View source for Mitral regurgitation

{{short description|Form of valvular heart disease}}

{{Infobox medical condition (new)
| name            = Mitral regurgitation
| synonyms        = Mitral incompetence, mitral insufficiency
| image           = Mitral Regurgitation scheme1.png
| caption         = '''Mitral regurgitation (schematic drawing)'''<br />During systole,  contraction of the left ventricle causes abnormal backflow (arrow) into the left atrium.<br />1 Mitral valve<br />2 Left ventricle<br />3 Left atrium<br />4 [[Aorta]]
| pronounce       =
| field           = [[Cardiology]]
| symptoms        = Heart murmur, shortness of breath during exercise or lying down, fatigue, palpitations, swollen feet or ankles<ref name="mayoclinic.org">{{Cite web|title=Mitral valve regurgitation - Symptoms and causes|url=https://www.mayoclinic.org/diseases-conditions/mitral-valve-regurgitation/symptoms-causes/syc-20350178|access-date=2021-12-01|website=Mayo Clinic|language=en}}</ref>
| complications   = In severe cases: [[Heart failure|congestive heart failure]], [[arrhythmia]]s ([[atrial fibrillation]]), [[pulmonary hypertension]]<ref name="mayoclinic.org"/>
| onset           =
| duration        =
| types           = Acute mitral regurgitation, chronic compensated mitral regurgitation, chronic decompensated mitral regurgitation<ref name="emedicine.medscape.com">{{cite web |title=Mitral Regurgitation: Practice Essentials, Background, Pathophysiology |url=https://emedicine.medscape.com/article/155618-overview |website=medscape |date=8 December 2021}}</ref>
| causes          = [[mitral valve prolapse]], [[ageing]], [[rheumatic fever]], [[mitral annular calcification]], [[infective endocarditis]], [[hypertrophic cardiomyopathy]]<ref name="emedicine.medscape.com"/>
| risks           =
| diagnosis       =
| differential    =
| prevention      =
| treatment       = [[Medication]], [[Mitral valve repair]], [[Mitral valve replacement]], [[MitraClip]]
| medication      =
| prognosis       =
| frequency       =
| deaths          =
}}
{{listen|filename=Mitral Valve Prolapse.wav|title=Mitral Valve Prolapse murmur at mitral area|description=Heart sounds of a 16-year-old girl diagnosed with [[mitral valve prolapse]] and mitral regurgitation. Auscultating her heart, a systolic murmur and click are heard. Recorded with the stethoscope over the mitral valve.|filename2=Liz-s-heart-at-tricuspid-holding-breath.wav|title2=Mitral Valve Prolapse murmur at tricuspid area|description2=Her heart sounds while holding her breath. Recorded with the stethoscope over the tricuspid valve.|filename3=Liz-s-heart-after-exercise-at-tricuspid.wav|title3=Mitral Valve Prolapse murmur at tricuspid area after exercising|description3=Her heart sounds during recovery after running. Recorded with the stethoscope over the tricuspid valve.|format=[[wav]]}}
'''Mitral regurgitation''' ('''MR'''), also known as '''mitral insufficiency''' or '''mitral incompetence''', is a form of [[valvular heart disease]] in which the [[mitral valve]] is insufficient and does not close properly when the [[heart]] pumps out [[blood]].<ref name="Douedi">{{cite journal |last1=Douedi |first1=Steven |last2=Douedi |first2=Hani |title=Mitral Regurgitation |url=https://www.ncbi.nlm.nih.gov/books/NBK553135/#article-25198.s3 |website=StatPearls |publisher=StatPearls Publishing |access-date=19 December 2021 |date=2021|pmid=31985928 }}</ref><ref name=mountsinai>[http://www.mountsinai.org/Other/Diseases/Mitral%20valve%20regurgitation Mitral valve regurgitation] at [[Mount Sinai Hospital, New York|Mount Sinai Hospital]]</ref><ref name="patient.info2020">{{cite web |title=What is mitral regurgitation? {{!}} Heart Disease |url=https://patient.info/heart-health/heart-valves-and-valve-disease/mitral-regurgitation |website=patient.info |access-date=15 February 2021 |language=en}}</ref> It is the abnormal leaking of blood backwards – [[Regurgitation (circulation)|regurgitation]] from the [[left ventricle]], through the mitral valve, into the [[left atrium]], when the left ventricle contracts.<ref name=mountsinai/> Mitral regurgitation is the most common form of [[valvular heart disease]].<ref name="Douedi"/>
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==Definition==
Mitral regurgitation, also known as mitral insufficiency or mitral incompetence, is the backward flow of blood from the [[left ventricle]], through the [[mitral valve]], and into the [[left atrium]], when the left ventricle contracts, resulting in a systolic [[Heart murmur|murmur]] radiating to the left [[axilla|armpit]].<ref name="patient.info2020"/><ref name="Douedi"/>

