A 49-year-old man presented to the emergency department after waking up with a mild headache, lightheadedness, and loss of balance that resulted in two falls. He had chest discomfort but no chest pain, palpitations, or shortness of breath. He had no significant medical history and took no prescription or herbal medications.

His initial vital signs were blood pressure of 70/30 mm Hg, pulse of 54 beats per minute, temperature of 97.3°F (36.3°C), respiratory rate of 18 breaths per minute, and oxygen saturation of 99% on room air. His physical examination was notable only for cool distal extremities and his cardiac examination was unremarkable. Electrocardiography (ECG) was performed (Figure 1).

Question

Based on the patient's history, physical examination, and initial ECG findings, which one of the following is the most likely diagnosis?

• A. de Winter pattern.

• B. Digitalis effect.

• C. Hypokalemia.

• D. Left ventricular hypertrophy with repolarization abnormality.

• E. Posterior myocardial infarction.

Discussion