ABSTRACT
INTRODUCTION The prevalence of mitral valve disease, especially mitral regurgitation (MR), is increasing. Despite significant gains in the eradication of rheumatic fever, rheumatic mitral stenosis (MS) remains a significant problem in underdeveloped countries. In addition to the increased incidence of degenerative mitral valve disease due to the aging population, the growing congestive heart failure epidemic has led to further increase in the proportion of patients with severe MR. The emergence of new percutaneous technologies for mitral valve disease has generated great interest in the interventional community. Although percutaneous balloon mitral valvuloplasty (BMV) is a wellestablished technique, the skill set necessary for this procedure remains critical to the well-rounded structural heart disease interventionalist. This chapter reviews the indications and techniques for percutaneous therapies for mitral valve disease.
PERCUTANEOUS TREATMENT OF MITRAL STENOSIS Fundamentals and Anatomic Considerations Etiology The most common cause of MS is rheumatic heart disease. Less commonly, congenital MS may be detected in children. Rarely, MS is a result of collagen vascular disease, mucopolysaccharidoses, amyloid deposits, or is drug-induced. In rheumatic mitral valve disease, fusion of the mitral valve apparatus may occur in the commissures, the cusps, or the chordae tendinae. While the majority of patients have a combination of the above, 30% of patients have isolated commissural thickening, 15% have thickening of the cusps only, and 10% have only chordal thickening. Generally, the mitral cusps thicken at the edges and fuse at the commissures, while the chordae thicken, shorten, and fuse. This leads to a funnel-shaped valve with reduced leaflet mobility and a fish-mouth shaped orifice (Fig. 43.1). If the commissures are predominantly involved, this leads mainly to MS. Isolated thickening and shortening of the chordae results mainly in MR; however, if the cusps are thickened and adherent, so they cannot adequately open or close, a combination of MS and regurgitation occurs.
