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{{Pulmonary hypertension}}
{{Pulmonary hypertension}}
{{CMG}}; '''Assistant Editor(s)-in-Chief:''' [[User:Ralph Matar|Ralph Matar]]
{{CMG}}; '''Assistant Editor(s)-in-Chief:''' [[User:Ralph Matar|Ralph Matar]]; [[User:Rim Halaby|Rim Halaby]] {{Jose}}
==Overview==
Pulmonary hypertension (PH) is a pathological condition of the pulmonary vasculature present in several disease states that presents with elevated mean pulmonary artery pressure (PAP) as measured by [[right heart catheterization]] at rest. The factors that are in involved in the pathophysiology of the increase in the mean pulmonary arterial pressure are: increase in pulmonary [[vascular resistance]], increase in the right-side cardiac output and increase in the [[mean pulmonary venous pressure]]. Pulmonary arterial hypertension is characterized by [[endothelial]] dysfunction resulting from an imbalance between [[apoptosis]] and proliferation of pulmonary artery smooth muscle cells favoring the proliferation. The other types of [[pulmonary hypertension]] are caused by hemodynamic changes that result in increased [[pulmonary blood pressure]] or architectural changes to the lung or its [[vasculature]] that result in the same outcome.


== Overview ==
==Pathophysiology==
The pulmonary artery pressure is considered normal at a mean pressure of ≤20 mmHg at rest. Pulmonary hypertension is defined as a mean pulmonary artery pressure ≥25 mmHg at rest.<ref name="pmid10973254">{{cite journal| author=International PPH Consortium. Lane KB, Machado RD, Pauciulo MW, Thomson JR, Phillips JA et al.| title=Heterozygous germline mutations in BMPR2, encoding a TGF-beta receptor, cause familial primary pulmonary hypertension. | journal=Nat Genet | year= 2000 | volume= 26 | issue= 1 | pages= 81-4 | pmid=10973254 | doi=10.1038/79226 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10973254  }} </ref>
The pathophysiology of pulmonary hypertension<ref name="pmid15059929">{{cite journal |vauthors=Marcos E, Fadel E, Sanchez O, Humbert M, Dartevelle P, Simonneau G, Hamon M, Adnot S, Eddahibi S |title=Serotonin-induced smooth muscle hyperplasia in various forms of human pulmonary hypertension |journal=Circ. Res. |volume=94 |issue=9 |pages=1263–70 |date=May 2004 |pmid=15059929 |doi=10.1161/01.RES.0000126847.27660.69 |url=}}</ref><ref name="pmid10024307">{{cite journal |vauthors=Eddahibi S, Fabre V, Boni C, Martres MP, Raffestin B, Hamon M, Adnot S |title=Induction of serotonin transporter by hypoxia in pulmonary vascular smooth muscle cells. Relationship with the mitogenic action of serotonin |journal=Circ. Res. |volume=84 |issue=3 |pages=329–36 |date=February 1999 |pmid=10024307 |doi= |url=}}</ref><ref name="pmid26479975">{{cite journal |vauthors=Huber LC, Bye H, Brock M |title=The pathogenesis of pulmonary hypertension--an update |journal=Swiss Med Wkly |volume=145 |issue= |pages=w14202 |date=2015 |pmid=26479975 |doi=10.4414/smw.2015.14202 |url=}}</ref><ref name="pmid23457160">{{cite journal |vauthors=Peacock A |title=Pulmonary hypertension |journal=Eur Respir Rev |volume=22 |issue=127 |pages=20–5 |date=March 2013 |pmid=23457160 |doi=10.1183/09059180.00006912 |url=}}</ref><ref name="pmid24267295">{{cite journal |vauthors=Tuder RM, Stacher E, Robinson J, Kumar R, Graham BB |title=Pathology of pulmonary hypertension |journal=Clin. Chest Med. |volume=34 |issue=4 |pages=639–50 |date=December 2013 |pmid=24267295 |doi=10.1016/j.ccm.2013.08.009 |url=}}</ref><ref name="pmid24951761">{{cite journal |vauthors=Michelakis ED |title=Pulmonary arterial hypertension: yesterday, today, tomorrow |journal=Circ. Res. |volume=115 |issue=1 |pages=109–14 |date=June 2014 |pmid=24951761 |doi=10.1161/CIRCRESAHA.115.301132 |url=}}</ref><ref name="pmid21110189">{{cite journal |vauthors=Douwes JM, Berger RM |title=The maze of vasodilator response criteria |journal=Pediatr Cardiol |volume=32 |issue=2 |pages=245–6 |date=February 2011 |pmid=21110189 |doi=10.1007/s00246-010-9849-8 |url=}}</ref><ref name="pmid25593290">{{cite journal |vauthors=Ranchoux B, Antigny F, Rucker-Martin C, Hautefort A, Péchoux C, Bogaard HJ, Dorfmüller P, Remy S, Lecerf F, Planté S, Chat S, Fadel E, Houssaini A, Anegon I, Adnot S, Simonneau G, Humbert M, Cohen-Kaminsky S, Perros F |title=Endothelial-to-mesenchymal transition in pulmonary hypertension |journal=Circulation |volume=131 |issue=11 |pages=1006–18 |date=March 2015 |pmid=25593290 |doi=10.1161/CIRCULATIONAHA.114.008750 |url=}}</ref><ref name="pmid27045138">{{cite journal |vauthors=Hopper RK, Moonen JR, Diebold I, Cao A, Rhodes CJ, Tojais NF, Hennigs JK, Gu M, Wang L, Rabinovitch M |title=In Pulmonary Arterial Hypertension, Reduced BMPR2 Promotes Endothelial-to-Mesenchymal Transition via HMGA1 and Its Target Slug |journal=Circulation |volume=133 |issue=18 |pages=1783–94 |date=May 2016 |pmid=27045138 |pmc=4856565 |doi=10.1161/CIRCULATIONAHA.115.020617 |url=}}</ref><ref name="pmid11401896">{{cite journal |vauthors=Jobe AH, Bancalari E |title=Bronchopulmonary dysplasia |journal=Am. J. Respir. Crit. Care Med. |volume=163 |issue=7 |pages=1723–9 |date=June 2001 |pmid=11401896 |doi=10.1164/ajrccm.163.7.2011060 |url=}}</ref>


The factors that are in involved in the pathophysiology of the increase in the mean pulmonary arterial pressure are:
PH is defined as an elevated mean pulmonary artery pressure (PAP) ≥ 25 mmHg as measured by right heart catheterization at rest.  The elevation in PAP results from an elevation in the pulmonary vascular resistance caused by a multifactorial pathogenesis involving genetic and environmental factors.


