Myxomatous degeneration: Difference between revisions
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{{CMG}} {{AE}} {{MIR}} | {{CMG}} {{AE}} {{MIR}} [[user: Shaik Aisha sultana|Shaik Aisha sultana, ]][mailto:aisha.aashu@gmail.com] | ||
==Overivew== | ==Overivew== | ||
'''Myxomatous degeneration''' | '''Myxomatous degeneration''' is a progressive, [[non-inflammatory]] disarray of the structure involved caused by a defect in the integrity of the structure, due to the alteration in the synthesis and [[remodelling]] of the tissue. Myxomatous is a term derived from the word [[Myxoma|Myxoma.]] [[Myxoma]] is derived from Greek word muxa, meaning mucus.[[Myxoma]] is a non-cancerous tumor growth, it contains mucus or gelatin like substance. The term is most often used in the context of [[Mitral valve prolapse]], which is known more technically as "Myxomatous degeneration of the mitral valve." It can also be used in reference to [[degeneration]] of the [[aortic valve]]. [[Myxomatous degeneration]] of the [[cardiac valves]] (MDMV) stands for the non-inflammatory progressive disarray of the [[valve]] structure caused by a defect in the mechanical integrity of the leaflet due to the altered synthesis and/or [[remodeling]] by [[type VI collagen]]]. The gross morphologic features are characterized by voluminous and thickened [[leaflets]], in both longitudinal and transversal axes. This entity involves not only the valve but also the [[chordae tendineae]] that has also become [[thickened]], elongated, and sometimes ruptured. | ||
==Pathophysiology== | ==Pathophysiology== | ||
The degeneration occurs in conjunction with an accumulation of [[dermatan sulfate]], a [[glycosaminoglycan]], within the [[connective tissue]][[ matrix ]]of the [[valve]]. The exact mechanism is unknown. | The [[degeneration]] occurs in conjunction with an accumulation of [[dermatan sulfate]], a [[glycosaminoglycan]], within the [[connective tissue]][[ matrix ]]of the [[valve]]. The exact mechanism is unknown. | ||
In many cases, the degeneration is limited to the [[Mitral valve|mitral valve]] and follows a benign course. When associated with systemic diseases, like [[Marfan syndrome]], the degeneration is more extensive and involves other heart valves. The valves can become sufficiently distorted to cause [[Aortic insufficiency|insufficiency]] and [[Regurgitation (circulation)|regurgitation]]. | In many cases, the degeneration is limited to the [[Mitral valve|mitral valve]] and follows a benign course. When associated with [[systemic diseases]], like [[Marfan syndrome]], the degeneration is more extensive and involves other[[ heart valves]]. The valves can become sufficiently distorted to cause [[Aortic insufficiency|insufficiency]] and [[Regurgitation (circulation)|regurgitation]]. | ||
Deposition of excessive proteoglycans causes widening of the fibrosa, which extends towards basal aspects and also tends to involve the annulus and chords, which further leads to loss of collagen | Deposition of excessive [[proteoglycans]] causes widening of the[[ fibrosa]], which extends towards basal aspects and also tends to involve the annulus and chords, which further leads to loss of [[collagen ]]and [[elastic tissue]]. | ||
Myxomatous degeneration can occur in other organs like uterus, where we can see myxomatous degeneration of uterine fibroids. | Myxomatous degeneration can occur in other organs like [[uterus]], where we can see myxomatous degeneration of [[uterine fibroids]]. | ||
{{see also|Mitral valve prolapse}} | {{see also|Mitral valve prolapse}} | ||
==Historical Perspective== | ==Historical Perspective== | ||
