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{{Aortic insufficiency}}
{{Aortic insufficiency}}
{{CMG}}; {{AE}} {{HP}}; {{CZ}}; [[Varun Kumar]], M.B.B.S.; [[Lakshmi Gopalakrishnan]], M.B.B.S.
{{CMG}}; {{AE}} {{HP}}; {{CZ}}; [[Varun Kumar]], M.B.B.S.; [[Lakshmi Gopalakrishnan]], M.B.B.S; {{USAMA}}  [[User:Mohammed Salih|Mohammed Salih, MD.]] [mailto:Mohammed.Salih@stjoeshealth.org]
==Overview==
Aortic insufficiency refers to the retrograde or backward flow of [[blood]] from the [[aorta]] into the [[left ventricle]] during [[diastole]]. When the pressure in the left ventricle falls below the pressure in the aorta, the aortic valve is not able to completely close. This causes a leaking of blood from the aorta into the left ventricle. The percentage of blood that regurgitates back through the aortic valve due to AI is known as the regurgitant fraction. The prevalence of aortic regurgitation varies with age, geographic location, and gender.  Aortic insufficiency is unusual before the age of 50 and then increases progressively later in life.  Aortic regurgitation is more commonly seen in men as compared to women. Worldwide the most common cause of aortic insufficiency is the [[rheumatic heart disease]], particularly in the Asia, the Middle East, and the North Africa. In the United States, [[senile]] degenerative [[calcific aortic valve disease]] and [[bicuspid aortic valve]] disease are the most common causes. The Framingham Heart Study, a prospective epidemiological study, evaluated the prevalence and severity of aortic regurgitation and other valvular diseases by color Doppler examinations in 1,696 men and 1,893 women. In acute aortic insufficiency symptoms of heart failure often develop acutely. Chronic aortic insufficiency is usually insidious and progressive and the patient may remain asymptomatic for years. Once left ventricular dilation and left ventricular failure occur, dyspnea on exertion and exercise intolerance begin to occur. Later symptoms such as angina, syncope, and other symptoms of heart failure are present. There are two main parameters that reflect the overall outcome in patients with aortic insufficiency: ejection fraction (the lower the ejection fraction, the poorer the outcome) and end systolic diameter. Left ventricular dysfunction develops in patients with aortic insufficiency after decades of the onset of the symptoms. This lag period is longer than that of mitral regurgitation. A detailed history and physical exam and diagnostic techniques like electrocardiogram, chest X-ray, echocardiography and a cardiac MRI can be used to diagnose aortic regurgitation. The symptoms of acute aortic regurgitation (AR) include dyspnea, chest pain (when aortic dissection is the cause of AR), weakness, and symptoms of congestive heart failure. Chronic AR may be without symptoms for several years until there is a decrease in the stroke volume and cardiac output due to heart failure progression. Symptoms of chronic aortic insufficiency include exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and palpitations. The [[echocardiogram]] is the single most useful diagnostic imaging study in the diagnosis and ongoing surveillance of the severity of aortic insufficiency. Echocardiography allows for serial assessment of left ventricular volumes which can be critical in determining the timing of [[aortic valve replacement]].  [[Echocardiography]] is used to assess the following parameters: end-diastolic diameter, end systolic diameter, and [[ejection fraction]]. Aortic valve replacement should be performed if the [[LVEF]] is ≤ 55% or if [[left ventricular]] end-systolic dimension is > 55mm. Pulsed Doppler echocardiography is more sensitive than auscultation specially in patients in whom no murmur is observed. Cardiac MRI may be used for assessing individuals with [[valvular heart disease]] in which evaluation of valvular stenosis, regurgitation, para- or perivalvular masses, perivalvular complications of infectious processes, or [[prosthetic valve]] disease are needed. CMR may be useful in identifying serial changes in [[LV]] volumes or mass in patients with valvular dysfunction. Aortic insufficiency can be treated either medically with [[vasodilators]] or surgically with [[aortic valve replacement]], depending upon the acuteness of presentation, the symptoms and signs associated with the disease process, and the degree of [[left ventricular dysfunction]]. [[Nitroprusside]] and ionotropes can be used to maintain [[blood pressure]].  Treatment options that are contraindicated include [[intra aortic balloon pump]], [[pressor]]s, and [[beta blockers]] (except in aortic dissection, where beta blockers can be used cautiously).


==Overview==
Aortic insufficiency refers to the retrograde or backward flow of [[blood]] from the [[aorta]] into the [[left ventricle]] during [[diastole]].<ref name="pmid9271479">{{cite journal |author=Connolly HM, Crary JL, McGoon MD, ''et al'' |title=Valvular heart disease associated with fenfluramine-phentermine |journal=N. Engl. J. Med. |volume=337 |issue=9 |pages=581–8 |year=1997 |pmid=9271479 |doi=10.1056/NEJM199708283370901|url=http://content.nejm.org/cgi/content/full/337/9/581}}</ref><ref name="pmid11307869">{{cite journal |author=Weissman NJ |title=Appetite suppressants and valvular heart disease |journal=Am. J. Med. Sci. |volume=321 |issue=4 |pages=285–91 |year=2001 |pmid=11307869|doi=10.1097/00000441-200104000-00008}}</ref><ref name="pmid17202453">{{cite journal |author=Schade R, Andersohn F, Suissa S, Haverkamp W, Garbe E |title=Dopamine agonists and the risk of cardiac-valve regurgitation |journal=N. Engl. J. Med. |volume=356 |issue=1 |pages=29–38 |year=2007 |pmid=17202453 |doi=10.1056/NEJMoa062222}}</ref><ref name="pmid17202454">{{cite journal |author=Zanettini R, Antonini A, Gatto G, Gentile R, Tesei S, Pezzoli G |title=Valvular heart disease and the use of dopamine agonists for Parkinson's disease |journal=N. Engl. J. Med. |volume=356 |issue=1 |pages=39–46 |year=2007 |pmid=17202454 |doi=10.1056/NEJMoa054830}}</ref>
==Pathophysiology==
==Pathophysiology==
In aortic insufficiency (AI), when the pressure in the [[left ventricle]] falls below the pressure in the [[aorta]], the [[aortic valve]] is not able to completely close. This causes a leaking of [[blood]] from the [[aorta]] into the [[left ventricle]]. This means that some of the [[blood]] that was already ejected from the [[heart]] is regurgitating back into the [[heart]]. The percentage of blood that regurgitates back through the [[aortic valve]] due to AI is known as the regurgitant fraction. For instance, if an individual with AI has a [[stroke volume]] of 100ml and during ventricular [[diastole]] 25ml regurgitates back through the [[aortic valve]], the regurgitant fraction is 25%. This regurgitant flow causes a decrease in the [[diastolic blood pressure]] in the [[aorta]], and therefore an increase in the [[pulse pressure]] (systolic pressure - diastolic pressure). Thus, physical examination will reveal a bounding [[pulse]], especially in the [[radial artery]].<ref name="pmid27106040">{{cite journal| author=Okafor I, Raghav V, Midha P, Kumar G, Yoganathan A| title=The hemodynamic effects of acute aortic regurgitation into a stiffened left ventricle resulting from chronic aortic stenosis. | journal=Am J Physiol Heart Circ Physiol | year= 2016 | volume= 310 | issue= 11 | pages= H1801-7 | pmid=27106040 | doi=10.1152/ajpheart.00161.2016 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27106040  }} </ref><ref name="pmid10051296">{{cite journal| author=Devlin WH, Petrusha J, Briesmiester K, Montgomery D, Starling MR| title=Impact of vascular adaptation to chronic aortic regurgitation on left ventricular performance. | journal=Circulation | year= 1999 | volume= 99 | issue= 8 | pages= 1027-33 | pmid=10051296 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10051296  }} </ref>
In aortic insufficiency (AI), when the pressure in the [[left ventricle]] falls below the pressure in the [[aorta]], the [[aortic valve]] is not able to completely close. This causes a leaking of [[blood]] from the [[aorta]] into the [[left ventricle]]. This means that some of the [[blood]] that was already ejected from the [[heart]] is regurgitating back into the [[heart]]. The percentage of blood that regurgitates back through the [[aortic valve]] due to AI is known as the regurgitant fraction. For instance, if an individual with AI has a [[stroke volume]] of 100ml and during ventricular [[diastole]] 25ml regurgitates back through the [[aortic valve]], the regurgitant fraction is 25%. This regurgitant flow causes a decrease in the [[diastolic blood pressure]] in the [[aorta]], and therefore an increase in the [[pulse pressure]] (systolic pressure - diastolic pressure). Thus, physical examination will reveal a bounding [[pulse]], especially in the [[radial artery]]. The percentage of blood that regurgitates back through the aortic valve due to AI is known as the regurgitant fraction. This regurgitant flow causes a decrease in the diastolic blood pressure in the aorta, and therefore a widening or increase in the pulse pressure (systolic pressure - diastolic pressure). As a result, the physical examination will often reveal a bounding pulse, especially in the radial artery. There is decreased effective forward flow in aortic insufficiency.


