Abstract
Hyperkalemia can lead to life-threatening arrhythmias, regardless of serum potassium levels. The electrocardiogram morphology lacks sensitivity and specificity in indicating the severity of hyperkalemia. Here, we present a case of an elderly woman with a history of end-stage renal disease on hemodialysis who developed sinus arrest due to moderate hyperkalemia without typical electrocardiographic findings of hyperkalemia, with subsequent restoration of sinus rhythm after correcting the electrolytic disturbance. The case highlights the importance of clinicians maintaining a high degree of suspicion for electrocardiographic abnormalities related to hyperkalemia, even in the absence of typical ECG findings, to ensure accurate diagnosis and timely intervention.