==Increase in the Pulmonary Vascular Resistance==
Pulmonary hypertension has several pathophysiologic mechanisms depending on the underlying etiology. Nevertheless, the following sequence of events is almost always present:


===Occlusive vasculopathy of the small pulmonary arteries and arteriole===
*Vasoconstriction (ocurring early in the disease);
*Thrombosis (during the evolution of the disease);
*Remodeling (then takes place and becomes the most important factor).<ref name="pmid26479975">{{cite journal| author=Huber LC, Bye H, Brock M, Swiss Society of Pulmonary Hypertension| title=The pathogenesis of pulmonary hypertension--an update. | journal=Swiss Med Wkly | year= 2015 | volume= 145 | issue=  | pages= w14202 | pmid=26479975 | doi=10.4414/smw.2015.14202 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26479975  }} </ref>
**An initiating factor leads to increased resistance in the pulmonary vasculature causing narrowing of the [[vessels]] and impaired [[blood flow]].
**As a consequence, the right [[ventricle]] adapts by increasing right ventricular [[systolic]] pressures to preserve the [[cardiac output]] from the right heart.
**Over time, increasing right ventricular [[systolic]] pressures will subsequently result in chronic changes in the [[pulmonary circulation]] and the affected blood vessels progressively become [[Fibrosis|stiffer and thicker]], further increasing the blood pressure within the lungs and impairing blood flow.
**In addition, the increased workload of the heart causes thickening and enlargement of the [[right ventricle]], making the heart less able to pump blood through the lungs, causing right [[heart failure]].  Factors that might affect the ability of the right ventricle to adapt to an increased pulmonary vascular resistance are:
*** Age of the patient at onset
*** Rapidity of onset of pulmonary hypertension
*** Coexisting [[hypoxemia]]


*Idiopathic PAH
==Pulmonary Arterial Hypertension==
*Connective tissue disease
===Molecular and Cellular Changes===
*[[HIV infection]]
* Pulmonary arterial hypertension is characterized by [[endothelial]] dysfunction resulting from an imbalance between [[apoptosis]] and proliferation of pulmonary artery smooth muscle cells favoring the proliferation.
*[[Congenital heart disease]]
* There is also thickened and disordered [[adventitia]] due to excessive amounts of adventitial [[metalloproteinase]]s. 
* Several pathways are implicated in development of vascular remodeling, which is the hallmark of pathologic changes in pulmonary hypertension:
1. '''''Vasoconstriction-mediated remodeling'''''
* Imbalance of vasoactive signals is suggested in the pathogenesis of remodeling.
* Reduced levels of vasodilatory mediators, in particular [[PGI2|prostaglandin I<sub>2</sub>]], [[nitric oxide]], and [[cGMP|cyclic guanine monophosphate]], and elevated levels of vasocontricting molecules such as [[endothelin 1]], [[thromboxane]], and [[5-hydroxytryptamine]] contribute to alterations in the vascular tone.
* Down regulation of the [[voltage-gated potassium channel]]s has also been linked with altered pulmonary vascular tone, dysregulation of cellular homeostasis, and induction of proliferative sequelae in vascular [[smooth muscle cell]]s.
* Patients with [[PAH]] seem to have higher concentrations of serum [[endothelin-1]] (a potent vasoconstrictor) than controls.<ref name="pmid26479975">{{cite journal| author=Huber LC, Bye H, Brock M, Swiss Society of Pulmonary Hypertension| title=The pathogenesis of pulmonary hypertension--an update. | journal=Swiss Med Wkly | year= 2015 | volume= 145 | issue=  | pages= w14202 | pmid=26479975 | doi=10.4414/smw.2015.14202 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26479975  }} </ref>
* May occur in response to [[hypoxia]];
* May be related to [[calcium channel]] dysfunction - in fact, there are mutations in the [[ion channels]] (KCNK3) which predispose to [[hereditary PAH]];
* May be reversible - patients treated early in the disease with [[calcium channel blockers]] seem to have a much better prognosis.<ref name="pmid26479975">{{cite journal| author=Huber LC, Bye H, Brock M, Swiss Society of Pulmonary Hypertension| title=The pathogenesis of pulmonary hypertension--an update. | journal=Swiss Med Wkly | year= 2015 | volume= 145 | issue=  | pages= w14202 | pmid=26479975 | doi=10.4414/smw.2015.14202 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26479975  }} </ref>
2. '''''Thrombosis-mediated remodeling'''''
* Many [[coagulopathies]] were described in patients with [[PAH]], such as increased [[von Willebrand factor]] activity, [[protein C]] and [[protein S deficiency]].<ref name="pmid8797416">{{cite journal| author=Welsh CH, Hassell KL, Badesch DB, Kressin DC, Marlar RA| title=Coagulation and fibrinolytic profiles in patients with severe pulmonary hypertension. | journal=Chest | year= 1996 | volume= 110 | issue= 3 | pages= 710-7 | pmid=8797416 | doi=10.1378/chest.110.3.710 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8797416  }} </ref><ref name="pmid9877507">{{cite journal| author=Hoeper MM, Sosada M, Fabel H| title=Plasma coagulation profiles in patients with severe primary pulmonary hypertension. | journal=Eur Respir J | year= 1998 | volume= 12 | issue= 6 | pages= 1446-9 | pmid=9877507 | doi=10.1183/09031936.98.12061446 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9877507  }} </ref>
* [[Thrombin]] plays a key role in mediating vascular remodeling by activating [[platelet]], upregulating [[angiogenesis]]-related genes (including [[tissue factor|tissue factor [TF]]], [[basic fibroblast growth factor|basic fibroblast growth factor [bFGF]]], and [[matrix metalloproteinase]]-2), and transactivating [[vascular endothelial growth factor|vascular endothelial growth factor (VEGF)]] by inducing the production of [[reactive oxygen species|reactive oxygen species (ROS)]] and the expression of the [[Hypoxia inducible factors|hypoxia inducible factor-1 alpha]].
* Upregulation of TF in the vasculature leads to initiation of coagulation cascade and migration and proliferation of [[smooth muscle cell]]s upon vascular injury.
* In addition, [[platelet activation]] by [[thrombin]] results in the release of granules containing substances that promote [[mitogenesis]] and [[vasoconstriction]] including [[VEGF]], [[bFGF]], [[platelet-derived growth factor]], and [[serotonin]], which also contribute to increased endothelial cell migration and proliferation.
3. '''''Proliferation-mediated remodeling'''''
* The pathogenic pathway of lung vasculature remodeling in PH is not fully understood;
* It is regulated by a variety of growth factors, cytokines, mytogens, ion channels, neurotransmitters viruses, transcription factors and receptors, the most studied being the [[bone morphogenetic protein receptor type II]] (BMPR2).
* BMPR2 loss-of-function mutations were found in 70% of patients with hereditary PAH and in 20% of patients with idiopathic PAH;<ref name="pmid25612240">{{cite journal| author=Momose Y, Aimi Y, Hirayama T, Kataoka M, Ono M, Yoshino H | display-authors=etal| title=De novo mutations in the BMPR2 gene in patients with heritable pulmonary arterial hypertension. | journal=Ann Hum Genet | year= 2015 | volume= 79 | issue= 2 | pages= 85-91 | pmid=25612240 | doi=10.1111/ahg.12096 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25612240  }} </ref><ref name="pmid16429403">{{cite journal| author=Aldred MA, Vijayakrishnan J, James V, Soubrier F, Gomez-Sanchez MA, Martensson G | display-authors=etal| title=BMPR2 gene rearrangements account for a significant proportion of mutations in familial and idiopathic pulmonary arterial hypertension. | journal=Hum Mutat | year= 2006 | volume= 27 | issue= 2 | pages= 212-3 | pmid=16429403 | doi=10.1002/humu.9398 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16429403  }} </ref>
* Anecdotal reports have stated that [[imatinib]] has been able to cause significant improvement of PAH patients;<ref name="pmid16192491">{{cite journal| author=Ghofrani HA, Seeger W, Grimminger F| title=Imatinib for the treatment of pulmonary arterial hypertension. | journal=N Engl J Med | year= 2005 | volume= 353 | issue= 13 | pages= 1412-3 | pmid=16192491 | doi=10.1056/NEJMc051946 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16192491  }} </ref>
* [[Serotonin]] exerts both vasoconstrictive and mitogenic effects on [[smooth muscle cell]]s (SMC).
* Serotonin m bind to 5-hydroxytryptamine 1A and 2B receptors or may enter SMC via [[SERT|serotonin transporter]] which induces generation of [[reactive oxygen species|ROS]], [[rho kinase]], and [[MAPK|mitogen-activated protein kinases]].
* This in turn leads to the expression of [[growth factor]]s and proliferation. [[Bone morphogenetic protein|Bone morphogenetic protein (BMP)]] is also involved in the SMC proliferation.
* Upon binding of BMP to its heterodimerized receptors, a group of cytoplasmic proteins known as receptor-mediated [[Smad]]s are phosphorylated and translocated to the nucleus where they upregulate genes related to anti-proliferation.
* Serotonin is shown to antagonize the BMP/Smad pathway thus facilitating the proliferation of [[smooth muscle cell]]s.
4. '''''Inflammation-mediated remodeling'''''
* Influx of inflammatory effector cells is stimulated by the release of chemokines such as [[CCL5]] and [[CX3CL1]].
* On the other hand, [[endothelial cell]] and [[smooth muscle cell]] dysfunction contributes to the release of vasomotor and [[growth factor]]s, activation of [[transcription factor]]s, influx of [[calcium]], and dysfunction of [[mitochondria]].
* The net effect is a shift of balance in favor of proliferation and suppressed [[apoptosis]], leading to remodeling of the pulmonary vasculature.
Shown below is an image depicting remodeling in pulmonary arterial hypertension.


