CASP3 and miotic rate: Of note, the expression of cleaved caspase-3 in the myolytic left atrial myocytes of the MR AF patients (4891266.4 ± 952777.4 vs. 1932986.9 ± 280229.3, p = 0.021) and the MR sinus patients (3785119.0 ± 540198.5 vs. 1932986.9 ± 280229.3, p = 0.018) were significantly higher than the expression of cleaved caspase-3 in the myolytic left atrial myocytes of the normal control subjects (Figs. 4 and 5).