Is left atrial fibrosis an independent determinant of atrial fibrillation in mitral stenosis?

We prospectively studied whether left atrial (LA) fibrosis is a determinant of atrial fibrillation (AF) in mitral stenosis in patients who underwent balloon mitral valvotomy. There were 2 groups: Group A (n = 16), with AF and Group B (n = 27), without AF. Fibrosis was assessed by MRI. Patients underwent cardioversion before MRI. There were 27 females and 16 males, aged 29 ± 6 years. The LA areas in Groups A and B were 54.3 ± 4.4 mm2 and 39.4 ± 2.3 mm2 (p < 0.05) and the LA volume index was 46.2 ± 2.9 ml/m2 vs 33 ± 3 ml/m2 respectively (p < 0.0001). The presence of LA scarring was not statistically different in the two groups.