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Aortic regurgitation

Updated : May 16, 2024





Background

Aortic regurgitation, also known as aortic insufficiency, is a heart valve disorder that occurs when the aortic valve in the heart does not close properly. The aortic valve is responsible for regulating the flow of oxygen-rich blood from the left ventricle of the heart into the aorta, which is the main artery that carries blood to the rest of the body.

When the aortic valve does not close tightly, some of the blood flows back into the left ventricle during each heartbeat rather than being efficiently pumped out to the body. The severity of aortic regurgitation can vary from mild to severe.
In its early stages, it may not produce noticeable symptoms. However, as the condition worsens, individuals may experience symptoms such as shortness of breath, fatigue, chest pain, palpitations, and, in severe cases, heart failure.

Epidemiology

Aortic regurgitation is not uncommon but can vary in prevalence depending on the population studied. In industrialized countries, it is estimated to affect about 2–3% of the population. The prevalence may be higher in older age groups. Aortic regurgitation can occur at any age, but it tends to be more common in older adults.

The acquired form of the condition, often related to degenerative changes in the aortic valve, is more frequently seen in older individuals. Congenital aortic regurgitation, which is present from birth, can affect individuals of all ages. Aortic regurgitation can affect both men and women, but some studies suggest a slightly higher prevalence in men.

This gender difference is more pronounced in cases of degenerative aortic regurgitation. Aortic regurgitation often progresses slowly, and many individuals with mild to moderate regurgitation may not experience noticeable symptoms for a long time. As the condition worsens, it can lead to symptoms and complications, which may require treatment.

Anatomy

Pathophysiology

Aortic regurgitation results from the improper closure of the aortic valve, which separates the left ventricle of the heart from the aorta. This failure of the aortic valve to seal tightly allows a portion of the oxygen-rich blood to flow backward into the left ventricle with each heartbeat rather than being efficiently pumped into the systemic circulation.

Over time, this regurgitant flow can lead to several pathophysiological changes. The heart must work harder to maintain an adequate forward blood flow, causing the left ventricle to enlarge and hypertrophy as it compensates for the increased volume load. This chronic overload can lead to progressive weakening of the left ventricular muscle, eventually resulting in heart failure.

Additionally, the backward flow of blood can cause increased pressure in the pulmonary circulation, potentially leading to pulmonary congestion and symptoms such as shortness of breath. The severity and rate of progression of aortic regurgitation can vary, with symptoms becoming more pronounced as the condition advances, underscoring the importance of timely diagnosis and appropriate management to prevent complications and maintain heart function.

Etiology

Acquired Causes

  • Aortic Dissection
  • Aortic Valve Degeneration
  • Hypertension
  • Infective Endocarditis
  • Rheumatic Heart Disease

Congenital Causes

  • Bicuspid Aortic Valve
  • Aortic Valve Malformations

Genetics

Prognostic Factors

Clinical History

The symptoms of chronic aortic regurgitation typically have a gradual onset, often spanning several decades. These symptoms encompass exertional dyspnea (breathlessness during physical activity), paroxysmal nocturnal dyspnea, orthopnea, angina pectoris, and a sensation of intense pulsations in the head.

Nocturnal angina occurs as a result of the heart rate slowing down during sleep, leading to a significant drop in arterial diastolic pressure, which can reach extremely low levels.

Physical Examination

Austin flint murmur is characterized by a low-pitched, rumbling mid-diastolic murmur, most distinctly audible at the apex of the heart. This murmur is believed to result from the premature closure of the mitral valve, a consequence of the regurgitant blood jet from aortic regurgitation.

The Becker sign pertains to the observation of visible pulsations in the retinal arteries when examining the eye using an ophthalmoscope.

A Bisferiens pulse refers to a pulse pattern exhibiting two distinct peaks due to the backflow of blood during early diastole.

Corrigan sign manifests as a water-hammer pulse marked by sudden distention and rapid collapse of arterial pulses.

de Musset sign is characterized by a noticeable nodding or bobbing of the head in sync with the arterial pulsations.

Duroziez sign involves the detection of a systolic murmur when compressing the femoral artery proximally and a diastolic murmur when compressing it distally using a stethoscope.

Gerhardt sign is recognized when pulsations of the spleen are evident, typically associated with an enlarged spleen (splenomegaly).

