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ESSENTIALS OF DIAGNOSIS
Exertional dyspnea and fatigue.
Opening snap, diastolic rumble murmur, loud S1, presystolic accentuated murmur.
Right ventricular heave and loud P2 if pulmonary hypertension and right heart failure are present.
A2-OS interval ≤ 80 ms in severe mitral stenosis.
Sinus rhythm or atrial fibrillation, notched P wave or P mitrale in leads II and III and/or biphasic P wave in V1, right axis deviation, high amplitude of P wave in lead II, and large R wave in V1 on electrocardiography.
Flattening of left atrial border and/or double density, elevated left main bronchus, enlarged pulmonary arteries, and Kerley B lines on chest radiography.
Thickened and/or calcified mitral leaflets and subvalvular apparatus resulting in “hockey-stick” motion of the anterior leaflet and fusion of commissures resulting in fish-mouth appearance of the rheumatic mitral valve on two- and three-dimensional echocardiography.
Reduced mitral valve area by planimetry on two- or three-dimensional echocardiography and by pressure half-time, continuity equation, and proximal isovelocity surface area quantification methods on Doppler echocardiography and increased mean transmitral valve gradient on Doppler echocardiography.
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General Considerations
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Mitral stenosis is a condition where the mitral valve area is reduced, causing obstruction of blood flow from the left atrium into the left ventricle during left ventricular diastole, which can lead to elevated left atrial pressure resulting in pulmonary hypertension, pulmonary edema, and right heart failure. The condition becomes clinically evident when the mitral valve area is reduced to approximately 2 cm2. Mitral stenosis occurs predominantly in adults and is one of the sequelae of rheumatic fever in about 90% of cases. Approximately two-thirds of cases occur in women. Twenty-five percent of patients have isolated mitral stenosis, and 50% have mixed mitral valve disease or combined mitral and aortic valve involvement. Unlike mitral regurgitation, which can present during the initial acute rheumatic carditis episode, mitral stenosis often develops after recurrent attacks, follows an indolent course, and has a latent period up to 40 years after the index episode of rheumatic fever. Only about 50–70% patients recall having had antecedent group A β-hemolytic streptococcal tonsillopharyngitis.
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Rheumatic fever is a major public health problem in developing countries. The prevalence in developing countries is 2.2 to 2.3 per 1000 using clinical screening compared to 0.5 per 1000 in developed countries. If echocardiography is used to screen, the prevalence increases from 21.5 to 30.4 per 1000 in underdeveloped countries. The prevalence in Western countries has not decreased substantially because of the increased rate of immigration from developing countries. Mitral stenosis still accounts for 10% of native valve pathology. The pattern of valvular involvement is associated with the rate of recurrent or reactivation of streptococcal infection and thus varies geographically. Individuals in developing countries are more likely to suffer from multiple episodes of rheumatic fever and thus become symptomatic at an earlier age compared to individuals in industrialized countries, who ...