==Signs and symptoms==
[[File:Phonocardiograms from normal and abnormal heart sounds.svg|thumb|left|Phonocardiograms from normal and abnormal heart sounds]]

Mitral regurgitation may be present for many years before any symptoms appear.<ref name="mayoclinic.org"/> The symptoms associated with MR are dependent on which phase of the disease process the individual is in. Individuals with acute MR are typically severely symptomatic and will have the signs and symptoms of acute decompensated [[congestive heart failure]] (i.e. [[shortness of breath]], [[pulmonary edema]], [[orthopnea]], and [[paroxysmal nocturnal dyspnea]]).<ref name=agabegi2nd-ch1/> In acute cases, a [[Heart murmur|murmur]] and [[tachycardia]] may be the only distinctive signs.<ref name=uas/>

Individuals with chronic compensated MR may be asymptomatic for long periods of time, with a normal exercise tolerance and no evidence of heart failure. Over time, however, there may be decompensation and patients can develop [[volume overload]] (congestive heart failure). Symptoms of entry into a decompensated phase may include fatigue, shortness of breath particularly on exertion, and leg swelling. Also, there may be development of an irregular heart rhythm known as [[atrial fibrillation]].<ref name=agabegi2nd-ch1/>

Findings on clinical examination depend on the severity and duration of MR. The mitral component of the [[first heart sound]] is usually soft and with a laterally displaced apex beat,<ref name=agabegi2nd-ch1/> often with [[Parasternal heave|heave]].<ref name=uas/> The first heart sound is followed by a high-pitched [[holosystolic murmur]] at the apex, radiating to the back or clavicular area.<ref name=agabegi2nd-ch1/> Its duration is, as the name suggests, the whole of systole. The loudness of the murmur does not correlate well with the severity of regurgitation. It may be followed by a loud, palpable [[P2 beat|P<sub>2</sub>]],<ref name=agabegi2nd-ch1/> heard best when lying on the left side.<ref name=uas/> A [[third heart sound]] is commonly heard.<ref name=agabegi2nd-ch1/>

Patients with [[mitral valve prolapse]] may have a holosystolic murmur or often a mid-to-late systolic click and a late systolic murmur. Cases with a late systolic regurgitant murmur may still be associated with significant hemodynamic consequences.<ref>{{cite journal | pmid = 19561453 | doi=10.1097/MAJ.0b013e31819d5ec6 | volume=338 | issue=2 | title=Mitral valve prolapse with a late-systolic regurgitant murmur may be associated with significant hemodynamic consequences. | date=Aug 2009 | journal=Am J Med Sci | pages=113–5| last1=Ahmed | first1=Mustafa I. | last2=Sanagala | first2=Thriveni | last3=Dell'Italia | first3=Louis J. | last4=Denney | first4=Thomas | last5=Inusah | first5=Seidu | last6=McGiffin | first6=David | last7=Knowlan | first7=Donald | last8=o'Rourke | first8=Robert A. | s2cid=44385990 }}</ref>

Mitral regurgitation as a result of papillary muscle damage or rupture may be a complication of a [[heart attack]] and lead to [[cardiogenic shock]].<ref name="Harrisons">{{cite book |title=Harrison's principles of internal medicine. |date=2012 |publisher=McGraw-Hill |location=New York |isbn=9780071748872 |page=2236 |edition=18th}}</ref>

==Cause==
[[File:Blausen 0645 MitralValve RegurgitationvsStenosis.png|thumb|left|Illustration comparing mitral valve regurgitation to mitral valve stenosis]]
The mitral valve apparatus comprises two valve leaflets, the [[mitral annulus]], which forms a ring around the valve leaflets, and the [[papillary muscles]], which tether the valve leaflets to the left ventricle and prevent them from prolapsing into the left atrium. The ''[[chordae tendineae]]'' is also present and connects the valve leaflets to the papillary muscles. Dysfunction of any of these portions of the mitral valve apparatus can cause regurgitation.{{citation needed|date=February 2021}}

