Patent Foramen Ovale as a Rare Focus of Origination of Atrial Tachycardia.

Supraventricular tachycardia refers to a group of arrhythmias whose mechanism involves tissues from the His bundle or above. Repetitive focal atrial tachycardia (AT) (FAT) accounts for less than 10% of supraventricular tachycardia cases. FAT originating from the patent foramen ovale (PFO) has not been well-described and is a rarely reported phenomenon to date. Here, we report a rare case of FAT arising from the PFO. To the best of our knowledge, this is the first detailed report of AT arising from the PFO. We have included the description of the ablation procedure and postulated the possible electrophysiological mechanisms of a regularly irregular FAT noted in our patient during the electrophysiology study. Our case shows catheter ablation to be a successful treatment strategy in AT arising from the PFO, with the possibility of providing a long-term cure and freedom from antiarrhythmic drugs.