Cardiac Anatomy

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Cardiac Anatomy Physiology
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The Heart

• Hollow, four chambered, muscular organ.
• The heart is found in the mediastinum between the
  right and left lungs.
• The four chambers are subdivided
• 2 atria (right left)
• 2 ventricles (right left)

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Atria

• Each atrium has thin-walls and is separated by
  the interatrial septum.
• The atria act as collecting or holding chambers.

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Ventricles

• Each ventricle has thick muscular walls and is
  separated by the interventricular septum.
• The ventricles act as pumps.
• The right ventricle pumps the unoxygenated blood
  from your organs and tissues to the lungs.
• The left ventricle pumps the oxygenated blood
  from your heart to your organs and tissues.

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Circulation

• The vasculature of your lungs is called pulmonary
  circulation.
• The vasculature that supplies the heart with
  oxygen and nutrients is called coronary
  circulation.
• The vasculature of all of your organs and tissues
  (everything besides your lungs and heart) is
  called systemic circulation.

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Circulation

• The right ventricle is responsible for pulmonary
  circulation.
• The left ventricle is responsible for systemic
  coronary circulation.

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Valves of the Heart

• You have four valves that separate the four
  chambers of the heart.
• Atrioventricular Valves (tricuspid and bicuspid)
• Semilunar Valves (pulmonic and aortic valves)

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The Valves of the Heart

• Atrioventricular Valves (tricuspid and bicuspid)
• Semilunar Valves (pulmonic and aortic valves)

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Valves

• The first valve is between the right atrium
  right ventricle.
• This valve is called the tricuspid valve.
• The valve is called tricuspid because the valve
  has three flaps.
• The flaps are held in place by tendinous cords
  called chordae tendinae.
• The chordae tendinae are secured to the walls of
  the ventricle by the papillary muscles.
• When the ventricles contract the tricuspid valve
  closes.
• When the ventricles relax the tricuspid valve
  opens.

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Valves

• The second valve is between the right ventricle
  and the pulmonary trunk.
• This valve is called the pulmonary semilunar.
• The valve is called semilunar because of its new
  moon shape.
• When the ventricles contract the pulmonary
  semilunar valve opens.
• This allows the blood from the right side of the
  heart to be pumped to the lungs.
• When the ventricles relax the pulmonary semilunar
  valve closes.

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Valves

• The third valve is between the left atrium and
  the left ventricle.
• This valve is called the mitral or bicuspid
  valve.
• The valve is called bicuspid because the valve
  has two flaps.
• The two flaps connect to the left ventricle by
  the same principle as the tricuspid valve.
• When the ventricles contract the bicuspid valve
  closes.
• When the ventricles relax the bicuspid valve
  opens

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Valves

• The forth valve is between the left ventricle and
  the aortic trunk.
• This valve is called the aortic semilunar.
• The valve is called semilunar because of its new
  moon shape.
• When the ventricles contract the aortic semilunar
  valve opens.
• This allows the blood from the left side of the
  heart to be pumped to the body.
• When the ventricles relax the aortic semilunar
  valve closes.

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Valves

• Valves are suppose to be one-way however they can
  malfunction.
• Valve regurgitation weak leaky valve
• Valve stenosis constriction or narrowing of
  passageway

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Valves

• Why do valves leak?
• Rheumatic fever
• Aging
• Congenital heart defects

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Layers of the Heart

• The heart is enclosed in a double walled sac
  called the pericardium.
• It consist of 2 layers
• The outer layer is called the fibrous
  pericardium.
• The inner layer is called the serous pericardium.
• The serous pericardium consist of 2 layers
• Parietal layer
• Visceral layer also called epicardium.

