Eisenmenger’s syndrome pathophysiology: Difference between revisions
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{{Template:Eisenmenger's syndrome}} | {{Template:Eisenmenger's syndrome}} | ||
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==Overview== | ==Overview== | ||
The progression of a heart defect to [[Eisenmenger's syndrome]] depends on the size of left to right [[Shunt (medical)|shunt]], severity of pulmonary vascular disease, and type of defect. The [[left-to-right shunt]] at the start increases the pulmonary vascular flow and leads to [[Pulmonary hypertension|pulmonary artery hypertension]]. This causes damage to the delicate pulmonary capillaries, creating [[Scar|scars]] and fibrous tissue. This leads to [[hypoxemia]], which is compensated by increased [[Red blood cell|RBCs]] production, leading to [[polycythemia]] and [[hyperviscosity syndrome]]. Eventually, the building pressure in the [[pulmonary circulation]] will cause shunt reversal and development of [[Eisenmenger's syndrome]]. | |||
==Pathophysiology== | ==Pathophysiology== | ||
=== Physiology === | === Physiology === | ||
* In unaffected individuals, the chambers of the left side of the [[heart]] make up a higher pressure system than the chambers of the right side of the heart. | |||
* This is because the [[left ventricle]] has to produce enough pressure to pump blood throughout the entire body, while the [[right ventricle]] only has to produce enough pressure to pump blood to the [[lung]]s. | |||
* Any process that increases the pressure in the [[left ventricle]] can cause worsening of the left-to-right shunt. This includes [[hypertension]], which increases the pressure that the [[left ventricle]] has to generate in order to open the [[aortic valve]] during ventricular [[systole]], and [[coronary artery disease]] which increases the stiffness of the [[left ventricle]], thereby increasing the filling pressure of the left ventricle during ventricular [[diastole]]<ref name="pmid31120797">{{cite journal| author=Favoccia C, Constantine AH, Wort SJ, Dimopoulos K| title=Eisenmenger syndrome and other types of pulmonary arterial hypertension related to adult congenital heart disease. | journal=Expert Rev Cardiovasc Ther | year= 2019 | volume= 17 | issue= 6 | pages= 449-459 | pmid=31120797 | doi=10.1080/14779072.2019.1623024 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=31120797 }}</ref>. | |||
=== Pathogenesis === | === Pathogenesis === | ||
| Line 14: | Line 18: | ||
* Eisenmenger's syndrome can develop in many types of [[Congenital heart disease|congenital heart diseases]]. | * Eisenmenger's syndrome can develop in many types of [[Congenital heart disease|congenital heart diseases]]. | ||
* It has been found that among all the congenital heart defects, [[ventricular septal defect]] most frequently develops Eisenmenger's syndrome followed by [[atrial septal defect]] and [[patent ductus arteriosus]]<ref name="pmid7960265">{{cite journal| author=Saha A, Balakrishnan KG, Jaiswal PK, Venkitachalam CG, Tharakan J, Titus T et al.| title=Prognosis for patients with Eisenmenger syndrome of various aetiology. | journal=Int J Cardiol | year= 1994 | volume= 45 | issue= 3 | pages= 199-207 | pmid=7960265 | doi= | pmc= | url= }} </ref>. | * It has been found that among all the congenital heart defects, [[ventricular septal defect]] most frequently develops Eisenmenger's syndrome followed by [[atrial septal defect]] and [[patent ductus arteriosus]]<ref name="pmid7960265">{{cite journal| author=Saha A, Balakrishnan KG, Jaiswal PK, Venkitachalam CG, Tharakan J, Titus T et al.| title=Prognosis for patients with Eisenmenger syndrome of various aetiology. | journal=Int J Cardiol | year= 1994 | volume= 45 | issue= 3 | pages= 199-207 | pmid=7960265 | doi= | pmc= | url= }} </ref>. | ||
* The progression of a heart defect to Eisenmenger's syndrome depends on: | * The progression of a heart defect to [[Eisenmenger's syndrome]] depends on: | ||
** Size of left to right [[Shunt (medical)|shunt]] | ** Size of left to right [[Shunt (medical)|shunt]] | ||
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* The left-to-right shunting causes an increase in pulmonary vascular flow, which in turn leads to [[Pulmonary hypertension|pulmonary artery hypertension]]. | * The left-to-right shunting causes an increase in pulmonary vascular flow, which in turn leads to [[Pulmonary hypertension|pulmonary artery hypertension]]. | ||
* This leads to reversal of shunt | * This leads to reversal of shunt and development of [[cyanosis]]. | ||
