University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

292

Pages:

3
Author:

Mariam A. A.

Atherosclerosis Definition: Arterial wall thickening and elasticity loss Aetiology • • • • • • • • • • Smoking Diabetes Arterial hypertension Obesity Stress Dyslipidaemia High alcohol consumption family history males over 45 females over 55 Pathogenesis Cause present -> stress against arterial wall -> endothelium breaks -> LDL comes in -> monocytes flow -> eat up LDL -> die -> foam cells -> cytokines -> increased monocytes -> increased foam cells -> fatty streak -> thrombogenic -> platelets gather at sight of damaged endothelium -> release platelet derived growth factor -> increased growth of smooth muscle cells and move from tunica media to tunica intima -> smooth muscle cells multiply -> release collagen, proteoglycans, elastic fibrous cells -> fibrous cap is formed -> prevents blood clotting -> fibrous cap + fatty streak -> plaque -> HDL and LDL balance disturbances -> HDL unable to remove Ca2+ -> Ca2+ crystallisation -> stiffen artery wall • sometimes the fibrous cap breaks which leads to rapid occlusion and thus further decreasing the blood flow -> cell death and injury (ischemia) Signs and Symptoms • • • • • • • • • fourth heart sound (this is where the ventricles stiffen -> push extra hard) - make a TA LUB TUB Racing heart beats Increased troponin T and C Angina If arteries leading to the brain, it may lead to: - Numbness & weakness in arm and leg - Difficulty speaking - Temporary vision loss - Weakness of muscles of the face Leg pain If in kindies -> high blood pressure or kidney failure If coronary artery -> angina If superior mesenteric artery -> blood supply is cut to the small intestine • • • • • • • Popliteal artery -> peripheral ischemia If internal carotid artery and/or middle cerebral -> brain stroke Sweating due to activation of the SNS Dyspnoea Numbness due to poor circulation Hypertension Impaired glucose tolerance reading on fasting blood glucose Diagnosis • • • • • • • Physical cardiovascular exam: - 4th heart sound - Whooshing sound over occluded arteries - May seem visible palpitations Angiogram ECG - ST depression Blood test - Checks for cholesterol levels Biochemical tests - Increased urea High-sensitivity Troponin T - Increased troponin T levels Check for vitals - Increased blood pressure - Increased pulse rate - Increased respiratory rate Treatment • • • Lifestyle changes - Reduce LDL intake - Increase physical activity - Weight loss - Cut smoking Surgery - Angioplasty ✓ Opens the blocked artery via a balloon, this is then followed by the placement of stent to keep the artery open - Bypass ✓ Taking a healthy blood vessel from another place of the body and then use it to get around blocked segment. - Endarterectomy ✓ Removal of fatty deposits Medications - Cholesterol meds -> improve lipid proliferation - Antiplatelet meds -> decrease blood clotting e.g., aspirin - Blood pressure meds, [beta blockers, ACE inhibitors etc.) • Pathology - Macroscopic: many thick white plaques can be seen - Microscopic (histology): ✓ Cholesterol and lipid deposits present within the tunica intima ✓ The vascular of the smooth muscle of the tunica media is atrophied in some places. ✓ Foam cells ✓ Fibrous cap can be seen ✓ Neutrophils ✓ Lymphocytes Complications • • • • • • Refer to signs and symptoms Ischemia Infarction Heart failure Stroke Peripheral artery disease