===Decrease in the area of the pulmonary vascular bed===
[[File:Pathophysiology of pulmonary hypertension.png|661x661px]]
*[[Pulmonary emboli]]
*[[Interstitial lung disease]]


===Hypoxic vasoconstriction<ref name="pmid19043010">{{cite journal| author=Sommer N, Dietrich A, Schermuly RT, Ghofrani HA, Gudermann T, Schulz R et al.| title=Regulation of hypoxic pulmonary vasoconstriction: basic mechanisms. | journal=Eur Respir J | year= 2008 | volume= 32 | issue= 6 | pages= 1639-51 | pmid=19043010 | doi=10.1183/09031936.00013908 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19043010  }} </ref>===
===Genetic Mutations===
*Hypoventilation syndromes
====TGF-β Receptor Pathway====
*Parenchymal lung disease
* The bone morphogenetic protein receptor II (BMPR2) gene encodes a [[serine]]/[[threonine]] [[kinase]] that functions as a receptor for bone morphogenetic proteins which forms a heterodimer cytoplasmic complex of two type II and two type I receptors. The downstream signaling involves activation of SMAD transcription factor which mediates anti-proliferation in smooth muscle cells.


'''2- Increase in the right-sided cardiac output'''
* Activin-like kinase 1 gene mutations are detected in patients with [[hereditary hemorrhagic telangiectasia]] and pulmonary arterial hypertension. Mutation would cause growth-promoting alterations.


*Left-to-right shunt
====Serotoninergic Pathway====
* 5- Hydroxytryptamine (serotonin) transporter mutations have also been associated with the proliferation of [[smooth muscle cell]]s of pulmonary arteries.<ref name="pmid11602621">{{cite journal| author=Eddahibi S, Humbert M, Fadel E, Raffestin B, Darmon M, Capron F et al.| title=Serotonin transporter overexpression is responsible for pulmonary artery smooth muscle hyperplasia in primary pulmonary hypertension. | journal=J Clin Invest | year= 2001 | volume= 108 | issue= 8 | pages= 1141-50 | pmid=11602621 | doi=10.1172/JCI12805 | pmc=PMC209526 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11602621  }} </ref>


