Ch. 18 Disorders of Blood Flow and Blood Pressure Flashcards
What are the five main types of lipoproteins?
Chylomicrions Very low density lipoprotein Low density lipoprotein Intermediate density lipoprotein high density lipoprotein
Why is LDL considered the “bad” cholesterol?
It is the main carrier of cholesterol and leaves it behind for uptake in the arterial wall.
Why is HDL considered the “good” cholesterol?
It carries cholesterol from the tissues to the liver for disposal.
How are blood lipid levels elevated?
Nutrition
Genetics
Comorbid conditions
Medications
How does nutrition affect blood lipid levels?
High-calorie diet increases production of VLDL and it’s conversion to LDL.
What are the non-modifiable risk factors for atherosclerosis?
Increasing age Male Post-menopausal women Family history of premature CAD Genetically determined alterations in lipoprotein and cholesterol metabolism
What are the modifiable risk factors for atherosclerosis?
Cigarette smoking Obesity Hypertension Hyperlipidemia Diabetes mellitus
What are some tests that can show risk factors for atherosclerosis?
C-reactive protein
Hyperhomocystinemia
Increased serum lipoprotein
How does tobacco use affect the development of atherosclerosis?
Increases blood lipid levels Damages endothelium Enhances thrombosis formation Increases blood viscosity Increases circulating catecholamines
What is arteriosclerosis?
Hardening of medium to large arteries.
What is arteriosclerosis?
Hardening of small arterioles.
What is atherosclerosis?
Hardening due to atheromatous plaque.
What are characteristics of stable plaques?
Thick fibrous caps
Partially block vessels
Don’t tend to form clots/emboli
What are characteristics of unstable plaques?
Thin fibrous caps
May rupture causing clot formation
May completely block artery
Clot may break free
What are the most common sites of atherosclerosis?
Abdominal aorta Proximal coronary Thoracic aorta Femoral & popliteal Iliac Internal carotid Vertebral, basilar, middle cerebral *At sites of vascular branches*
What are the tree types of atherosclerotic lesions?
Fatty streak
Fibrous atheromatous plaque
Complicated lesion
What are fatty streaks?
Fat deposits in the arteries found in all ages/geographic areas/races/lifestyles.
What are fibrous atheromatous plaques?
Made of lipids, smooth muscle, and scar tissue.
These predispose to thrombus formation.
What is a complicated lesion?
A combination of fatty streak and fibrous atheromatous plaque.
What is peripheral artery disease?
Atherosclerosis distal to the aortic arch.
What are the risk factors for peripheral artery disease?
Male
>60 years old
Smokers
Diabetes mellitus
What are the manifestations of peripheral artery disease?
Intermittent claudication (legs hurt when walking)
Thinning of skin and subcutaneous tissue
Gradual atrophy of muscle
Decreased blood supply
What are the results of decreased blood supply due to periopheral artery disease?
Weak/absent pulses Cool extremities Brittle toenails Hair loss Pallor Dependent rubor
How is peripheral artery disease diagnosed?
Blood pressure changes in leg Pulse changes Doppler Ultrasound MRI Ateriography/Spiral CT arteriography Contrast angiography.
What are the complications of peripheral artery disease?
Ulcerations/gangrene
What are the treatment methods for peripheral artery disease?
Walking to the point of claudication Avoiding surface injury as slow to heal Address causes Antiplatelet therapy (ASA, Clopidogrel) Statins Femoralpopliteal bypass grafting Percutaneous transluminal angioplasty and stenting
What is raynaud phenomenon?
Intense episodic vasospastic disorder of arteries and arterioles
(usually fingers, less often toes)
What are the manifestations of raynaud phenomenon?
Tingling and numbness/aching/throbbing pain
Pallor to cyanosis
What are the treatments for raynaud phenomenon?
Avoidance of triggers
Avoidance of vasoconstrictive medications
Vasodilatory medications
Sympathectomy.
What are the differences between primary and secondary raynaud phenomenon?
Primary: symmetrical
Secondary: non-symmetrical
Associated with pre-existing PAD
Frostbite, occupational trauma (vibrating tools, hot/cold environment)
What is an aneurysm?
Abnormal localized dilation of blood vessel.
What are the three forms of true aneurysm?
Berry (bipurcation)
Saccular (sac like)
Fusiform (involves the whole circumference of the artery)
What is considered a “false” aneurysm?
Dissecting
What is the difference between a true and a false aneurysm?
In true aneurysms, the arterial wall is intact. In a false aneurysm, the wall is broken (dissecting).
How are aortic aneurysms diagnosed?
Often discovered during routine X-ray.
Other diagnostics” ECG, ultrasound, MRI, CT
What are the manifestations of a thoracic aortic aneurysm?
Substernal, back, neck pain Pressure on: Trachea = stridor, cough, dyspnea Laryngeal nerve = hoarsness Esophagus = difficulty swallowing Superior vena cava = facial/neck edema
What are the risk factors for an aortic aneurysm?
Atherosclerosis
Age+
What are the manifestations of an abdominal aortic aneurysm (Triple A)?
Asymptomatic
Pulsating mass if >4cm often first sign
Mild to severe abdominal and back pain.
