The Interplay between Cardiomyocytes and Non-cardiomyocytes in Postoperative Atrial Fibrillation

Postoperative atrial fibrillation is a common complication after cardiac surgery, and changes in atrial structure may be the substrate for atrial fibrillation. In this study, including 10 coronary patients admitted at the Cardiovascular Disease Institute in 2012, we attempted to identify histopathological and immunohistological changes in right atrial tissue that might explain the development of postoperative atrial fibrillation. Atrial tissue samples from patients in the atrial fibrillation group were compared with samples from patients who remained in postopertive sinus rhythm. Lesions identification requires microscopic examination using special histological techniques and immunohistochemistry.Atrial tissue from 10 patients who underwent elective coronary artery bypass grafting was sampled. Histological and immunhistochemical methods were used for revealing atrial lesions. Five patients developed postoperative atrial fibrillation. Both groups of patients developed degenerative and adaptive lesions, but in different degrees, values recorded in postoperative atrial fibrillation being much higher than in postoperative sinus rhythm.Abnormalities in atrial biopsies can indicate the morphological substrate for postoperative atrial fibrillation development. The same lesions, with various degrees of intensity, make the difference between the severely ischemic myocardium in postoperative atrial fibrillation hearts compared to mild ischemia in postoperative sinus rhythm hearts.