A 62-year-old man with past medical history significant for childhood rheumatic fever presents with chronic dyspnea that has progressed over the past 6 months. He can now only walk 2 to 3 blocks before becoming short of breath. An echocardiogram shows normal left ventricular function, a moderately calcified mitral valve with thickening of the leaflets, and subvalvular apparatus (Figure 22-1). The mean gradient across the mitral valve is 15 mm Hg. What should be done next?
Two-dimensional echocardiogram showing moderately thickened and calcified mitral valve leaflets and subvalvular apparatus. (A) Long axis showing thickened leaflets and subvalvular apparatus and an enlarged left atrium. (B) Short axis at the mitral level showing commissural fusion and evidence of right ventricular pressure overload (flattened intraventricular septum). Used with permission from Agarwal BL, Kapoor A, Singh R, et al. Predictive accuracy of commissural morphology and its role in determining the outcome following Inoue balloon mitral valvotomy. Indian Heart J. 2002;54:39-45.
Mitral stenosis (MS) is a narrowing of the mitral valve (MV) orifice, resulting in impairment of left ventricle filling in diastole. Worldwide, it is most commonly caused by rheumatic heart disease. Other causes include severe calcification of the mitral annulus, infective endocarditis, systemic lupus erythematosus, rheumatoid arthritis, and carcinoid heart disease. The incidence of rheumatic heart disease has steeply declined during the past 4 decades in the United States, but it still remains a major cause of cardiovascular disease in the developing countries. It is estimated that 15.6 million people suffer from rheumatic heart disease worldwide, with approximately 282,000 new cases and 233,000 related deaths each year.1
The treatment for MS is often mitral commissurotomy, resulting in a reduction in the obstruction, a decrease in left atrial pressure, and improvement in patient symptoms. Surgical mitral commissurotomy was first performed in the 1920s and was accepted as an effective clinical procedure for treating severe MS in symptomatic patients. Percutaneous balloon mitral valvuloplasty (PBMV) has replaced surgical mitral commissurotomy as the preferred treatment of rheumatic MS in appropriate patients.2
The MV apparatus consists of the mitral annulus, 2 leaflets, chordae tendineae, and papillary muscles. The 2 leaflets of the MV are referred to as the anterior and posterior leaflets or aortic and mural leaflets, respectively. The mural (posterior) leaflet is narrow and has indentations or clefts that form 3 scallops. Carpentier’s nomenclature3 describes the most lateral segment as P1, the central segment as P2, and the most medial segment as P3. The aortic (anterior) leaflet is larger and also divided into 3 regions labeled A1, A2, and A3 corresponding to the adjacent regions of the mural leaflet.