''Congenital heart diseases: atrial septal defects, ventricular septal defects, patent ductus arteriosus''
==Genetics==
'''Familial PAH''' often results from a [[mutation]] in the bone morphogenic protein receptor-2 (BMPR2) and is inherited as an [[autosomal dominant]] disease with incomplete [[penetrance]] and anticipation.<ref name="Rich-1987">{{Cite journal  | last1 = Rich | first1 = S. | last2 = Dantzker | first2 = DR. | last3 = Ayres | first3 = SM. | last4 = Bergofsky | first4 = EH. | last5 = Brundage | first5 = BH. | last6 = Detre | first6 = KM. | last7 = Fishman | first7 = AP. | last8 = Goldring | first8 = RM. | last9 = Groves | first9 = BM. | title = Primary pulmonary hypertension. A national prospective study. | journal = Ann Intern Med | volume = 107 | issue = 2 | pages = 216-23 | month = Aug | year = 1987 | doi =  | PMID = 3605900 }}</ref>
==Associated conditions==
*PAH is also associated with:<ref>ACCF/AHA 2009 Expert Consensus Document on Pulmonary Hypertension</ref>
#[[Congenital heart disease]] (30% of untreated cases)
#[[Connective tissue diseases]] (12% of patients with [[scleroderma]] and up to 21% of patients with [[rheumatoid arthritis]])
#[[HIV]] (0.5%)
#[[Portal hypertension]] (2-6%)
#[[Sickle cell disease]] (20 to 40%)
#[[Systemic lupus erythematosus]] (4 to 14%)
#[[Hemoglobinopathies]]
#[[Myeloproliferative disorders]]
#Drugs and toxins
==Histopathology==
PH is a pathological condition present in different disease states that share similar clinical manifestation and some common histopathological features. Shown below is a table that summarizes the classification of PH based on histopathology findings.<ref name="pmid15194175">{{cite journal| author=Pietra GG, Capron F, Stewart S, Leone O, Humbert M, Robbins IM et al.| title=Pathologic assessment of vasculopathies in pulmonary hypertension. | journal=J Am Coll Cardiol | year= 2004 | volume= 43 | issue= 12 Suppl S | pages= 25S-32S | pmid=15194175 | doi=10.1016/j.jacc.2004.02.033 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15194175  }} </ref>
{| style="cellpadding=0; cellspacing= 0; width: 600px;"
|-
| style="padding: 0 5px; font-size: 100%; background: #4682B4; color: #FFFFFF" align="left" |'''Class''' || style="padding: 0 5px; font-size: 100%; background: #4682B4; color: #FFFFFF" align="left" |'''Histopathological findings'''<ref name="pmid15194175">{{cite journal| author=Pietra GG, Capron F, Stewart S, Leone O, Humbert M, Robbins IM et al.| title=Pathologic assessment of vasculopathies in pulmonary hypertension. | journal=J Am Coll Cardiol | year= 2004 | volume= 43 | issue= 12 Suppl S | pages= 25S-32S | pmid=15194175 | doi=10.1016/j.jacc.2004.02.033 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15194175  }} </ref>
! style="padding: 0 5px; font-size: 100%; background: #4682B4; color: #FFFFFF" align="left" |Images
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |'''Pulmonary arteriopathy''' || style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |'''''Constrictive lesions in pulmonary arteries''''' <br>
* Medial hypertrophy
* Intimal thickening
* Adventitial thickening <br>
'''''Complex lesions in pulmonary arteries''''' <br>
* Plexiform lesions
* Dilatation lesions
* [[Arteritis]] <br>
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |[[File:Pulmonary hypertension arteriopathy intimal and medial thickening.jpg|thumb]][[File:Pulmonary hypertension arteriopathy adventitial thickening.jpg|thumb]][[File:Pulmonary hypertension arteriopathy intimal and adventitial thickening.jpg|thumb]]
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |'''Pulmonary arteriopathy with venous-venular changes''' || style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" | ''Changes similar to pulmonary arteriopathy'' <br> PLUS<br> ''Changes in venules and veins''
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |[[File:Pulmonary hypertension arteriopathy medial muscle layer thickening.jpg|thumb]][[File:Pulmonary hypertension Plexiform lesion 2.jpg|thumb]]
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5; width:50%" align="left" |'''Pulmonary occlusive venopathy''' <br> (with or without arteriopathy) || style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |'''''Changes in venules and veins''''' <br>
* Diffuse fibrotic occlusion
* Intimal thickening
* Medial thickening
* Adventitial thickening <br>
'''''Changes in the capillaries'''''
* Dilatation
* Congestion <br>
'''''Changes in the interstitium'''''
* [[Edema]]
* [[Fibrosis]]
* [[Hemosiderosis]]
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |'''Pulmonary microvasculopathy''' <br> (with or without arteriopathy and/on venopathy)|| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |'''''Changes in the capillaries'''''
* Localized capillary proliferation <br>
'''''Changes in the interstitium'''''
* [[Edema]]
* [[Fibrosis]]
* [[Hemosiderosis]]
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |[[File:Pulmonary hypertension Pulmonary capillary hemangiomatosis.jpg|thumb]][[File:Pulmonary hypertension pulmonary capillary hemangiomatosis.jpg|thumb]]
|-
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |'''Unclassified''' || style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" | ''Non specific changes''
| style="padding: 0 5px; font-size: 100%; background: #F5F5F5;" align="left" |
|}


''Liver cirrhosis''
==Gallery==
'''The images below are courtesy of Dr. Yale Rosen (''Source:Wikimedia Commons'').'''


'''3- Increase in the mean pulmonary venous pressure'''
<gallery>
Image:Pulmonary hypertension arteriopathy intimal and medial thickening.jpg|Marked intimal and medial thickening


* Mitral valve disease, left ventricular systolic or diastolic dysfunction, constrictive pericarditis, restrictive cardiomyopathy or pulmonary venous obstruction (example, pulmonary veno-occlusive disease)
Image:Pulmonary hypertension arteriopathy medial muscle layer thickening.jpg|Medial muscle layer thickening involving multiple pulmonary arteries.
 
 
To note that “Pulmonary arterial hypertension” (PAH) refers to group 1 PAH in the updated WHO classification. “Pulmonary hypertension” (PH) refers to any of group 2 PH through group 5 PH. PH is also used when referring to all five groups collectively.
 
Pulmonary hypertension has several pathophysiologic mechanisms depending on the underlying etiology. Nevertheless, the following sequence of events is almost always present:


*An initiating factor leads to increased resistance in the pulmonary vasculature causing narrowing of the [[vessels]] and impaired [[blood flow]], much as it is harder to make water flow through a narrow pipe as opposed to a wide one.
Image:Pulmonary hypertension associated with vasculitis fibrinoid necrosis.jpg|This arteriole exhibits fibrinoid necrosis.


*As a consequence, the right [[ventricle]] adapts by increasing right ventricular [[systolic]] pressures to preserve the [[cardiac output]] from the right heart.  
Image:Pulmonary hypertension arteriopathy medial thickening.jpg|Pronounced thickening of the medial muscle layer.


*Over time, increasing right ventricular [[systolic]] pressures will subsequently result in chronic changes in the [[pulmonary circulation]] and progressively the affected blood vessels become both [[Fibrosis|stiffer and thicker]], further increasing the blood pressure within the lungs and impairing blood flow.  
Image:Pulmonary hypertension arteriopathy intimal and medial thickening.jpg|Marked intimal and medial thickening.


*In addition, the increased workload of the heart causes thickening and enlargement of the [[right ventricle]], making the heart less able to pump blood through the lungs, causing right [[heart failure]].
Image:Pulmonary hypertension arteriopathy intimal thickening.jpg|This artery exhibits marked intimal thickening The red-staining cells in the intima are probably myofibroblasts. Masson trichrome stain.


