Aortic regurgitation (1).pptx

AORTIC REGURGITATION BACKGROUND Aortic regurgitation is the diastolic backflow of blood from the aorta into the left ventricle. Regurgitation is due to: - an intrinsic valvular defect (leaflet) - or - an abnormality of the ascending aorta (annulus of the aorta) CLASSIFICATION Acute AR (primari...

AORTIC REGURGITATION BACKGROUND Aortic regurgitation is the diastolic backflow of blood from the aorta into the left ventricle. Regurgitation is due to: - an intrinsic valvular defect (leaflet) - or - an abnormality of the ascending aorta (annulus of the aorta) CLASSIFICATION Acute AR (primarily caused by bacterial endocarditis or aortic dissection) Chronic AR (e.g., due to a congenital bicuspid valve or rheumatic fever). In most cases, acute AR leads to rapid deterioration, with subsequent pulmonary edema and cardiac decompensation. Chronic AR may remain compensated for a long period of time, becoming symptomatic only when left heart PATHOPHYSIOLOGY  Diastolic reflux through the aortic valve can lead to left ventricular volume overload.  The severity of the aortic regurgitation is dependent on the:  area of the valvular orifice in diastola  the diastolic pressure gradient between the aorta and left ventricle  the duration of diastole.  An increase in systolic stroke volume → ↑ Systolic BP  Backflow of blood in diastole →↓ Diastolic BP  Increased pulse pressure= Systolic Aortic Valve Regurgitation: Pathophysiology - Acute vs. Chronic Pulmonary Congestion Pressure Pressure Pressure N- Pressure N- ETIOLOGY ACUTE AR  Infective endocarditis  Aortic dissection (ascending aorta)  Chest trauma-which may be either penetrating or blunt. Acute AR ACUTE AR ETIOLOGY CHRONIC AR  Primary valvular defect  Congenital bicuspid aortic valve: young adults in high-income countries  Calcific aortic valve disease: older patients in high-income countries  Rheumatic heart disease: most common, in lowerincome countries  Aortic dilatation  Connective tissue disorders (e.g., Marfan syndrome, Ehlers-Danlos syndrome)  Chronic hypertension  Aortitis of any etiology (e.g., tertiary syphilis)  Thoracic aortic aneurysm CLINICAL FEATURES ACUTE AR Sudden, severe dyspnea with orthopneea Rapid cardiac decompensation secondary to heart failure Pulmonary edema Symptoms related to underlying disease (e.g., fever due to endocarditis, chest pain due to aortic dissection) - Auscultation Soft S1 Soft and short early diastolic murmur CLINICAL FEATURES CHRONIC AR May be asymptomatic for up to decades despite progressive LV dilation Symptoms Palpitations Symptoms of left heart failure Exertional dyspnea, orthopnea Angina Easy fatigability Syncope CLINICAL FEATURES CHRONIC AR PHYSICAL EXAMINATION Palpation: apex beat hyperdynamic, and displaced inferolaterally Auscultation  High-pitched, blowing, decrescendo early diastolic murmur, is heard best while the patient is leaning forward on deep expiration.  AR due to valvular disease: heard best in the left 3- rd and 4-th intercostal spaces and along the left sternal border (Erb point)  AR due to aortic root disease (e.g., aortic dissection): heard best along the right sternal border AUSCULTATION AR CLINICAL FEATURES CHRONIC AR PHYSICAL EXAMINATION  Austin Flint murmur  Rumbling, low-pitched, mid-diastolic or presystolic murmur heard best at the apex  Caused by regurgitant blood striking the anterior leaflet of the mitral valve, which leads to premature closure of the mitral leaflets CLINICAL FEATURES CHRONIC ARPERIPHERAL SIGNS Water hammer pulse of peripheral arteries characterized by rapid upstroke and downstroke Corrigan pulse: pulse of carotid arteries characterized by rapid upstroke and downstroke Traube sign: pistol shot-like sounds (loud systolic sound) over the femoral artery on auscultation Duroziez sign: Systolic-diastolic murmur over the femoral artery that is heard when slight pressure is applied with a stethoscope Quincke sign: visible capillary pulse when pressure is applied to the tip of a fingernail De Musset sign: rhythmic bobbing of the head in synchrony with heartbeats CLINICAL FEATURES CHRONIC AR PERIPHERAL SIGNS Muller sign - Pulsations of the uvula Hill sign - Systolic pressure in lower extremity greater than systolic pressure in upper extremity by at least 60 mm Hg Increased pulse pressure: SBP elevated, DBP reduced DIAGNOSTIC APPROACH TRANSTHORACIC ECHOCARDIOGRAPHY  is the primary diagnostic tool to diagnose AR and assess the severity of disease. Acute AR is an emergency