Etiology

Most commonly rheumatic, though history of acute rheumatic fever is now uncommon; rare causes include congenital MS and severe calcification of the mitral annulus with extension onto the leaflets.

History

Symptoms most commonly begin in the fourth decade, but MS often causes severe disability at earlier ages in developing nations. Principal symptoms are dyspnea and cough precipitated by exertion, excitement, fever, anemia, tachycardia, pregnancy, sexual intercourse, and thyrotoxicosis.

Physical Examination

Right ventricular lift; palpable S₁; opening snap (OS) follows A₂ by 0.05-0.12 s; OS-A₂ interval inversely proportional to severity of obstruction. Diastolic rumbling murmur, best heard at apex in left lateral decubitus position, with presystolic accentuation when in sinus rhythm. Duration of murmur correlates with severity of obstruction.

Complications

Hemoptysis, pulmonary embolism, respiratory infections, systemic embolization; endocarditis is uncommon in pure MS.

ECG

Typically shows atrial fibrillation (AF) or left atrial (LA) enlargement when sinus rhythm is present. Right-axis deviation and RV hypertrophy in the presence of pulmonary hypertension.

CXR

LA and RV enlargement, pulmonary artery prominence, and Kerley B lines.

Echocardiogram

Shows reduced separation, thickening and calcification of mitral leaflets and subvalvular apparatus, LA enlargement. Doppler assessment provides estimation of transvalvular peak and mean gradients, mitral valve area, and degree of pulmonary hypertension (Chap. 114 Noninvasive Examination of the Heart).

Etiology

Acute MR: Infective endocarditis, papillary muscle rupture post-MI, ruptured chordae tendineae. Chronic MR: Myxomatous deformity (mitral valve prolapse [MVP]), mitral annular calcification, rheumatic, healed endocarditis, congenital, radiation damage, LV enlargement of any cause, hypertrophic cardiomyopathy (with systolic anterior motion of anterior mitral leaflet).

Clinical Manifestations

Acute MR: Commonly presents with symptoms and signs of acute pulmonary edema. Chronic MR: Mild-moderate disease is typically asymptomatic. In chronic severe MR, fatigue, exertional dyspnea, orthopnea, palpitations are common, and physical examination shows sharp low-volume carotid upstroke, laterally displaced apical impulse, LV is hyperdynamic, S₁ diminished, wide splitting of S₂; S₃ common; loud holosystolic murmur at the apex and often a brief early-mid-diastolic murmur due to increased transvalvular flow. Murmur typically radiates to axilla, but may radiate to base instead when due to prolapsing or flail posterior leaflet.

Echocardiography

Often identifies mechanism of MR (TEE provides greater anatomic detail, when needed). Measures LA size and LV dimensions and contractile function, which are important to follow serially over time. Doppler techniques quantify severity of MR and provide estimate of pulmonary artery systolic pressure.

Etiology

Excessive/redundant mitral leaflet tissue typically of unknown cause; may also accompany certain connective tissue disorders, e.g., Marfan syndrome, Ehlers-Danlos syndrome.

Pathology

Redundant mitral valve tissue often with myxedematous degeneration and increased glycosaminoglycans.

Clinical Manifestations

More common in females, most pts are asymptomatic. Yet MVP is the most common cause of primary MR ultimately requiring surgical treatment in North America. Potential symptoms include vague chest discomforts and supraventricular and ventricular arrhythmias. Most important complication is progressive MR. Rarely, systemic emboli from platelet-fibrin deposits on valve lead to transient ischemic attacks. Sudden death is a very rare outcome of MVP.

Physical Examination

Mid or late systolic click(s) followed by high-pitched late systolic murmur at the apex (radiates to axilla with anterior leaflet prolapse, often to base with posterior leaflet prolapse). Click and murmur move earlier and are exaggerated by Valsalva maneuver; they are delayed and softened by squatting and isometric exercise (Chap. 112 Physical Examination of the Heart).

Echocardiogram

Shows posterior displacement of one or both mitral leaflets late in systole. Doppler techniques assess severity of accompanying MR. 3-D echo or magnetic reasonance imaging are sometimes used to precisely determine LV volumes.

Etiologies

Most common: (1) degenerative calcification of a congenitally bicuspid valve, (2) chronic deterioration and calcification of a trileaflet valve, and (3) rheumatic disease (almost always associated with rheumatic mitral disease).

