Cardiovascular Flashcards
Hyperlipidemia: Causes
Primary - genetically based
Secondary- diabetes, thyroid disease, renal disorder, liver disorders, cushings, obesity, high calorie diet, alcohol, drugs (beta blocker, protease inhibitors, estrogen)
Hyperlipidemia: types of lipoproteins
Chylomicrons
Very low density lipoprotein (VLDL) - high amounts of triglycerides
Intermediate density lipoprotein (IDL
Low density lipoprotein (LDL) - carrier of cholesterol; deposits for uptake in arterial wall
High density lipoprotein (HDL) - 50% protein carrying less cholesterol and little triglyceride; carries cholesterol from tissues to liver for disposal
Risk Factors for Atherosclerosis
Increasing age Male Postmenopausal women Family history Genetics
Smoking Obesity Hypertension Hyperlipidemia Diabetes
Systemic inflammation marked by elevated C reactive protein
Hyperhomocysteinemia
Increased lipoprotein a levels
Infectious agents
Types of Plaques
Stable - thick fibrous caps that partially block vessels; dont tend to form clots
Unstable - thin fibrous caps that completely block artery; clot may rupture and break free
Fatty Streaks - thin yellow lines running along major arteries
Smooth muscle cells filled with cholesterol and macrophages can develop into fibrous
Fibrous atheromatous plaques - basic lesion of clinical atherosclerosis
Accumulation of lipids and proliferation of vascular smooth muscle, formation of scar tissue and calcification
May eventually occlude vessel or predispose to thrombus formation
Complicated atherosclerotic lesion - fibrous plaque breaks open producing hemorrhage, ulceration, and scar tissue deposits
Development of Atherosclerosis
- Injury to endothelium - inflammation is key
- LDL accumulates and undergoes chemical changes in arterial wall signaling endothelial cells to latch onto WBC in the blood
- WBC penetrate intimate and trigger inflammatory response and devour LDL creating foam cells
Growth factors contribute to migration and proliferation of smooth muscle and elaborations of Extracellular matrix - Formation of fatty streak
- Plaque continues to grow and forms fibrous cap
- Substances released by foam cells can eventually destabilize and rupture creating clots
Peripheral Artery Disease: risk factors
Atherosclerosis distal to the aortic arch
Male
Greater than 60yrs old
Smokers
Diabetes Mellitus
Peripheral Artery Disease: manifestations
Intermittent claudication Thinning of skin and subcutaneous tissue Gradual atrophy of muscles Decreased blood supply Absent or weak pulses Cool extremities Brittle nails and hair loss Pallor Dependent rubor
Ischemic pain
Ulceration
Gangrene
Raynaud Phenomenon: causes
Intense episode vasospsatic disorder of the arteries and arterioles
Primary - symmetrical vasospasm precipitated by cold or strong emotions; minimal pain
Secondary - non symmetrical association with previous vessel injury
Frostbite, occupational trauma, temp extremes; very painful
Raynaud Phenomenon: manifestations
Ischemic - pallor to cyanosis, cold, numbness and tingling
Hyperemia- intense redness, throbbing, paresthesia
Return to normal colour
True Aneurysms
Bounded by a complete vessel wall - blood remains within the vascular compartment
Berry - small spherical dilation at a bifurcation
Circle of Willis
Fusiform - entire circumference of vessel; gradual progressive dilation of the vessel varying in diameter and length
Ascending and transverse thoracic and abdominal aorta
Saccular - extends over part of the circumference of the vessel and appears saclike
False Aneurysms
Localized dissection or tear in the inner wall of the artery with formation of extravascular hematoma that causes vessel enlargement
Bounded by outer layers of the vessel or supporting tissue
Dissecting - tear of the intima allowing blood to enter the vessel wall dissecting into layers to create a blood filled cavity
Aortic Aneurysm
Age and atherosclerosis are risk factors
Abdominal Aortic:
Asymptomatic pulsating mass if large can cause abdominal and back pain; commonly located below the renal artery
Thoracic Aorta
Due to Atherosclerosis
Often asymptomatic
Substernal, back, or neck pain
Pressure on trachea = stridor, cough, dyspnea
Laryngeal nerve = hoarseness
Esophagus = difficulty swallowing
Superior vena cava = facial and neck edema
Define: Arterial Blood Pressure Systolic Blood Pressure Diastolic Blood Pressure Pulse Pressure Mean Arterial Blood Pressure
Arterial Blood Pressure - ejection of blood from lt ventricle
Systolic Blood Pressure - highest pressure on contraction
Diastolic Blood Pressure - lowest pressure on relaxation
Pulse Pressure - systolic and diastolic difference
Mean Arterial Blood Pressure - average pressure in the arterial system during contraction and relaxation indicates tissue perfusion
Cardiac output and peripheral resistance
CO = product of stroke volume and heart rate
Peripheral resistance reflects changes in radius of the arterioles and viscosity of the blood
BP = COXPR