*As the blood flowing through the lungs decreases, the left side of the heart receives less blood. This blood may also carry less oxygen than normal. Therefore it becomes harder and harder for the left side of the heart to pump to supply sufficient [[oxygen]] to the rest of the body, especially during physical activity.
Image:Pulmonary hypertension arteriopathy adventitial thickening.jpg|Marked adventitial thickening. Masson trichrome stain.


=== Pulmonary Arterial Hypertension===
Image:Pulmonary hypertension arteriopathy intimal and adventitial thickening.jpg|This artery exhibits marked intimal thickening as well as adventitial thickening. The red-staining cells in the intima are probably myofibroblasts. Masson trichrome stain.
PAH is a proliferative vasculopathy of the small muscular arteries and arterioles, involving vasoconstriction, endothelial and smooth cell proliferation, fibrosis, and thrombosis. Multiple pathologic patterns are found in PAH, including:
# [[Intimal]] [[hyperplasia]].
# [[Medial]] [[hypertrophy]].
# [[Adventitial]] proliferation.
# In-situ [[thrombosis]].
# [[Inflammation]]
# Plexiform arteriopathy.


Medial hypertrophy is considered an early and reversible lesion in contrast to intimal fibrosis or plexogenic arteriopathy.
Image:Pulmonary hypertension arteriopathy adventitial thickening and hemangiomatosis.jpg|Pulmonary hypertension associated with pulmonary hemangiomatosis. A muscular pulmonary artery surrounded by angiomatous vessels exhibits marked intimal and adventitial thickening.


[[Image:Plexiform_lesion_-_Pulmonary_hypertension.jpg‎|300px]]
Image:Pulmonary hypertension arteriopathy intimal and medial thickening 2.jpg|There is thickening of the medial muscle layer as well as mild intimal thickening.


Image:Pulmonary hypertension pulmonary capillary hemangiomatosis.jpg|Alveolar capillary proliferation as well as the proliferation of larger blood vessels, probably venules.


In fact, the vascular proliferative nature of PAH is probably the result of sequences of injury and repair of the pulmonary vasculature in the context of a combination of noxious stimuli affecting a predisposed vasculature. Some of the well-described predisposing factors are the mutations in the BMPR2 gene<ref name="pmid15699271">{{cite journal| author=Yuan JX, Rubin LJ| title=Pathogenesis of pulmonary arterial hypertension: the need for multiple hits. | journal=Circulation | year= 2005 | volume= 111 | issue= 5 | pages= 534-8 | pmid=15699271 | doi=10.1161/01.CIR.0000156326.48823.55 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15699271  }} </ref>.  
Image:Pulmonary hypertension associated vasculitis fibrinoid necrosis 2.jpg|This artery exhibits vasculitis characterized by focal necrosis of the wall accompanied by inflammation.


The increase in pulmonary vascular resistance results from vascular changes that are the consequences of:
Image:Pulmonary hypertension Plexiform and dilatation lesions.jpg|A large dilatation lesion is present on the right side of this image adjacent to an angiomatoid lesion.
# '''Release of cytokines and chemokines and influx of inflammatory cells and mediators'''


# '''An imbalance between:'''
Image:Pulmonary hypertension Plexiform and dilatation lesions 2.jpg|Two angiomatoid lesions are present. A large dilatation lesion is a present adjacent to the angiomatoid lesion that is located just above center.
* Locally produced vasodilators (nitric oxide and prostacyclin) <ref name="pmid7540722">{{cite journal| author=Giaid A, Saleh D| title=Reduced expression of endothelial nitric oxide synthase in the lungs of patients with pulmonary hypertension. | journal=N Engl J Med | year= 1995 | volume= 333 | issue= 4 | pages= 214-21 | pmid=7540722 | doi=10.1056/NEJM199507273330403 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7540722  }} </ref>
* Vasoconstrictors (endothelin and thromboxane)<ref name="pmid1603138">{{cite journal| author=Christman BW, McPherson CD, Newman JH, King GA, Bernard GR, Groves BM et al.| title=An imbalance between the excretion of thromboxane and prostacyclin metabolites in pulmonary hypertension. | journal=N Engl J Med | year= 1992 | volume= 327 | issue= 2 | pages= 70-5 | pmid=1603138 | doi=10.1056/NEJM199207093270202 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1603138  }} </ref>
* Apoptotic and mitogenic factors
* Prothrombotic and antithrombotic factors


# '''Vascular wall remodeling'''
Image:Pulmonary hypertension Plexiform lesion.jpg|There is angiomatoid (plexiform) lesion.
* Endothelial and smooth muscle cells proliferation in addition to changes in the extracellular matrix<ref name="pmid10973254">{{cite journal| author=International PPH Consortium. Lane KB, Machado RD, Pauciulo MW, Thomson JR, Phillips JA et al.| title=Heterozygous germline mutations in BMPR2, encoding a TGF-beta receptor, cause familial primary pulmonary hypertension. | journal=Nat Genet | year= 2000 | volume= 26 | issue= 1 | pages= 81-4 | pmid=10973254 | doi=10.1038/79226 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10973254  }} </ref>


[[Image:Pathophysiology_of_pulmonary_hypertension.png‎|500px]]
Image:Pulmonary hypertension Plexiform lesion 2.jpg|The appearance suggests multiple lesions but a single lesion cannot be excluded. Note the destruction of the arterial wall at the site of the angiomatoid lesion. Destructive arterial changes are frequently associated with angiomatoid lesions. There is an elastic stain.


=== A role for endothelial injury ===
Image:Pulmonary hypertension Plexiform lesion 3 and associated inflammation.jpg|This angiomatoid lesion is accompanied by inflammation which is frequently associated with these lesions.


All classes of pulmonary hypertension are associated with narrowing and obliteration of the pulmonary arterioles due to thickening of the [[intima]] by [[fibromuscular dysplasia]]. This constant finding has increased the interest in the role of [[endothelial]] injury and the release of [[vasoactive]] mediators in the pathogenesis of pulmonary hypertension. These mediators include both [[vasoconstrictors]] and [[vasodilators]]. Whereas the main vasoconstrictor is [[Endothelin]], Nitric Oxide (NO), [[PGI2]] and endothelium derived hyperpolarizing factor (EDHF) are vasodilators, of which NO is the most potent in reversing the effects of Endothelin.<ref> Higenbottam Tim(1994) "Pathophysiology of Pulmonary Hypertension, A role for endothelial dysfunction" Chest journal"</ref>
Image:Pulmonary hypertension Pulmonary capillary hemangiomatosis.jpg|There is a proliferation of alveolar wall capillaries which are markedly dilated.
=== Factors determining the ability of the RV to adapt to increased PVR ===


#Age of the patient at onset.
Image:Pulmonary hypertension Plexiform and dilatation lesions 4.jpg|A dilatation lesion is seen in the left lower quadrant adjacent to the angiomatoid lesion. There is an elastic stain.
#Rapidity of onset of pulmonary hypertension.
#Coexisting [[hypoxemia]].