Symptoms

Exertional dyspnea, angina, and syncope are cardinal symptoms; they occur late, after years of obstruction and aortic valve area ≤1.0 cm² .

Physical Examination

Weak and delayed (parvus et tardus) arterial pulses with carotid thrill. A₂ soft or absent; S₄ common. Crescendo-decrescendo systolic murmur, often with systolic thrill. Murmur is typically loudest at second right intercostal space, with radiation to carotids and sometimes to the apex (Gallavardin effect).

ECG

Often shows LV hypertrophy, with lateral ST depression and T wave inversion.

Echocardiogram

Identifies LV hypertrophy, calcification and thickening of aortic valve cusps with reduced systolic opening, and any accompanying enlargement of aortic root and/or ascending aorta. Dilatation of LV and impaired contraction indicate poor prognosis. Doppler quantitates systolic gradient and allows calculation of valve area. Dobutamine stress echocardiography is helpful to assess severity of AS when there is accompanying LV systolic dysfunction.

Etiology

Valvular: Includes congenitally bicuspid valve, endocarditis, or rheumatic (especially if rheumatic mitral disease is present). Dilated aortic root: dilatation due to cystic medial necrosis, aortic dissection, ankylosing spondylitis, syphilis.

Clinical Manifestations

When chronic severe AR is symptomatic, manifests as awareness of forceful heartbeat, exertional dyspnea, and other signs of LV failure (orthopnea, paroxysmal nocturnal dyspnea) and sometimes angina pectoris. A widened pulse pressure, rapidly rising “water hammer” pulse, capillary pulsations (Quincke's sign), and a heaving, laterally displaced LV impulse are common. On auscultation A₂ is soft or absent, an S₃ may be present, and there is a high-pitched, blowing, decrescendo early diastolic murmur along the left sternal border (but often along right sternal border when AR is due to aortic dilatation). In acute severe AR, the pulse pressure is typically not widened and the diastolic murmur is often short and soft.

Laboratory ECG and CXR

ECG: Signs of LV hypertrophy with “strain.” CXR: apex is displayed downward and to the left; aneurysmal dilatation of the aorta may be present.

Echocardiogram

LV enlargement, possible aortic dilatation, high-frequency diastolic fluttering of mitral valve. Failure of coaptation of aortic valve leaflets may be present. Doppler studies detect and quantify AR. Cardiac magnetic resonance imaging helpful for quantification of AR, LV contractile function, and aortic enlargement if echo is inadequate.

Etiology

Usually rheumatic; most common in females; almost invariably associated with MS.

Clinical Manifestations

Hepatomegaly, ascites, peripheral edema, jaundice, jugular venous distention with slow y descent (Chap. 112 Physical Examination of the Heart). Diastolic rumbling murmur along left sternal border increased by inspiration with loud presystolic component. ECG shows tall P waves in lead II (right atrial enlargement) without RV hypertrophy. Chest X-ray shows right atrial and superior vena caval enlargement. Doppler echocardiography demonstrates thickened valve and impaired separation of leaflets and provides estimate of transvalvular gradient.

Etiology

Usually functional and secondary to marked RV dilatation of any cause, often associated with pulmonary hypertension. Other causes include rheumatic disease, endocarditis, myxomatous valve disease, and carcinoid valvular disease.

Clinical Manifestations

RV failure, with edema, hepatomegaly, and prominent c-v waves in jugular venous pulse with rapid y descent (Chap. 112 Physical Examination of the Heart). Systolic murmur along lower left sternal edge is increased by inspiration. A prominent RV pulsation at left sternal edge may be present. Doppler echocardiography confirms diagnosis and estimates severity of disease.

Etiology

Almost always congenital; carcinoid syndrome is a rare cause of PS.

Clinical Manifestations

Symptoms occur only with severe disease (peak transvalvular gradient >50 mmHg) and include exertional dyspnea, fatigue, and occasionally angina, owing to RV oxygen demand. Physical findings include a crescendo-decrescendo systolic murmur at the second left interspace typically preceded by a systolic ejection click. A right-sided S₄ may be present. A prominent a wave is typical in the jugular venous pulse. The ECG in severe PS shows right ventricular hypertrophy and right atrial enlargement. The chest x-ray shows right atrial and right ventricular enlargement; post-stenotic enlargement of the pulmonary artery may be present. Doppler echocardiography demonstrates the stenotic valve and quantitates the transvalvular gradient.