The most common cause of MR in developed countries is [[mitral valve prolapse]].<ref name='MedicineNetMVP-Kulick'>{{cite web|url=http://www.medicinenet.com/mitral_valve_prolapse/article.htm |title=Mitral Valve Prolapse (MVP) |access-date=2010-01-18 |last=Kulick |first=Daniel |work=MedicineNet.com |publisher=MedicineNet, Inc }}</ref> It is the most common cause of primary mitral regurgitation in the [[United States]], causing about 50% of cases. Myxomatous degeneration of the mitral valve is more common in women as well as with advancing age, which causes a stretching of the leaflets of the valve and the chordae tendineae. Such elongation prevents the valve leaflets from fully coming together when the valve closes, causing the valve leaflets to prolapse into the left atrium, thereby causing MR.{{citation needed|date=February 2021}}

[[Ischemic heart disease]] causes MR by the combination of ischemic dysfunction of the papillary muscles, and the dilatation of the left ventricle. This can lead to the subsequent displacement of the papillary muscles and the dilatation of the [[Mitral annulus|mitral valve annulus]].{{citation needed|date=February 2021}}

[[Rheumatic fever]] (RF), [[Marfan's syndrome]] and the [[Ehlers–Danlos syndromes]] are other typical causes.<ref name=agabegi2nd-ch1/> [[Mitral valve stenosis]] (MVS) can sometimes be a cause of mitral regurgitation (MR) in the sense that a [[Stenosis|stenotic valve]] ([[Calcification|calcified]] and with restricted range of movement) allows backflow (regurgitation) if it is too stiff and misshapen to close completely. Most MVS is caused by RF, so one can say that MVS is sometimes the proximal cause of MI/MR (that is, stenotic MI/MR) and that RF is often the distal cause of MVS, MI/MR, or both. MR and mitral valve prolapse are also common in [[Ehlers–Danlos syndromes]].<ref>[https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002439] NIH US National Library of Medicine, A.D.A.M. Medical Encyclopedia, Ehlers Danlos Syndrome- PMH0002439</ref>

'''Secondary mitral regurgitation''' is due to the dilatation of the [[left ventricle]] that causes stretching of the mitral valve annulus and displacement of the papillary muscles. This dilatation of the left ventricle can be due to any cause of [[dilated cardiomyopathy]] including [[aortic insufficiency]], nonischemic dilated [[cardiomyopathy]], and [[noncompaction cardiomyopathy]]. Because the papillary muscles, chordae, and valve leaflets are usually normal in such conditions, it is also called '''functional mitral regurgitation'''.<ref>[http://www.uptodate.com/patients/content/topic.do?topicKey=~Ux3kbGWsXmiaqiH Functional mitral regurgitation] {{webarchive|url=https://web.archive.org/web/20100822161845/http://www.uptodate.com/patients/content/topic.do?topicKey=~Ux3kbGWsXmiaqiH |date=2010-08-22 }} By William H Gaasch, MD. Retrieved on Jul 8, 2010</ref>

Acute MR is most often caused by [[endocarditis]], mainly ''[[Staphylococcus aureus|S. aureus]]''.<ref name=agabegi2nd-ch1>{{cite book |author1=Elizabeth D Agabegi |author2=Agabegi, Steven S. |title=Step-Up to Medicine (Step-Up Series) |publisher=Lippincott Williams & Wilkins |location=Hagerstwon, MD |year=2008 |isbn=978-0-7817-7153-5 |url-access=registration |url=https://archive.org/details/stepuptomedicine0000agab }}  Chapter 1: Diseases of the Cardiovascular system > Section: Valvular Heart Disease</ref> Rupture or dysfunction of the [[papillary muscle]] are also common causes in acute cases,<ref name=agabegi2nd-ch1/> dysfunction, which can include mitral valve prolapse.<ref name=uas>VOC=VITIUM ORGANICUM CORDIS, a compendium of the Department of Cardiology at Uppsala Academic Hospital. By Per Kvidal September 1999, with revision by Erik Björklund May 2008</ref>

==Pathophysiology==
The pathophysiology of MR can be broken into three phases of the disease process: the acute phase, the chronic compensated phase, and the chronic decompensated phase.{{Citation needed|date=December 2021}}
[[File:MI Schema leicht Kopie.png|thumb|'''Mild mitral regurgitation.''' The colored cloud symbolizes the return blood flow. 1. left ventricle, 2. left atrium]]