===Molecular abnormalities===
Image:Pulmonary hypertension Plexiform and dilatation lesions 5.jpg|This angiomatoid lesion contains multiple thrombi within the vascular spaces. A large dilatation lesion is a present adjacent to the bottom of the angiomatoid lesion.


*Pulmonary arterial hypertension is characterized by [[endothelial]] dysfunction such that there is an imbalance between [[apoptosis]] and pulmonary artery smooth muscle proliferation favoring the proliferation. There is also thickened and disordered [[adventitia]] due to excessive amounts of adventitial [[metalloproteases]].
Image:Pulmonary hypertension Plexiform and dilatation lesions 6.jpg|A dilatation lesion is present adjacent to the right side of the angiomatoid lesion.


* [[Mutations]] of two genes in the TGF-beta receptor pathway have been identified in familial pulmonary arterial hypertension:
Image:Pulmonary hypertension Plexiform and dilatation lesions 7.jpg|There is a disappearance of the arterial wall at the site of the angiomatoid lesions. Arterial wall destruction is a frequent finding in association with angiomatoid lesions. A dilatation lesion encircles the angiomatoid lesion
# '''BMPR2''': Modulates vascular cell growth. A loss of function mutation would cause unregulated smooth muscle growth.
# '''Activin-like kinase 1''': detected in patients with [[hereditary hemorrhagic telangiectasia]] and pulmonary arterial hypertension. Mutation would cause growth-promoting alterations.


Both [[genes]] are involved SMAD-dependant signaling pathways.
</gallery>


==References==
==References==
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[[Category:Medicine]]
[[Category:Cardiology]]
[[Category:Cardiology]]
[[Category:Pulmonology]]
[[Category:Pulmonology]]
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Latest revision as of 16:56, 9 June 2021

Pulmonary Hypertension Microchapters

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Assistant Editor(s)-in-Chief: Ralph Matar; Rim Halaby José Eduardo Riceto Loyola Junior, M.D.[2]

Overview

Pulmonary hypertension (PH) is a pathological condition of the pulmonary vasculature present in several disease states that presents with elevated mean pulmonary artery pressure (PAP) as measured by right heart catheterization at rest. The factors that are in involved in the pathophysiology of the increase in the mean pulmonary arterial pressure are: increase in pulmonary vascular resistance, increase in the right-side cardiac output and increase in the mean pulmonary venous pressure. Pulmonary arterial hypertension is characterized by endothelial dysfunction resulting from an imbalance between apoptosis and proliferation of pulmonary artery smooth muscle cells favoring the proliferation. The other types of pulmonary hypertension are caused by hemodynamic changes that result in increased pulmonary blood pressure or architectural changes to the lung or its vasculature that result in the same outcome.

Pathophysiology

The pathophysiology of pulmonary hypertension[1][2][3][4][5][6][7][8][9][10]

PH is defined as an elevated mean pulmonary artery pressure (PAP) ≥ 25 mmHg as measured by right heart catheterization at rest. The elevation in PAP results from an elevation in the pulmonary vascular resistance caused by a multifactorial pathogenesis involving genetic and environmental factors.

Pulmonary hypertension has several pathophysiologic mechanisms depending on the underlying etiology. Nevertheless, the following sequence of events is almost always present:

  • Vasoconstriction (ocurring early in the disease);
  • Thrombosis (during the evolution of the disease);
  • Remodeling (then takes place and becomes the most important factor).[3]
    • An initiating factor leads to increased resistance in the pulmonary vasculature causing narrowing of the vessels and impaired blood flow.
    • As a consequence, the right ventricle adapts by increasing right ventricular systolic pressures to preserve the cardiac output from the right heart.
    • Over time, increasing right ventricular systolic pressures will subsequently result in chronic changes in the pulmonary circulation and the affected blood vessels progressively become stiffer and thicker, further increasing the blood pressure within the lungs and impairing blood flow.
    • In addition, the increased workload of the heart causes thickening and enlargement of the right ventricle, making the heart less able to pump blood through the lungs, causing right heart failure. Factors that might affect the ability of the right ventricle to adapt to an increased pulmonary vascular resistance are:
      • Age of the patient at onset
      • Rapidity of onset of pulmonary hypertension
      • Coexisting hypoxemia

Pulmonary Arterial Hypertension

Molecular and Cellular Changes

  • Pulmonary arterial hypertension is characterized by endothelial dysfunction resulting from an imbalance between apoptosis and proliferation of pulmonary artery smooth muscle cells favoring the proliferation.
  • There is also thickened and disordered adventitia due to excessive amounts of adventitial metalloproteinases.
  • Several pathways are implicated in development of vascular remodeling, which is the hallmark of pathologic changes in pulmonary hypertension:

1. Vasoconstriction-mediated remodeling

2. Thrombosis-mediated remodeling

3. Proliferation-mediated remodeling

  • The pathogenic pathway of lung vasculature remodeling in PH is not fully understood;
  • It is regulated by a variety of growth factors, cytokines, mytogens, ion channels, neurotransmitters viruses, transcription factors and receptors, the most studied being the bone morphogenetic protein receptor type II (BMPR2).
  • BMPR2 loss-of-function mutations were found in 70% of patients with hereditary PAH and in 20% of patients with idiopathic PAH;[13][14]
  • Anecdotal reports have stated that imatinib has been able to cause significant improvement of PAH patients;[15]
  • Serotonin exerts both vasoconstrictive and mitogenic effects on smooth muscle cells (SMC).
  • Serotonin m bind to 5-hydroxytryptamine 1A and 2B receptors or may enter SMC via serotonin transporter which induces generation of ROS, rho kinase, and mitogen-activated protein kinases.
  • This in turn leads to the expression of growth factors and proliferation. Bone morphogenetic protein (BMP) is also involved in the SMC proliferation.
  • Upon binding of BMP to its heterodimerized receptors, a group of cytoplasmic proteins known as receptor-mediated Smads are phosphorylated and translocated to the nucleus where they upregulate genes related to anti-proliferation.
  • Serotonin is shown to antagonize the BMP/Smad pathway thus facilitating the proliferation of smooth muscle cells.

4. Inflammation-mediated remodeling

Shown below is an image depicting remodeling in pulmonary arterial hypertension.

