Coronary sinus diverticulum with a concealed posteroseptal accessory pathway: a red herring?

ABSTRACT

A 21-year-old male presented with episodes of paroxysmal tachycardia mediated via a concealed posteroseptal accessory pathway. He was also found to have a diverticulum of the coronary sinus. However, successful radiofrequency ablation was achieved only endocardially under the mitral annulus and not within the diverticulum.