Hill sign indicates that the blood pressure in the lower extremity is higher than in the upper extremity.

Mayne sign signifies a drop in diastolic blood pressure of more than 15 mmHg upon raising the arm.

Muller sign points to the presence of systolic pulsation in the uvula, the conical projection hanging at the back of the throat.

Quincke sign involves the observation of capillary pulsations, typically manifesting as alternating flushing and paling at the base of the nail when pressure is applied to the nail’s tip.

Rosenbach sign is noted when pulsations are discernible in the liver.

Traube sign is characterized by the presence of a distinctive “pistol-shot” systolic and diastolic sound heard over the femoral artery, often resembling the sound of a gunshot.

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Pulmonic regurgitation

Infective Endocarditis

Hypertrophic Cardiomyopathy

Aortic Stenosis

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

The treatment paradigm for aortic regurgitation involves a multi-faceted approach tailored to the severity of the condition and the presence of symptoms. Asymptomatic patients with mild to moderate AR and normal cardiac size are primarily managed with regular clinical and echocardiographic follow-up.

In cases of chronic severe AR with normal left ventricular function and no symptoms, evaluations occur every six months. For patients with acute severe AR, emergency surgery is typically indicated, while medical management is reserved for temporary stabilization. This may include vasodilator therapy for those with systemic arterial hypertension associated with chronic AR.

Additionally, surgical intervention is recommended in cases of active infective endocarditis or the development of hemodynamic instability. The specific treatment approach is contingent on the stage of AR and individual patient factors, with the goal of preventing further complications and maintaining optimal cardiac function.

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Phase of Management

Acute Regurgitation 

In cases of acute severe aortic regurgitation, emergency surgical intervention is the primary and most appropriate course of action. Medical management plays a limited role and is mainly used to stabilize the patient temporarily. To reduce the afterload on the heart and enhance forward blood flow, intravenous diuretics and vasodilators, such as sodium nitroprusside, are employed.

Inotropic agents like dopamine or dobutamine may also be administered to bolster cardiac output. However, it is important to avoid the use of beta-blockers, as they tend to decrease cardiac output and slow the heart rate, which, in turn, allows more time for diastolic filling of the left ventricle. It is worth noting that intra-aortic balloon counter pulsation is not advisable. 

For patients with acute AR caused by active infective endocarditis, there might be a brief period where surgical intervention can be deferred, typically for 5 to 7 days, while the patient receives antibiotic therapy. However, it’s essential to closely monitor the patient’s condition during this period. If hemodynamic instability arises or if abscess formation is evident, surgical intervention must be promptly undertaken to address the urgent cardiovascular concerns. 

Chronic Regurgitation 

For individuals with mild or moderate aortic regurgitation who are asymptomatic and have normal cardiac size, a clinical and echocardiographic follow-up is recommended every 12 to 24 months. In contrast, patients with chronic severe AR and normal left ventricular function who do not display symptoms should undergo evaluations every 6 months. The use of medical treatment for AR is generally limited.

In cases where systemic arterial hypertension coexists with chronic AR, the recommended approach is to implement vasodilator therapy. Preferred options for this purpose include dihydropyridine calcium channel blockers or medications such as angiotensin-converting enzyme inhibitors. These treatments can help manage blood pressure and alleviate the burden on the heart associated with AR. 

Stage A: This stage involves patients who are at risk for AR. They do not exhibit hemodynamic issues or symptoms related to the condition.  

<b>Stage B: Stage B encompasses patients with progressive aortic regurgitation. These individuals have mild to moderate AR but maintain normal left ventricular systolic function and remain asymptomatic.  

Stage C:  Asymptomatic, severe AR characterizes Stage C. In this stage, AR jet width is equal to or greater than 65% of the left ventricular outflow tract (LVOT). Further subclassifications are made based on LV systolic function: C1 involves patients with normal LV ejection fraction and mild to moderate LV dilation (LV end-systolic diameter <50 mm), while C2 includes patients with reduced LV ejection fraction (<50%) and severe LV dilation (LV end-systolic diameter >50 mm).  

Stage D: In Stage D, patients have symptomatic severe AR, as confirmed by the presence of a severe AR jet on echocardiography. Symptoms may include exertional dyspnea, heart failure, or angina. LV ejection fraction can be either normal or abnormal in this stage. 

