Intraoperative epicardial focal pulmonary venous electrocardiography in patients with atrial fibrillation.

OBJECTIVES: In patients referred to off-pump coronary artery bypass grafting, pulmonary vein isolation (PVI) may be used for those with persistent atrial fibrillation (AF), an alternative to the Maze procedure. However, the success rate of PVI in persistent AF is limited. The study assesses the prognostic value of focal epicardial electrocardiography of the pulmonary veins (PVs) for surgical ablation results.

METHODS: We mapped 140 PV in 35 cases undergoing off-pump coronary artery bypass grafting. Data obtained using a sensing-pacing probe before ablation were analysed. The composite study end-point consisted of the need for electrical cardioversion for in-hospital recurrence of AF and the presence of AF at hospital discharge and after 6 months follow-up confirmed by 24-h Holter electrocardiographic monitoring.

RESULTS: In patients with epicardial far-field (FF) signals recorded over at least 1 PV, the composite end-point occurred in 61% (14) vs 25% (3) of patients with no FF signal recorded over any PV (P = 0.04). The presence of FF signals in at least 1 PV significantly increased the risk of composite end-point occurrence (odds ratio 3; P = 0.04). The composite end-point occurred in 86% (6) of patients with FF signals recorded over all PVs and in 39% (11) in the remainder of the study population (P = 0.03).

CONCLUSIONS: Intraoperative epicardial focal electrocardiography of PVs revealed more than 40% of PVs had only FF atrial signals. The presence of FF signals in PVs is related to a lower early effectiveness of PVI on ablating AF. Epicardial focal electrocardiography of PVs may be a clinically effective intraoperative tool in the decision-making process between less invasive PVI and the standard Maze procedure.