Substrate Ablation and Remodelling in Non-paroxysmal Atrial Fibrillation (AF)

Using a 4mm irrigated tip radiofrequency ablation catheter a series of lesions \>2 mm outside pulmonary vein (PV) ostia will be made to encircle and electrically isolate the pulmonary veins in two ipsilateral pairs (wide area circumferential ablation, WACA). A 20-pole PV mapping catheter will be used to confirm electrical isolation. If the patient is in atrial fibrillation at this stage, sinus rhythm would be restored with electrical cardioversion and PVI would be confirmed in sinus rhythm

Using a 4mm irrigated tip radiofrequency ablation catheter a series of lesions \>2 mm outside PV ostia will be made to encircle and electrically isolate the pulmonary veins in two ipsilateral pairs (wide area circumferential ablation, WACA)34. A 20-pole PV mapping catheter will be used to confirm electrical isolation. Once PVI has been achieved, patients will go onto to receive additional linear ablation lesions. These will include a left atrial roof line, mitral isthmus line, (including ablation inside the coronary sinus if necessary), and ablation on the cavotricuspid isthmus. If the patient is in atrial fibrillation at this stage, the acute end-point would be signal obliteration at the ablated area. Once sinus rhythm is restored with electrical cardioversion, PVI would be confirmed in sinus rhythm and conduction block across the LA roof line, Mitral line and CTI will then be verified with appropriate pacing manoeuvres.

at least 6 weeks therapy with oral amiodarone prior to the ablation procedure and 6 weeks post.