Congenital mitral stenosis

Congenital mitral stenosis (CMS) is a rare congenital heart defect in which the mitral valve — the valve between the left atrium and left ventricle of the heart — is abnormally narrowed at birth. This narrowing obstructs blood flow from the left atrium into the left ventricle, leading to increased pressure in the left atrium and pulmonary veins, which can result in pulmonary hypertension and heart failure if left untreated. The malformation can involve various components of the mitral valve apparatus, including the valve leaflets, chordae tendineae, papillary muscles, or the supravalvular ring. A particularly recognized subtype is the parachute mitral valve, in which the chordae tendineae insert into a single papillary muscle. Congenital mitral stenosis may occur as an isolated defect or in association with other congenital heart anomalies, such as coarctation of the aorta, aortic stenosis, ventricular septal defect, or as part of Shone complex (a combination of multiple left-sided obstructive lesions). Key symptoms include difficulty breathing (dyspnea), poor feeding, failure to thrive, recurrent respiratory infections, and signs of pulmonary congestion such as tachypnea and wheezing. In more severe cases, infants may present with cyanosis and overt heart failure shortly after birth. A heart murmur is typically detected on physical examination. Diagnosis is confirmed through echocardiography, which can delineate the anatomy of the mitral valve apparatus and assess the severity of obstruction. Treatment depends on the severity of the stenosis and the presence of associated cardiac anomalies. Medical management may include diuretics and medications to manage heart failure symptoms. Definitive treatment is surgical and may involve mitral valve repair (valvuloplasty) or, in cases where repair is not feasible, mitral valve replacement. Balloon valvuloplasty (catheter-based intervention) may be considered in select cases. Outcomes depend on the specific anatomy, severity of stenosis, associated anomalies, and timing of intervention. Long-term follow-up with a cardiologist is essential, as many patients require multiple interventions over their lifetime.

Common questions about Congenital mitral stenosis