Genetic Mutations

TGF-β Receptor Pathway

  • The bone morphogenetic protein receptor II (BMPR2) gene encodes a serine/threonine kinase that functions as a receptor for bone morphogenetic proteins which forms a heterodimer cytoplasmic complex of two type II and two type I receptors. The downstream signaling involves activation of SMAD transcription factor which mediates anti-proliferation in smooth muscle cells.
  • Activin-like kinase 1 gene mutations are detected in patients with hereditary hemorrhagic telangiectasia and pulmonary arterial hypertension. Mutation would cause growth-promoting alterations.

Serotoninergic Pathway

  • 5- Hydroxytryptamine (serotonin) transporter mutations have also been associated with the proliferation of smooth muscle cells of pulmonary arteries.[16]

Genetics

Familial PAH often results from a mutation in the bone morphogenic protein receptor-2 (BMPR2) and is inherited as an autosomal dominant disease with incomplete penetrance and anticipation.[17]

Associated conditions

  • PAH is also associated with:[18]
  1. Congenital heart disease (30% of untreated cases)
  2. Connective tissue diseases (12% of patients with scleroderma and up to 21% of patients with rheumatoid arthritis)
  3. HIV (0.5%)
  4. Portal hypertension (2-6%)
  5. Sickle cell disease (20 to 40%)
  6. Systemic lupus erythematosus (4 to 14%)
  7. Hemoglobinopathies
  8. Myeloproliferative disorders
  9. Drugs and toxins

Histopathology

PH is a pathological condition present in different disease states that share similar clinical manifestation and some common histopathological features. Shown below is a table that summarizes the classification of PH based on histopathology findings.[19]

Class Histopathological findings[19] Images
Pulmonary arteriopathy Constrictive lesions in pulmonary arteries
  • Medial hypertrophy
  • Intimal thickening
  • Adventitial thickening

Complex lesions in pulmonary arteries

  • Plexiform lesions
  • Dilatation lesions
  • Arteritis
Pulmonary arteriopathy with venous-venular changes Changes similar to pulmonary arteriopathy
PLUS
Changes in venules and veins
Pulmonary occlusive venopathy
(with or without arteriopathy)		 Changes in venules and veins
  • Diffuse fibrotic occlusion
  • Intimal thickening
  • Medial thickening
  • Adventitial thickening

Changes in the capillaries

  • Dilatation
  • Congestion

Changes in the interstitium

Pulmonary microvasculopathy
(with or without arteriopathy and/on venopathy)		 Changes in the capillaries
  • Localized capillary proliferation

Changes in the interstitium

Unclassified Non specific changes

Gallery

The images below are courtesy of Dr. Yale Rosen (Source:Wikimedia Commons).

  • Marked intimal and medial thickening

    Marked intimal and medial thickening

  • Medial muscle layer thickening involving multiple pulmonary arteries.

    Medial muscle layer thickening involving multiple pulmonary arteries.

  • This arteriole exhibits fibrinoid necrosis.

    This arteriole exhibits fibrinoid necrosis.

  • Pronounced thickening of the medial muscle layer.

    Pronounced thickening of the medial muscle layer.

  • Marked intimal and medial thickening.

    Marked intimal and medial thickening.

  • This artery exhibits marked intimal thickening The red-staining cells in the intima are probably myofibroblasts. Masson trichrome stain.

    This artery exhibits marked intimal thickening The red-staining cells in the intima are probably myofibroblasts. Masson trichrome stain.

  • Marked adventitial thickening. Masson trichrome stain.

    Marked adventitial thickening. Masson trichrome stain.

  • This artery exhibits marked intimal thickening as well as adventitial thickening. The red-staining cells in the intima are probably myofibroblasts. Masson trichrome stain.

    This artery exhibits marked intimal thickening as well as adventitial thickening. The red-staining cells in the intima are probably myofibroblasts. Masson trichrome stain.

  • Pulmonary hypertension associated with pulmonary hemangiomatosis. A muscular pulmonary artery surrounded by angiomatous vessels exhibits marked intimal and adventitial thickening.

    Pulmonary hypertension associated with pulmonary hemangiomatosis. A muscular pulmonary artery surrounded by angiomatous vessels exhibits marked intimal and adventitial thickening.

  • There is thickening of the medial muscle layer as well as mild intimal thickening.

    There is thickening of the medial muscle layer as well as mild intimal thickening.

  • Alveolar capillary proliferation as well as the proliferation of larger blood vessels, probably venules.

    Alveolar capillary proliferation as well as the proliferation of larger blood vessels, probably venules.

  • This artery exhibits vasculitis characterized by focal necrosis of the wall accompanied by inflammation.

    This artery exhibits vasculitis characterized by focal necrosis of the wall accompanied by inflammation.

  • A large dilatation lesion is present on the right side of this image adjacent to an angiomatoid lesion.

    A large dilatation lesion is present on the right side of this image adjacent to an angiomatoid lesion.

  • Two angiomatoid lesions are present. A large dilatation lesion is a present adjacent to the angiomatoid lesion that is located just above center.

    Two angiomatoid lesions are present. A large dilatation lesion is a present adjacent to the angiomatoid lesion that is located just above center.

  • There is angiomatoid (plexiform) lesion.

    There is angiomatoid (plexiform) lesion.

  • The appearance suggests multiple lesions but a single lesion cannot be excluded. Note the destruction of the arterial wall at the site of the angiomatoid lesion. Destructive arterial changes are frequently associated with angiomatoid lesions. There is an elastic stain.

    The appearance suggests multiple lesions but a single lesion cannot be excluded. Note the destruction of the arterial wall at the site of the angiomatoid lesion. Destructive arterial changes are frequently associated with angiomatoid lesions. There is an elastic stain.

  • This angiomatoid lesion is accompanied by inflammation which is frequently associated with these lesions.

    This angiomatoid lesion is accompanied by inflammation which is frequently associated with these lesions.

  • There is a proliferation of alveolar wall capillaries which are markedly dilated.

    There is a proliferation of alveolar wall capillaries which are markedly dilated.

  • A dilatation lesion is seen in the left lower quadrant adjacent to the angiomatoid lesion. There is an elastic stain.

    A dilatation lesion is seen in the left lower quadrant adjacent to the angiomatoid lesion. There is an elastic stain.

  • This angiomatoid lesion contains multiple thrombi within the vascular spaces. A large dilatation lesion is a present adjacent to the bottom of the angiomatoid lesion.

    This angiomatoid lesion contains multiple thrombi within the vascular spaces. A large dilatation lesion is a present adjacent to the bottom of the angiomatoid lesion.

