Transcript Cardiovascular System Biomedicine Review

Cardiovascular
System Biomedicine
Review
Felix Hernandez, M.D.
Normal Heart
Chambers of the
Heart
The Peripheral
Vascular System
Blood Pressure
• Blood
pressure is regulated by cardiac output
and peripheral vascular resistance
• Systolic Blood Pressure
• the
blood pressure measured during the period
of ventricular contraction
• Intheatwo
blood pressure reading, it is the higher of
measurements.
• Diastolic Blood Pressure
• the
minimum level of blood pressure measured
between contractions of the heart.
• Can
vary with age, gender, weight and
emotional state.
• Primary Hypertension
Hypertension
• elevated
blood pressure without a known
causative factor
• this is the most common type
• causes:
• genetic predisposition and obesity
• stress, increased alcohol intake
• diabetes, sodium and water retention
• Secondary Hypertension
• elevated
blood pressure with an identifiable
cause
• Causes:
• renal
artery stenosis, congenital heart
defects, cushing’s syndrome, sleep apnea,
pregnancy, stimulants
Risk Factors
Hypertension
• Signs and Symptoms
• no initial symptoms usually occur
• chronic fatigue
• headache
• dizziness
• dyspnea
• chest pain and palpitations
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Treatment
ABC
A: ACE Inhibitor
Enalapril (Vasotec), Lisinopril (Zestril)
block the conversion of angiotensin I to angiotensin II which
would normaly act as a vasoconstrictor
this blocking causes vasodilation which will cause a decrease in
resistance and a decrease in BP
B: Beta Blocker
Action: blocks the beta adrenergic receptors of the sympathetic
nervous system which results in vasodilation and a decrease in
the release of renin
Contraindications: Pregnancy and Lactation
Cautions: asthma, diabetes
Side Effects: Hypotension, bradycardia, wheezing, dyspnea
C: Calcium Chanel Blocker
Amlodipine (Norvasc), Diltiazem (Cardizem), Nifedipine
(Procardia)
block calcium influx into the beta receptors which causes a
decrease in the force of contraction and reduces the heart rate
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Specific Side Effects of Beta
Blockers
• Propranolol (Inderal)
• bradycardia, CHF, impotence
• Atenolol (Tenormin)
• dizziness,
fatigue, cold extremities,
depression, impotence
• Timolol (Blocarden)
• fatigue,
bradycardia, extremity pain,
impotence
• Metoprolol (Lopressor)
• fatigue,
dizziness, depression, confusion,
short term memory loss, headache,
impotence
• Diuretics Treatment
• Loop Diuretics
• Furosemide (Lasix)
• inhibit
the reabsorption of sodium and
chloride in the ascending loop of Henle
• Thiazide Diuretics
• Hydrochlorothiazide
• inhibit
sodium and chloride reabsorption in
the the distal tubules
• Used to treat hypertension and edema
• Contraindications:
hypersensitivity to
sulfonamides, anuria, oliguria, fluid and
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electrolyte depletion
Side Effects: tiredness, weakness,
Treatment
• Potassium Sparring Diuretic
• Spironolactone (Aldactone)
• MOA: Antagonist of Aldosterone
• Side
Effects: Hyperkalemia, glucose
intolerance in DM patients
Unstable Angina
• an
anginal attack occurring at rest or
increasing in frequency
• caused by blockage of the coronary arteries
• has
a high risk of subsequent myocardial
infarction
• Labs:
is evaluated with EKG. First you do a
resting EKG, if that comes back normal then
you perform an exercise stress test.
Treatment
• Nitroglycerin
• Uses:
Relief of anginal pain and to suppress
tachycardia
• MOA:
relaxes vasculature (both arteries and
veins but mostly veins) causing a decreased
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in preload and afterload
Contraindications: hypersensitivity, severe
anemia, head trauma or cerebral
hemorrhage
Side Effects: orthostatic hypotension, dry
mouth, blurred vision, tachycardia, headache
Myocardial Infarction
• Is the leading cause of death
• caused by an obstruction of a coronary artery
• S/S:
chest pain that lasts for more than 30
minutes and radiates to the left arm. The pain
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is not relieved by nitroglycerin
Labs: Increased Troponin and CK-MB
EKG Changes: T-wave inversion, ST elevation,
Q-wave formation
Treatment: Oxygen, aspirin, morphine, betablocker, ARB
Ventricular Fibrillation
• Dangerous electrical dysfunction
• Commonly associated with MI, CHF and shock
• EKG: rapid, chaotic, and distorted
• S/S: cheat pain, SOB, sudden death
• Tx: Direct Current Cardioversion
Ventricular Flutter
• Heart rate of 150-350 BPM
• Associated with hypoxia or ischemic insults
• S/S: hypotension and sudden death
• EKG: loss of normal QRS morphology
• Tx: defibrillation
Atrial Fibrillation
• Uncoordinated rapid contractions of the
atria
• S/S: dizziness, papitations, irregularly
irregular pulse
• associated with the development of
thrombi that can embolize
• Tx: Warfarin (Coumadin), antiarrhythmics
Renal Artery Stenosis
• Caused
by fibromuscular dysplasia in young
women and atherosclerosis in older men
• S/S:
HTN, audible abdominal bruit, high renin
levels
• Tx: ACE, angioplasty
Hypothermia
• A decrease in body temperature
• S/S:
decreased peripheral perfusion,
decreased respiratory rate, decreased bowel
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sounds, decreased DTR
Can also cause arrhythmia, bradycardia and
hypotension
Deep Vein
Thrombosis
• Development
of a blood clot in the deep veins
of the lower extremity
• Associated
with cancer, estrogen therapy, and
prolonged immobility
• Virchow’s
Triad: hypercoagulability, venostasis,
endothelial injury
• S/S: Homan’s Sign --> pain on foot dorsiflexion
• Tx:
Heparin (works faster so it is used initially)
and Warfarin (Coumadin)
• Prothrombin
Time (PT) is used to measure
the effects of Warfarin
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Cholesterol
Total Cholesterol
desired levels is <200
>240 is considered high risk
HDL
desired level is >60
considered protective against heart disease
levels are increase by: vigorous exercise, insulin,
estrogens
levels are decreased by starvation, obesity,
hypothyroidism, smoking, DM and liver disease
LDL
desired level <100
>190 gives you the highest increased risk of heart
disease
Levels are increased by atherosclerosis, CHD
Levels are decreased by depression, anxiety
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Cholesterol Lowering
Drugs
• Cholestyramine
• MOA:
forms insoluble complexes with bile
salts allowing them to be excreted in feces.
