B.33 Aortic Regurgitation Flashcards
B.33 Aortic Regurgitation
define
Aortic regurgitation is the backflow of blood from the aorta into the left ventricle during diastole, due to incompetent aortic valve closure.
early diastolic decrescendo murmur
Aortic regurgitation (AR) is a valvular heart disease characterized by incomplete closure of the aortic valve leading to the reflux of blood from the aorta into the left ventricle (LV) during diastole. Aortic regurgitation can be acute (primarily caused by bacterial endocarditis or aortic dissection) or chronic (e.g., due to a congenital bicuspid valve or rheumatic fever) and may be caused by a valvular defect or an abnormality of the aorta.
B.33 Aortic Regurgitation
Chronic etiology
Chronic AR:
Bicuspid aortic valve
Aortic root dilation (e.g., Marfan syndrome, syphilis, aortic aneurysm)
Rheumatic heart disease
Hypertension
Primary valvular defect - Aortic root dilation is often secondary in primary valvular defects.
- Congenital bicuspid aortic valve: most common cause of AR in young adults in high-income countries
- Calcific aortic valve disease: most common cause of AR in older patients in high-income countries
- Rheumatic heart disease: most common cause of AR in lower-income countries
Aortic dilatation - This can be caused by any disease or defect of the ascending aorta and/or the aortic root and does not always directly involve the aortic valve.
- Connective tissue disorders (e.g., Marfan syndrome, Ehlers-Danlos syndrome)
- Chronic hypertension
- Aortitis of any etiology (e.g., tertiary syphilis)
- Thoracic aortic aneurysm
B.33 Aortic Regurgitation
Acute etiology
- Infective endocarditis - Most common valvular cause of acute AR
- Aortic dissection (ascending aorta) - Most common aortic cause of acute AR
- Chest trauma
- Iatrogenic complications E.g., after percutaneous aortic balloon dilation or transcatheter aortic valve replacement (TAVR)
B.33 Aortic Regurgitation
American Heart Association (AHA)/American College of Cardiology (ACC) staging system for chronic AR
Staging is based on echocardiographic criteria and the presence of symptoms.
Stage A aortic valve regurgitation: At risk of AR - E.g., bicuspid aortic valve, aortic valve sclerosis, or history of rheumatic fever
Stage B aortic valve regurgitation: Progressive AR. with: Mild OR Moderate Regurgitation
Stage C1 aortic valve regurgitation Asymptomatic severe AR (LVEF > 55%)
Stage C2 aortic valve regurgitation Asymptomatic severe AR (LVEF ≤ 55% or LV dilatation > 50 mm)
Stage D aortic valve regurgitation Symptomatic severe AR
B.33 Aortic Regurgitation
pathophys
Volume overload of the LV due to regurgitant flow
Leads to eccentric hypertrophy + dilation Eventually → ↓ contractility, heart failure
In acute AR, the LV doesn’t have time to adapt → sudden LV failure + pulmonary edema
General Pathophys:
Regurgitation of blood from the aorta into the left ventricle (LV) leads to:
- Increased systolic blood pressure - The LV receives blood from the left atrium and the regurgitant aorta, resulting in higher preload.
- and decreased diastolic pressure - Due to the rapid return of blood to the LV through the incompetent aorta
Widened pulse pressure → water hammer pulse
B.33 Aortic Regurgitation
Acute AR pathophys
Acute AR
- Because LV cannot sufficiently dilate in response to regurgitant blood, LV end-diastolic pressure increases rapidly → pressure transmits backwards into pulmonary circulation → pulmonary edema and dyspnea
- Decreased cardiac output if severe → cardiogenic shock and myocardial ischemia
B.33 Aortic Regurgitation
Chronic AR pathophys
- Initially, a compensatory increase in stroke volume can maintain adequate cardiac output despite regurgitation (compensated heart failure)
- Over time, increased left ventricular end-diastolic volume → LV enlargement and eccentric hypertrophy of myocardium → left ventricular systolic dysfunction → decompensated heart failure
B.33 Aortic Regurgitation
Acute AR clinical
Signs and symptoms - Sudden dyspnea, hypotension, flash pulmonary edema, shock
- Sudden, severe dyspnea
- 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 - This is due to elevated LV end-diastolic pressure leading to an early closure of the mitral valve.