*Myxomatous Mitral Valve disease was first reported by Delabere Blaine in 1817 in dogs.<ref name="pmid223865883">{{cite journal| author=Borgarelli M, Buchanan JW| title=Historical review, epidemiology and natural history of degenerative mitral valve disease. | journal=J Vet Cardiol | year= 2012 | volume= 14 | issue= 1 | pages= 93-101 | pmid=22386588 | doi=10.1016/j.jvc.2012.01.011 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22386588 }}</ref> | *Myxomatous Mitral Valve disease was first reported by Delabere Blaine in 1817 in dogs.<ref name="pmid223865883">{{cite journal| author=Borgarelli M, Buchanan JW| title=Historical review, epidemiology and natural history of[[ degenerative mitral valve disease]]. | journal=J Vet Cardiol | year= 2012 | volume= 14 | issue= 1 | pages= 93-101 | pmid=22386588 | doi=10.1016/j.jvc.2012.01.011 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22386588 }}</ref> | ||
*Myxomatous Degeneration of Mitral Valve is a | *Myxomatous Degeneration of Mitral Valve is a [[genetic abnormality]] mapped to Xq28 gene. | ||
==Classification== | ==Classification== | ||
*Myxomatous degeneration may be classified as: | *Myxomatous degeneration may be classified as: | ||
**Primary | **Primary | ||
**Secondary | **Secondary | ||
*Whitney in1967 classified Myxomatous Mitral Valve Disease into 4 types based on the structures involved-<ref name="pmid223865883" /> | *Whitney in1967 classified Myxomatous[[ Mitral Valve Disease]] into 4 types based on the structures involved-<ref name="pmid223865883" /> | ||
:* Type I,II- Small nodular thickening of mitral leaflets without chordae tendinae involvement | :* Type I,II- Small [[nodular thickening]] of[[ mitral leaflets ]]without [[chordae tendinae]] involvement | ||
:* Type III-Severe thickening and ballooning of valve cusps | :* Type III-Severe thickening and [[ballooning ]]of valve cusps | ||
:* Type IV- Chordae tendinae thickening and Occasional rupture | :* Type IV-[[ Chordae tendinae]] thickening and Occasional [[rupture]] | ||
==Pathophysiology== | ==Pathophysiology== | ||
*The pathogenesis of Myxomatous mitral valve degeneration is characterized by Valvular or chordal degeneration with excesssive systolic movement of leaflet defined by a prolapse in Left atrium >/2mm. | *The pathogenesis of Myxomatous mitral valve degeneration is characterized by [[Valvular ]]or [[chordal degeneration ]]with excesssive [[systolic movement of leaflet ]]defined by a prolapse in[[ Left atrium ]]>/2mm. | ||
*It can affect one or both leaflets and can affect one or multiple scallops. | *It can affect one or both [[leaflets]] and can affect one or[[ multiple scallops]]. | ||
*Degeneration of Mitral valve is divided into two phenotypes:<ref name="AntoineMantovani2018">{{cite journal|last1=Antoine|first1=Clemence|last2=Mantovani|first2=Francesca|last3=Benfari|first3=Giovanni|last4=Mankad|first4=Sunil V.|last5=Maalouf|first5=Joseph F.|last6=Michelena|first6=Hector I.|last7=Enriquez-Sarano|first7=Maurice|title=Pathophysiology of Degenerative Mitral Regurgitation|journal=Circulation: Cardiovascular Imaging|volume=11|issue=1|year=2018|issn=1941-9651|doi=10.1161/CIRCIMAGING.116.005971}}</ref> | *[[Degeneration ]]of[[ Mitral valve ]]is divided into two[[ phenotypes]]:<ref name="AntoineMantovani2018">{{cite journal|last1=Antoine|first1=Clemence|last2=Mantovani|first2=Francesca|last3=Benfari|first3=Giovanni|last4=Mankad|first4=Sunil V.|last5=Maalouf|first5=Joseph F.|last6=Michelena|first6=Hector I.|last7=Enriquez-Sarano|first7=Maurice|title=Pathophysiology of Degenerative Mitral Regurgitation|journal=Circulation: Cardiovascular Imaging|volume=11|issue=1|year=2018|issn=1941-9651|doi=10.1161/CIRCIMAGING.116.005971}}</ref> | ||
