Spontaneous coronary artery dissection pathophysiology: Difference between revisions
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At present the pathophysiology of SCAD continues to be poorly understood due to the rarity of this condition and its heterogeneous pathology. In SCAD the affected [[coronary artery]] develops a tear, causing blood to flow between the coronary arterial layers eventually forcing them apart. The pattern of dissection in SCAD is different from the pattern observed in patients with pre-existing [[atherosclerosis]]. In SCAD the plane of dissection lies within the outer third of the [[tunica media]] or between the [[media]] and [[adventitia]]. Dissections can be present in either one artery or several arteries concomitantly.<ref name="pmid12403896">{{cite journal |author=Choi JW, Davidson CJ |title=Spontaneous multivessel coronary artery dissection in a long-distance runner successfully treated with oral antiplatelet therapy |journal=[[The Journal of Invasive Cardiology]] |volume=14 |issue=11 |pages=675–8 |year=2002 |month=November |pmid=12403896 |doi= |url=}}</ref> The dissecting plane between [[intima]] and [[media]] creates a false lumen and the resulting [[hematoma]] compresses the vessel lumen causing [[myocardial ischemia]] or [[myocardial infarction]] (MI). | At present the pathophysiology of SCAD continues to be poorly understood due to the rarity of this condition and its heterogeneous pathology. In SCAD the affected [[coronary artery]] develops a tear, causing blood to flow between the coronary arterial layers eventually forcing them apart. The pattern of dissection in SCAD is different from the pattern observed in patients with pre-existing [[atherosclerosis]]. In SCAD the plane of dissection lies within the outer third of the [[tunica media]] or between the [[media]] and [[adventitia]]. Dissections can be present in either one artery or several arteries concomitantly.<ref name="pmid12403896">{{cite journal |author=Choi JW, Davidson CJ |title=Spontaneous multivessel coronary artery dissection in a long-distance runner successfully treated with oral antiplatelet therapy |journal=[[The Journal of Invasive Cardiology]] |volume=14 |issue=11 |pages=675–8 |year=2002 |month=November |pmid=12403896 |doi= |url=}}</ref> The dissecting plane between [[intima]] and [[media]] creates a false lumen and the resulting [[hematoma]] compresses the vessel lumen causing [[myocardial ischemia]] or [[myocardial infarction]] (MI). | ||
Spontaneous arterial dissection can develop in any layer (intima , media, or adventitia) of the coronary artery wall. Two possible mechanisms may be responsible for the arterial wall separation. The first one is, the intimal tear hypothesis, in which intramural blood accumulation may develop through a primary entry tear which occurs due to the damaged intimal surface and causes separation of the arterial wall. The second one is, medial hemorrhage hypothesis, in which hemorrhage can occur in between the arterial wall layers due to a spontaneous rupture of newly formed vasa vasorum in response to injury. High pressure of haematoma within the aortic wall may rupture through the intima and create a “reverse” intimal rupture. | |||
Although intimal tear or bleeding of vasa vasorum with intramedial hemorrhage seems to be most probable reason, the exact underlying mechanism of non-atherosclerotic spontaneous coronary artery dissection (NA-SCAD) is still unknown [1]. Consequently intramural hematoma creates a false lumen [2]. Progressive expansion of the false lumen may cause subsequent myocardial ischemia and infarction. | Although intimal tear or bleeding of vasa vasorum with intramedial hemorrhage seems to be most probable reason, the exact underlying mechanism of non-atherosclerotic spontaneous coronary artery dissection (NA-SCAD) is still unknown [1]. Consequently intramural hematoma creates a false lumen [2]. Progressive expansion of the false lumen may cause subsequent myocardial ischemia and infarction. | ||
Revision as of 17:39, 23 November 2017
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Spontaneous Coronary Artery Dissection Microchapters |
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Differentiating Spontaneous coronary artery dissection from other Diseases |
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Diagnosis |
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Treatment |
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Case Studies |
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Type 1 Type 2A Type 2B Type 3 |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Nate Michalak, B.A.
Synonyms and keywords: SCAD
Overview
Pathophysiology
At present the pathophysiology of SCAD continues to be poorly understood due to the rarity of this condition and its heterogeneous pathology. In SCAD the affected coronary artery develops a tear, causing blood to flow between the coronary arterial layers eventually forcing them apart. The pattern of dissection in SCAD is different from the pattern observed in patients with pre-existing atherosclerosis. In SCAD the plane of dissection lies within the outer third of the tunica media or between the media and adventitia. Dissections can be present in either one artery or several arteries concomitantly.[1] The dissecting plane between intima and media creates a false lumen and the resulting hematoma compresses the vessel lumen causing myocardial ischemia or myocardial infarction (MI).
Spontaneous arterial dissection can develop in any layer (intima , media, or adventitia) of the coronary artery wall. Two possible mechanisms may be responsible for the arterial wall separation. The first one is, the intimal tear hypothesis, in which intramural blood accumulation may develop through a primary entry tear which occurs due to the damaged intimal surface and causes separation of the arterial wall. The second one is, medial hemorrhage hypothesis, in which hemorrhage can occur in between the arterial wall layers due to a spontaneous rupture of newly formed vasa vasorum in response to injury. High pressure of haematoma within the aortic wall may rupture through the intima and create a “reverse” intimal rupture.
Although intimal tear or bleeding of vasa vasorum with intramedial hemorrhage seems to be most probable reason, the exact underlying mechanism of non-atherosclerotic spontaneous coronary artery dissection (NA-SCAD) is still unknown [1]. Consequently intramural hematoma creates a false lumen [2]. Progressive expansion of the false lumen may cause subsequent myocardial ischemia and infarction.
References
- ↑ Choi JW, Davidson CJ (2002). "Spontaneous multivessel coronary artery dissection in a long-distance runner successfully treated with oral antiplatelet therapy". The Journal of Invasive Cardiology. 14 (11): 675–8. PMID 12403896. Unknown parameter
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