Hyperkalaemia induced complete atrioventricular block with a narrow QRS complex

A 77 year old woman was admitted to the hospital because of dyspnoea and dizziness for 3 hours. Upon physical examination, her blood pressure was 80/40 mm Hg, with a regular pulse rate of 33 beats per minute. The ECG on admission exhibited P waves with a rate of 100 beats/min and a positive pattern in …