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Layers of the Heart

• What is Pericarditis?
• It is inflammation of the double walled sac
  called the pericardium.
• What causes pericarditis?
• Trauma
• Infection
• Tumors
• What are the symptoms?
• Chest pain
• Audible friction rub

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Layers of the Heart

• If worsening pericarditis or pericardial effusion
  can result in cardiac tamponade.
• Cardiac tamponade intrapericardial pressures
  increase to the point that it impairs the filling
  of the heart
• Cardiac Tamponade is life threatening and is
  sometimes treated with pericardiocentesis.

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Layers of the heart

• The wall of the heart is made up of three layers.
• Epicardium
• Corresponds to the visceral pericardium.
• Functions as an outer protective layer.
• Serous membrane that consists of connective
  tissue covered by epithelium.
• Includes blood capillaries, lymph capillaries,
  and nerve fibers.

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Layers of the heart

• The wall of the heart is made up of three layers.
• Myocardium
• Relatively thick.
• Consists largely of cardiac muscle tissue
  responsible for forcing blood out of the heart
  chambers.
• Muscle fibers are arranged in planes, separated
  by connective tissues that are richly supplied
  with blood capillaries, and nerve fibers.

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Layers of the heart

• The wall of the heart is made up of three layers.
• Endocardium
• Consists of epithelial and connective tissue that
  contains many elastic and collagenous fibers.
• Connective tissue also contains blood vessels and
  some specialized cardiacmuscle fibers called
  Purkinje fibers.
• Lines all of the heart chambers and covers heart
  valves.
• Is continuous with the inner lining of blood
  vessels--endothelium.

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Wall of the Heart

• What is endocarditis?
• It is an infection and inflammation of the
  heart's inner lining (endocardium). It is most
  common in people with damaged, diseased, or
  artificial heart valves.
• What causes it?
• It is caused by bacteria that enter the
  bloodstream and settle on the heart valves.
• What are the symptoms?
• Chills Fever
• Fatigue
• Weight loss
• Painful joints
• Persistent cough and SOB
• How is it treated?
• IV Antibiotics

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Blood supply to the Heart

• The two main arteries that feed the heart
• Left coronary artery
• Circumflex branch
• Anterior interventricular branch
• Right coronary artery
• Marginal branch
• Posterior interventricular branch

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Blood supply to the Heart

• The main veins that drain used blood from the
  heart
• Great cardiac veins
• drains the anterior side of the heart
• Middle cardiac vein
• Drains the posterior side of the heart
• The great cardiac and middle veins merge together
  into a cavity called the coronary sinus.
• The thebesian vein then carries the used blood
  into the left and right atria.

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Disorders

• Atherosclerosis hardening of the arteries which
  promotes clots and/or occlusions.
• Thrombosis a clot /coagulation of blood
• Embolism thrombosis that has traveled from
  location it was formed.
• Myocardial Ischemia decreased oxygen
  availability to the heart because of decreased
  blood flow or decreased oxygen in blood.
• Myocardial Infarction tissue death due to a
  loss of blood glucose to the heart muscle.

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Disorders

• Congestive Heart Failure (CHF) condition where
  the left side of the heart is damaged.
• Cor Pulmonale condition where the right side of
  the heart has decreased function.
• Angina Pectoris a severe pain or pressure in
  the chest caused by inadequate blood flow and
  oxygen content to the heart muscle.

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Treatment for Disorders

• Coronary Angioplasty treats blockages of
  vasculature with a catheter or balloon.
• Coronary Artery Bypass Graft (CABG) artery
  graft from the leg or arm is inserted into
  coronary vasculature to bypass blocked arteries.

