26th February 2025

An 84-year-old male is seen on the post-take ward round.

An 84-year-old male is seen on the post-take ward round. He presented to the emergency department with repeated syncopal episodes. He has a past medical history of heart failure with preserved ejection fraction and bilateral carpal tunnel syndrome requiring surgical release.

ECG is performed and reveals complete dissociation between P waves and QRS complexes. 

Echocardiogram shows biatrial dilatation, left ventricular hypertrophy, and grade II diastolic dysfunction with preserved left ventricular systolic function. 

Cardiac MRI shows transmural myocardial late gadolinium enhancement.

What is the most likely diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.