==Causes==
==Causes==
Aortic insufficiency can be an [[acute]] illness or a [[chronic]] illness and the causes differ depending upon the acuity of the disease. In general, aortic insufficiency is due to abnormalities of the [[aortic valve]] itself or the [[aortic root]]. Aortic regurgitation secondary to dilation of the [[ascending aorta]] has overtaken the valvular aortic disease as the most common cause of aortic regurgitation.It can also occur after surgical valve placement. <ref name="pmid27676407">{{cite journal| author=Phan K, Haswell JM, Xu J, Assem Y, Mick SL, Kapadia SR et al.| title=Percutaneous transcatheter interventions for aortic insufficiency in continuous-flow left ventricular assist device patients: A systematic review and meta-analysis. | journal=ASAIO J | year= 2016 | volume=  | issue=  | pages=  | pmid=27676407 | doi=10.1097/MAT.0000000000000447 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27676407  }} </ref><ref name="pmid15470217">{{cite journal| author=Enriquez-Sarano M, Tajik AJ| title=Clinical practice. Aortic regurgitation. | journal=N Engl J Med | year= 2004 | volume= 351 | issue= 15 | pages= 1539-46 | pmid=15470217 | doi=10.1056/NEJMcp030912 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15470217  }} </ref>
Aortic insufficiency can be an [[acute]] illness or a [[chronic]] illness and the causes differ depending upon the acuity of the disease. In general, aortic insufficiency is due to abnormalities of the [[aortic valve]] itself or the [[aortic root]]. Aortic regurgitation secondary to dilation of the [[ascending aorta]] has overtaken the valvular aortic disease as the most common cause of aortic regurgitation.It can also occur after surgical valve placement.  


==Epidemiology and Demographics==
==Epidemiology and Demographics==
The prevalence of aortic regurgitation varies with age, geographic location, and gender.<ref name="pmid10190406">{{cite journal |author=Singh JP, Evans JC, Levy D, Larson MG, Freed LA, Fuller DL, Lehman B, Benjamin EJ |title=Prevalence and clinical determinants of mitral, tricuspid, and aortic regurgitation (the Framingham Heart Study) |journal=[[The American Journal of Cardiology]] |volume=83 |issue=6 |pages=897–902 |year=1999 |month=March |pmid=10190406 |doi= |url=http://linkinghub.elsevier.com/retrieve/pii/S0002-9149(98)01064-9 |accessdate=2011-12-27}}</ref> Aortic insufficiency is unusual before the age of 50 and then increases progressively later in life.<ref name="pmid27547149">{{cite journal| author=Tomsic A, Li WW, van Paridon M, Bindraban NR, de Mol BA| title=Infective Endocarditis of the Aortic Valve with Anterior Mitral Valve Leaflet Aneurysm. | journal=Tex Heart Inst J | year= 2016 | volume= 43 | issue= 4 | pages= 345-9 | pmid=27547149 | doi=10.14503/THIJ-15-5322 | pmc=4979397 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27547149 }} </ref> Aortic regurgitation is more commonly seen in men as compared to women.<ref name="pmid9283535">{{cite journal| author=Klodas E, Enriquez-Sarano M, Tajik AJ, Mullany CJ, Bailey KR, Seward JB| title=Optimizing timing of surgical correction in patients with severe aortic regurgitation: role of symptoms. | journal=J Am Coll Cardiol | year= 1997 | volume= 30 | issue= 3 | pages= 746-52 | pmid=9283535 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9283535  }} </ref><ref name="pmid10199882">{{cite journal| author=Dujardin KS, Enriquez-Sarano M, Schaff HV, Bailey KR, Seward JB, Tajik AJ| title=Mortality and morbidity of aortic regurgitation in clinical practice. A long-term follow-up study. | journal=Circulation | year= 1999 | volume= 99 | issue= 14 | pages= 1851-7 | pmid=10199882 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10199882  }} </ref>Worldwide the most common cause of aortic insufficiency is the [[rheumatic heart disease]], particularly in the Asia, the Middle East, and the North Africa. In the United States, [[senile]] degenerative [[calcific aortic valve disease]] and [[bicuspid aortic valve]] disease are the most common causes.<ref name="pmid15470217">{{cite journal| author=Enriquez-Sarano M, Tajik AJ| title=Clinical practice. Aortic regurgitation. | journal=N Engl J Med | year= 2004 | volume= 351 | issue= 15 | pages= 1539-46 | pmid=15470217 | doi=10.1056/NEJMcp030912 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15470217  }} </ref>
The prevalence of aortic regurgitation varies with age, geographic location, and gender. Aortic insufficiency is unusual before the age of 50 and then increases progressively later in life.  Aortic regurgitation is more commonly seen in men as compared to women. Worldwide the most common cause of aortic insufficiency is the [[rheumatic heart disease]], particularly in the Asia, the Middle East, and the North Africa. In the United States, [[senile]] degenerative [[calcific aortic valve disease]] and [[bicuspid aortic valve]] disease are the most common causes. .The Framingham Heart Study, a prospective epidemiological study, evaluated the prevalence and severity of aortic regurgitation and other valvular diseases by color Doppler examinations in 1,696 men and 1,893 women.The study revealed that the prevalence of aortic regurgitation (ranging in severity from trace to ≥ moderate regurgitation) is 13.0% in men and 8.5% in women. The prevalence of aortic regurgitation increases with age. It is infrequent in young patients, and occurs in < 1% of subjects under the age of 70. However people with congenital aortic valve/root defects such as bicuspid aortic valve disease and Marfan syndrome may develop aortic regurgitation much earlier in life.


