose, and nebulized salbutamol, the patient remained hemodynamically unstable with no improvement in heart rate. Emergency temporary transvenous pacing was therefore performed, resulting in immediate hemodynamic stabilization. Definitive treatment with urgent hemodialysis led to normalization of serum potassium levels and complete recovery of normal sinus rhythm within 24 hours, allowing safe removal of the temporary pacemaker. This case highlights a rare and life-threatening presentation of hyperkalemia-induced complete atrioventricular block and underscores the limitations of medical therapy alone in advanced conduction disturbances. Early recognition and timely implementation of temporary transvenous pacing can be life-saving in hemodynamically unstable patients while definitive correction of hyperkalemia is achieved.