Electrocardiographic features of hyperkalemia during acute kidney injury in a patient with pacemaker

We describe a case of a 79-year-old man with pacemaker who presented to the Emergency Department due to asthenia and acute confusional state. He had a history of atrial fibrillation, anemia and colostomy and he was on treatment with diuretics. The electrocardiogram (ECG) showed pacemaker-induced ventricular activity, QRS complexes excessively wide with sine-wave appearance, tall and peaked T waves, without electrically evident atrial activity. Potassium concentration on arterial blood gas analysis was 8.8 mmol/L. ECG abnormalities disappeared after therapy with calcium chloride and spontaneous cardiac activity reappeared.