Disorders of blood flow and blood pressure Flashcards
hyperlipidemia
Cholesterol & triglycerides (dietary lipids) are insoluble in plasma as encapsulated by lipoproteins 5 types of lipoproteins Chylomicrons VLDL LDL IDL HDL
- LDL is the main carrier of cholesterol but leaves some behind for uptake in arterial wall
- HDL also carry cholesterol but remove it from tissues and take to liver for disposal.
- Genetic defect of these proteins may accelerate atherosclerosis
hyperlipidemia causes/risks
Lipid blood levels raised by Nutrition - High-calorie diet increases production of VLDL & it’s conversion to LDL Genetics Comorbid conditions/diseases Medication
Atherosclerosis Risk Factors: non-modifiable
Risk Factors: non-modifiable
- Age
- Gender
- Post-menopausal women
- Family hx of premature CAD
- Genetically determined alteration in lipoprotein and cholesterol metabolism.
Atherosclerosis Risk Factors: modifiable
Risk Factors: modifiable
- Cigarette smoking
- Obesity
- Hypertension
- Hyperlipidemia
- Diabetes mellitus
C-reactive protein
Hyperhomocystinemia
Increased serum lipoprotein
Tobacco use
- Increases blood lipid levels
- Damages endothelium
- Enhances thrombosis formation
- Increases blood viscosity
- Increases circulating catecholamines.
Arteriosclerosis, Arteriolosclerosis, & Atherosclerosis
Arteriosclerosis
Hardening of medium to large arteries
Arteriolosclerosis
Hardening of small arterioles
Atherosclerosis
Hardening d/t atheromatous plaque
Atherosclerosis plaques
Stable plaques
- Thick fibrous caps
- Partially block vessels
- Don’t tend to form clots/emboli
Unstable plaques
- Thin fibrous caps
- May rupture causing clot formation
- May completely block artery
- Clot may break free
Sites of Atherosclerosis: Arteries
- Abdominal aorta
- Proximal coronary
- Thoracic aorta
- Femoral & popliteal
- tend to form at branches*
Types of Atherosclerotic Lesions
- Fatty Streak
- Found in all ages/geographic areas/race/lifestyle, etc. - Fibrous Atheromatous Plaque
- Lipids, smooth muscle, scar tissue
- Predispose to thrombus formation - Complicated Lesion- clots & lesions forming
Peripheral Artery Disease & Risk Factors
- Atherosclerosis distal to the
aortic arch
Risk Factors
- Male
- > 60 years old
- Smokers
- Diabetes Mellitus
Peripheral Artery Disease Manifestations
- Intermittent claudication (pain in the legs when moving)
- Thinning of skin & tissue
- Gradual atrophy of muscles
- Decreases blood supply, leads to: weak/absent pulses, cool extremities, brittle toenails, hair loss, pallor, dependent rubor.
Peripheral Artery Disease Complications
-Ulceration, gangrene
Peripheral Artery Disease Diagnosis
- Blood pressure changes in leg
- Pulse changes
- Doppler Ultrasound
- MRI Ateriography/Spiral CT arteriography
- Contrast angiography.
Raynaud Phenomenon
Intense episodic vasospastic disorder of arteries and arterioles
- Usually fingers, less often toes
Primary: symmetrical
- Secondary: non-symmetrical
- Associated with pre-existing PAD
- Frostbite, occupational trauma (vibrating tools, hot/cold environment)
- Usually young women
Raynaud Phenomenon Manifestations
Precipitated by cold, strong emotions
Manifestations
Tingling/numbness/aching/throbbing pain
Pallor to cyanosis
Aneurysms
Abnormal localized dilation of blood vessel
- True
- Berry (happens at a branch of an artery)
- Saccular (pouches out)
- Fusiform (all the way around the artery) - False
- Dissecting (layers of the wall separate b/c there is blood leaking)
Aortic Aneurysm
Often discovered during routine Xray
- ECG, Ultrasound, MRI, CT
Risk Factors
- Atherosclerosis
- Age+
Manifestations
- Dependent on size, location, stage
Aneurysm: Thoracic
Substernal, back, neck pain
Pressure on: Trachea = cough, stridor, dyspnea Laryngeal nerve = hoarseness Esophagus = difficulty swallowing Superior vena cava = facial/neck edema
Aneurysm: Abdominal Aortic
“Triple A” – Most Common
- Asymptomatic
- Pulsating mass if >4cm often first sign
- Mild to severe abdominal and back pain.
