Background: Few is known about the prognostic value of inducible atrial fibrillation after pulmonary vein isolation using phased radiofrequency ablation.
Methods: 84 consecutive patients with paroxysmal (76%) or persistent (24%) atrial fibrillation (AF) have been followed for 3 months after pulmonary vein (PV) isolation using the PVAC technique. The PVAC (Medtronic, Minneapolis, Minnesota, USA) is a steerable over-the-wire circular ablation catheter utilizing phased radiofrequency (RF). After successful PV isolation (confirmed as PV entrance and exit block) and waiting time as well as optional additional ablation for PV reconnection a programmed atrial stimulation with a base cycle length of 400ms and up to two extra stimuli as well as an atrial burst stimulation was performed. Any atrial fibrillation or atypical flutter >30s was counted as a positive test. Since PV isolation could be completed in all patients, in case of inducible persistent AF the patient underwent electrical cardioversion to sinus rhythm before discharge. Two patients suffered from a groin hematoma with conservative treatment, no severe complications occurred. Complete follow-up was available in 71 patients including at least two 24h holter ECG (pre-discharge and after 3 month) as well as assessment of symptomatic atrial fibrillation.
Results: At 3 month follow-up 77.5% of the patients remained free of atrial fibrillation. Of these patients, in 32.7% AF had been inducible AF post ablation, corresponding to 20% in patients with recurrent AF during follow-up. Sensitivity, specificity, positive and negative predictive value was 33%; 80%; 15% and 75%, respectively.
Conclusions: In this single center series the PVAC technique was safe and offered a good short-term success. Recurrent AF could not be predicted by programmed atrial stimulation, but non-inducibility of AF after procedure had an acceptable negative predictive value.