Abstract:

Objective To investigate the correlation between atrial fibrosis and atrial fibrillation after coronary artery bypass grafting (CABG). Methods Forty-seven patients with coronary atherosclerotic heart disease were assigned to the atrial fibrillation group and non-atrial fibrillation group (control group) according to whether atrial fibrillation occurred after CABG. Right atrial appendage sample was harvested before cardiopulmonary bypass. Collagen fiber content in samples was semi-quantitatively measured after Masson staining. Myocardial collagen volume fraction (CVF) in atrial tissues was calculated and atrial fibrosis was assessed. Results Among 47 patients undergoing CABG, 15 (31.9%) of them developed postoperative atrial fibrillation. Myocardial CVF was 21.6%±8.1% (4.1%-39.1%). Analysis by group showed that the age in the atrial fibrillation group was significantly older than that in the control group (P=0.032). Myocardial CVFs in the atrial fibrillation group and the control group were 25.4%±7.9% and 19.9%±7.7%, respectively. Myocardial CVF in the atrial fibrillation group was significantly higher than that in the control group (P=0.020). The differences in other preoperative, intraoperative and postoperative data between two groups were not markedly. Correlation analysis showed that the age of patients was significantly correlated to myocardial CVF (r=0.876, P=0.007). Conclusion The age is significantly correlated to atrial fibrosis and atrial fibrosis is correlated to atrial fibrillation after CABG. Atrial fibrosis may be one of important mechanisms of developing atrial fibrillation after CABG.

Key words: coronary artery bypass grafting, atrial fibrillation, atrial fibrosis