==Risk Factors==
==Risk Factors==
In the past, the most common risk factor for aortic valvular disease had been the [[rheumatic fever]], with subsequent [[fibrosis]] of the scarred valve then leading to retraction of the [[aortic valve cusps]] and prevention of their apposition during [[diastole]]. In the modern era, a more common risk factor for acquired aortic regurgitation is [[degenerative]] disease of the [[aorta]] and [[aortic valve]] in which case there is [[calcification]] and [[fibrosis]] of the cusps. [[Infective endocarditis]] remains an important risk factor and cause of aortic insufficiency. [[Congenital]] conditions such as congenital [[bicuspid aortic valve]] or a [[ventricular septal defect]] can also result in aortic insufficiency. Patients with [[bicuspid aortic valve]] are at increased risk of developing [[aortic dissection]].<ref name="pmid27106040">{{cite journal| author=Okafor I, Raghav V, Midha P, Kumar G, Yoganathan A| title=The hemodynamic effects of acute aortic regurgitation into a stiffened left ventricle resulting from chronic aortic stenosis. | journal=Am J Physiol Heart Circ Physiol | year= 2016 | volume= 310 | issue= 11 | pages= H1801-7 | pmid=27106040 | doi=10.1152/ajpheart.00161.2016 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27106040  }} </ref><ref name="pmid12186790">{{cite journal |author=Fedak PW, Verma S, David TE, Leask RL, Weisel RD, Butany J |title=Clinical and pathophysiological implications of a bicuspid aortic valve |journal=[[Circulation]] |volume=106 |issue=8 |pages=900–4 |year=2002 |month=August |pmid=12186790 |doi= |url=http://circ.ahajournals.org/cgi/pmidlookup?view=long&pmid=12186790 |accessdate=2011-03-28}}</ref>
In the past, the most common risk factor for aortic valvular disease had been the [[rheumatic fever]], with subsequent [[fibrosis]] of the scarred valve then leading to retraction of the [[aortic valve cusps]] and prevention of their apposition during [[diastole]]. In the modern era, a more common risk factor for acquired aortic regurgitation is [[degenerative]] disease of the [[aorta]] and [[aortic valve]] in which case there is [[calcification]] and [[fibrosis]] of the cusps. [[Infective endocarditis]] remains an important risk factor and cause of aortic insufficiency. [[Congenital]] conditions such as congenital [[bicuspid aortic valve]] or a [[ventricular septal defect]] can also result in aortic insufficiency. Patients with [[bicuspid aortic valve]] are at increased risk of developing [[aortic dissection]].


==Natural History, Complications and Prognosis==
==Natural History, Complications and Prognosis==
In acute aortic insufficiency symptoms of [[heart failure]] often develop acutely. Chronic aortic insufficiency is usually insidious and progressive and the patient may remain asymptomatic for years. Once left ventricular dilation and left ventricular failure occur, [[dyspnea on exertion]] and [[exercise intolerance]] begin to occur. Later symptoms such as [[angina]], [[syncope]], and other symptoms of [[heart failure]] are present.  There are two main parameters that reflect the overall outcome in patients with aortic insufficiency: [[ejection fraction]] (the lower the [[ejection fraction]], the poorer the outcome) and end systolic diameter.  [[Left ventricular dysfunction]] develops in patients with aortic insufficiency after decades of the onset of the symptoms. This lag period is longer than that of [[mitral regurgitation]].<ref name="pmid27676407">{{cite journal| author=Phan K, Haswell JM, Xu J, Assem Y, Mick SL, Kapadia SR et al.| title=Percutaneous transcatheter interventions for aortic insufficiency in continuous-flow left ventricular assist device patients: A systematic review and meta-analysis. | journal=ASAIO J | year= 2016 | volume=  | issue=  | pages=  | pmid=27676407 | doi=10.1097/MAT.0000000000000447 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27676407  }} </ref>
In acute aortic insufficiency symptoms of [[heart failure]] often develop acutely. Chronic aortic insufficiency is usually insidious and progressive and the patient may remain asymptomatic for years. Once left ventricular dilation and left ventricular failure occur, [[dyspnea on exertion]] and [[exercise intolerance]] begin to occur. Later symptoms such as [[angina]], [[syncope]], and other symptoms of [[heart failure]] are present.  There are two main parameters that reflect the overall outcome in patients with aortic insufficiency: [[ejection fraction]] (the lower the [[ejection fraction]], the poorer the outcome) and end systolic diameter.  [[Left ventricular dysfunction]] develops in patients with aortic insufficiency after decades of the onset of the symptoms. This lag period is longer than that of [[mitral regurgitation]]. A detailed history and physical exam and diagnostic techniques like electrocardiogram, chest X-ray, echocardiography and a cardiac MRI can be used to diagnose aortic regurgitation.The prognosis and survival of patients with symptomatic aortic regurgitation has improved significantly over the last decade. The five year survival rate for symptomatic patients is now more than 80 percent. The prognosis among patients with aortic insufficiency is poor with a high mortality and morbidity due to the acute onset of left ventricular failure, pulmonary edema, or myocardial ischemia due to the abrupt rise in LV wall stress and sudden cardiac death. Early surgical intervention improves the prognosis in these patients.


==Diagnosis==
==Diagnosis==
===History and Symptoms===
===History and Symptoms===
The symptoms of acute aortic regurgitation (AR) include [[dyspnea]], [[chest pain]] (when [[aortic dissection]] is the cause of AR), [[weakness]], and symptoms of [[congestive heart failure]]. Chronic AR may be without symptoms for several years until there is a decrease in the [[stroke volume]] and [[cardiac output]] due to [[heart failure]] progression.  Symptoms of chronic aortic insufficiency include [[exertional dyspnea]], [[orthopnea]], [[paroxysmal nocturnal dyspnea]], and [[palpitations]].<ref name="pmid24603191">{{cite journal| author=Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA et al.| title=2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. | journal=J Am Coll Cardiol | year= 2014 | volume= 63 | issue= 22 | pages= e57-185 | pmid=24603191 | doi=10.1016/j.jacc.2014.02.536 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24603191  }} </ref>
The symptoms of acute aortic regurgitation (AR) include [[dyspnea]], [[chest pain]] (when [[aortic dissection]] is the cause of AR), [[weakness]], and symptoms of [[congestive heart failure]]. Chronic AR may be without symptoms for several years until there is a decrease in the [[stroke volume]] and [[cardiac output]] due to [[heart failure]] progression.  Symptoms of chronic aortic insufficiency include [[exertional dyspnea]], [[orthopnea]], [[paroxysmal nocturnal dyspnea]], and [[palpitations]].


===Physical Examination===
===Physical Examination===
A patient with suspected aortic insufficiency may have an early [[diastolic heart murmur]] which is usually a high-pitched sound best heard at the left sternal border. An [[Systolic murmur|ejection systolic 'flow' murmur]] may also be present. The [[apex beat]] is typically displaced down and to the left. A patient with chronic aortic insufficiency may present with signs of [[congestive heart failure]].  Other significant findings on physical exam include:<ref name="pmid9870202">{{cite journal| author=Bonow RO, Carabello B, de Leon AC, Edmunds LH, Fedderly BJ, Freed MD et al.| title=ACC/AHA Guidelines for the Management of Patients With Valvular Heart Disease. Executive Summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease). | journal=J Heart Valve Dis | year= 1998 | volume= 7 | issue= 6 | pages= 672-707 | pmid=9870202 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9870202  }} </ref>
A patient with suspected aortic insufficiency may have an early [[diastolic heart murmur]] which is usually a high-pitched sound best heard at the left sternal border. An [[Systolic murmur|ejection systolic 'flow' murmur]] may also be present. The [[apex beat]] is typically displaced down and to the left. A patient with chronic aortic insufficiency may present with signs of [[congestive heart failure]].  Other significant findings on physical exam include:
 