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The body compensates by increasing the
number of LDL receptors and oxidizing
cholesterol to bile acids
Indications: LDL>190 or 160 with 2 risk
factors
Lipid Profile Effects:
decreases TC, and LDL
Increases Triglycerides, VLDL and HDL
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Cholesterol Lowering
Drugs
• MOA: inhibit HMG-CoA reductase in the liver
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which is the enzyme that catalyzes the rate
limiting step in cholesterol synthesis.
Profile Changes:
Decreases TC, LDL, VLDL and
Triglycerides
Increases HDL
Side Effects: Myalgia
Drugs:
Simvastatin (Zocor)
Atorvastatin (Lipitor)
Rosuvastatin (Crestor)
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Chronic Congestive Heart
Disease
Chronic Congestive Heart
Disease
Digitalis
• MOA:
inhibits the Na-K ATPase which alters
the mechanical and electrical actions of the
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heart and causes an increase in myocardial
contractility
Uses: Heart Failure (improves CO) and atrial
fibrillation
Contraindications: hypersensitivity, ventricular
tachycardia
Side Effects: dizziness, muscle weakness,
visual disturbances, hypokalemia, bradycardia,
arrhythmia
Cardiomyopathy
• Dilated—viral
infection, alcohol, cardiotoxic
drugs
• Ventricles
are dilated and the myocardium is
flabby and thinned
• Hypertrophic—genetic
• Thickening of LV myocardium
• Mutation
in the genes that code for
myocardium constrictive proteins
• Restrictive—amyloidosis,
endomyocardial
fibrosis
• Heart cant expand to receive inflowing blood
• Heart transplant is the only treatment
Leukocytes
• Granulocytes
• Basophil: allergic and histamine reactions
• Eosinophil:
parasitic infection, fungal
infection
• Neutrophil:
bacterial infection, inflammation,
stress (Not Viral)
• Agranulocytes
• Lymphocyte: viral infection, chronic infection
• Monocyte: chronic infection
White Blood Cell
Count
• Increased by:
• acute infection, neoplasm, leukemia
• Decreased by:
• bone
marrow malfunction, immune
deficiency, iron deficiency, AIDS,
chemotherapy
Immunoglobulins
• IgG:
most predominant, can cross the placenta
and pass immunity to the fetus
• IgM: is the first to appear
• IgA:
secretory antibody, is found in colostrum,
secretions, saliva, tears
• IgE:
least predominant, promotes histamine
allergic reactions
• IgD: serves as a receptor on B-cells
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Anemia
General Causes:
chemo, GI bleed, rheumatoid arthritis, Lupus, AIDS, Cancer
S/S: decreased hemoglobin, decreased hematocrit, changes in
fingernail beds, pale skin, fatigue
Specific Types:
Aplastic anemia: caused by damage to the bone marrow from
toxic chemicals or radiation
Hemolytic Anemia: destruction of red blood cells by toxic
chemicals or antibodies
Iron Deficiency Anemia: caused by a dietary lack of iron which
leads to deficient hemoglobin synthesis
Pernicious Anemia: caused by an inability to absorb B12 which
leads to immature RBCs
Sickle Cell Disease: caused by a defective gene leading to
sickle shaped RBCs
Thalassemia: caused by a defective gene which causes the
formation of abnormal hemoglobin and a shortened lifespan of
RBCs
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Blood Labs
Red Blood Cell Count (RBC)
increased in: polycythemia, renal disease,
pulmonary disease
decreased in: anemia, Hodgkin’s leukemia, sickle
cell disease
Hemoglobin and Hematocrit
Increased by: dehydration, shock, COPD, CHF,
polycythemia
Decreased by: anemia, leukemia, hyperthyroidism,
cirrhosis, massive trauma
Iron
Increased by: acute hepatitis, nephrosis
Decreased by: anemia, lupus, RA, hypothyroidism,
3rd trimester of pregnancy
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Aspirin
• MOA: inhibits cyclooxygenase which is required for
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prostaglandin synthesis.
Decreases inflammation and pyrogen-induced fever
Decreases pain caused by injury or inflammation
Prevents platelet aggregation
Indications: symptomatic relief of minor main,
inflammation, fever or RA. Reduction of stroke risk.
Side Effects: GI upset and bleeding, allergic reaction.
Increased risk of Reye’s Syndrome in children
Occurs when giving aspirin after an infection. Can
cause brain, liver and kidney damage with possible
death
Overdose is called salicylism and involves tinnitus,
dizziness, HA, fever, mental status changes,
hyperventilation, and respiratory alkalosis which can lead
to a metabolic acidosis
Contraindications: bleeding disorders and peptic ulcer
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Quiz Next Week
• 25 questions
• 20 Cardiovascular
• 5 Musculoskeletal
• 2 bone diagrams
• 3innervation,
multiple choice on muscles (action,
special notes)