===Acute phase===
Acute MR (as may occur due to the sudden rupture of the [[chordae tendinae]] or papillary muscle) causes a sudden volume overload of both the left atrium and the left ventricle. The left ventricle develops volume overload because with every contraction it now has to pump out not only the volume of blood that goes into the [[aorta]] (the forward [[cardiac output]] or forward stroke volume) but also the blood that regurgitates into the left atrium (the regurgitant volume). The combination of the forward stroke volume and the regurgitant volume is known as the total stroke volume of the left ventricle.<ref name="Aortic Regurgitation">{{cite web |url= https://www.lecturio.com/concepts/aortic-regurgitation/ | title= Aortic Regurgitation
| website= The Lecturio Medical Concept Library | date= October 2020
|access-date= 29 June 2021}}</ref>

In the acute setting, the stroke volume of the left ventricle is increased (increased [[ejection fraction]]); this happens because of more complete emptying of the heart. However, as it progresses the LV volume increases and the contractile function deteriorates, thus leading to dysfunctional LV and a decrease in ejection fraction.<ref>Harrison's Internal Medicine 17th edition</ref> The increase in stroke volume is explained by the [[Frank–Starling mechanism]], in which increased ventricular pre-load stretches the myocardium such that contractions are more forceful.{{citation needed|date=February 2021}}

The regurgitant volume causes a volume overload and a [[pressure overload]] of the left atrium and the left ventricle. The increased pressures in the left side of the heart may inhibit drainage of blood from the lungs via the pulmonary veins and lead to [[congestive heart failure|pulmonary congestion]].<ref name="Aortic Regurgitation" />

===Chronic phase===

====Compensated====
If the MR develops slowly over months to years or if the acute phase cannot be managed with medical therapy, the individual will enter the chronic compensated phase of the disease. In this phase, the left ventricle develops eccentric hypertrophy in order to better manage the larger than normal stroke volume. The eccentric hypertrophy and the increased diastolic volume combine to increase the stroke volume (to levels well above normal) so that the forward stroke volume (forward cardiac output) approaches the normal levels.In the left atrium, the volume overload causes enlargement of the left atrium, allowing the filling pressure in the left atrium to decrease. This improves the drainage from the pulmonary veins, and signs and symptoms of pulmonary congestion will decrease.{{citation needed|date=February 2021}}

These changes in the left ventricle and left atrium improve the low forward cardiac output state and the pulmonary congestion that occur in the acute phase of the disease. Individuals in the chronic compensated phase may be asymptomatic and have normal exercise tolerances.<ref name="Mitral Regurgitation">{{cite web |url= https://www.lecturio.com/concepts/mitral-regurgitation/| title= Mitral Regurgitation
|website=The Lecturio Medical Concept Library |access-date= 11 August 2021}}</ref>

====Decompensated====
An individual may be in the compensated phase of MR for years, but will eventually develop left ventricular dysfunction, the hallmark for the chronic decompensated phase of MR. It is currently unclear what causes an individual to enter the decompensated phase of this disease. However, the decompensated phase is characterized by calcium overload within the cardiac [[myocyte]]s.{{citation needed|date=February 2021}}

In this phase, the ventricular myocardium is no longer able to contract adequately to compensate for the volume overload of mitral regurgitation, and the stroke volume of the left ventricle will decrease. The decreased stroke volume causes a decreased forward cardiac output and an increase in the [[Systole (medicine)|end-systolic]] volume. The increased end-systolic volume translates to increased filling pressures of the left ventricle and increased pulmonary venous congestion. The individual may again have symptoms of congestive heart failure.<ref name="Mitral Regurgitation" />

The left ventricle begins to dilate during this phase. This causes a dilatation of the mitral valve annulus, which may worsen the degree of MR. The dilated left ventricle causes an increase in the wall stress of the cardiac chamber as well.While the [[ejection fraction]] is less in the chronic decompensated phase than in the acute phase or the chronic compensated phase, it may still be in the normal range (i.e.: > 50 percent), and may not decrease until late in the disease course. A decreased ejection fraction in an individual with MR and no other cardiac abnormality should alert the physician that the disease may be in its decompensated phase.{{citation needed|date=February 2021}}