* Further, the increased pressure causes damage to delicate [[capillaries]], which then are replaced with [[scar]] tissue. | |||
* The scar tissue does not contribute to oxygen transfer, therefore decreasing the useful volume of the pulmonary vasculature. The scar tissue also provides less flexibility than normal lung tissue, causing further increases in blood pressure, | * The [[scar]] tissue does not contribute to [[oxygen]] transfer, therefore decreasing the useful volume of the [[pulmonary vasculature]]. The scar tissue also provides less flexibility than normal lung tissue, causing further increases in [[blood pressure]]<ref name="pmid318135033">{{cite journal| author=Chaix MA, Gatzoulis MA, Diller GP, Khairy P, Oechslin EN| title=Eisenmenger Syndrome: A Multisystem Disorder-Do Not Destabilize the Balanced but Fragile Physiology. | journal=Can J Cardiol | year= 2019 | volume= 35 | issue= 12 | pages= 1664-1674 | pmid=31813503 | doi=10.1016/j.cjca.2019.10.002 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=31813503 }}</ref>. | ||
* The reduction in oxygen transfer reduces [[oxygen saturation]] in the blood, leading to increased production of red blood cells in an attempt to bring the oxygen saturation up. The excess of red blood cells is called [[polycythemia]]. | * The reduction in oxygen transfer reduces [[oxygen saturation]] in the blood, leading to increased production of [[Red blood cell|red blood cells]] in an attempt to bring the [[oxygen saturation]] up. The excess of [[red blood cells]] is called [[polycythemia]]. | ||
* Desperate for enough circulating oxygen, the body begins to dump immature red cells into the blood stream. Immature red cells are not as efficient at carrying oxygen as mature red cells, and they are less flexible, less able to easily squeeze through tiny capillaries in the lungs, and so contribute to death of pulmonary capillary beds. The increase in red blood cells also causes [[hyperviscosity syndrome]]. | * Desperate for enough circulating [[oxygen]], the body begins to dump immature red cells into the [[blood stream]]. Immature [[Red blood cell|red cells]] are not as efficient at carrying oxygen as mature red cells, and they are less flexible, less able to easily squeeze through tiny [[capillaries]] in the lungs, and so contribute to death of pulmonary capillary beds. The increase in red blood cells also causes [[hyperviscosity syndrome]]. | ||
* A person with Eisenmenger's Syndrome is paradoxically subject to the possibility of both uncontrolled bleeding due to damaged capillaries and high pressure, and random clots due to hyperviscosity and [[stasis (medicine)|stasis]] of blood. | * A person with [[Eisenmenger's syndrome|Eisenmenger's Syndrome]] is paradoxically subject to the possibility of both uncontrolled [[bleeding]] due to damaged capillaries and high pressure, and random clots due to [[Hyperviscosity syndrome|hyperviscosity]] and [[stasis (medicine)|stasis]] of blood. | ||
* Eventually, due to increased resistance, pulmonary pressures may increase sufficiently to cause a reversal of blood flow, so blood begins to travel from the right side of the heart to the left side, and the body is supplied with deoxygenated blood, leading to [[cyanosis]] and resultant organ damage. | * Eventually, due to increased resistance, pulmonary pressures may increase sufficiently to cause a reversal of [[blood flow]], so blood begins to travel from the right side of the heart to the left side, and the body is supplied with deoxygenated blood, leading to [[cyanosis]] and resultant organ damage<ref name="pmid318135032">{{cite journal| author=Chaix MA, Gatzoulis MA, Diller GP, Khairy P, Oechslin EN| title=Eisenmenger Syndrome: A Multisystem Disorder-Do Not Destabilize the Balanced but Fragile Physiology. | journal=Can J Cardiol | year= 2019 | volume= 35 | issue= 12 | pages= 1664-1674 | pmid=31813503 | doi=10.1016/j.cjca.2019.10.002 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=31813503 }}</ref>. | ||
[[File:Atrial septal defect-en.png|center|thumb|Cardiac shunt with atrial septal defect.]] | |||
<br /> | |||
== Genetics == | == Genetics == | ||
* [ | *[[Eisenmenger's syndrome|Eisenmenger's Syndrome]] is not currently identified as an inherited disorder. | ||
* [ | |||
* Specific genes that cause [[Eisenmenger's syndrome]] have not been identified so far. | |||
== Associated Conditions == | == Associated Conditions == | ||
Conditions associated with [ | Conditions associated with [[Eisenmenger's syndrome]] include: | ||
* [ | * Causative [[Congenital heart disease|congenital heart diseases]]. | ||
* [ | * Tricuspid and pulmonary valve [[regurgitation]] | ||
