Characterization of pre-existing Arrhythmogenic substrate associated with De novo early and late postoperative atrial fibrillation

• Published in: International journal of cardiology Vol. 363; pp. 71 - 79
• Main Authors: van Schie, Mathijs S., Veen, Danny, Kharbanda, Rohit K., Heida, Annejet, Starreveld, Roeliene, van Schaagen, Frank R.N., Bogers, Ad J.J.C., Taverne, Yannick J.H.J., de Groot, Natasja M.S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.09.2022
• Subjects: Atrial fibrillation; Cardiac electrophysiology; Cardiac surgery; High-resolution Epicardial mapping; Postoperative atrial fibrillation; Sinus rhythm; High-resolution Epicardial mapping; Cardiac surgery; Postoperative atrial fibrillation; Sinus rhythm; Atrial fibrillation; Cardiac electrophysiology
• ISSN: 0167-5273; 1874-1754
• DOI: 10.1016/j.ijcard.2022.06.015

Background: PoAF is the most common complication after cardiac surgery and may occur in patients with pre-existing arrhythmogenic substrate. Characterization of this substrate could aid in identifying patients at risk for PoAF. We therefore compared intra-atrial conduction parameters and electrogram morphology between patients without and with early- (≤5 days after surgery) and late- (up to 5 years) postoperative atrial fibrillation (PoAF). Methods and Results: Epicardial mapping of the right and left atrium and Bachmann's Bundle (BB) was performed during sinus rhythm (SR) in 263 patients (207male, 67 ± 11 years). Unipolar potentials were classified as single, short or long double and fractionated potentials. Unipolar voltage, fractionation delay (time difference between the first and last deflection), conduction velocity (CV) and conduction block (CB) prevalence were measured. Comparing patients without (N = 166) and with PoAF (N = 97), PoAF was associated with lower CV and more CB at BB. Unipolar voltages were lower and more low-voltage areas were found at the left and right atrium and BB in PoAF patients. These differences were more pronounced in patients with late-PoAF (6%), which could even occur up to 5 years after surgery. Although several electrophysiological parameters were related to PoAF, age was the only independent predictor. Conclusions: Patients with de novo PoAF have more extensive arrhythmogenic substrate prior to cardiac surgery compared to those who remained in SR, which is even more pronounced in late-PoAF patients. Future studies should evaluate whether intra-operative electrophysiological examination enables identification of patients at risk for developing PoAF and hence (preventive) therapy. [Display omitted] •Development of de novo postoperative atrial fibrillation (PoAF) is associated with extensive pre-existing arrhythmogenic substrate, consisting of areas of conduction slowing, conduction block, lower unipolar voltages and more low-voltage areas.•Patients with late-PoAF have even more pronounced arrhtyhmogenic substrates prior to cardiac surgery.•This substrate is particularly located at Bachmann's Bundle, although clear differences in electrophysiological parameters are also present at the left and right atrium.•The first episode of late-PoAF could even occur up to 5 years after surgery and occurred only in patients who also developed early-PoAF.