What is the most common kind of aortic aneurysm?
Abdominal aortic aneurysm
What are the complications of an aneurysm?
Thrombi
Compression of vasculature and nerves
Rupture
What are the risk factors of a dissecting aortic aneurysm?
Hypertension 40-60 year old men Marfan’s syndrome Pregnancy Congenital defects of aortic valve Aortic coarctation Blunt trauma
What are the manifestations of dissecting aortic aneurysm?
Excruciating pain anterior chest and back
Blood pressure
Initially high
Later unobtainable in one or both arms
Syncope
Lower extremity hemiplegia/paralysis
Heart failure if aortic valve involvement
How is mean arterial blood pressure calculated?
Systolic + two diastolic divided by 3.
What is the mean arterial blood pressure?
The amount of blood pressure in general that is supplied to your organs.
What are the mechanisms of short term regulation of blood pressure?
Neural Mechanisms Humoral Mechanisms (hormones)
What are the mechanisms of long term regulation of blood pressure?
Kidneys retain or excrete water and sodium to regulate vascular volume (ECV)
What are the neural mechanisms (autonomic nervous system) that mediate blood pressure?
Medulla and lower pons
Parasympathetic impulses via vagus nerve to heart = slows HR
Sympathetic impulses via spinal cord & peripheral sympathetic nerves to heart and blood vessels = increased HR and vasoconstriction (jncr PVR).
What are the intrinsic reflexes that mediate blood pressure?
Baroreceptors/stretch receptors
Chemoreceptors
What are the extrinsic reflexes that mediate blood pressure?
Diffuse reactions due to pain, cold via hypothalamus/SNS pathways.
How do the humoral mechanisms control blood pressure?
Renin-Angiotension-Aldosterone System
Released in response to SNS activity, decreased volumes
Converts angiotensin I to angiotension II
Vasopressin (ADH)
Epinephrine
What is primary/essential hypertension?
Chronic/ Without evidence of other disease processes
What are the risk factors for primary/essential hypertension?
Family history
Race
Older age
Lifestyle factors
What blood pressure is considered hypertensive?
140/90 or higher
What is secondary hypertension?
Results from another disorder.
What are the risk factors for secondary hypertension?
Kidney disease Adrenal cortical disorders Pheochromocytoma Coarctation of the Aorta Pharmaceuticals Obstructive Sleep Apnea
What are lifestyle factors that put people at risk for primary/essential hypertension?
High salt/caloric/fat intake
Chronic excessive alcohol consumption
Smoking
Stress
Which organs are damaged by hypertension over the long term?
Heart Brain Kidney Liver Lungs Eye
What is a hypertensive crisis?
Elevated BP with impending target organ damage.
What blood pressure is considered severe hypertension/hypertensive crisis?
180/110 mmHg
What blood pressure is an emergency?
Diastolic >120 mmHg
What is orthostatic hypotension?
Sustained drop in BP d/t a change in body position (usually standing)
What are the causes of orthostatic hypotension?
Reduced blood volume
Pharmaceuticals
Aging
Bedrest/immobility
What are the manifestations of orthostatic hypotension?
Visual changes
Dizziness
Syncope
Nausea
How is orthostatic hypotension defined?
Drop in systolic BP of 20 and diastolic BP of 10 when moving from laying down/sitting to standing.
How is orthostatic hypotension diagnosed?
Lying/Standing Blood Pressure with 2-3 minute wait
Tilt Table
What are vericose veins?
Diated tortuous veins
What are the risk factors for vericose veins?
Obesity
>50 years old
What do primary vericose veins originate?
Originate in superficial saphenous veins
What causes primary vericose veins?
Caused by prolonged standing, pregnancy, abdominal pressure, prolonged heavy lifting
What is secondary varicose veins?
Impaired flow in deep veins due to other disease
What causes secondary vericose veins?
Caused by arteriovenous fistulas
Venous malformations
Tumor
Pregnancy
What are the causes of chronic venous insufficiency?
Venous hypertension - dilation and stretching of the vessel wall
What are the manifestations of chronic venous insufficiency?
Impaired blood flow, which results in: Edema, impaired tissue nutrition Ischemia, necrosis Brown pigmentation (hemosiderin deposits) Statis dermatitis Venous ulcers
What are the three main risk factors for deep vein thrombosis? (Virchow’s triad)
Stasis
Vessel wall injury
Hypercoagulability
What are some causes of venous stasis?
Bedrest/immobility
SC injury
AMI/CHF/Shock
Venous obstruction
What are some causes of vascular trauma?
Venous catheters
Surgery, especially orthopedic
Trauma/infection
Fractured hip
What are some causes of hypercoagulability?
Genetics Stress/trauma Pregnancy/Childbirth Oral contraceptives/hormone replacement Dehydration Cancer
What are the manifestations of deep vein thrombosis?
Often asymptomatic (50%) Pain Swelling Deep muscle tenderness Signs of inflammation
What are some complications of deep vein thrombosis?
Pulmonary/cerebral embolus
What are the treatments for deep vein thrombosis?
Prevention Anticoagulation Elevate limb Bedrest Gradual ambulation with elastic support Heat
