The highest frequency of AF in RHD occurs in those with mitral stenosis, mitral regurgitation, and tricuspid regurgitation in combination. AF, while occurring in 29% of patients with isolated mitral stenosis and in 16% with isolated mitral regurgitation, is an infrequent finding (1%) in patients with aortic valvular disease. Left atrial diameter by univariate analysis, and age and left atrial diameter by multivariate analysis have been shown to be the most important parameters to determine the occurrence of AF in patients with RHD.