Clinical & Experimental Cardiology
Open Access

Intra-operative mapping of atrial fibrillation: Lessons to be learned

9^th Annual Meeting on Arrhythmia and Cardiac Surgery

July 14-15, 2016 Brisbane, Australia

Natasja de Groot

Erasmus MC, Netherlands

Posters & Accepted Abstracts: J Clin Exp Cardiolog

Abstract :

Epicardial mapping is routinely performed during cardiac surgery in our centers. One of the most recent projects include simultaneously endo-epicardial mapping of the right atrial free wall. The presence of focal fibrillation waves during atrial fibrillation (AF) can, beside ectopic activity, also be explained by asynchronous activation of the atrial endo- and epicardial layer and transmurally propagating fibrillation waves. In order to provide direct proof of endo-epicardial asynchrony, we performed simultaneous high-resolution mapping of the right atrial endo-and epicardial wall during AF in humans. Intra-operative mapping of the endo- and epicardial right atrial wall was performed during (induced) AF in 10 patients with AF (paroxysmal: N=3, persistent: N=4, longstanding persistent: N=3) and 4 patients without a history of AF. A clamp made of two rectangular 8x16 electrode arrays (inter-electrode distance 2 mm) was inserted into the incision in the right atrial appendage. Recordings of 10 seconds of AF were analysed to determine the incidence of asynchronous endo-epicardial activation times (â�?¥15 ms) of opposite electrodes. Asynchronous endo-epicardial activation ranged between 0.9-55.9% without preference for either side. Focal waves appeared equally frequent at endocardium and epicardium (11% vs 13%, p=0.18). Using strict criteria for breakthrough (presence of an opposite wave within 4mm and â�?¤14 ms before the origin of the focal wave), the majority (65%) of all focal fibrillation waves could be attributed to endoepicardial excitation. So in this study, we provided the first evidence for asynchronous activation of the endo-epicardial wall during AF in humans. Endo-epicardial asynchrony may play a major role in the pathophysiology of AF and may offer an explanation why in some patients therapy fails.

Biography :

Email: n.m.s.degroot@erasmusmc.nl