* <u>Fibro Elastic Deficiency</u>: | * <u>[[Fibro Elastic Deficiency]]</u>: | ||
**localised to one segment. | **localised to one segment. | ||
**involves ruptured chords. | **involves ruptured [[chords]]. | ||
**Histologically- Myxomatous degeneration | **Histologically- Myxomatous degeneration | ||
**Macroscopically- Leaflet redundancy and thickening predominant on the flail segment. | **Macroscopically- Leaflet [[redundancy]] and thickening predominant on the flail segment. | ||
**Reminder of the valve is thin and translucent. | **Reminder of the valve is thin and translucent. | ||
**Patients present in older ages | **Patients present in older ages | ||
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* <u>Diffuse Myxomatous Degeneration:</u> | * <u>Diffuse Myxomatous Degeneration:</u> | ||
**Generalised | **[[Generalised]] | ||
**Redundancy and thickening of both leaflets involving multiple segments | **[[Redundancy ]]and [[thickening ]]of both leaflets involving multiple segments | ||
**.Mitral Regurgitation typically predominates in | **[[Mitral regurgitation|.Mitral Regurgitation typically]] predominates in [[Mid late systole|mid-late systole]]. | ||
**Severeity varies from mild to severe. | **Severeity varies from mild to severe. | ||
==Clinical Features:== | ==Clinical Features:== | ||
Patients can be asymptomatic,or can have mild to severe symptoms. | Patients can be [[asymptomatic]],or can have mild to severe symptoms. | ||
Patients can have heart murmur, cough, dyspnea, signs and symptoms of Congestive Heart Failure, Arrythmias.<br /> | Patients can have heart [[Murmur|murmur,]] [[cough]], [[dyspnea]], signs and symptoms of [[Congestive Heart Failure]], [[Arrythmias]].<br /> | ||
==Differentiating Myxomatous Mitral Valve Degeneration from other Diseases== | ==Differentiating Myxomatous Mitral Valve Degeneration from other Diseases== | ||
*Myxomatous degeneration of Mitral Valve must be differentiated from other diseases that cause [[Mitral | *Myxomatous degeneration of Mitral Valve must be differentiated from other diseases that cause [[Mitral valve regurgitation|Mitral Valve Regurgitation,]] such as:<ref>{{cite journal|year=2007|doi=10.1016/B978-1-4160-2971-7.X1000-8}}</ref> | ||
:*Ischemic Injury to Mitral Valve | :*[[Ischemic Injury]] to Mitral Valve | ||
:*[[Rheumatic Heart Disease]] | :*[[Rheumatic Heart Disease]] | ||
:*[[Connective tissue disorder]] | :*[[Connective tissue disorder]] | ||
| Line 84: | Line 84: | ||
== Diagnosis == | == Diagnosis == | ||
===Diagnostic Criteria=== | ===Diagnostic Criteria=== | ||
* | * Currently there is no diagnostic criteria available. | ||
=== Symptoms === | === Symptoms === | ||
*Myxomatous degeneration of mitral valve can be asymptomatic. | *Myxomatous degeneration of mitral valve can be asymptomatic. | ||
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*Physical examination may be remarkable for: | *Physical examination may be remarkable for: | ||
:*Systolic click or mid-late systolic murmur. | :*[[Systolic click—murmur syndrome|Systolic click]] or [[Systolic click—murmur syndrome|mid-late systolic murmur]]. | ||
:*Apical holosystolic murmur<ref>{{cite journal|year=2016|doi=10.1016/C2013-0-12761-4}}</ref> | :*[[Apical holosystolic murmur]]<ref>{{cite journal|year=2016|doi=10.1016/C2013-0-12761-4}}</ref> | ||
=== Laboratory Findings === | === Laboratory Findings === | ||
*There are no specific laboratory findings associated with Myxomatous degeneration of Mitral valve | *There are no specific laboratory findings associated with Myxomatous degeneration of [[Mitral valve]] | ||
===Imaging Findings=== | ===Imaging Findings=== | ||
| Line 116: | Line 112: | ||