Medication

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References

Aortic regurgitation

Updated : May 16, 2024




Aortic regurgitation, also known as aortic insufficiency, is a heart valve disorder that occurs when the aortic valve in the heart does not close properly. The aortic valve is responsible for regulating the flow of oxygen-rich blood from the left ventricle of the heart into the aorta, which is the main artery that carries blood to the rest of the body.

When the aortic valve does not close tightly, some of the blood flows back into the left ventricle during each heartbeat rather than being efficiently pumped out to the body. The severity of aortic regurgitation can vary from mild to severe.
In its early stages, it may not produce noticeable symptoms. However, as the condition worsens, individuals may experience symptoms such as shortness of breath, fatigue, chest pain, palpitations, and, in severe cases, heart failure.

Aortic regurgitation is not uncommon but can vary in prevalence depending on the population studied. In industrialized countries, it is estimated to affect about 2–3% of the population. The prevalence may be higher in older age groups. Aortic regurgitation can occur at any age, but it tends to be more common in older adults.

The acquired form of the condition, often related to degenerative changes in the aortic valve, is more frequently seen in older individuals. Congenital aortic regurgitation, which is present from birth, can affect individuals of all ages. Aortic regurgitation can affect both men and women, but some studies suggest a slightly higher prevalence in men.

This gender difference is more pronounced in cases of degenerative aortic regurgitation. Aortic regurgitation often progresses slowly, and many individuals with mild to moderate regurgitation may not experience noticeable symptoms for a long time. As the condition worsens, it can lead to symptoms and complications, which may require treatment.

Aortic regurgitation results from the improper closure of the aortic valve, which separates the left ventricle of the heart from the aorta. This failure of the aortic valve to seal tightly allows a portion of the oxygen-rich blood to flow backward into the left ventricle with each heartbeat rather than being efficiently pumped into the systemic circulation.

Over time, this regurgitant flow can lead to several pathophysiological changes. The heart must work harder to maintain an adequate forward blood flow, causing the left ventricle to enlarge and hypertrophy as it compensates for the increased volume load. This chronic overload can lead to progressive weakening of the left ventricular muscle, eventually resulting in heart failure.

Additionally, the backward flow of blood can cause increased pressure in the pulmonary circulation, potentially leading to pulmonary congestion and symptoms such as shortness of breath. The severity and rate of progression of aortic regurgitation can vary, with symptoms becoming more pronounced as the condition advances, underscoring the importance of timely diagnosis and appropriate management to prevent complications and maintain heart function.

Acquired Causes

  • Aortic Dissection
  • Aortic Valve Degeneration
  • Hypertension
  • Infective Endocarditis
  • Rheumatic Heart Disease

Congenital Causes

  • Bicuspid Aortic Valve
  • Aortic Valve Malformations

The symptoms of chronic aortic regurgitation typically have a gradual onset, often spanning several decades. These symptoms encompass exertional dyspnea (breathlessness during physical activity), paroxysmal nocturnal dyspnea, orthopnea, angina pectoris, and a sensation of intense pulsations in the head.

Nocturnal angina occurs as a result of the heart rate slowing down during sleep, leading to a significant drop in arterial diastolic pressure, which can reach extremely low levels.

Austin flint murmur is characterized by a low-pitched, rumbling mid-diastolic murmur, most distinctly audible at the apex of the heart. This murmur is believed to result from the premature closure of the mitral valve, a consequence of the regurgitant blood jet from aortic regurgitation.

The Becker sign pertains to the observation of visible pulsations in the retinal arteries when examining the eye using an ophthalmoscope.

A Bisferiens pulse refers to a pulse pattern exhibiting two distinct peaks due to the backflow of blood during early diastole.

Corrigan sign manifests as a water-hammer pulse marked by sudden distention and rapid collapse of arterial pulses.

de Musset sign is characterized by a noticeable nodding or bobbing of the head in sync with the arterial pulsations.

Duroziez sign involves the detection of a systolic murmur when compressing the femoral artery proximally and a diastolic murmur when compressing it distally using a stethoscope.

Gerhardt sign is recognized when pulsations of the spleen are evident, typically associated with an enlarged spleen (splenomegaly).