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Blood flow through the Heart

• Inferior Vena Cava/ Superior Vena Cava
• Right Atrium
• Tricuspid Valve
• Right Ventricle
• Pulmonary Semilunar Valve
• Pulmonary artery trunk
• Pulmonary artery
• Left/Right pulmonary artery
• Lungs

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Blood flow through the Heart

• Left/Right pulmonary vein
• Left Atrium
• Bicuspid/Mitral Valve
• Left Ventricle
• Aortic Semilunar Valve
• Aortic artery trunk
• Ascending Aorta
• Brachiocephalic artery
• Left common carotid artery
• Left Subclavian artery
• Descending Aorta
• xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

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• Show cardiac cycle video

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Cardiac Cycle

• Cardiac cycle is the term referring to all or any
  of the events related to the flow of blood that
  occur from the beginning of one heartbeat to the
  beginning of the next

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• The frequency of the cardiac cycle is the heart
  rate
• Every single 'beat' of the heart involves three
  major stages
• atrial systole
• ventricular systole
• complete cardiac diastole
• The term diastole is synonymous with relaxation
  of a muscle.
• It is the period of time when the heart relaxes
  after contraction in preparation for refilling
  with circulating blood.

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• The term systole is synonymous with contraction
  (movement or stretching) of a muscle. Think
  squeeze
• The term diastole is synonymous with relaxation
  of a muscle. Think dilate.
• It is the period of time when the heart relaxes
  after contraction in preparation for refilling
  with circulating blood.

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Heart Rate

• Heart rate is a term used to describe the
  frequency of the cardiac cycle.
• It is considered one of the four vital signs
• Usually it is calculated as the number of
  contractions (heart beats) of the heart in one
  minute and expressed as "beats per minute" (bpm).
  
• Normal Heart rate in adults 60-100 bpm

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Stroke Volume

• Stroke volume is the amount of blood pumped by
  the left ventricle of the heart in one
  contraction
• The heart does not pump all the blood out of the
  ventricle. Normally, only about two-thirds of the
  blood in the ventricle is put out with each beat
• Normal range
• 60 -120mL

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Cardiac Output (Qt)

• Cardiac output is the volume of blood being
  pumped by the heart, in particular a ventricle in
  a minute.
• Cardiac Output (CO) SV HR
• Normal range is 4-6 lpm

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Electrophysiology of the Heart

• Contraction of the heart is initiated by an
  electrical stimulus
• These contractions are a function of action
  potentials (electrical currents)
• Action potentials consist of 5 phases
• 0 depolarization
• 1-4 represent polarization

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Electrical System of the Heart

• Depolarization electrical activity that
  triggers contraction of the heart muscle.
• Depolarization typically results from the influx
  of positively charged sodium ions into the cell.
• Repolarization The restoration of a polarized
  state across a membrane, as in a muscle fiber
  following contraction.
• Repolarization results from the movement of
  positively charged potassium ions out of the
  cell.

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DEPOLARIZATION     REPOLARIZATION     RESTORATION OF IONIC BALANCE
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Cardiac Cell Types

• Contractile Muscle Fibers
• Bulk of myocardium responsible for the pumping
  activity of the heart
• Autorhythmic cells
• Pacemaker cells
• 1 of tissue, mostly located in the SA node
• Unique ability to spontaneously initiate an
  action potential which in turn cause muscle
  fibers to contract

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Cardiac Cells

• Four Properties
• Automaticity
• Generates an action potential without stimulation
• Excitability
• Irritability lower stimulus needed to activate
  cell
• Conductivity
• Transmits electrical current effectively
  intercalated disks
• Contractility
• Shortening and contraction in response to
  stimulus

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Electrical Conduction System of the Heart

• There are four structures embedded in the walls
  of the heart muscles that generate strong
  impulses and conduct them rapidly through the
  heart wall.

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Electrical System of the Heart

• Sino-atrial Node
• SA node
• Pacemaker 60 -100 bpm
• Atrioventricular Node
• AV node 40- 60 bpm
• Bundle of His
• AV bundle 20 40 bpm
• Right and Left bundle branches
• Purkinje Fibers

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Electrical System of the Heart
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EKG

• Electrocardiogram graphic representation of the
  electrical activity of the hearts conductive
  system over time.
• electrical NOT mechanical
• EMD/PEA
• Leads are placed on the patient to evaluate the
  electrical system of the heart.
• 3 lead (monitoring)
• 12 lead (diagnostic)

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standard limb lead configurations
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• A typical ECG tracing of a normal heartbeat
  (or cardiac cycle) consists of
• a P wave,
• a QRS complex
• a T wave.
• A small U wave is normally visible in 50 to 75
  of ECGs.
• The baseline voltage of the electrocardiogram is
  known as the isoelectric line.
• Typically the isoelectric line is measured as
  the portion of the tracing following the T wave
  and preceeding the next P wave.

