Right bundle branch block: a new parameter revealing the progression rate of mitral stenosis

Mitral stenosis has a generally slow but often variable clinical course. However, the factors that influence the rate of stenosis progression have not been completely identified. The aim of this study was to evaluate whether right bundle branch block (RBBB) may be related to the rapid progression of pure mitral stenosis besides echocardiographic parameters.

Four hundred and thirty-six patients (300 females) were reviewed retrospectively. The patients were classified according to RBBB existence in electrocardiography: group A included 83 patients with RBBB existence, and group B contained 353 patients without RBBB. The patients were further classified as subjects who had an echocardiographic valve score < or =8 (325 patients, group 1) and those with a valve score >8 (111 patients, group 2).

The mean age of the patients was similar in groups A and B. In group A, the mean mitral valve gradient was higher (12.63 +/- 4.43 vs. 10.58 +/- 3.37 mm Hg; p < 0.0001), the mitral valve area smaller (1.05 +/- 0.2 vs. 1.14 +/- 0.52 cm2; p = 0.011), and the systolic pulmonary artery pressure higher (53.5 +/- 16.2 vs. 46.9 +/- 13.2 mm Hg; p = 0.001) than in group B. The mean age and mitral valve area were similar in groups 1 and 2. The mean mitral valve gradient (10.5 +/- 3.7 vs. 12.3 +/- 3.0 mm Hg; p < 0.0001) and systolic pulmonary artery pressure were higher in group 2 (46.7 +/- 13.3 vs. 52.5 +/- 15 mm Hg; p < 0.0001).

These findings indicate that RBBB existence correlates with the severity of the disease and the grade of valve calcification in moderate and severe pure mitral stenosis.