Spontaneous return of sinus rhythm in older patients with chronic atrial fibrillation and rheumatic mitral valve disease. Description of three patients

Three patients with rheumatic mitral stenosis had had atrial fibrillation for over ten years before spontaneously restoring normal sinus rhythm. Each had undergone a closed mitral commissurotomy ten to twelve years before the conversion. Their ages at the time of resuming normal rhythm were 47, 59, and 71 years. This unusual phenomenon has no satisfactory explanation by our present knowledge of the natural history of mitral valve disease and the pathogenesis of atrial fibrillation.