==Diagnosis==
There are many diagnostic tests that have abnormal results in the presence of MR. These tests suggest the diagnosis of MR and may indicate to the physician that further testing is warranted. For instance, the [[electrocardiogram]] (ECG) in long-standing MR may show evidence of left atrial enlargement and left ventricular dilatation. [[Atrial fibrillation]] may also be noted on the ECG in individuals with chronic mitral regurgitation. The ECG may not show any of these findings in the setting of acute MR.{{citation needed|date=February 2021}}
{| class="wikitable"
|+ Comparison of acute and chronic phases of MR
|-
!
! scope="col" | Acute
! scope="col" | Chronic
|-
! scope="row" | [[Electrocardiogram]]
| Normal
| P mitrale, [[Atrial fibrillation]], [[left ventricular hypertrophy]]
|-
! scope="row" | Heart size
| Normal
| [[Cardiomegaly]], left atrial enlargement
|-
! scope="row" | [[Heart sounds|Systolic murmur]]
| Heard at the base, radiates to the neck, spine, or top of head
| Heard at the apex, radiates to the axilla
|-
! scope="row" | Apical thrill
| May be absent
| Present
|-
! scope="row" | [[Jugular venous pressure|Jugular venous distension]]
| Present
| Absent
|}

The quantification of MR usually employs [[medical imaging technique|imaging studies]] such as [[echocardiography]] or [[magnetic resonance angiography]] of the heart.

===Chest X-ray===
The chest [[X-ray]] in individuals with chronic MR is characterized by enlargement of the left atrium and the left ventricle, and then maybe [[Mitral annular calcification|calcification of the mitral valve]].<ref name="Clarke2002">{{cite book |last1=Camm |first1=A. J. |editor1-last=Kumar |editor1-first=Parveen |editor2-last=Clark |editor2-first=Michael |title=Clinical Medicine |date=2002 |publisher=Saunders |isbn=0-702-02579-8 |pages=786–788 |edition=5th |chapter=13. Cardiovascular disease}}</ref>

===Echocardiogram===
[[File:Mitralinsuff TEE.jpg|thumb|left|400px|[[Transesophageal echocardiogram]] of [[mitral valve prolapse]]]]
{| border="1" cellspacing="0" cellpadding="2" style="float:right;margin-left:0.5em;border-collapse:collapse;" | class="wikitable floatright"
| style="border-right:white" align="center" |[[File:Mitral regurgitation echo 4chamber.jpg|150px]]
| style="border-left:white" align="center" |[[File:Mitral regurgitation echo 4chamber description.png|150px]]
|-
| style="border-right:white" align="center" |Severe MR
| style="border-left:white" align="center" |Legend
|-
| colspan="2" bgcolor="#ABCDEF" |<small>1 Left atrium (LA) – 2 MR Jet</small>, <small>LV Left ventricle – RV Right ventricle – RA Right atrium</small>
|}
[[File:Doppler mitral valve.gif|thumb|Animation of a mitral valve regurgitation in a dog, left apical view]]
An [[echocardiogram]] is commonly used to confirm the diagnosis of MR.<ref name="Clarke2002"/> Color doppler flow on the transthoracic echocardiogram (TTE) will reveal a jet of blood flowing from the left ventricle into the left atrium during ventricular [[Systole (medicine)|systole]]. Also, it may detect a dilated left atrium and ventricle and decreased left ventricular function.<ref name=agabegi2nd-ch1/> A [[transesophageal echocardiogram]] can give clearer images if needed as the back of the heart can also be viewed.<ref name="rbht">{{cite web |title=Transoesophageal echocardiogram (TOE) {{!}} Royal Brompton & Harefield hospitals |url=https://www.rbht.nhs.uk/our-services/transoesophageal-echocardiogram-toe |website=www.rbht.nhs.uk |access-date=19 December 2021}}</ref>

===Electrocardiography===
[[P wave (electrocardiography)#Pathology|P mitrale]] is a broad, bifid notched P wave in several or many leads with a prominent late negative component to the P wave in lead V<sub>1</sub>, and may be seen in MR, but also in [[mitral stenosis]], and, potentially, any cause of overload of the left atrium.<ref name=stedmans>[http://www.medilexicon.com/medicaldictionary.php?t=70229 medilexicon.com < P mitrale] {{Webarchive|url=https://web.archive.org/web/20111103185603/http://www.medilexicon.com/medicaldictionary.php?t=70229 |date=2011-11-03 }} Citing. Stedman's Medical Dictionary. Copyright 2006</ref>

===Quantification of mitral regurgitation===
The degree of severity of MR can be quantified by the [[regurgitant fraction]], which is the percentage of the left ventricular stroke volume that regurgitates into the left atrium.{{citation needed|date=February 2021}}

