Author/Editor		Blinc, Aleš
Title		Stabilna in nestabilna aterosklerotična leha
Translated title		Stable and unstable atherosclerotic plaque
Type		članek
Source		Med Razgl
Vol. and No.		Letnik 37, št. Suppl 3
Publication year		1998
Volume		str. 85-90
Language		slo
Abstract		Atherosclerosis progresses asymptomatically until superimposed arterial thrombosis is triggered by disruption of the fibrous cap of an advanced atheroma. Most fissures of atherosclerotic plaques remain asymptomatic, although the mural thrombus contributes to plaque growth and luminal narrowing. Disruption of an atheroma in coronary arteries that gives rise to nearly- occlusive or occlusive thrombosis results in unstable angina, myocardial infarction or sudden cardiac death. The risk of plaque disruption is much more dependent on plaque composition than on the degree of luminal narrowing. Unstable atherosclerotic plaques have a thin fibrous cap and an abundant lipid-rich core, which is highly thrombogenic due to its tissue factor content. Disruption of an atherosclerotic plaque is triggered by mechanical factors, but the susceptibility for rupture is determined by ongoing inflammation and repair within the atheroma. Macrophages secrete and activate matrix metalloproteinases that weaken the mechanical stability of the fibrous cap. Lowering the serum concentration of low density lipoprotein cholesterol has a beneficial effect on plaque stability.
Summary		Ateroskleroza poteka asimptomatsko, dokler požkodba fibroznega pokrova napredovale lehe ne sproži arterijske tromboze. Večina drobnih razpok aterosklerotičnih leh ne sproži akutne simptomatike, vendar muralna tromboza prispeva k napredovanju ateroskleroze in postopnemu zoževanju žilne svetline. Če na razpoki lehe v koronarnih arterijah nastane obsežna arterijska tromboza, ki pomembno zoži ali zapre žilno svetlino, pride do nestabilne angine pektoris, srčnega infarkta ali nenadne srčne smrti. Tveganje za raztrganje aterosklerotične lehe je mnogo bolj odvisno od njene sestave kot od stopnje žilne zožitve. Nestabilne aterosklerotične lehe imajo tanek vezivni pokrov in obilno lipidno jedro, bogato s tkivnim dejavnikom, ki ob stiku s krvjo sproži koagulacijo. Raztrganje aterosklerotične lehe povzročijo mehanični dejavniki, dovzetnost zanje pa je v veliki meri posledica vnetne in reparativne aktivnosti v ateromu. Makrofagi v lehi izločajo in aktivirajo matriksne metaloproteinaze, ki slabijo odpornost fibroznega pokrova lehe. Zniževanje serumske koncentracije holesterola lipoproteinov majhne gostote prispeva k stabilizaciji aterosklerotičnih leh.
Descriptors		ATHEROSCLEROSIS CORONARY ARTERIOSCLEROSIS ENDOTHELIUM, VASCULAR