During the baseline conditions without AADs, the PITX2+/− deficiency group had a shorter APD90 at a pacing cycle length of 600 ms (p < 0.001, effect size = 2.553, Figure 2A), lower mean Smax during ramp pacing (p < 0.001, effect size = 1.080, Figure 2C), and lower mean DF (p = 0.012, effect size = 0.737, Figure 2E) and PS number (p < 0.001, effect size = 1.239, Figure 2F) after AF induction as compared with the wild type (Table 3). This evidence concerns the gene PITX2 and atrial fibrillation.