=== Other Diagnostic Studies=== | === Other Diagnostic Studies=== | ||
*Xray | *[[Xray Ches]]<nowiki/>t- can show [[cardiomegaly.]] | ||
*Electrocardiogram (ECG)- non invasive test, Can help in detecting [[Cardiac arrhythmia|arrythmias]], [[Left atrial enlargement]], [[Left ventricular hypertrophy|Left Ventricle hypertrophy]]. | *Electrocardiogram [[ECG|(ECG]])- non invasive test, Can help in detecting [[Cardiac arrhythmia|arrythmias]], [[Left atrial enlargement]], [[Left ventricular hypertrophy|Left Ventricle hypertrophy]]. | ||
*CT Scan-non invasive imaging test,Can measure the degree of leaflet displacement and relation between valve leaflets and annulus. | *[[CT Scan]]-non invasive imaging test,Can measure the degree of leaflet displacement and relation between valve [[leaflets]] and annulus. | ||
*MRI- non invasive, can provide information on the severeity of Mitral Regurgitation<ref>{{cite journal|year=2010|doi=10.1016/B978-1-4160-6231-8.X0001-3}}</ref>. | *[[MRI]]- non invasive, can provide information on the severeity of [[Mitral Regurgitation]]<ref>{{cite journal|year=2010|doi=10.1016/B978-1-4160-6231-8.X0001-3}}</ref>. | ||
== Treatment == | == Treatment == | ||
| Line 133: | Line 129: | ||
*Surgery is the mainstay of therapy for Myxomatous degeneration of Mitral Valve. | *Surgery is the mainstay of therapy for Myxomatous degeneration of Mitral Valve. | ||
*[[Mitral valve repair|Mitral Valve repair]] is the preferred surgical technique.<ref>{{cite journal|year=2010|doi=10.1016/B978-1-4160-6231-8.X0001-3}}</ref> | *[[Mitral valve repair|Mitral Valve repair]] is the preferred surgical technique.<ref>{{cite journal|year=2010|doi=10.1016/B978-1-4160-6231-8.X0001-3}}</ref> | ||
*Mitral valve repair when compared to replacement improves survival, Left ventricular function, and decreased chance of reoperation. | *[[Mitral valve repair]] when compared to replacement improves survival, [[Left ventricular function]], and decreased chance of reoperation. | ||
*Mitral Valve replacement can also be done. | *[[Mitral valve replacement|Mitral Valve replacement]] can also be done. | ||
=== Prevention === | === Prevention === | ||
*There are no primary preventive measures available for Myxomatous degeneration of Mitral Valve. | *There are no primary preventive measures available for Myxomatous degeneration of [[Mitral valve|Mitral Valve]]. | ||
==References== | ==References== | ||
Latest revision as of 19:25, 6 July 2020
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Mahshid Mir, M.D. [2] Shaik Aisha sultana, [3]
Overivew
Myxomatous degeneration is a progressive, non-inflammatory disarray of the structure involved caused by a defect in the integrity of the structure, due to the alteration in the synthesis and remodelling of the tissue. Myxomatous is a term derived from the word Myxoma. Myxoma is derived from Greek word muxa, meaning mucus.Myxoma is a non-cancerous tumor growth, it contains mucus or gelatin like substance. The term is most often used in the context of Mitral valve prolapse, which is known more technically as "Myxomatous degeneration of the mitral valve." It can also be used in reference to degeneration of the aortic valve. Myxomatous degeneration of the cardiac valves (MDMV) stands for the non-inflammatory progressive disarray of the valve structure caused by a defect in the mechanical integrity of the leaflet due to the altered synthesis and/or remodeling by type VI collagen]. The gross morphologic features are characterized by voluminous and thickened leaflets, in both longitudinal and transversal axes. This entity involves not only the valve but also the chordae tendineae that has also become thickened, elongated, and sometimes ruptured.