Aneurysm: Complications
Thrombi
Compression
- Vasculature
- Nerves
Rupture
Risk Factors for Aortic Aneurysm
Often occurs without atherosclerotic changes
Risk Factors
- Hypertension
- 40-60 year old men
- Marfan’s syndrome
- Pregnancy
- Congenital defects of aortic valve
- Aortic coarctation (band around the aorta which decreases bloodflow)
- Blunt trauma.
Dissecting AA Manifestations
> Excruciating pain anterior chest & back
> Blood pressure
- Initially high
- Later unobtainable in one or both arms
> Syncope
Lower extremity hemiplegia/paralysis
Heart failure if aortic valve involvement
Determinants of Blood Pressure (review!)
Short-Term Regulation
Neural Mechanisms
Humoral Mechanisms
Long-Term Regulation
Kidneys retain or excrete water and sodium to regulate vascular volume (ECV)
Neural Mechanisms: ANS
Medulla and lower pons (CV center)
Parasympathetic impulses via vagus nerve to heart = slows HR
Sympathetic impulses via spinal cord & peripheral sympathetic nerves to heart and blood vessels = increased HR & vasoconstriction (incr PVR)
Neural Mechanisms con’t
Intrinsic reflexes
Baroreceptors/stretch receptors
- Carotid & aortic walls, heart
Chemoreceptors
- Carotid and aortic bifurcation
Extrinsic reflexes: diffuse reactions d/t pain, cold via hypothalamus/SNS pathways.
Humoral Mechanisms
> Renin-Angiotension-Aldosterone System (renin released by JG cells in smooth muscle increases BP)
- Released in response to SNS activity, decreased volumes
- Converts angiotensin I to angiotension II
Vasopressin (ADH)
Epinephrine
Primary/Essential Hypertension (Risk Factors)
- Chronic/ Without evidence of other disease processes
Risk Factors - Family history
- Race
- Older age
- Lifestyle factors: high salt/caloric/fat intake, chronic excessive alcohol consumption, smoking, stress
Secondary Hypertension
- Results from another disorder
- Numerous risk factors
Target Organ Damage
Hypertension is asymptomatic until long-term effects are seen in organs
Heart Brain Kidney Liver Lungs Eye
Hypertensive Crisis
Elevated BP with impending target-organ damage
Severe: SBP >180 mmHg & DBP >110 mmHg
Emergency: DBP >120 mmHg
Vascular damage!
Symptoms!
Orthostatic Hypotension
Sustained drop in BP d/t a change in body position (usually standing)
Causes Reduced blood volume Pharmaceuticals Aging Bedrest/immobility
Orthostatic Hypotension (cont) manifestations & diagnosis
Manifestations
- Visual changes, dizziness, syncope
- Drop in systole BP of 20 mmHg and –diastolic BP of 10 mmHg
Diagnosis
- Lying/Standing Blood Pressure with 2-3 minute wait
- Tilt Table
Disorders of Venous Circulation
- Skin
- Subcutaneous tissues
- Superficial veins
- Deep veins
- Heart
-Low Pressure System
Varicose Veins
Dilated tortuous veins
Aching/edema (slower blood movement –> increased pressure)
25-30% of women; 10-20% of men
Risk Factors
Obesity
>50 years old.
Varicose Veins: Primary & Secondary
- Primary
- Originate in superficial saphenous veins
- Caused by prolonged standing, pregnancy, abdominal pressure, prolonged heavy lifting - Secondary
- Impaired flow in deep veins d/t other disease
- Caused by arteriovenous fistulas, venous malformations, tumor, pregnancy.
Chronic Venous Insufficiency: Causes/Manifestations
Causes/Manifestations -Venous hypertension -Dilation & stretching of vessel wall -Impaired blood flow results in: Edema, impaired issue nutrition Ischemia, necrosis Brown pigmentation Stasis dermatitis Venous ulcers
Deep Vein Thrombosis
Thrombus & Inflammation
Superficial or Deep Veins
Virchow’s Triad:
- Venous stasis
- Vascular trauma
Risk Factors for DVT
- Venous stasis
- Bedrest/immobility
- SC injury
- AMI/CHF/Shock
- Venous obstruction - Vascular trauma
- Venous catheters
- Surgery, especially orthopedic
- Trauma/infection
- # hip
Risk Factors for DVT con’t
Hypercoagulability Genetics Stress/trauma Pregnancy/Childbirth Oral contraceptives/hormone replacement Dehydration Cancer
DVT manifestations
Often asymptomatic (50%) Pain Swelling Deep muscle tenderness Signs of inflammation
DVT complications and treatment
> Complication -Pulmonary/cerebral embolus > Treatment -Prevention -Anticoagulation -Elevate limb -Bedrest -Gradual ambulation with elastic support -Heat