* [ | *[[Atherosclerosis]] | ||
== Gross Pathology == | == Gross Pathology == | ||
On gross pathology, [ | On gross pathology, [[Eisenmenger's syndrome]] may show the following<ref name="pmid28536680">{{cite journal| author=de Campos FPF, Benvenuti LA| title=Eisenmenger syndrome. | journal=Autops Case Rep | year= 2017 | volume= 7 | issue= 1 | pages= 5-7 | pmid=28536680 | doi=10.4322/acr.2017.006 | pmc=5436914 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=28536680 }}</ref>: | ||
* Atrial or [[ventricular septal defect]]. | |||
* Right [[ventricular hypertrophy]] | |||
*Pulmonary trunk dilatation | |||
*[[Atherosclerosis]] of [[pulmonary artery]] and its branches. | |||
*[[Tricuspid regurgitation]] may be seen. | |||
== Microscopic Pathology == | == Microscopic Pathology == | ||
According to the histopathologic criteria of Heath and Edwards, there are six stages of pulmonary vascular disease (including [[Eisenmenger's syndrome]])<ref name="pmid13573570">{{cite journal| author=HEATH D, EDWARDS JE| title=The pathology of hypertensive pulmonary vascular disease; a description of six grades of structural changes in the pulmonary arteries with special reference to congenital cardiac septal defects. | journal=Circulation | year= 1958 | volume= 18 | issue= 4 Part 1 | pages= 533-47 | pmid=13573570 | doi=10.1161/01.cir.18.4.533 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=13573570 }}</ref>: | |||
* Stage I: Medial [[Hypertrophy (medical)|hypertrophy]] (reversible) | |||
* Stage II: Cellular intimal [[hyperplasia]] in an abnormally muscular artery (reversible) | |||
* Stage III: Lumen [[occlusion]] from intimal [[hyperplasia]] of fibroelastic tissue (partially reversible) | |||
* Stage IV: Arteriolar dilatation and medial thinning (irreversible) | |||
* Stage V: Plexiform lesion, which is an angiomatoid formation (terminal and irreversible) | |||
* Stage VI: Fibrinoid/necrotizing [[arteritis]] (terminal and irreversible) | |||
==References== | ==References== | ||
Latest revision as of 05:13, 27 January 2020
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Risk calculators and risk factors for Eisenmenger’s syndrome pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Abdelrahman Ibrahim Abushouk, MD[2]
Overview
The progression of a heart defect to Eisenmenger's syndrome depends on the size of left to right shunt, severity of pulmonary vascular disease, and type of defect. The left-to-right shunt at the start increases the pulmonary vascular flow and leads to pulmonary artery hypertension. This causes damage to the delicate pulmonary capillaries, creating scars and fibrous tissue. This leads to hypoxemia, which is compensated by increased RBCs production, leading to polycythemia and hyperviscosity syndrome. Eventually, the building pressure in the pulmonary circulation will cause shunt reversal and development of Eisenmenger's syndrome.
Pathophysiology
Physiology
- In unaffected individuals, the chambers of the left side of the heart make up a higher pressure system than the chambers of the right side of the heart.
- This is because the left ventricle has to produce enough pressure to pump blood throughout the entire body, while the right ventricle only has to produce enough pressure to pump blood to the lungs.
- Any process that increases the pressure in the left ventricle can cause worsening of the left-to-right shunt. This includes hypertension, which increases the pressure that the left ventricle has to generate in order to open the aortic valve during ventricular systole, and coronary artery disease which increases the stiffness of the left ventricle, thereby increasing the filling pressure of the left ventricle during ventricular diastole[1].
Pathogenesis
- Eisenmenger's syndrome can develop in many types of congenital heart diseases.
- It has been found that among all the congenital heart defects, ventricular septal defect most frequently develops Eisenmenger's syndrome followed by atrial septal defect and patent ductus arteriosus[2].
- The progression of a heart defect to Eisenmenger's syndrome depends on:
- Size of left to right shunt
- Severity of pulmonary vascular disease.
- Type of defect (it develops more frequently in uncorrected ventricular septal defect compared to atrial septal defect)[3]
- The left-to-right shunting causes an increase in pulmonary vascular flow, which in turn leads to pulmonary artery hypertension.
- This leads to reversal of shunt and development of cyanosis.
- Further, the increased pressure causes damage to delicate capillaries, which then are replaced with scar tissue.