Pathophysiology
The degeneration occurs in conjunction with an accumulation of dermatan sulfate, a glycosaminoglycan, within the connective tissuematrix of the valve. The exact mechanism is unknown.
In many cases, the degeneration is limited to the mitral valve and follows a benign course. When associated with systemic diseases, like Marfan syndrome, the degeneration is more extensive and involves otherheart valves. The valves can become sufficiently distorted to cause insufficiency and regurgitation.
Deposition of excessive proteoglycans causes widening of thefibrosa, which extends towards basal aspects and also tends to involve the annulus and chords, which further leads to loss of collagen and elastic tissue.
Myxomatous degeneration can occur in other organs like uterus, where we can see myxomatous degeneration of uterine fibroids.
Historical Perspective
- Myxomatous Mitral Valve disease was first reported by Delabere Blaine in 1817 in dogs.[1]
- Myxomatous Degeneration of Mitral Valve is a genetic abnormality mapped to Xq28 gene.
Classification
- Myxomatous degeneration may be classified as:
- Primary
- Secondary
- Whitney in1967 classified MyxomatousMitral Valve Disease into 4 types based on the structures involved-[1]
- Type I,II- Small nodular thickening ofmitral leaflets without chordae tendinae involvement
- Type III-Severe thickening and ballooning of valve cusps
- Type IV-Chordae tendinae thickening and Occasional rupture
Pathophysiology
- The pathogenesis of Myxomatous mitral valve degeneration is characterized by Valvular or chordal degeneration with excesssive systolic movement of leaflet defined by a prolapse inLeft atrium >/2mm.
- It can affect one or both leaflets and can affect one ormultiple scallops.
- Degeneration ofMitral valve is divided into twophenotypes:[2]
- localised to one segment.
- involves ruptured chords.
- Histologically- Myxomatous degeneration
- Macroscopically- Leaflet redundancy and thickening predominant on the flail segment.
- Reminder of the valve is thin and translucent.
- Patients present in older ages
- Diffuse Myxomatous Degeneration:
- Generalised
- Redundancy and thickening of both leaflets involving multiple segments
- .Mitral Regurgitation typically predominates in mid-late systole.
- Severeity varies from mild to severe.
Clinical Features:
Patients can be asymptomatic,or can have mild to severe symptoms.
Patients can have heart murmur, cough, dyspnea, signs and symptoms of Congestive Heart Failure, Arrythmias.
Differentiating Myxomatous Mitral Valve Degeneration from other Diseases
- Myxomatous degeneration of Mitral Valve must be differentiated from other diseases that cause Mitral Valve Regurgitation, such as:[3]
- Ischemic Injury to Mitral Valve
- Rheumatic Heart Disease
- Connective tissue disorder
Epidemiology and Demographics
- The prevalence of Myxomatous Mitral Valve Degeneration in Canines, increases as age increase, and the prevalence especially in old, small breed dogs is 100%.
- It affects about 5% of the Human population.[4]
Age and Gender
- It is more common in Young females.
- It is frequently symptomatic in males.
Risk Factors
- Common risk factors in the development of Myxomatous degeneration are Connective tissue disorders like Marfan's Syndrome, Ehlers-Danlos syndrome, and other conditions with collagen abnormalities.
Natural History, Complications and Prognosis
- The majority of patients with Myxomatous degeneration of Mitral Valve are asymptomatic.
- Early clinical features include presence of a heart murmur.
