Atrial Contractility and Force Kinetics Are Associated with Atrial Fibrillation after Elective on Pump Cardiac Surgery

Background: New-onset postoperative atrial fibrillation is common after cardiac surgery and increases mortality and in hospital stay. Less has been reported about the relationship among calcium-induced left atrial and right atrial contractile forces and kinetics, preoperative clinical patient state, and postoperative atrial fibrillation.

Methods: From 2018 to 2022, we evaluated 119 patients who had preoperative sinus rhythm before elective on pump cardiac surgery. Of 119 patients, 65 maintained sinus rhythm postoperatively, whereas 54 patients developed atrial fibrillation. Preoperative C-reactive protein, pro BNP, Creatinine, NYHA and demographic data were collected. Calcium-induced force measurements from left atrial and right atrial derived skinned myocardial fibers as well as myofilament kinetics in intact right and left atrial fibers were recorded.

Results: We detected lower left and atrial force values at calcium-induced force measurements over all calcium stages in patients with postoperative atrial fibrillation (p < 0.001). In intact fiber measurements we observed prolonged half relaxation time and TAU in low calcium stages 0.5–1.0 mM Ca (p < 0.014) in right atrial fibers and prolonged time to peak at 2.0–2.5 mM Ca (p < 0.023) in left atrial fibers. Demographic analysis showed no differences between the groups. Also there was no difference in pro BNP levels, creatinine, hematocrit and HbA1c.

Conclusion: Our results showed a altered contractile and kinetic conduct of cardiac myofilaments and intact muscle cells of POAF patients before the clinical appearance after cardiac surgery. The importance of detecting these patients preoperative could change the prophylaxis, treatment and outcome of POAF patients.

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
13 February 2024