* Bounding [[pulse]]s may be present.
* Bounding [[pulse]]s may be present.
* [[Head]] nodding ([[de Musset's sign]]) - rhythmic nodding or bobbing of the head in synchrony with the beating of the heart.
* [[Head]] nodding ([[de Musset's sign]]) - rhythmic nodding or bobbing of the head in synchrony with the beating of the heart.
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===Cardiac Stress Test===
===Cardiac Stress Test===
A [[exercise stress test|cardiac stress test (CST)]] is an evaluation modality used in cardiology in which the ability of the [[heart]] to respond to stress, either actually induced by exercise or stimulated by pharmacologic agents, is measured in a controlled clinical setting. CST for chronic aortic insufficiency is reasonable for assessment of functional capacity and symptomatic response in patients with a history of equivocal symptoms.<ref name="pmid9870202">{{cite journal| author=Bonow RO, Carabello B, de Leon AC, Edmunds LH, Fedderly BJ, Freed MD et al.| title=ACC/AHA Guidelines for the Management of Patients With Valvular Heart Disease. Executive Summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease). | journal=J Heart Valve Dis | year= 1998 | volume= 7 | issue= 6 | pages= 672-707 | pmid=9870202 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9870202  }} </ref>
A [[exercise stress test|cardiac stress test (CST)]] is an evaluation modality used in cardiology in which the ability of the [[heart]] to respond to stress, either actually induced by exercise or stimulated by pharmacologic agents, is measured in a controlled clinical setting. CST for chronic aortic insufficiency is reasonable for assessment of functional capacity and symptomatic response in patients with a history of equivocal symptoms.


===Electrocardiogram===
===Electrocardiogram===
Electrocardiographic abnormalities in the patient with aortic insufficiency include [[left ventricular hypertrophy]] and [[left axis deviation]].<ref name="pmid9870202">{{cite journal| author=Bonow RO, Carabello B, de Leon AC, Edmunds LH, Fedderly BJ, Freed MD et al.| title=ACC/AHA Guidelines for the Management of Patients With Valvular Heart Disease. Executive Summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease). | journal=J Heart Valve Dis | year= 1998 | volume= 7 | issue= 6 | pages= 672-707 | pmid=9870202 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9870202  }} </ref>
The echocardiogram is the single most useful diagnostic imaging study in the diagnosis and ongoing surveillance of the severity of aortic insufficiency. Echocardiography allows for serial assessment of left ventricular volumes which can be critical in determining the timing of aortic valve replacement. Aortic valve replacement should be performed if the LVEF is ≤ 55% or if left ventricular end-systolic dimension is > 55mm.


===Chest X Ray===
===Chest X Ray===
[[Chest x ray]] findings associated with aortic insufficiency may include [[left ventricular enlargement]], [[cardiomegaly]], prominent [[aortic root]] with valvular [[calcification]], [[prosthetic valve]] dis-lodgement, or aortic dilation. If aortic insufficiency is severe, signs of [[pulmonary edema]] may also be present.
[[Chest x ray]] findings associated with aortic insufficiency may include [[left ventricular enlargement]], [[cardiomegaly]], prominent [[aortic root]] with valvular [[calcification]], [[prosthetic valve]] dis-lodgement, or aortic dilation. If aortic insufficiency is severe, signs of [[pulmonary edema]] may also be present.
===Echocardiography===
===Echocardiography===
The [[echocardiogram]] is the single most useful diagnostic imaging study in the diagnosis and ongoing surveillance of the severity of aortic insufficiency. Echocardiography allows for serial assessment of left ventricular volumes which can be critical in determining the timing of [[aortic valve replacement]].  [[Echocardiography]] is used to assess the following parameters: end-diastolic diameter, end systolic diameter, and [[ejection fraction]].<ref name="pmid27373822">{{cite journal| author=Grinstein J, Kruse E, Sayer G, Fedson S, Kim GH, Sarswat N et al.| title=Novel echocardiographic parameters of aortic insufficiency in continuous-flow left ventricular assist devices and clinical outcome. | journal=J Heart Lung Transplant | year= 2016 | volume= 35 | issue= 8 | pages= 976-85 | pmid=27373822 | doi=10.1016/j.healun.2016.05.009 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27373822  }} </ref>Aortic valve replacement should be performed if the [[LVEF]] is ≤ 55% or if [[left ventricular]] end-systolic dimension is > 55mm.
The [[echocardiogram]] is the single most useful diagnostic imaging study in the diagnosis and ongoing surveillance of the severity of aortic insufficiency. Echocardiography allows for serial assessment of left ventricular volumes which can be critical in determining the timing of [[aortic valve replacement]].  [[Echocardiography]] is used to assess the following parameters: end-diastolic diameter, end systolic diameter, and [[ejection fraction]]. Aortic valve replacement should be performed if the [[LVEF]] is ≤ 55% or if [[left ventricular]] end-systolic dimension is > 55mm. Pulsed Doppler echocardiography is more sensitive than auscultation specially in patients in whom no murmur is observed.


===Cardiac MRI===
===Cardiac MRI===
Cardiac MRI may be used for assessing individuals with [[valvular heart disease]] in which evaluation of valvular stenosis, regurgitation, para- or perivalvular masses, perivalvular complications of infectious processes, or [[prosthetic valve]] disease are needed. CMR may be useful in identifying serial changes in [[LV]] volumes or mass in patients with valvular dysfunction. For patients with suboptimal [[echocardiogram]]s showing aortic regurgitation, [[radionuclide angiography]] or [[magnetic resonance imaging]] is indicated to assess [[left ventricular]] volume and function at rest. CMR can also be used to determine the severity of [[AR]] in patients with suboptimal [[echocardiogram]]s.<ref name="pmid24603191">{{cite journal| author=Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA et al.| title=2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. | journal=J Am Coll Cardiol | year= 2014 | volume= 63 | issue= 22 | pages= e57-185 | pmid=24603191 | doi=10.1016/j.jacc.2014.02.536 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24603191  }} </ref><ref name="pmid21784393">{{cite journal| author=Gabriel RS, Renapurkar R, Bolen MA, Verhaert D, Leiber M, Flamm SD et al.| title=Comparison of severity of aortic regurgitation by cardiovascular magnetic resonance versus transthoracic echocardiography. | journal=Am J Cardiol | year= 2011 | volume= 108 | issue= 7 | pages= 1014-20 | pmid=21784393 | doi=10.1016/j.amjcard.2011.05.034 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21784393  }} </ref><ref name="pmid19652976">{{cite journal| author=Goffinet C, Kersten V, Pouleur AC, le Polain de Waroux JB, Vancraeynest D, Pasquet A et al.| title=Comprehensive assessment of the severity and mechanism of aortic regurgitation using multidetector CT and MR. | journal=Eur Radiol | year= 2010 | volume= 20 | issue= 2 | pages= 326-36 | pmid=19652976 | doi=10.1007/s00330-009-1544-x | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19652976  }} </ref><ref name="pmid17686805">{{cite journal| author=Debl K, Djavidani B, Buchner S, Heinicke N, Fredersdorf S, Haimerl J et al.| title=Assessment of the anatomic regurgitant orifice in aortic regurgitation: a clinical magnetic resonance imaging study. | journal=Heart | year= 2008 | volume= 94 | issue= 3 | pages= e8 | pmid=17686805 | doi=10.1136/hrt.2006.108720 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17686805  }} </ref>
Cardiac MRI may be used for assessing individuals with [[valvular heart disease]] in which evaluation of valvular stenosis, regurgitation, para- or perivalvular masses, perivalvular complications of infectious processes, or [[prosthetic valve]] disease are needed. CMR may be useful in identifying serial changes in [[LV]] volumes or mass in patients with valvular dysfunction. For patients with suboptimal [[echocardiogram]]s showing aortic regurgitation, [[radionuclide angiography]] or [[magnetic resonance imaging]] is indicated to assess [[left ventricular]] volume and function at rest. CMR can also be used to determine the severity of [[AR]] in patients with suboptimal [[echocardiogram]]s.