:regurgitant fraction &nbsp; = &nbsp; <math>\frac{V_{mitral} - V_{aortic}} {V_{mitral}}  \times  100\%</math>

where V<sub>mitral</sub> and V<sub>aortic</sub> are, respectively, the volumes of blood that flow forward through the mitral valve and aortic valve during a [[cardiac cycle]].
Methods that have been used to assess the regurgitant fraction in mitral regurgitation include echocardiography, cardiac catheterization, fast CT scan, and cardiac MRI.The echocardiographic technique to measure the regurgitant fraction is to determine the forward flow through the mitral valve (from the left atrium to the left ventricle) during ventricular [[diastole]], and comparing it with the flow out of the left ventricle through the aortic valve in ventricular [[Systole (medicine)|systole]]. This method assumes that the aortic valve does not have [[aortic insufficiency]].Another way to quantify the degree of MR is to determine the area of the regurgitant flow at the level of the valve. This is known as the regurgitant orifice area and correlates with the size of the defect in the mitral valve. One particular echocardiographic technique used to measure the orifice area is measurement of the [[proximal isovelocity surface area]] (PISA). The flaw of using PISA to determine the mitral valve regurgitant orifice area is that it measures the flow at one moment in time in the [[cardiac cycle]], which may not reflect the average performance of the regurgitant jet.{{citation needed|date=February 2021}}
[[File:The PISA Method for Quantification of Mitral Regurgitation.svg|thumb|The PISA Method for Quantification of Mitral Regurgitation]]

{| class="wikitable" style="margin:auto"
|+ Determination of the degree of mitral regurgitation
|-
!Grade<ref>{{Cite journal|last1=Zoghbi|first1=William A.|last2=Adams|first2=David|last3=Bonow|first3=Robert O.|last4=Enriquez-Sarano|first4=Maurice|last5=Foster|first5=Elyse|last6=Grayburn|first6=Paul A.|last7=Hahn|first7=Rebecca T.|last8=Han|first8=Yuchi|last9=Hung|first9=Judy|last10=Lang|first10=Roberto M.|last11=Little|first11=Stephen H.|date=April 2017|title=Recommendations for Noninvasive Evaluation of Native Valvular Regurgitation: A Report from the American Society of Echocardiography Developed in Collaboration with the Society for Cardiovascular Magnetic Resonance|url=https://pubmed.ncbi.nlm.nih.gov/28314623/|journal=Journal of the American Society of Echocardiography|volume=30|issue=4|pages=303–371|doi=10.1016/j.echo.2017.01.007|issn=1097-6795|pmid=28314623}}</ref>
! Degree of mitral regurgitation
! Regurgitant fraction
! width="100px" | Regurgitant Orifice area
|-
|1
|Mild || < 20 percent || rowspan="3" |
|-
|2
|Moderate || 20 - 40 percent
|-
|3
|Moderate to severe || 40 - 60 percent
|-
|4
|Severe || > 60 percent || > 0.4&nbsp;cm<sup>2</sup>
|}

==Treatment==
The treatment of MR depends on the acuteness of the disease and whether there are associated signs of hemodynamic compromise. In general, medical therapy is non-curative and is used for mild-to-moderate regurgitation or in patients unable to tolerate surgery.<ref name="Mitral Regurgitation"/>

In acute MR secondary to a mechanical defect in the heart (i.e., rupture of a papillary muscle or chordae tendineae), the treatment of choice is mitral valve surgery. If the patient is hypotensive prior to the surgical procedure, an [[intra-aortic balloon pump]] may be placed in order to improve perfusion of the organs and to decrease the degree of MR.<ref name=agabegi2nd-ch1/>

===Medicine===
If the individual with acute MR is normotensive, [[vasodilator]]s may be of use to decrease the [[afterload]] seen by the left ventricle and thereby decrease the regurgitant fraction. The vasodilator most commonly used is [[nitroprusside]].<ref>{{cite web|title=Sodium Nitroprusside|url=https://www.drugs.com/monograph/sodium-nitroprusside.html|publisher=The American Society of Health-System Pharmacists|access-date=8 December 2016|url-status=live|archive-url=https://web.archive.org/web/20161221004712/https://www.drugs.com/monograph/sodium-nitroprusside.html|archive-date=21 December 2016|df=dmy-all}}</ref>

