Potassium has an important role in the electrophysiological function of the myocardium. Na–K ATPase pumps maintain a resting membrane potential of −90 mV across the myocardial cell membrane. Hyperkalemia is a common electrolyte abnormality seen in chronic kidney disease patients. Hyperkalemia is associated with electrocardiographic abnormalities as it decreases the excitability and conduction velocity of pacemaker cells and conducting tissues. Typical electrocardiogram (ECG) findings in hyperkalemia are tall T waves and a short QT interval, which progresses to prolonged PR interval and the latter loss of P waves and widening of the QRS complex. Classical of the “sine wave” pattern, complete atrioventricular (heart block) block is a very rare presentation of hyperkalemia. We are presenting a case of a 65-year-old male who presented to the hospital with a history of hypotension, bradycardia, and syncope. Electrocardiogram (ECG) suggestive of complete heart block, was treated with a temporary pacemaker. After the evaluation, it was found that his serum potassium level (hyperkalemia) was very high and he responded to antihyperkalemic measures.