===Cardiac Catheterization===
===Cardiac Catheterization===
Although [[echocardiography]] is now the primary imaging modality used to evaluate aortic insufficiency, [[cardiac catheterization]] is often performed in patients with aortic insufficiency primarily to assess for the presence of epicardial [[coronary artery]] disease prior to surgical [[aortic valve replacement]].<ref name="pmid24603191">{{cite journal| author=Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA et al.| title=2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. | journal=J Am Coll Cardiol | year= 2014 | volume= 63 | issue= 22 | pages= e57-185 | pmid=24603191 | doi=10.1016/j.jacc.2014.02.536 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24603191  }} </ref>[[Aortography]] can also be performed to assess the severity of aortic insufficiency. The presence or absence of an [[aortic dissection]] can be evaluated. [[Left ventricular]] function (hemodynamics), size, and systolic function ([[ejection fraction]]) can also be evaluated.<ref name="pmid9870202">{{cite journal| author=Bonow RO, Carabello B, de Leon AC, Edmunds LH, Fedderly BJ, Freed MD et al.| title=ACC/AHA Guidelines for the Management of Patients With Valvular Heart Disease. Executive Summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease). | journal=J Heart Valve Dis | year= 1998 | volume= 7 | issue= 6 | pages= 672-707 | pmid=9870202 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9870202  }} </ref>
Although [[echocardiography]] is now the primary imaging modality used to evaluate aortic insufficiency, [[cardiac catheterization]] is often performed in patients with aortic insufficiency primarily to assess for the presence of epicardial [[coronary artery]] disease prior to surgical [[aortic valve replacement]]. [[Aortography]] can also be performed to assess the severity of aortic insufficiency. The presence or absence of an [[aortic dissection]] can be evaluated. [[Left ventricular]] function (hemodynamics), size, and systolic function ([[ejection fraction]]) can also be evaluated.


==Treatment==
==Treatment==
Aortic insufficiency can be treated either medically with [[vasodilators]] or surgically with [[aortic valve replacement]], depending upon the acuteness of presentation, the symptoms and signs associated with the disease process, and the degree of [[left ventricular dysfunction]]. [[Nitroprusside]] and ionotropes can be used to maintain [[blood pressure]].  Treatment options that are contraindicated include [[intra aortic balloon pump]], [[pressor]]s, and [[beta blockers]] (except in aortic dissection, where beta blockers can be used cautiously).<ref name="pmid9870202">{{cite journal| author=Bonow RO, Carabello B, de Leon AC, Edmunds LH, Fedderly BJ, Freed MD et al.| title=ACC/AHA Guidelines for the Management of Patients With Valvular Heart Disease. Executive Summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease). | journal=J Heart Valve Dis | year= 1998 | volume= 7 | issue= 6 | pages= 672-707 | pmid=9870202 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9870202  }} </ref>
Aortic insufficiency can be treated either medically with [[vasodilators]] or surgically with [[aortic valve replacement]], depending upon the acuteness of presentation, the symptoms and signs associated with the disease process, and the degree of [[left ventricular dysfunction]]. [[Nitroprusside]] and ionotropes can be used to maintain [[blood pressure]].  Treatment options that are contraindicated include [[intra aortic balloon pump]], [[pressor]]s, and [[beta blockers]] (except in aortic dissection, where beta blockers can be used cautiously).


===Acute Aortic Insufficiency===
===Acute Aortic Insufficiency===
Patients with acute severe aortic insufficiency are usually managed with emergency [[aortic valve replacement]] or repair. However, they can be stabilized medically before surgery with [[vasodilators]].
Patients with acute severe aortic regurgitation (AR) are managed with emergency aortic valve replacement or repair. Medical therapy is used for the stabilization of patients prior to surgery.
 
===Chronic Aortic Insufficiency===
===Chronic Aortic Insufficiency===
In the management of chronic aortic insufficiency, the [[left ventricular]] size and function should be monitored closely along with the exercise tolerance of the patient. If the patient develops [[heart failure]] symptoms and the disease starts to be symptomatic, then [[aortic valve replacement]] or valve repair is indicated. Annual echocardiographic studies are indicated in all patients with significant aortic insufficiency. [[Vasodilator]]s such as [[ACE inhibitor]]s, [[nifedipine]], [[sodium nitroprusside]], and [[hydralazine]] may slow the rate of progression of aortic insufficiency. The greatest benefit of medical therapy is in symptomatic patients and for those with [[heart failure]] symptoms due to advanced disease, but in general, they have a limited role in aortic insufficiency because symptomatic cases should be treated with valve replacement if the patient is a good candidate for surgery. [[Warfarin]] and long-term [[anticoagulation]] is not recommended in aortic insufficiency if there are no other indications for [[anticoagulation]].<ref>Salem DN, O'Gara PT, Madias C, et al. Valvular and structural heart disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008; 133:593S</ref>
In the management of chronic aortic regurgitation, the left ventricular size and function should be monitored closely along with the exercise tolerance of the patient. If the patient develops heart failure symptoms and the disease starts to be symptomatic, then aortic valve replacement or valve repair is indicated. Annual echocardiographic studies are indicated in all patients with significant AR. Vasodilators such as ACE inhibitors, nifedipine, sodium nitroprusside, and hydralazine may slow the rate of progression of AR. The greatest benefit of medical therapy is among symptomatic patients and those with heart failure symptoms due to advanced disease, but in general, medical therapy has a limited role in AR because symptomatic cases should be treated with valve replacement if the patient is a good candidate for surgery. Warfarin and long-term anticoagulation is not recommended in AR if there are no other indications for anticoagulation.
 
===Surgery===
Severe acute AR requires emergency surgery if there are no absolute contraindications to surgery. The surgery should be performed as early as possible without a delay, particularly if hypotension, decreased perfusion, or pulmonary edema are present. In chronic AR, aortic valve replacement (AVR) is indicated in patients with severe AR who are either symptomatic regardless of LV systolic function, or those who are asymptomatic and have left ventricular ejection fraction <55%, or in patients with stage C or D AR who are undergoing cardiac surgery for other indications.
==Prevention==
===Primary prevention===
Limiting the factors that lead to the development of Aortic regurgitation will decrease its incidence. Optimal blood pressure control, especially in elderly population is of utmost importance. cessation of smoking and opting for a healthy life style that includes balanced diet and regular exercise. Prevention of the initial development of acute rheumatic fever by prompt diagnosis and antibiotic treatment of group A streptococcal (GAS) infection predominantly due to tonsillopharyngitis. In tropical countries, a link between GAS pyoderma and subsequent ARF/RHD is highly likely.
 
