cardiovascular disorders
Mitral Stenosis
Symptoms and Signs of Mitral Stenosis
Symptoms of mitral stenosis correlate poorly with disease severity because the disease often progresses slowly, and patients unconsciously reduce their activity. Many patients are asymptomatic until they become pregnant or atrial fibrillation develops. Initial symptoms are usually those of heart failure (eg, exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, fatigue). Symptoms typically do not appear until 15 to 40 years after an episode of rheumatic fever. In medically underserved regions, young children may become symptomatic because streptococcal infections are treated with antibiotics, and recurrent infections are common. Paroxysmal or chronic atrial fibrillation further reduces blood flow into the left ventricle (LV), precipitating Pulmonary Edema and acute dyspnea when ventricular rate is poorly controlled. Atrial fibrillation may also cause palpitations. In up to 15% of patients not taking anticoagulants, it causes systemic embolism with symptoms of stroke or other organ ischemia. Less common symptoms include hemoptysis due to rupture of small pulmonary vessels and pulmonary edema, particularly during pregnancy when blood volume increases. Hoarseness due to compression of the left recurrent laryngeal nerve by a dilated LA or pulmonary artery (Ortner syndrome) and symptoms of Symptoms and Signs and Mitral stenosis may cause signs of Cor Pulmonale . The classic facial appearance in mitral stenosis, a plum-colored malar flush, occurs only when cardiac output is low and pulmonary hypertension is severe; cause is cutaneous vasodilation and chronic hypoxemia. In patients with dark skin, the malar flush may produce a darker shade of the patient's skin. Occasionally, the initial symptoms and signs of mitral stenosis are those of an embolic event such as stroke. Endocarditis is rare in mitral stenosis unless mitral regurgitation is also present. Palpable first and second heart sounds (S1 and S2) may be detected. S1 is best palpated at the apex, and S2 is best felt at the upper left sternal border. The pulmonic component of S2 (P2) is responsible for the impulse and results from pulmonary hypertension. An RV impulse (heave) palpable at the left sternal border may accompany jugular venous distention when pulmonary hypertension is present and RV diastolic dysfunction develops. Loud S1 Early diastolic opening snap Low-pitched decrescendo-crescendo rumbling diastolic murmur Auscultatory findings in mitral stenosis include a loud S1 caused by the leaflets of a stenotic mitral valve closing abruptly (M1); it is heard best at the apex. S1 may be absent when the valve is heavily calcified and immobile. A normally split S2 with an exaggerated P2 due to pulmonary hypertension is also heard (see table). Most prominent is an early diastolic opening snap as the leaflets billow into the LV, which is loudest close to left lower sternal border; it is followed by a low-pitched decrescendo-crescendo rumbling diastolic murmur, heard best with the bell of the stethoscope at the apex (or over the palpable apex beat) at end-expiration when the patient is in the left lateral decubitus position. The opening snap may be soft or absent if the mitral valve is calcified; the snap moves closer to S2 (increasing duration of the murmur) as mitral stenosis becomes more severe and LA pressure increases. The diastolic murmur increases after a Valsalva maneuver (when blood pours into the LA), after exercise, and in response to maneuvers that increase afterload (eg, squatting, isometric handgrip). The murmur may be softer or absent when an enlarged RV displaces the LV posteriorly and when other disorders (pulmonary hypertension, right-sided valve abnormalities, atrial fibrillation with fast ventricular rate) decrease blood flow across the mitral valve. The presystolic crescendo is caused by increased flow with atrial contraction. However, the closing mitral valve leaflets during LV contraction may also contribute to this finding but only at the end of short diastoles when LA pressure is still high. Diastolic murmurs that may coexist with the MS murmur are Early diastolic murmur of coexisting Aortic Regurgitation (AR), which may be conducted to the apex Diastolic flow murmur in the presence of severe MR Mid-diastolic murmur of obstructing left atrial myxoma or ball thrombus (rare) Graham Steell murmur (a soft decrescendo diastolic murmur heard best along the left sternal border and caused by Pulmonic Regurgitation secondary to severe pulmonary hypertension) 