Fig. 3

Cox-proportional hazard model for survival free of atrial fibrillation by tertiles of post-ablation contractile strain (ℇCT), adjusted for age, gender, hypertension, and obstructive sleep apnea. Tertiles one, two, three corresponded to a post-ablation ℇCT of < 5.3, 5.3–8 and > 8, respectively