Individuals with chronic MR can be treated with vasodilators as well to decrease afterload.<ref name=agabegi2nd-ch1/> In the chronic state, the most commonly used agents are [[ACE inhibitor]]s and [[hydralazine]]. Studies have shown that the use of ACE inhibitors and hydralazine can delay surgical treatment of MR.<ref>{{cite journal |vauthors=Greenberg BH, Massie BM, Brundage BH, Botvinick EH, Parmley WW, Chatterjee K |title=Beneficial effects of hydralazine in severe mitral regurgitation |journal=Circulation |volume=58 |issue=2 |pages=273–9 |year=1978 |pmid=668075 |doi= 10.1161/01.cir.58.2.273|doi-access=free }}</ref><ref>{{cite journal |author=Hoit BD |title=Medical treatment of valvular heart disease |journal=Curr. Opin. Cardiol. |volume=6 |issue=2 |pages=207–11 |year=1991 |pmid=10149580 |doi= 10.1097/00001573-199104000-00005|s2cid=40731762 }}</ref> The current guidelines for treatment of MR limit the use of vasodilators to individuals with [[hypertension]], however. Any hypertension is treated aggressively,<ref name=uas/> e.g. by [[diuretics]] and a [[low sodium diet]].<ref name=agabegi2nd-ch1/> In both hypertensive and normotensive cases, [[digoxin]] and [[antiarrhythmic]]s are also indicated.<ref name=agabegi2nd-ch1/><ref name=uas/> Also, chronic [[anticoagulation]] is given where there is concomitant [[mitral valve prolapse]]<ref name=uas/> or [[atrial fibrillation]].<ref name=agabegi2nd-ch1/>

===Surgery===
Surgery is curative of mitral valve regurgitation. There are two surgical options for the treatment of MR: [[mitral valve replacement]] and [[mitral valve repair]].<ref name=agabegi2nd-ch1/> Mitral valve repair is preferred to mitral valve replacement where a repair is feasible as bioprosthetic replacement valves have a limited lifespan of 10 to 15 years, whereas synthetic replacement valves require ongoing use of blood thinners to reduce the risk of stroke. There are two general categories of approaches to mitral valve repair: resection of the prolapsed valvular segment (sometimes referred to as the "Carpentier" approach) and installation of artificial chordae to "anchor" the prolapsed segment to the papillary muscle (sometimes referred to as the "David" approach). With the resection approach, any prolapsing tissue is resected, in effect removing the hole through which the blood is leaking. In the artificial chordae approach, ePTFE (expanded polytetrafluoroethylene, or [[Gore-Tex]]) sutures are used to replace the broken or stretched chordae tendonae, bringing the natural tissue back into the physiological position, thus restoring the natural anatomy of the valve. With both techniques, an annuloplasty ring is typically secured to the annulus, or opening of the mitral valve, to provide additional structural support. In some cases, the "double orifice" (or 'Alfieri') technique for mitral valve repair, the opening of the mitral valve is sewn closed in the middle, leaving the two ends still able to open. This ensures that the mitral valve closes when the left ventricle pumps blood, yet allows the mitral valve to open at the two ends to fill the left ventricle with blood before it pumps. In general, mitral valve surgery requires "open-heart" surgery in which the heart is arrested and the patient is placed on a heart-lung machine ([[cardiopulmonary bypass]]). This allows the complex surgery to proceed in a still environment.{{citation needed|date=February 2021}}

Due to the physiological stress associated with open-heart surgery, elderly and very sick patients may be subject to increased risk, and may not be candidates for this type of surgery. As a consequence, there are attempts to identify means of correcting MR on a beating heart. The Alfieri technique for instance, has been replicated using a percutaneous [[catheter]] technique, which installs a "[[MitraClip]]" device to hold the middle of the mitral valve closed.<ref>{{cite journal |vauthors=Garg P, Walton AS |title=The new world of cardiac interventions: a brief review of the recent advances in non-coronary percutaneous interventions |journal=Heart Lung Circ |volume=17 |issue=3 |pages=186–99 |date=June 2008 |pmid=18262841 |doi=10.1016/j.hlc.2007.10.019 }}</ref><ref>{{cite journal|last=Feldman M.D.|first=Ted |author2=Elyse Foster |author3=Donald G. Glower |author4=Saibal Kar |author5=Michael J. Rinaldi |author6=Peter S. Fail |author7=Richard W. Smalling |author8=Robert Siegel |author9=Geoffrey A. Rose |author10=Eric Engeron |author11=Catalin Loghin |author12=Alfredo Trento |author13=Eric R. Skipper |author14=Tommy Fudge |author15=George V. Letsou |author16=Joseph M. Massaro |author17=Laura Mauri |collaboration=EVEREST II Investigators |title=Percutaneous Repair or Surgery for Mitral Regurgitation|journal=New England Journal of Medicine|date=14 April 2011|volume=364|issue=15 |pages=1395–1406|doi=10.1056/NEJMoa1009355|pmid=21463154 |s2cid=205092586 |url=https://semanticscholar.org/paper/43d99e403a99c644e217c802fe4c190afac86f9c |doi-access=free }}</ref>