===Secondary prevention===
 
Aortic reguritation is associated with a higher rate of infection of the valve, that is infective endocarditis.To reduce the risk of developing infective endocarditis among high-risk patients, antibiotic prophylaxis should be considered prior to certain dental/medical/surgical procedures. Such procedures may include dental extraction, deep scaling of the teeth, gum surgery, dental implants, treatment of esophageal varices, dilation of esophageal strictures, gastrointestinal surgery where the intestinal mucosa will be disrupted, prostate surgery, urethral stricture dilation, and cystoscopy. Secondary prevention of recurrent ARF with continuous antibiotic prophylaxis is recommended for patients with definite history of ARF or diagnosis of definite RHD. Continuous antimicrobial prophylaxis is recommended because recurrent ARF can be triggered by GAS infection even if asymptomatic. Patients should be registered in regional ARF prevention programs, where available.


==Special Scenarios==
==Special Scenarios==
===Elderly patients===
The incidence of aortic regurgitation in the elderly is low in comparison to the incidence of aortic stenosis and mitral regurgitation. The majority of elderly patients have combined aortic stenosis and aortic insufficiency and the incidence of pure aortic insufficiency is rare.
===Pregnancy===
===Pregnancy===
Isolated aortic insufficiency in pregnant patients can be managed with combination of [[diuretics]] and [[vasodilators]].<ref name="pmid8547563">{{cite journal |author=Sheikh F, Rangwala S, DeSimone C, Smith HS, O'Leary AM |title=Management of the parturient with severe aortic incompetence |journal=[[Journal of Cardiothoracic and Vascular Anesthesia]] |volume=9 |issue=5 |pages=575–7 |year=1995 |month=October |pmid=8547563 |doi= |url=http://linkinghub.elsevier.com/retrieve/pii/S1053-0770(05)80145-4 |accessdate=2011-03-25}}</ref> [[ACE inhibitors]] are contraindicated in [[pregnancy]]. Patients with signs and symptoms of left ventricular failure should be monitored throughout labor and delivery with strict attention to volume status and [[blood pressure]].
Isolated aortic insufficiency in pregnant patients can be managed with combination of [[diuretics]] and [[vasodilators]]. [[ACE inhibitors]] are contraindicated in [[pregnancy]]. Patients with signs and symptoms of left ventricular failure should be monitored throughout labor and delivery with strict attention to volume status and [[blood pressure]].
===Young Adults===
===Young Adults===
Congenital [[aortic insufficiency]] rarely occurs alone and is often associated with [[aortic stenosis]] or [[ventricular septal defect]]. It may occasionally be observed in adolescents and young adults with a [[bicuspid aortic valve]], discrete subaortic obstruction, or prolapse of one of the aortic cusp into a [[ventricular septal defect]]. [[Turner syndrome]], [[osteogenesis imperfecta]], [[tetralogy of Fallot]], and [[truncus arteriosus]] are other congenital disorders that are associated with aortic insufficiency in young patients. [[Rheumatic heart disease]] is one of the important causes for acquired aortic insufficiency in young patients in developing countries. It can also occur following an episode of [[infective endocarditis]] or as a consequence of attempts to relieve [[aortic stenosis]] by either balloon [[valvuloplasty]] or surgical valvulotomy, or when the [[pulmonary artery]] is relocated in the aortic position during repair of [[transposition of great vessels]].<ref name="pmid9870202">{{cite journal| author=Bonow RO, Carabello B, de Leon AC, Edmunds LH, Fedderly BJ, Freed MD et al.| title=ACC/AHA Guidelines for the Management of Patients With Valvular Heart Disease. Executive Summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease). | journal=J Heart Valve Dis | year= 1998 | volume= 7 | issue= 6 | pages= 672-707 | pmid=9870202 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9870202  }} </ref>
Congenital [[aortic insufficiency]] rarely occurs alone and is often associated with [[aortic stenosis]] or [[ventricular septal defect]]. It may occasionally be observed in adolescents and young adults with a [[bicuspid aortic valve]], discrete subaortic obstruction, or prolapse of one of the aortic cusp into a [[ventricular septal defect]]. [[Turner syndrome]], [[osteogenesis imperfecta]], [[tetralogy of Fallot]], and [[truncus arteriosus]] are other congenital disorders that are associated with aortic insufficiency in young patients. [[Rheumatic heart disease]] is one of the important causes for acquired aortic insufficiency in young patients in developing countries. It can also occur following an episode of [[infective endocarditis]] or as a consequence of attempts to relieve [[aortic stenosis]] by either balloon [[valvuloplasty]] or surgical valvulotomy, or when the [[pulmonary artery]] is relocated in the aortic position during repair of [[transposition of great vessels]].


===End-stage Renal Disease===
===End-stage Renal Disease===
[[Aortic insufficiency]] in patients with [[ESRD|end stage renal disease]] can be due to either [[Aortic insufficiency in renal disease#Valvular calcification|valvular calcification]] or [[Aortic insufficiency in renal disease#Infective Endocarditis|infective endocarditis]].
[[Aortic insufficiency]] in patients with [[ESRD|end stage renal disease]] can be due to either [[Aortic insufficiency in renal disease#Valvular calcification|valvular calcification]] or [[Aortic insufficiency in renal disease#Infective Endocarditis|infective endocarditis]]. Valvular/annular thickening, and calcification of heart valves occur commonly in patients undergoing dialysis, thereby leading to valvular regurgitation and/or stenosis. Hyperparathyroidism occurring secondary to renal disease is one of the most significant predisposing factor for valular calcification. Aortic insufficiency is seen less commonly than mitral or tricuspid insufficiency. In a study on 75 patients with end stage renal disease (ESRD) undergoing hemodialysis, 38% of patients were found to have developed aortic insufficiency.


==References==
==References==

Latest revision as of 02:58, 27 June 2020



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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Hardik Patel, M.D.; Cafer Zorkun, M.D., Ph.D. [2]; Varun Kumar, M.B.B.S.; Lakshmi Gopalakrishnan, M.B.B.S; Usama Talib, BSc, MD [3] Mohammed Salih, MD. [4]

