atherosclerosis 3
DESCRIPTION
this includes morpho,clinical features,complications,diagnosis,treatment....TRANSCRIPT
ATHEROSCLEROSISATHEROSCLEROSISATHEROSCLEROSISATHEROSCLEROSIS
MORPHOLOGY
&
COMPLICATIONS
MORPHOLOGY
&
COMPLICATIONS
-S.SHRINATH
83 Batch.
MORPHOLOGY
FATTY STREAK
ATHEROSCLEROTIC PLAQUE
-:FATTY STREAK:-
•It is the earliest lesions in Atherosclerosis which is composed of foam cells.
•Earlier formed as small flat yellow spots and then to a plaque.
•Does not cause any obstruction to the blood flow.
-:ATHEROSCLEROTIC PLAQUE:-
•Intimal thickening and lipid accumulation.
•Lodged in the lumen of the artery (0.3-1.5 cm in dia).
•Grossly they appear as white to yellow patches.
•Lesions are mostly eccentric but rarely circumferential.
•Local flow disturbances –increased susceptibility to plaque formation.
Most extensively affected vessels are:
•Abdominal aorta
•Coronary arteries
•Popliteal arteries
•Internal carotid arteries
•Circle of willis
Components of Plaque:
Cells
•T-cells
•Smooth muscle cells
•Macrophages.
ECM
•Collagen
•Elastic fibers
•Proteoglycans
Lipids
•Intracellular and extracellular.
-:DESCRIPTION – PLAQUE:-
•Typically composed of superficial composed fibrous cap (smooth muscle cells and collagen).
•Beneath it contains cellular area.
•Deeply containing lipid core, cell debris, foam cells, fibrin, thrombus, plasma proteins.
•Periphery shows neovascularisation.
-:NATURE OF THE PLAQUE:-
Progressively enlarges due to:-
•Cell death and degeneration.
•Synthesis and remodeling of collagen.
•Organization of thrombus.
Often undergo calcification.
CHANGES IN THE ATHEROSCLEROTIC PLAQUE
•Rupture ,erosion ,ulceration.
•Hemorrhage into a plaque.
•Atheroembolism.
•Aneurysm formation.
RUPTURE
HEMORRHAGE INTO PLAQUE
ATHERO EMBOLISM
ANEURYSMS FORMATION
COMPLICATIONSCOMPLICATIONS
-:COMPLICATIONS:-
•Myocardial infarction
•Cerebral infarction (stroke).
•Aneurysm
•Peripheral vascular disease (PVD).
Atherosclerotic stenosis
Small arteries plaques occlude lumen compromising blood flow ischemia.
Critical stenosis
•Chronic occlusion significantly limits flow .
occurs at approx 70% occlusion in coronary circulation.
Consequences of stenosis
•Mesenteric occlusion
and bowel ischemia.
•Chronic IHD.
•Ischemic encephalopathy.
•Intermittent claudication.
ACUTE PLAQUE CHANGE
•Partial or complete vascular thrombosis due to erosion or rupture of plaque resulting in acute tissue infarction.
•Rupture expose high thrombogenic substances.
•Erosion expose thrombogenic sub endothelial basement membrane.
•Hemorrhage expands the volume.
PLAQUE CONFIGURATION
•Composition of plaque is dynamic .
•Based on the plaque configuration it may be of stable or vulnerable.
•Stable plaque•Thick fibrous cap
•Small lipid core
•Vulnerable plaque•Thin fibrous cap
•Dense lipid core
EVENTS TRIGGERING CHANGES IN PLAQUE CONFIGURATION
INTRINSIC FACTORS - plaque structure and composition
Fibrous cap
•Collagen (produced by smooth cells).
•Collagen turnover is regulated by
•Matrix metalloproteinase (macrophages within plaque),
•Tissue inhibitors of metalloproteinase (endothelial cells,smooth muscle cells)
EXTRINSIC FACTORS -BP and platelet activity.
•adrenergic stimulation increase BP increasing physical stress.
ROLE OF FREE RADICALS
(OXIDATIVE STRESS)
LDL Oxidised LDL
Release of free radicals
DAMAGE TO THE ARTERIAL WALL
Into macrophages
THROMBOSIS
•Partial or complete thrombosis associated with disrupted plaque is critical to the pathogenesis of acute stenosis.
•Thrombosis is a potent activator of multiple growth related signals which contribute to the growth of atherosclerotic lesion.
VASOCONSTRICTION
•This compromises lumen size and by increasing the local mechanical forces and can potentiate the plaque disruption.
CLINICAL FEATURES
ON CORONARY ARTERIES:
•Angina
•Hyperhidrosis•Shortness of breath•Palpitations•Tachycardia•Weakness or dizziness•Nausea
ON CAROTID ARTERIES:
•Transient ischemic attacks
•Dizziness ,Confusion ,Fainting , Coma
•Loss of eyesight
•Hemiplegia.
•Claudication is the most common symptom of this condition.
•Pain
•Coolness, numbness
• Poor healing of wounds
•Ulcers leading to Gangrene formation
•Black discoloration
ON PERIPHERAL ARTERIES:
DIAGNOSISDIAGNOSIS
DIAGNOSIS
SEROLOGICAL IMAGING
LIPID PROFILE
HbA1c
CRP-HS
HOMOCYSTEINE
LDL LEVEL
LIPOPROTEIN a
CT SCAN
INTRAVASCULAR ULTRASOUND
ANGIOGRAPHY
DOPPLER STUDY
TREATMENTTREATMENT
TREATMENT
NON-PHARMACEUTICAL PHARMACEUTICAL
NON-FAT DIET
CESSATION OF SMOKING
REGULAR EXERCISE
REDUCE ALCOHOL CONSUMPTION
Use of drug
surgical
PHARMACOTHERAPY
DRUGS FOR REDUCING HYPERCHOLESTROLEMIA
STATINS
ATORVASTATIN
FLUVASTATIN
LOVASTATIN
PRAVASTATIN
SIMVASTATIN
ROSUVASTATIN
USES OF STATINS
•REDUCING PLAQUE SIZE.
•STABILIZING PLAQUES.
•DECREASING BLOOD CLOT FORMATION.
•DECREASING CRP LEVELS.
DRUGS FOR REDUCING CLOT FORMATION
VITAMIN –K ANTAGONIST
WARFARIN ACENOCOUMAROL PHENINDIONE
HEPARIN DERIVATIVES
HEPARIN FONDAPARINUX INDRAPARINUX
DIRECT THROMBIN INHIBITORS
ARGATROBAN LEPIRUDIN BIVALURIDIN
THE DRUGS THAT BREAKSDOWN THE BLOOD CLOT
tissue plasminogen activator t-PA:
alteplase (Activase)reteplase (Retavase)tenecteplase (TNKase)
antistreplase (Eminase)
streptokinase (Kabikinase, Streptase)
urokinase (Abbokinase)
SURGICAL INTERVENTION
•BALOON ANGIOPLASTY AND STENTING
•ATHERECTOMY
•SURGICAL BYPASS
•ENDATERECTOMY
SUMMARY
MORPHOLOGY
MORPHOLOGY
COMPLICATIONS
MYOCARDIAL INFARCTIONSTROKEPERIPHERAL VASCULAR DISEASEANEURYSM FORMATION
COMPLICATIONS
Atherosclerotic stenosis
•Critical stenosis
•Consequences of stenosis
Acute plaque change
•Stable plaque & vulnerable plaque
•Factors that bring about the Change.
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