Indications for surgery for chronic MR include signs of left ventricular dysfunction with ejection fraction less than 60%, severe pulmonary hypertension with pulmonary artery systolic pressure greater than 50 mmHg at rest or 60 mmHg during activity, and new-onset [[atrial fibrillation]].{{citation needed|date=February 2021}}
{| class="wikitable" style="margin:auto"
|+ Indications for surgery for chronic MR<ref>{{cite journal  |vauthors=Bonow R, et al |title=2008 Focused update incorporated into the ACC/AHA 2006 guidelines 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 (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. |journal=Circulation |volume=118 |issue=15 |pages=e523-661 |year=2008|pmid=18820172 |doi= 10.1161/CIRCULATIONAHA.108.190748|doi-access=free }}</ref>
!  Symptoms
!  LV EF
!  LVESD
|-
|[[New York Heart Association Functional Classification|NYHA II]] || > 30 percent || < 55&nbsp;mm
|-
|NYHA III-IV || < 30 percent || > 55&nbsp;mm
|-
|Asymptomatic || 30 - 60 percent || ≥ 40&nbsp;mm
|-
|Asymptomatic with pulmonary hypertension || colspan="2" | LV EF > 60 percent and pulmonary artery systolic pressure >50-60&nbsp;mmHg
|-
|Asymptomatic and chance for a repair without residual MR is >90% || > 60 percent || < 40&nbsp;mm
|}

==Epidemiology==
Significant mitral valve regurgitation has a [[Prevalence (epidemiology)|prevalence]] of approximately 2% of the population, affecting males and females equally.<ref>[http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/mitral-valve-disease/ The Cleveland Clinic Center for Continuing Education > Mitral Valve Disease: Stenosis and Regurgitation] Authors:  Ronan J. Curtin and Brian P. Griffin. Retrieved September 2010</ref> It is one of the two most common valvular heart diseases in the elderly,<ref name=uptodate>[http://www.uptodate.com/patients/content/topic.do?topicKey=~PxxZxAzdJkaEgaZ Valvular heart disease in elderly adults] Authors: Dania Mohty, Maurice Enriquez-Sarano. Section Editors:Catherine M Otto, Kenneth E Schmader. Deputy Editor: Susan B Yeon. This topic last updated: April 20, 2007. Last literature review version 18.2: May 2010</ref> and the commonest type of valvular heart disease in [[low and middle income countries]].<ref name="Douedi"/>

In a study of 595 male elite [[Association football|football]] players aged 18–38 and 47 sedentary non-athletes, mitral regurgitation was found in 20% football players and 15% in control group. Football players with mitral regurgitation were found to have larger mitral annulus diameter compared to athletes without regurgitation, and left atrium diameter was larger in athletes with MR.<ref>{{Cite journal|last1=Gjerdalen|first1=G. F.|last2=Hisdal|first2=J.|last3=Solberg|first3=E. E.|last4=Andersen|first4=T. E.|last5=Radunovic|first5=Z.|last6=Steine|first6=K.|date=December 2015|title=Atrial Size and Function in Athletes|url=http://www.thieme-connect.de/DOI/DOI?10.1055/s-0035-1555780|journal=International Journal of Sports Medicine|language=en|volume=36|issue=14|pages=1170–1176|doi=10.1055/s-0035-1555780|pmid=26509381 |hdl=11250/2412820 |s2cid=2631112 |issn=0172-4622|hdl-access=free}}</ref>

==See also==
* [[Tricuspid regurgitation]]
* [[Aortic regurgitation]]
* [[Pulmonary insufficiency]]
{{notelist}}

==References==
{{Reflist}}

==External links==
{{Medical resources
|  ICD10          = {{ICD10|I|05|1|i|05}}, {{ICD10|I|34|0|i|30}}, {{ICD10|Q|23|3|q|20}}
|  ICD9           = {{ICD9|394.1}}, {{ICD9|424.0}}, {{ICD9|746.6}}
|  ICDO           =
|  OMIM           =
|  OMIM_mult      =
|  MedlinePlus    = 000176
|  eMedicineSubj  = emerg
|  eMedicineTopic = 314
|  DiseasesDB     = 8275
|  MeshID         = D008944
}}
{{Commons}}	

{{Scholia|topic}}
{{Circulatory system pathology}}
{{Congenital malformations and deformations of circulatory system}}

{{DEFAULTSORT:Mitral Regurgitation}}
[[Category:Valvular heart disease]]
[[Category:Chronic rheumatic heart diseases]]