Echocardiographic study of left atrial thrombi in mitral stenosis.

Sixty-nine patients with predominant mitral stenosis were examined by echocardiographic means to detect the presence of left atrial thrombi. Forty-nine of these patients were in sinus rhythm and twenty in atrial fibrillation. Four percent of patients in the sinus rhythm group and 45% of those in the atrial fibrillation group had left atrial thrombi. The two risk factors identified for left atrial thrombi in mitral stenosis were atrial fibrillation and left atrial enlargement.