- If left untreated,about 10% of patients with Myxomatous degeneration of Mitral Valve may progress to develop severe Mitral regurgitation requiring surgical repair of the valve.[5]
- Common complications of Myxomatous degeneration of Mitral Valve include rupture of the chordae tendinae leading to acute mitral regurgitation, Arrythmias, Congestive Heart Failure,Endocarditis ,rarely Sudden cardiac death.
- Prognosis is generally good after Mitral Valve repair.
Diagnosis
Diagnostic Criteria
- Currently there is no diagnostic criteria available.
Symptoms
- Myxomatous degeneration of mitral valve can be asymptomatic.
- Symptoms of Myxomatous degeneration of Mitral valve may include the following:
- Apical Holosystolic murmur
- Systolic click to mid late systolic murmur
- Cough - due to Heart failure
- Dyspnea- Pulmonary edema, Pulmonary Hypertension.
- Syncope- arrythmias
Physical Examination
- Patients with Myxomatous degeneration of mitral valve usually present with Mitral Valve prolapse.
- Physical examination may be remarkable for:
Laboratory Findings
- There are no specific laboratory findings associated with Myxomatous degeneration of Mitral valve
Imaging Findings
- 2D Echocardiography is the imaging modality of choice.
- Transesophageal Echo- shows Mitral valve prolapse and Mitral valve thickening.[7]
Other Diagnostic Studies
- Xray Chest- can show cardiomegaly.
- Electrocardiogram (ECG)- non invasive test, Can help in detecting arrythmias, Left atrial enlargement, Left Ventricle hypertrophy.
- CT Scan-non invasive imaging test,Can measure the degree of leaflet displacement and relation between valve leaflets and annulus.
- MRI- non invasive, can provide information on the severeity of Mitral Regurgitation[8].
Treatment
Medical Therapy
- There is no medical therapy for Myxomatous degeneration of Mitral Valve, the mainstay of therapy is supportive care.
- Diuretics- if symptoms of Heart failure
- ACE inhibitors
- β blockers
- Vasodilators
Surgery
- Surgery is the mainstay of therapy for Myxomatous degeneration of Mitral Valve.
- Mitral Valve repair is the preferred surgical technique.[9]
- Mitral valve repair when compared to replacement improves survival, Left ventricular function, and decreased chance of reoperation.
- Mitral Valve replacement can also be done.
Prevention
- There are no primary preventive measures available for Myxomatous degeneration of Mitral Valve.
References
- ↑ 1.0 1.1 Borgarelli M, Buchanan JW (2012). "Historical review, epidemiology and natural history of[[ degenerative mitral valve disease]]". J Vet Cardiol. 14 (1): 93–101. doi:10.1016/j.jvc.2012.01.011. PMID 22386588. URL–wikilink conflict (help)
- ↑ Antoine, Clemence; Mantovani, Francesca; Benfari, Giovanni; Mankad, Sunil V.; Maalouf, Joseph F.; Michelena, Hector I.; Enriquez-Sarano, Maurice (2018). "Pathophysiology of Degenerative Mitral Regurgitation". Circulation: Cardiovascular Imaging. 11 (1). doi:10.1161/CIRCIMAGING.116.005971. ISSN 1941-9651.
- ↑ . 2007. doi:10.1016/B978-1-4160-2971-7.X1000-8. Missing or empty
|title=(help) - ↑ . 2016. doi:10.1016/C2013-0-12761-4. Missing or empty
|title=(help) - ↑ . 2019. doi:10.1016/C2017-0-02974-9. Missing or empty
|title=(help) - ↑ . 2016. doi:10.1016/C2013-0-12761-4. Missing or empty
|title=(help) - ↑ . 2010. doi:10.1016/B978-1-4160-6231-8.X0001-3. Missing or empty
|title=(help) - ↑ . 2010. doi:10.1016/B978-1-4160-6231-8.X0001-3. Missing or empty
|title=(help) - ↑ . 2010. doi:10.1016/B978-1-4160-6231-8.X0001-3. Missing or empty
|title=(help)