Impact of a patent foramen ovale on paroxysmal atrial fibrillation ablation.
INTRODUCTION
A patent foramen ovale (PFO) is located at the anterior and superior part of the anatomical interatrial septum, the area that is targeted during transseptal puncture. This study sought to investigate the impact of accessing the left atrium via a PFO on paroxysmal AF ablation.


METHODS
From March 2004, 203 patients (55 +/- 11 years) underwent catheter ablation for paroxysmal AF (80 +/- 71 months), with the endpoint being electrical isolation of all pulmonary veins (PV) and AF noninducibility. The presence of a PFO was determined by both transesophageal echocardiography and catheter probing. Procedural difficulty was evaluated by radiofrequency (RF), procedural, and fluoroscopic durations. Clinical follow-up was also investigated.


RESULTS
A PFO was detected in 27 patients (13%) by transesophageal echocardiography and in 22 additional patients (total 49 patients, 24%), by catheter probing (P < 0.001). A PFO was associated with longer total RF applications (57 +/- 19 vs 51 +/- 18 min, P = 0.04) and RF applications to isolate the PVs (42 +/- 16 vs 35 +/- 12 min, P = 0.001). Procedural and fluoroscopic times were unaffected. Seventy-three patients (36%) required a second procedure; there was no difference in the number of PV reconnections (1.3 vs 1.8 veins, P = NS). After a mean follow-up of 19 +/- 9 months, 194/203 patients (96%) were free of AF, with no difference in patients in whom a PFO had been used.


CONCLUSION
Although isolation of PVs is longer, overall procedural duration and success is not affected when using a PFO compared with a transseptal puncture. The presence of a PFO is underestimated by transesophageal echocardiography with brachial injection when compared with catheter probing.