BACKGROUND: Hyperkalemia is a potentially fatal electrolyte disturbance that typically manifests as progressive conduction abnormalities, bradyarrhythmias, and sine-wave electrocardiographic changes. In rare cases, however, severe hyperkalemia also presents with malignant ventricular tachyarrhythmias and transient electrocardiographic abnormalities involving the right precordial leads, potentially leading to diagnostic confusion with primary arrhythmic disorders.

CASE REPORT: A 55-year-old man with no known cardiovascular disease presented with palpitations, dyspnea, and diaphoresis. Electrocardiography demonstrated sustained wide-QRS ventricular tachycardia accompanied by hemodynamic instability. Following electrical cardioversion, recurrent ventricular tachyarrhythmias occurred, requiring repeated defibrillation, cardiopulmonary resuscitation, intravenous amiodarone, and mechanical ventilation. Laboratory testing revealed severe hyperkalemia (7.6 mmol/L), profound metabolic acidosis (pH 7.059, HCO₃⁻ 13.8 mmol/L), and advanced renal dysfunction. Serum potassium was confirmed on repeat testing. Subsequent electrocardiography demonstrated marked QRS widening, terminal conduction delay, and transient right precordial ST-segment abnormalities involving leads V1-V2. Intravenous calcium gluconate and sodium bicarbonate rapidly improved the electrocardiographic abnormalities. Continuous hemodiafiltration and bladder catheterization were performed after postrenal acute kidney injury caused by urinary retention was identified. Correction of hyperkalemia together with treatment of metabolic acidosis resulted in complete resolution of the ventricular arrhythmias and electrocardiographic abnormalities without recurrence. No evidence of structural heart disease or persistent myocardial ischemia was identified during subsequent evaluation.

CONCLUSIONS: This case illustrates that severe hyperkalemia secondary to reversible postrenal acute kidney injury can simultaneously present with malignant ventricular tachyarrhythmia and transient electrocardiographic abnormalities. Recognition of this reversible metabolic condition is essential to avoid diagnostic error and facilitate prompt life-saving treatment.

Keywords: Hyperkalemia, Ventricular Flutter