- The scar tissue does not contribute to oxygen transfer, therefore decreasing the useful volume of the pulmonary vasculature. The scar tissue also provides less flexibility than normal lung tissue, causing further increases in blood pressure[4].
- The reduction in oxygen transfer reduces oxygen saturation in the blood, leading to increased production of red blood cells in an attempt to bring the oxygen saturation up. The excess of red blood cells is called polycythemia.
- Desperate for enough circulating oxygen, the body begins to dump immature red cells into the blood stream. Immature red cells are not as efficient at carrying oxygen as mature red cells, and they are less flexible, less able to easily squeeze through tiny capillaries in the lungs, and so contribute to death of pulmonary capillary beds. The increase in red blood cells also causes hyperviscosity syndrome.
- A person with Eisenmenger's Syndrome is paradoxically subject to the possibility of both uncontrolled bleeding due to damaged capillaries and high pressure, and random clots due to hyperviscosity and stasis of blood.
- Eventually, due to increased resistance, pulmonary pressures may increase sufficiently to cause a reversal of blood flow, so blood begins to travel from the right side of the heart to the left side, and the body is supplied with deoxygenated blood, leading to cyanosis and resultant organ damage[5].
Genetics
- Eisenmenger's Syndrome is not currently identified as an inherited disorder.
- Specific genes that cause Eisenmenger's syndrome have not been identified so far.
Associated Conditions
Conditions associated with Eisenmenger's syndrome include:
- Causative congenital heart diseases.
- Tricuspid and pulmonary valve regurgitation
- Atherosclerosis
Gross Pathology
On gross pathology, Eisenmenger's syndrome may show the following[6]:
- Atrial or ventricular septal defect.
- Right ventricular hypertrophy
- Pulmonary trunk dilatation
- Atherosclerosis of pulmonary artery and its branches.
- Tricuspid regurgitation may be seen.
Microscopic Pathology
According to the histopathologic criteria of Heath and Edwards, there are six stages of pulmonary vascular disease (including Eisenmenger's syndrome)[7]:
- Stage I: Medial hypertrophy (reversible)
- Stage II: Cellular intimal hyperplasia in an abnormally muscular artery (reversible)
- Stage III: Lumen occlusion from intimal hyperplasia of fibroelastic tissue (partially reversible)
- Stage IV: Arteriolar dilatation and medial thinning (irreversible)
- Stage V: Plexiform lesion, which is an angiomatoid formation (terminal and irreversible)
- Stage VI: Fibrinoid/necrotizing arteritis (terminal and irreversible)
References
- ↑ Favoccia C, Constantine AH, Wort SJ, Dimopoulos K (2019). "Eisenmenger syndrome and other types of pulmonary arterial hypertension related to adult congenital heart disease". Expert Rev Cardiovasc Ther. 17 (6): 449–459. doi:10.1080/14779072.2019.1623024. PMID 31120797.
- ↑ Saha A, Balakrishnan KG, Jaiswal PK, Venkitachalam CG, Tharakan J, Titus T; et al. (1994). "Prognosis for patients with Eisenmenger syndrome of various aetiology". Int J Cardiol. 45 (3): 199–207. PMID 7960265.
- ↑ Granton JT, Rabinovitch M (2002). "Pulmonary arterial hypertension in congenital heart disease". Cardiol Clin. 20 (3): 441–57, vii. PMID 12371012.
- ↑ Chaix MA, Gatzoulis MA, Diller GP, Khairy P, Oechslin EN (2019). "Eisenmenger Syndrome: A Multisystem Disorder-Do Not Destabilize the Balanced but Fragile Physiology". Can J Cardiol. 35 (12): 1664–1674. doi:10.1016/j.cjca.2019.10.002. PMID 31813503.
- ↑ Chaix MA, Gatzoulis MA, Diller GP, Khairy P, Oechslin EN (2019). "Eisenmenger Syndrome: A Multisystem Disorder-Do Not Destabilize the Balanced but Fragile Physiology". Can J Cardiol. 35 (12): 1664–1674. doi:10.1016/j.cjca.2019.10.002. PMID 31813503.
- ↑ de Campos FPF, Benvenuti LA (2017). "Eisenmenger syndrome". Autops Case Rep. 7 (1): 5–7. doi:10.4322/acr.2017.006. PMC 5436914. PMID 28536680.
- ↑ HEATH D, EDWARDS JE (1958). "The pathology of hypertensive pulmonary vascular disease; a description of six grades of structural changes in the pulmonary arteries with special reference to congenital cardiac septal defects". Circulation. 18 (4 Part 1): 533–47. doi:10.1161/01.cir.18.4.533. PMID 13573570.