ESSENTIALS OF DIAGNOSIS
Fatigue, exertional dyspnea, and orthopnea when the stenosis becomes severe.
Symptoms often precipitated by onset of atrial fibrillation or pregnancy.
Prominent mitral first sound, opening snap (usually), and apical diastolic rumble.
Auscultatory A2 to opening snap interval shortens as the mitral stenosis worsenes (increased LA pressure).
ECG shows LA abnormality and, commonly, atrial fibrillation.
Echocardiography/Doppler is diagnostic.
Intervention indicated for symptoms, atrial fibrillation, or evidence of pulmonary hypertension. Most symptomatic patients have a mitral valve area of less than 1.5 cm2.
Most patients with native valve mitral stenosis are presumed to have had rheumatic heart disease, although a history of rheumatic fever is noted in only about one-third. (Also see section on Rheumatic Fever.) Rheumatic mitral stenosis results in thickening of the leaflets, fusion of the mitral commissures, retraction, thickening and fusion of the chordae, and calcium deposition in the valve. Mitral stenosis can also occur due to congenital disease with chordal fusion or papillary muscle malposition. The papillary muscles may be abnormally close together, sometimes so close that they merge into a single papillary muscle (the “parachute mitral valve”). In these patients, the chordae or valvular tissue (or both) may also be fused. In older patients and in those undergoing dialysis, mitral annular calcification may stiffen the mitral valve and reduce its motion to the point where a mitral gradient is present. Calcium in the mitral annulus virtually invades the mitral leaflet from the annulus inward as opposed to the calcium buildup in the leaflets and commissures as seen in rheumatic heart disease. Mitral valve obstruction may also develop in patients who have had mitral valve repair with a mitral annular ring that is too small, or in patients who have had a surgical valve replacement (prosthetic valve-patient mismatch or degeneration of the prosthetic valve over time) (eFigures 10–32 and 10–33).
Mitral stenosis. A: Chest radiograph showing generalized cardiac enlargement. B: On the lateral view, the enlarged left atrium indents the esophagus. (Used, with permission, from H Goldberg.)
Chest radiograph of a 60-year-old woman with cardiac enlargement resulting from mitral stenosis with pulmonary hypertension. Ventricular enlargement is right-sided. (AO, aorta; PA, pulmonary artery.) (Reproduced, with permission, from Cheitlin MD, Sokolow M, McIlroy MB. Clinical Cardiology, 6th ed. Originally published by Appleton & Lange. Copyright © 1993 by The McGraw-Hill Companies, Inc.)
Two clinical syndromes classically occur in patients with mitral stenosis. In mild to moderate mitral stenosis, LA pressure and cardiac output may be essentially normal, and the patient is ...