that must be diagnosed and treated immediately. Angio-CT of the aorta (or TEE) is the preferred diagnostic tool if aortic dissection is suspected. Additional tests depend on patient stability and the suspected underlying condition (e.g., blood cultures for endocarditis). In chronic AR, TEE, CMR,can be used to confirm the diagnosis if TTE findings are inconclusive. ECHOCARDIOGRAPHY • Acute aortic regurgitation • Valve anatomy disrupted • Echo signs of aortic dissection • Vegetations on valve in endocarditis • Chronic aortic regurgitation • Valve anatomy disrupted, aortic valve morphology • Estimation of degree of regurgitation • Aortic root or ascending aorta enlargement and anatomy • Left ventricular dilatation and function IMAGING STUDIES Chest radiography • Acute aortic regurgitation • Minimal cardiac enlargement • Normal aortic root/arch • Pulmonary venous pattern increased • Chronic aortic regurgitation • Marked cardiac enlargement • Prominent aortic root/arch • Normal pulmonary venous pattern OTHER TESTS ECG • Normal (early in disease) • Left axis deviation (chronic aortic regurgitation) • Left ventricular hypertrophy • RV6+SV2 > 35 mm • T wave inverted with ST-segment depression in left leads • Atrial fibrillation. This is uncommon before disease has become advanced and has an ominous prognosis unless caused by another disease. ECG ECG OTHER TESTS Laboratory studies: not routinely indicated  Blood cultures: in suspected infective endocarditis (at least three sets)  BNP/NT-proBNP ADVANCED IMAGING Cardiac MRI  Indication: moderate to severe AR with inadequate echocardiographic imaging or a discrepancy between clinical presentation and echocardiographic findings  Objective: precise evaluation of anatomy and hemodynamics CARDIAC CATHETERIZATION/ANGIOGRAPHY  Cardiac catheterization Indication: moderate to severe AR with inadequate echocardiographic imaging or a discrepancy between clinical presentation and echocardiographic findings Objective: hemodynamic evaluation (e.g., severity of regurgitation, intracardiac pressures, cardiac function)  Coronary angiography  Indications: preoperative cardiac risk stratification in patients with angina, reduced LVEF, signs of ischemia, or coronary risk factors  Findings: signs of CAD (e.g., coronary stenosis) TREATMENT Emergency Department Care • General • Provide adequate airway management. • Intubate when necessary. • Consider prompt surgical intervention in acute aortic regurgitation. • Acute aortic regurgitation • Administer a positive inotrope (eg, dopamine, dobutamine) and a vasodilator (eg, nitroprusside, NTG). • Rarely, administration of cardiac glycosides (eg, digoxin) for rate control may be necessary. • Avoid beta-blockers in the acute setting. • Administration of vasodilators may be appropriate to improve systolic function and to decrease afterload. TREATMENT Chronic aortic regurgitation - Medical treatment - - vasodilator therapy may reduce afterload and diminish regurgitant volume (ACE inhibitors) - - diuretics in heart failure  Prophylactic antibiotics  At-risk patients, e.g., with prosthetic valves or a history of infective endocarditis: Consider antibiotic prophylaxis prior to certain dental procedures.  Rheumatic heart disease: long-term secondary prophylaxis INTERVENTION • Hemodynamically significant aortic regurgitation may require surgical intervention • Percutaneous interventional treatment modality for aortic regurgitation is in study. • Surgical treatment consists of replacement or repair of the valve (± the ascending aorta) • Prompt surgical treatment is recommended for symptomatic patients and patients with acute aortic regurgitation. • For asymptomatic patients with chronic AR, aortic valve replacement is deferred as long as: • -the patient has good exercise tolerance, • -normal ejection fraction, • -and an LV end-diastolic diameter of under 7 INTERVENTION • In asymptomatic patients with normal LVEF, close follow-up at 6month intervals is recommended. • Aortic valve replacement surgery or valve repair should be undertaken if: - the LV end-diastolic dimension increases to greater than 7 cm/if the end-systolic diameter becomes 5.0 cm or more - if the ejection fraction decreases to less than 50%. PROGNOSIS  Asymptomatic patients with normal LVEF: progression to symptoms or LV dysfunction at a rate of < 6% per year  Asymptomatic patients with decreased EF progression to symptoms at a rate of > 25% per year  Symptomatic patients: mortality rate is > 10% per year