Hill sign indicates that the blood pressure in the lower extremity is higher than in the upper extremity.

Mayne sign signifies a drop in diastolic blood pressure of more than 15 mmHg upon raising the arm.

Muller sign points to the presence of systolic pulsation in the uvula, the conical projection hanging at the back of the throat.

Quincke sign involves the observation of capillary pulsations, typically manifesting as alternating flushing and paling at the base of the nail when pressure is applied to the nail’s tip.

Rosenbach sign is noted when pulsations are discernible in the liver.

Traube sign is characterized by the presence of a distinctive “pistol-shot” systolic and diastolic sound heard over the femoral artery, often resembling the sound of a gunshot.

Pulmonic regurgitation

Infective Endocarditis

Hypertrophic Cardiomyopathy

Aortic Stenosis

The treatment paradigm for aortic regurgitation involves a multi-faceted approach tailored to the severity of the condition and the presence of symptoms. Asymptomatic patients with mild to moderate AR and normal cardiac size are primarily managed with regular clinical and echocardiographic follow-up.

In cases of chronic severe AR with normal left ventricular function and no symptoms, evaluations occur every six months. For patients with acute severe AR, emergency surgery is typically indicated, while medical management is reserved for temporary stabilization. This may include vasodilator therapy for those with systemic arterial hypertension associated with chronic AR.

Additionally, surgical intervention is recommended in cases of active infective endocarditis or the development of hemodynamic instability. The specific treatment approach is contingent on the stage of AR and individual patient factors, with the goal of preventing further complications and maintaining optimal cardiac function.

Acute Regurgitation 

In cases of acute severe aortic regurgitation, emergency surgical intervention is the primary and most appropriate course of action. Medical management plays a limited role and is mainly used to stabilize the patient temporarily. To reduce the afterload on the heart and enhance forward blood flow, intravenous diuretics and vasodilators, such as sodium nitroprusside, are employed.

Inotropic agents like dopamine or dobutamine may also be administered to bolster cardiac output. However, it is important to avoid the use of beta-blockers, as they tend to decrease cardiac output and slow the heart rate, which, in turn, allows more time for diastolic filling of the left ventricle. It is worth noting that intra-aortic balloon counter pulsation is not advisable. 

For patients with acute AR caused by active infective endocarditis, there might be a brief period where surgical intervention can be deferred, typically for 5 to 7 days, while the patient receives antibiotic therapy. However, it’s essential to closely monitor the patient’s condition during this period. If hemodynamic instability arises or if abscess formation is evident, surgical intervention must be promptly undertaken to address the urgent cardiovascular concerns. 

Chronic Regurgitation 

For individuals with mild or moderate aortic regurgitation who are asymptomatic and have normal cardiac size, a clinical and echocardiographic follow-up is recommended every 12 to 24 months. In contrast, patients with chronic severe AR and normal left ventricular function who do not display symptoms should undergo evaluations every 6 months. The use of medical treatment for AR is generally limited.

In cases where systemic arterial hypertension coexists with chronic AR, the recommended approach is to implement vasodilator therapy. Preferred options for this purpose include dihydropyridine calcium channel blockers or medications such as angiotensin-converting enzyme inhibitors. These treatments can help manage blood pressure and alleviate the burden on the heart associated with AR. 

Stage A: This stage involves patients who are at risk for AR. They do not exhibit hemodynamic issues or symptoms related to the condition.  

<b>Stage B: Stage B encompasses patients with progressive aortic regurgitation. These individuals have mild to moderate AR but maintain normal left ventricular systolic function and remain asymptomatic.  

Stage C:  Asymptomatic, severe AR characterizes Stage C. In this stage, AR jet width is equal to or greater than 65% of the left ventricular outflow tract (LVOT). Further subclassifications are made based on LV systolic function: C1 involves patients with normal LV ejection fraction and mild to moderate LV dilation (LV end-systolic diameter <50 mm), while C2 includes patients with reduced LV ejection fraction (<50%) and severe LV dilation (LV end-systolic diameter >50 mm).  

Stage D: In Stage D, patients have symptomatic severe AR, as confirmed by the presence of a severe AR jet on echocardiography. Symptoms may include exertional dyspnea, heart failure, or angina. LV ejection fraction can be either normal or abnormal in this stage.