Overview

Aortic insufficiency refers to the retrograde or backward flow of blood from the aorta into the left ventricle during diastole. When the pressure in the left ventricle falls below the pressure in the aorta, the aortic valve is not able to completely close. This causes a leaking of blood from the aorta into the left ventricle. The percentage of blood that regurgitates back through the aortic valve due to AI is known as the regurgitant fraction. The prevalence of aortic regurgitation varies with age, geographic location, and gender. Aortic insufficiency is unusual before the age of 50 and then increases progressively later in life. Aortic regurgitation is more commonly seen in men as compared to women. Worldwide the most common cause of aortic insufficiency is the rheumatic heart disease, particularly in the Asia, the Middle East, and the North Africa. In the United States, senile degenerative calcific aortic valve disease and bicuspid aortic valve disease are the most common causes. The Framingham Heart Study, a prospective epidemiological study, evaluated the prevalence and severity of aortic regurgitation and other valvular diseases by color Doppler examinations in 1,696 men and 1,893 women. In acute aortic insufficiency symptoms of heart failure often develop acutely. Chronic aortic insufficiency is usually insidious and progressive and the patient may remain asymptomatic for years. Once left ventricular dilation and left ventricular failure occur, dyspnea on exertion and exercise intolerance begin to occur. Later symptoms such as angina, syncope, and other symptoms of heart failure are present. There are two main parameters that reflect the overall outcome in patients with aortic insufficiency: ejection fraction (the lower the ejection fraction, the poorer the outcome) and end systolic diameter. Left ventricular dysfunction develops in patients with aortic insufficiency after decades of the onset of the symptoms. This lag period is longer than that of mitral regurgitation. A detailed history and physical exam and diagnostic techniques like electrocardiogram, chest X-ray, echocardiography and a cardiac MRI can be used to diagnose aortic regurgitation. The symptoms of acute aortic regurgitation (AR) include dyspnea, chest pain (when aortic dissection is the cause of AR), weakness, and symptoms of congestive heart failure. Chronic AR may be without symptoms for several years until there is a decrease in the stroke volume and cardiac output due to heart failure progression. Symptoms of chronic aortic insufficiency include exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and palpitations. The echocardiogram is the single most useful diagnostic imaging study in the diagnosis and ongoing surveillance of the severity of aortic insufficiency. Echocardiography allows for serial assessment of left ventricular volumes which can be critical in determining the timing of aortic valve replacement. Echocardiography is used to assess the following parameters: end-diastolic diameter, end systolic diameter, and ejection fraction. Aortic valve replacement should be performed if the LVEF is ≤ 55% or if left ventricular end-systolic dimension is > 55mm. Pulsed Doppler echocardiography is more sensitive than auscultation specially in patients in whom no murmur is observed. Cardiac MRI may be used for assessing individuals with valvular heart disease in which evaluation of valvular stenosis, regurgitation, para- or perivalvular masses, perivalvular complications of infectious processes, or prosthetic valve disease are needed. CMR may be useful in identifying serial changes in LV volumes or mass in patients with valvular dysfunction. Aortic insufficiency can be treated either medically with vasodilators or surgically with aortic valve replacement, depending upon the acuteness of presentation, the symptoms and signs associated with the disease process, and the degree of left ventricular dysfunction. Nitroprusside and ionotropes can be used to maintain blood pressure. Treatment options that are contraindicated include intra aortic balloon pump, pressors, and beta blockers (except in aortic dissection, where beta blockers can be used cautiously).

Pathophysiology

In aortic insufficiency (AI), when the pressure in the left ventricle falls below the pressure in the aorta, the aortic valve is not able to completely close. This causes a leaking of blood from the aorta into the left ventricle. This means that some of the blood that was already ejected from the heart is regurgitating back into the heart. The percentage of blood that regurgitates back through the aortic valve due to AI is known as the regurgitant fraction. For instance, if an individual with AI has a stroke volume of 100ml and during ventricular diastole 25ml regurgitates back through the aortic valve, the regurgitant fraction is 25%. This regurgitant flow causes a decrease in the diastolic blood pressure in the aorta, and therefore an increase in the pulse pressure (systolic pressure - diastolic pressure). Thus, physical examination will reveal a bounding pulse, especially in the radial artery. The percentage of blood that regurgitates back through the aortic valve due to AI is known as the regurgitant fraction. This regurgitant flow causes a decrease in the diastolic blood pressure in the aorta, and therefore a widening or increase in the pulse pressure (systolic pressure - diastolic pressure). As a result, the physical examination will often reveal a bounding pulse, especially in the radial artery. There is decreased effective forward flow in aortic insufficiency.

Causes

Aortic insufficiency can be an acute illness or a chronic illness and the causes differ depending upon the acuity of the disease. In general, aortic insufficiency is due to abnormalities of the aortic valve itself or the aortic root. Aortic regurgitation secondary to dilation of the ascending aorta has overtaken the valvular aortic disease as the most common cause of aortic regurgitation.It can also occur after surgical valve placement.

Epidemiology and Demographics

The prevalence of aortic regurgitation varies with age, geographic location, and gender. Aortic insufficiency is unusual before the age of 50 and then increases progressively later in life. Aortic regurgitation is more commonly seen in men as compared to women. Worldwide the most common cause of aortic insufficiency is the rheumatic heart disease, particularly in the Asia, the Middle East, and the North Africa. In the United States, senile degenerative calcific aortic valve disease and bicuspid aortic valve disease are the most common causes. .The Framingham Heart Study, a prospective epidemiological study, evaluated the prevalence and severity of aortic regurgitation and other valvular diseases by color Doppler examinations in 1,696 men and 1,893 women.The study revealed that the prevalence of aortic regurgitation (ranging in severity from trace to ≥ moderate regurgitation) is 13.0% in men and 8.5% in women. The prevalence of aortic regurgitation increases with age. It is infrequent in young patients, and occurs in < 1% of subjects under the age of 70. However people with congenital aortic valve/root defects such as bicuspid aortic valve disease and Marfan syndrome may develop aortic regurgitation much earlier in life.

Risk Factors

In the past, the most common risk factor for aortic valvular disease had been the rheumatic fever, with subsequent fibrosis of the scarred valve then leading to retraction of the aortic valve cusps and prevention of their apposition during diastole. In the modern era, a more common risk factor for acquired aortic regurgitation is degenerative disease of the aorta and aortic valve in which case there is calcification and fibrosis of the cusps. Infective endocarditis remains an important risk factor and cause of aortic insufficiency. Congenital conditions such as congenital bicuspid aortic valve or a ventricular septal defect can also result in aortic insufficiency. Patients with bicuspid aortic valve are at increased risk of developing aortic dissection.

Natural History, Complications and Prognosis

In acute aortic insufficiency symptoms of heart failure often develop acutely. Chronic aortic insufficiency is usually insidious and progressive and the patient may remain asymptomatic for years. Once left ventricular dilation and left ventricular failure occur, dyspnea on exertion and exercise intolerance begin to occur. Later symptoms such as angina, syncope, and other symptoms of heart failure are present. There are two main parameters that reflect the overall outcome in patients with aortic insufficiency: ejection fraction (the lower the ejection fraction, the poorer the outcome) and end systolic diameter. Left ventricular dysfunction develops in patients with aortic insufficiency after decades of the onset of the symptoms. This lag period is longer than that of mitral regurgitation. A detailed history and physical exam and diagnostic techniques like electrocardiogram, chest X-ray, echocardiography and a cardiac MRI can be used to diagnose aortic regurgitation.The prognosis and survival of patients with symptomatic aortic regurgitation has improved significantly over the last decade. The five year survival rate for symptomatic patients is now more than 80 percent. The prognosis among patients with aortic insufficiency is poor with a high mortality and morbidity due to the acute onset of left ventricular failure, pulmonary edema, or myocardial ischemia due to the abrupt rise in LV wall stress and sudden cardiac death. Early surgical intervention improves the prognosis in these patients.

Diagnosis

History and Symptoms

The symptoms of acute aortic regurgitation (AR) include dyspnea, chest pain (when aortic dissection is the cause of AR), weakness, and symptoms of congestive heart failure. Chronic AR may be without symptoms for several years until there is a decrease in the stroke volume and cardiac output due to heart failure progression. Symptoms of chronic aortic insufficiency include exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and palpitations.

Physical Examination

A patient with suspected aortic insufficiency may have an early diastolic heart murmur which is usually a high-pitched sound best heard at the left sternal border. An ejection systolic 'flow' murmur may also be present. The apex beat is typically displaced down and to the left. A patient with chronic aortic insufficiency may present with signs of congestive heart failure. Other significant findings on physical exam include:

Cardiac Stress Test

A cardiac stress test (CST) is an evaluation modality used in cardiology in which the ability of the heart to respond to stress, either actually induced by exercise or stimulated by pharmacologic agents, is measured in a controlled clinical setting. CST for chronic aortic insufficiency is reasonable for assessment of functional capacity and symptomatic response in patients with a history of equivocal symptoms.

