Increase of lesion time using epimyocardial cryoablation for atrial fibrillation improves incidence of stabile sinusrhythm

Objective: Epimyocardial Cryoablation (ECA) for surgical atrial ablation induces transmural myocardial necrosis. After our initial series of 28 patients we increased the applied time per lesion from 60 to 90s to test, if this leads to a higher incidence of sinusrhythm (SR).

Methods: From 1/2003–08/2005 28 patients with chronic/paroxysmal atrial fibrillation (AF) underwent ECA with concomittant cardiac surgery with 60s lesiontime (GroupI), 09/2005 until now 17 further patients received ECA with 90s lesiontime (Group II). Ablation was performed during cardiac arrest. Postoperative regimes included amiodarone, metoprolol and Phenprocoumon.

	Group I	Group II
n	28	17
Age	64.7±7.6	71.1±8.3
Ejection fraction (%)	54±9.6	49±12
CABG	8	7
AVR	13	5
CABG + AVR	1	3
MVR + TVR/CABG	5	2
Ascending-aortic-replacement	1	0

Results: No intra-/perioperative ECA related complications. Average ablationtime 10±6min. SR in Group I in 24%, 48%, 60% and 68% at discharge, 3, 6 and 12 month respectively, in Group II in 35%, 64% and 70% at discharge, 3 and 6 month follow-up.

Conclusion: ECA is safe, without excessive prolongation of operative time and without the neccessity to open the left-atrium. Extension of lesiontime seems to translate into a higher quote of SR.