Hyperkalaemia Induced Narrow QRS Complex Complete Heart Block

Potassium is an important extracellular ion with an important role in the myocardial cells function. Hyperkalaemia is a potentially life-threatening electrolyte disturbance which can impair cardiac conduction. Here, we report a case of a 72-year-old woman with past medical history of chronic kidney disease secondary to insulin dependent diabetes, who was brought to the Emergency Department with unresponsiveness 15 minutes after acute dyspnea. On arrival, the patient was in asystole without any cardiac output. Cardiopulmonary resuscitation (CPR) was commenced immediately. In addition to the resuscitation guideline during the CPR, with the presumed Hyperkalemia, treatment was started empirically while awaiting point of care electrolyte result. After treatment and during 3rd cycle of CPR, ECG demonstrated sinoventricular rhythm with ROSC. QRS subsequent narrowed down in her ECG followed by narrow QRS complete heart block within 15 minutes. Minutes later, she gained consciousness. Pathology demonstrated potassium level of 7.8 mEq/L and hemodialysis was scheduled. 2.5 hours post urgent hemodialysis, her ECG normalized to the sinus rhythm. She was admitted into the High dependency unit for ongoing management and was discharged home without any neurological sequalae after 12 days. This case demonstrated the wide variety of signs and symptoms as well as ECG changed secondary to Hyperkalaemia.