- Soft and short early diastolic murmur
B.33 Aortic Regurgitation
Chronic AR clinical
Chronic AR:
Asymptomatic for years
Exertional dyspnea, orthopnea, fatigue
Palpitations (esp. when lying down)
Angina or signs of heart failure
May be asymptomatic for up to decades despite progressive LV dilation
Palpitations
Symptoms of high pulse pressure
- 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 heard over the femoral artery on auscultation
- Duroziez sign: to-and-fro bruit 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 nodding or bobbing of the head in synchrony with heartbeats
Symptoms of left heart failure
- Exertional dyspnea
- Angina - Due to reduced coronary flow reserve as coronary flow shifts from diastole to systole, as well as reduced coronary diastolic perfusion pressure with relative bradycardia, especially at night
- Orthopnea
- Easy fatigability
- Syncope
Point of maximal impulse (PMI): diffuse, hyperdynamic, and displaced inferolaterally - Due to eccentric hypertrophy and increased stroke volume
Corrigan pulse
pulse of carotid arteries characterized by rapid upstroke and downstroke
- Traube sign:
pistol shot-like sounds heard over the femoral artery on auscultation
-
Duroziez sign:
to-and-fro bruit 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 nodding or bobbing of the head in synchrony with heartbeats
B.33 Aortic Regurgitation
Chronic AR Auscultation
S3 - A sign of volume overload
High-pitched, blowing, decrescendo early diastolic murmur- As a result of regurgitant, retrograde blood flow over the aortic valve
Worsens with squatting and handgrip
Austin Flint murmur - Rumbling, low-pitched, middiastolic 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
In more severe stages, possibly a harsh, crescendo-decrescendo midsystolic murmur that resembles the ejection murmur heard in aortic stenosis - As a result of a large volume of blood ejected over the aortic valve in an anterograde direction
B.33 Aortic Regurgitation
type of murmur
early diastolic decrescendo murmur, best at left sternal border (3rd ICS), with patient sitting up and leaning forward, after exhalation
B.33 Aortic Regurgitation
pulse findings
Wide pulse pressure
Water-hammer (Corrigan) pulse – bounding & collapsing De Musset's sign – head bobbing Quincke’s sign – capillary pulsations in nailbed Traube’s sign – pistol-shot sounds over femoral artery Duroziez’s sign – systolic & diastolic femoral bruit with pressure 🧠 Remember: AR = “Hyperdynamic circulation” signs
B.33 Aortic Regurgitation
echocardiogram
Transthoracic echocardiography (TTE) is the primary diagnostic tool to diagnose AR and assess the severity of disease.
Indication: assessment of aortic valve structure and function, cause and severity of regurgitation, the left ventricle and other heart valves - Parameters include LVEF, LV end-diastolic dimension and pressure, quantification of regurgitant volume and effective regurgitant orifice area, and width of regurgitant jet relative to LVOT.
Acute AR is an emergency that must be diagnosed and treated immediately.
Computed tomography angiography (CTA) Chest (or TEE) is the preferred diagnostic tool if aortic dissection is suspected.
In chronic AR, TEE, CMR, or cardiac catheterization can be used to confirm the diagnosis if TTE findings are inconclusive.
What is cardiac catheterization
A percutaneous procedure in which a catheter (thin, hollow tube) is inserted through a vessel in the groin, arm, or neck and passed into the coronary vessels and/or chambers of the heart. It allows for the diagnosis of heart diseases as well as therapeutic interventions.
Wha is Transthoracic echocardiography (TTE)
A noninvasive ultrasound examination of the heart. Provides detailed images of the heart’s chambers and valves, the ascending aorta, and pericardium, and can assess valvular function and myocardial contractility. Used in the diagnosis of various cardiac conditions, including valvular heart diseases, heart failure, aneurysms, and pericardial effusion.
B.33 Aortic Regurgitation
echocardiogram/ TTE findings that indication AR
General findings
- Abnormal aortic valve leaflets
- Fluttering of the anterior mitral valve leaflet
- Regurgitant AR jet on Doppler flow tracing
- Dilated aorta
Findings specific to acute AR
- Reduced cardiac output
- Elevated end-diastolic left ventricular pressure
- Early mitral valve closing - The sudden and massive volume increase in the left ventricle leads to an elevation in LV pressure, which then rapidly exceeds left atrial pressure, leading to the early closing of the mitral valve.
- Rapid equilibration of aortic and left ventricular pressure
Findings specific to chronic AR:
increased LV size and volume - Due to eccentric hypertrophy and dilation. LV function is often preserved.
B.33 Aortic Regurgitation
ECG
ECG: - used to help ddx
LVH (chronic) or signs of acute overload
Acute AR: possible signs of the underlying cause (e.g., signs of myocardial ischemia in aortic dissection)
Chronic AR
- ECG signs of LVH
- ST-segment depression and T-wave inversion in I, aVL, V5, and V6
B.33 Aortic Regurgitation
CXR
used to assess for pulmonary edema and rule out other causes of acute dyspnea
Acute AR
Normal heart silhouette
X-ray signs of pulmonary congestion or edema
Chronic AR
X-ray signs of LVH
Enlarged cardiac silhouette
B.33 Aortic Regurgitation
management acute AR
Acute aortic regurgitation
Severe acute AR requires surgical treatment as soon as possible.
Consult cardiology and cardiothoracic surgery immediately.
Medical management of complications (e.g., pulmonary edema) should not delay definitive treatment.
Emergency surgery (valve replacement)
Medical management is focused on stabilizing hemodynamics prior to surgery, e.g., via:
Management of cardiogenic shock with inoconstrictors or inodilators (e.g., dobutamine or dopamine)
Afterload reduction with vasodilators for acute heart failure (e.g., nitroprusside)
Beta blockers may be indicated in aortic dissection; avoid in other causes of acute AR.
