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Valvular Heart Disease: Difference between revisions
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In contrast to the compensatory mechanism in mitral valve regurgitation, a modest concentric left ventricular hypertrophy accompanies the eccentric hypertrophy, with a normal mass-to-volume ratio(Feiring and Rumberger 1423-32). In a chronic state, progressive left ventricle dilatation leads to pre- and afterload mismatch. With gradually decompensation and deterioration of systolic function, the ventricle is not able to sustain perfusion. | In contrast to the compensatory mechanism in mitral valve regurgitation, a modest concentric left ventricular hypertrophy accompanies the eccentric hypertrophy, with a normal mass-to-volume ratio(Feiring and Rumberger 1423-32). In a chronic state, progressive left ventricle dilatation leads to pre- and afterload mismatch. With gradually decompensation and deterioration of systolic function, the ventricle is not able to sustain perfusion. | ||
==== Clinical presentation ==== | |||
Patients with aortic regurgitation typically present with symptoms of left sided heart failure including dyspnea on exertion, orthopnea, fatigue, and occasionally paroxysmal nocturnal dyspnea. Angina is less common in patients with aortic regurgitation compared to aortic stenosis. The reduced aortic diastolic blood pressure reduces the coronary blood flow, resulting in angina. The same mechanism is presumed to cause syncope. | |||
=== Diagnostics === | |||
==== Chest Radiography ==== | |||
Chest Radiography in acute aortic regurgitation reveals minimal cardiac enlargement, with normal aortic root and arch. In acute aortic regurgitation, signs of left heart failure are frequent. Cardiomegaly with left ventricular enlargement is the main feature on chest radiography in chronic aorta regurgitation. The ascending aorta may be enlarged in case of an aortic aneurysm or aortic dissection but Chest X-ray is not a sensitive examination to detect ascending aortic aneurysm. | |||
Pulmonary congestion is noted at advanced stages of chronic AR, when heart failure has developed. | |||
==== Electrocardiography ==== | |||
Electrocardiography in patients with aortic regurgitation may be normal early in the disease. Left ventricular hypertrophy is the main feature of aortic regurgitation, with or without associated repolarization abnormalities. Left axis deviation may be present. | |||
==== Echocardiography ==== | |||
Echocardiography is used to evaluate the anatomy of the aortic valve and other valves, as well as aortic leaflets and the aortic root. The regurgitation mechanism and aetiology can be assessed. Three types of mechanisms can be identified; enlargement of aortic root with normal cusps, cusp prolapse or fenestration and poor cusp tissue quality or quantity. Doppler is used for quantifying the aortic regurgitation by the width of regurgitant jet and its extension into the LV, the rate of decline of aortic regurgitant flow and diastolic flow reversal in the descending aorta. | |||
Severe aortic regurgitation is defined as effective regurgitant orifice (ERO) area of >0.30cm2, regurgitant volume >60mL, or a regurgitant fraction of >50%. | |||
Preoperatively transoesophageal echocardiography is performed to more accurately evaluate the anatomy and mechanism of the aortic valve regurgitation. | |||
==== Treatment ==== | |||
The only direct method to reduce aortic regurgitation is surgical treatment. However, some patients may benefit from medical treatment. | |||
=== Medical treatment === | |||
The relative reduction of myocardial blood due to increased demand and/or associated obstructive coronary artery disease may cause angina. Angina may be treated by reducing aortic regurgitation, reduction of myocardial demand of revascularization of the myocardium. Clinical heart failure is treated with traditional therapy, including digitalis, diuretics, and ACEI. In severe heart failure, parenteral inotropic and vasodilator therapy may be needed. | |||