Electrocardiogram

The echocardiogram is the single most useful diagnostic imaging study in the diagnosis and ongoing surveillance of the severity of aortic insufficiency. Echocardiography allows for serial assessment of left ventricular volumes which can be critical in determining the timing of aortic valve replacement. Aortic valve replacement should be performed if the LVEF is ≤ 55% or if left ventricular end-systolic dimension is > 55mm.

Chest X Ray

Chest x ray findings associated with aortic insufficiency may include left ventricular enlargement, cardiomegaly, prominent aortic root with valvular calcification, prosthetic valve dis-lodgement, or aortic dilation. If aortic insufficiency is severe, signs of pulmonary edema may also be present.

Echocardiography

The echocardiogram is the single most useful diagnostic imaging study in the diagnosis and ongoing surveillance of the severity of aortic insufficiency. Echocardiography allows for serial assessment of left ventricular volumes which can be critical in determining the timing of aortic valve replacement. Echocardiography is used to assess the following parameters: end-diastolic diameter, end systolic diameter, and ejection fraction. Aortic valve replacement should be performed if the LVEF is ≤ 55% or if left ventricular end-systolic dimension is > 55mm. Pulsed Doppler echocardiography is more sensitive than auscultation specially in patients in whom no murmur is observed.

Cardiac MRI

Cardiac MRI may be used for assessing individuals with valvular heart disease in which evaluation of valvular stenosis, regurgitation, para- or perivalvular masses, perivalvular complications of infectious processes, or prosthetic valve disease are needed. CMR may be useful in identifying serial changes in LV volumes or mass in patients with valvular dysfunction. For patients with suboptimal echocardiograms showing aortic regurgitation, radionuclide angiography or magnetic resonance imaging is indicated to assess left ventricular volume and function at rest. CMR can also be used to determine the severity of AR in patients with suboptimal echocardiograms.

Cardiac Catheterization

Although echocardiography is now the primary imaging modality used to evaluate aortic insufficiency, cardiac catheterization is often performed in patients with aortic insufficiency primarily to assess for the presence of epicardial coronary artery disease prior to surgical aortic valve replacement. Aortography can also be performed to assess the severity of aortic insufficiency. The presence or absence of an aortic dissection can be evaluated. Left ventricular function (hemodynamics), size, and systolic function (ejection fraction) can also be evaluated.

Treatment

Aortic insufficiency can be treated either medically with vasodilators or surgically with aortic valve replacement, depending upon the acuteness of presentation, the symptoms and signs associated with the disease process, and the degree of left ventricular dysfunction. Nitroprusside and ionotropes can be used to maintain blood pressure. Treatment options that are contraindicated include intra aortic balloon pump, pressors, and beta blockers (except in aortic dissection, where beta blockers can be used cautiously).

Acute Aortic Insufficiency

Patients with acute severe aortic regurgitation (AR) are managed with emergency aortic valve replacement or repair. Medical therapy is used for the stabilization of patients prior to surgery.

Chronic Aortic Insufficiency

In the management of chronic aortic regurgitation, the left ventricular size and function should be monitored closely along with the exercise tolerance of the patient. If the patient develops heart failure symptoms and the disease starts to be symptomatic, then aortic valve replacement or valve repair is indicated. Annual echocardiographic studies are indicated in all patients with significant AR. Vasodilators such as ACE inhibitors, nifedipine, sodium nitroprusside, and hydralazine may slow the rate of progression of AR. The greatest benefit of medical therapy is among symptomatic patients and those with heart failure symptoms due to advanced disease, but in general, medical therapy has a limited role in AR because symptomatic cases should be treated with valve replacement if the patient is a good candidate for surgery. Warfarin and long-term anticoagulation is not recommended in AR if there are no other indications for anticoagulation.

Surgery

Severe acute AR requires emergency surgery if there are no absolute contraindications to surgery. The surgery should be performed as early as possible without a delay, particularly if hypotension, decreased perfusion, or pulmonary edema are present. In chronic AR, aortic valve replacement (AVR) is indicated in patients with severe AR who are either symptomatic regardless of LV systolic function, or those who are asymptomatic and have left ventricular ejection fraction <55%, or in patients with stage C or D AR who are undergoing cardiac surgery for other indications.

Prevention

Primary prevention

Limiting the factors that lead to the development of Aortic regurgitation will decrease its incidence. Optimal blood pressure control, especially in elderly population is of utmost importance. cessation of smoking and opting for a healthy life style that includes balanced diet and regular exercise. Prevention of the initial development of acute rheumatic fever by prompt diagnosis and antibiotic treatment of group A streptococcal (GAS) infection predominantly due to tonsillopharyngitis. In tropical countries, a link between GAS pyoderma and subsequent ARF/RHD is highly likely.

Secondary prevention

Aortic reguritation is associated with a higher rate of infection of the valve, that is infective endocarditis.To reduce the risk of developing infective endocarditis among high-risk patients, antibiotic prophylaxis should be considered prior to certain dental/medical/surgical procedures. Such procedures may include dental extraction, deep scaling of the teeth, gum surgery, dental implants, treatment of esophageal varices, dilation of esophageal strictures, gastrointestinal surgery where the intestinal mucosa will be disrupted, prostate surgery, urethral stricture dilation, and cystoscopy. Secondary prevention of recurrent ARF with continuous antibiotic prophylaxis is recommended for patients with definite history of ARF or diagnosis of definite RHD. Continuous antimicrobial prophylaxis is recommended because recurrent ARF can be triggered by GAS infection even if asymptomatic. Patients should be registered in regional ARF prevention programs, where available.

Special Scenarios

Elderly patients

The incidence of aortic regurgitation in the elderly is low in comparison to the incidence of aortic stenosis and mitral regurgitation. The majority of elderly patients have combined aortic stenosis and aortic insufficiency and the incidence of pure aortic insufficiency is rare.

Pregnancy

Isolated aortic insufficiency in pregnant patients can be managed with combination of diuretics and vasodilators. ACE inhibitors are contraindicated in pregnancy. Patients with signs and symptoms of left ventricular failure should be monitored throughout labor and delivery with strict attention to volume status and blood pressure.

Young Adults

Congenital aortic insufficiency rarely occurs alone and is often associated with aortic stenosis or ventricular septal defect. It may occasionally be observed in adolescents and young adults with a bicuspid aortic valve, discrete subaortic obstruction, or prolapse of one of the aortic cusp into a ventricular septal defect. Turner syndrome, osteogenesis imperfecta, tetralogy of Fallot, and truncus arteriosus are other congenital disorders that are associated with aortic insufficiency in young patients. Rheumatic heart disease is one of the important causes for acquired aortic insufficiency in young patients in developing countries. It can also occur following an episode of infective endocarditis or as a consequence of attempts to relieve aortic stenosis by either balloon valvuloplasty or surgical valvulotomy, or when the pulmonary artery is relocated in the aortic position during repair of transposition of great vessels.

End-stage Renal Disease

Aortic insufficiency in patients with end stage renal disease can be due to either valvular calcification or infective endocarditis. Valvular/annular thickening, and calcification of heart valves occur commonly in patients undergoing dialysis, thereby leading to valvular regurgitation and/or stenosis. Hyperparathyroidism occurring secondary to renal disease is one of the most significant predisposing factor for valular calcification. Aortic insufficiency is seen less commonly than mitral or tricuspid insufficiency. In a study on 75 patients with end stage renal disease (ESRD) undergoing hemodialysis, 38% of patients were found to have developed aortic insufficiency.

References

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