Dan Smith is a 69-year-old with a history of hypertension who presents to the emergency room 4 hours after the onset of palpitations. His heart rate is 149 beats/min and blood pressure is 129/74 mmHg. The ECG reveals atrial fibrillation (AF). He says he knows the exact time the palpitations began in the morning and that he has never had these symptoms before.
According to the current guidelines, what is the recommended next step in management?
A. Synchronized cardioversion
B. Warfarin or novel oral anticoagulant for 4 weeks followed by cardioversion
C. Transesophageal echocardiogram (TEE) followed by cardioversion
D. Any of the above