Song C, et al. - Among patients with obstructive hypertrophic cardiomyopathy (HOCM, n=118), researchers investigated plasma big endothelin-1 level as a predictor of atrial fibrillation following surgical septal myectomy. They measured plasma big endothelin-1 level and continuously monitored heart rhythm during hospital stay. The characteristics identified in patients with postoperative atrial fibrillation (POAF) vs those without POAF were: old age, more prone to undergo mitral valve surgery, and exhibited higher plasma big endothelin-1 levels, longer hospital stay, larger preoperative left atria. In HOCM patients undergoing surgical septal myectomy, POAF was independently predicted by elevated preoperative plasma big endothelin-1 level.