As generalists, on the post-call ward round, we are often faced with difficult ECG dilemmas. Important findings are easily missed or misinterpreted.

An 85 year old man is seen with resolving delirium and a normal CT brain. In view of the new diagnosis of atrial fibrillation, the senior doctor leading the round asks for anticoagulants to be prescribed. A junior doctor, of considerable ability, nervously suggests to her boss that the diagnosis should be re-considered.

Is she correct?

Which is the most likely ECG abnormality?

A. Atrial fibrillation B. Atrial flutter C. Marked sinus arrhythmia D. Second degree AV block E. Junctional escape rhythm