Cases in Electrocardiography
An 86-year-old woman with a history of hypertension, atrial fibrillation, and sick sinus syndrome with a pacemaker is brought to the ED complaining of not feeling well for one day. Her symptoms include diffuse generalized weakness and nausea. She denies chest pain, shortness of breath, abdominal pain, palpitations, or lightheadedness.
The patient's medications include digoxin, metoprolol, warfarin, and thyroid replacement. Her vital signs are pulse, 58 beats/minute; blood pressure, 98/41 mmHg; respiratory rate, 16 breaths/minute; and temperature, 98.6°F.
On examination, the patient is in minimal distress with a cardiac exam notable for an occasionally irregular bradycardia without murmurs. The remainder of her examination is unremarkable.
A 12-lead ECG (Fig. 1) is obtained. What is your diagnosis? See p. 11.