  • A dilatation lesion is present adjacent to the right side of the angiomatoid lesion.

    A dilatation lesion is present adjacent to the right side of the angiomatoid lesion.

  • There is a disappearance of the arterial wall at the site of the angiomatoid lesions. Arterial wall destruction is a frequent finding in association with angiomatoid lesions. A dilatation lesion encircles the angiomatoid lesion

    There is a disappearance of the arterial wall at the site of the angiomatoid lesions. Arterial wall destruction is a frequent finding in association with angiomatoid lesions. A dilatation lesion encircles the angiomatoid lesion

References

  1. ↑ Marcos E, Fadel E, Sanchez O, Humbert M, Dartevelle P, Simonneau G, Hamon M, Adnot S, Eddahibi S (May 2004). "Serotonin-induced smooth muscle hyperplasia in various forms of human pulmonary hypertension". Circ. Res. 94 (9): 1263–70. doi:10.1161/01.RES.0000126847.27660.69. PMID 15059929.
  2. ↑ Eddahibi S, Fabre V, Boni C, Martres MP, Raffestin B, Hamon M, Adnot S (February 1999). "Induction of serotonin transporter by hypoxia in pulmonary vascular smooth muscle cells. Relationship with the mitogenic action of serotonin". Circ. Res. 84 (3): 329–36. PMID 10024307.
  3. ↑ 3.0 3.1 3.2 3.3 Huber LC, Bye H, Brock M (2015). "The pathogenesis of pulmonary hypertension--an update". Swiss Med Wkly. 145: w14202. doi:10.4414/smw.2015.14202. PMID 26479975.
  4. ↑ Peacock A (March 2013). "Pulmonary hypertension". Eur Respir Rev. 22 (127): 20–5. doi:10.1183/09059180.00006912. PMID 23457160.
  5. ↑ Tuder RM, Stacher E, Robinson J, Kumar R, Graham BB (December 2013). "Pathology of pulmonary hypertension". Clin. Chest Med. 34 (4): 639–50. doi:10.1016/j.ccm.2013.08.009. PMID 24267295.
  6. ↑ Michelakis ED (June 2014). "Pulmonary arterial hypertension: yesterday, today, tomorrow". Circ. Res. 115 (1): 109–14. doi:10.1161/CIRCRESAHA.115.301132. PMID 24951761.
  7. ↑ Douwes JM, Berger RM (February 2011). "The maze of vasodilator response criteria". Pediatr Cardiol. 32 (2): 245–6. doi:10.1007/s00246-010-9849-8. PMID 21110189.
  8. ↑ Ranchoux B, Antigny F, Rucker-Martin C, Hautefort A, Péchoux C, Bogaard HJ, Dorfmüller P, Remy S, Lecerf F, Planté S, Chat S, Fadel E, Houssaini A, Anegon I, Adnot S, Simonneau G, Humbert M, Cohen-Kaminsky S, Perros F (March 2015). "Endothelial-to-mesenchymal transition in pulmonary hypertension". Circulation. 131 (11): 1006–18. doi:10.1161/CIRCULATIONAHA.114.008750. PMID 25593290.
  9. ↑ Hopper RK, Moonen JR, Diebold I, Cao A, Rhodes CJ, Tojais NF, Hennigs JK, Gu M, Wang L, Rabinovitch M (May 2016). "In Pulmonary Arterial Hypertension, Reduced BMPR2 Promotes Endothelial-to-Mesenchymal Transition via HMGA1 and Its Target Slug". Circulation. 133 (18): 1783–94. doi:10.1161/CIRCULATIONAHA.115.020617. PMC 4856565. PMID 27045138.
  10. ↑ Jobe AH, Bancalari E (June 2001). "Bronchopulmonary dysplasia". Am. J. Respir. Crit. Care Med. 163 (7): 1723–9. doi:10.1164/ajrccm.163.7.2011060. PMID 11401896.
  11. ↑ Welsh CH, Hassell KL, Badesch DB, Kressin DC, Marlar RA (1996). "Coagulation and fibrinolytic profiles in patients with severe pulmonary hypertension". Chest. 110 (3): 710–7. doi:10.1378/chest.110.3.710. PMID 8797416.
  12. ↑ Hoeper MM, Sosada M, Fabel H (1998). "Plasma coagulation profiles in patients with severe primary pulmonary hypertension". Eur Respir J. 12 (6): 1446–9. doi:10.1183/09031936.98.12061446. PMID 9877507.
  13. ↑ Momose Y, Aimi Y, Hirayama T, Kataoka M, Ono M, Yoshino H; et al. (2015). "De novo mutations in the BMPR2 gene in patients with heritable pulmonary arterial hypertension". Ann Hum Genet. 79 (2): 85–91. doi:10.1111/ahg.12096. PMID 25612240.
  14. ↑ Aldred MA, Vijayakrishnan J, James V, Soubrier F, Gomez-Sanchez MA, Martensson G; et al. (2006). "BMPR2 gene rearrangements account for a significant proportion of mutations in familial and idiopathic pulmonary arterial hypertension". Hum Mutat. 27 (2): 212–3. doi:10.1002/humu.9398. PMID 16429403.
  15. ↑ Ghofrani HA, Seeger W, Grimminger F (2005). "Imatinib for the treatment of pulmonary arterial hypertension". N Engl J Med. 353 (13): 1412–3. doi:10.1056/NEJMc051946. PMID 16192491.
  16. ↑ Eddahibi S, Humbert M, Fadel E, Raffestin B, Darmon M, Capron F; et al. (2001). "Serotonin transporter overexpression is responsible for pulmonary artery smooth muscle hyperplasia in primary pulmonary hypertension". J Clin Invest. 108 (8): 1141–50. doi:10.1172/JCI12805. PMC 209526. PMID 11602621.
  17. ↑ Rich, S.; Dantzker, DR.; Ayres, SM.; Bergofsky, EH.; Brundage, BH.; Detre, KM.; Fishman, AP.; Goldring, RM.; Groves, BM. (1987). "Primary pulmonary hypertension. A national prospective study". Ann Intern Med. 107 (2): 216–23. PMID 3605900. Unknown parameter |month= ignored (help)
  18. ↑ ACCF/AHA 2009 Expert Consensus Document on Pulmonary Hypertension
  19. ↑ 19.0 19.1 Pietra GG, Capron F, Stewart S, Leone O, Humbert M, Robbins IM; et al. (2004). "Pathologic assessment of vasculopathies in pulmonary hypertension". J Am Coll Cardiol. 43 (12 Suppl S): 25S–32S. doi:10.1016/j.jacc.2004.02.033. PMID 15194175.

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