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EKG
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EKG
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EKG

• Des Jardins Pg. 416-417
• Normal durations
• P wave 0.08 0.11 sec
• P-R interval 0.12 0.20 sec
• QRS complex lt 0.10 sec
• S-T segment lt 0.12 sec
• T wave lt 0.20
• Q-T interval lt 0.38

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EKG BASICS

• EKGs are printed on standardized graph paper
• The Y axis represents VOLTAGE
• The X axis represents TIME
• The Y axis is generally set at 5 or 10 mm/mV
• The X axis units are seconds

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• There are two sized boxes.
• 5 small boxes make up one large box
• Each small box equals 40 msec.
• Each large box equals 200 msec
• 5 large boxes equals 1 second

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ECG paper is designed to move through the ECG
machine at 25 mm per second. Each of the
smallest boxes are l mm square making the darker
lined boxes 5 mm square. Thus, at the usual
rate of 25 mm/second flow of the paper through
the machine, 5 large boxes pass through the
machine per second or (5 x 60 seconds) 300 boxes
per minute.
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Large boxes are used to estimate heart rate.
Measure from QRS to QRS.

• Rates are approximate
• 1 large box 300 bpm.2 large boxes 150
  bpm.3 large boxes 100 bpm.4 large boxes 75
  bpm.5 large boxes 60 bpm.

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Basic ECG Interpretation
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NORMAL SINUS RHYTHM

• Impulses originate at S-A node at normal rate.
  All complexes normal and evenly spaced.Rate 60 -
  100/min

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SINUS BRADYCARDIA

• Impulses originate at S-A node at slow rate. All
  complexes normal and evenly spaced.Rate lt 60/min

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CAUSES OF SINUS BRADYCARDIA

• Coronary artery disease
• Increased intracranial pressure
• Hypothyroidism
• Hypoxemia
• Vagal stimulation
• Gagging
• Coughing
• Suctioning

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SINUS TACHYCARDIA

• Impulses originate at S-A node at rapid rate.
  All complexes normal and evenly spaced.Rate
  100-160/min

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CAUSES OF SINUS TACHYCARDIA

• Fever
• Sepsis
• Hypoxemia
• CHF
• Shock
• Fear
• Exercise

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ATRIAL FLUTTER

• Impulses travel in circular course in atria.
  Rapid flutter waves and ventricular response can
  be irregular.

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ATRIAL FIBRILLATION

• Impulses have chaotic, random pathways in atria.
  Baseline irregular ventricular response
  irregular.

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PREMATURE VENTRICULAR CONTRACTION (PVC)

• A single impulse originates in the right
  ventricle. Time interval between normal R peaks
  is a multiple of R-R intervals.

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VENTRICULAR TACHYCARDIA

• Impulse originates at ventricular pacemaker.
  Wide ventricular complexes. Rate here isgt 120/min

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VENTRICULAR FIBRILLATION

• Chaotic ventricular depolarization. Rapid, wide,
  irregular ventricular complexes.

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ASYSTOLE

• Rate none
• P wave may be seen, but there is no ventricular
  response
• QRS none
• Conduction none
• Rhythm none

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Neural Control of the Heart

• Many things play a role in controlling heart
  rate.
• Autonomic nervous system
• Baroreceptors
• Anxiety
• Body temperature

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Baroreceptors

• Arterioles are controlled by sympathetic
  impulses.
• There are sympathetic fibers located in the
  vessels.
• The medulla receives information from the
  baroreceptors located in the carotid the aorta.
  
• The medulla (vasomotor center) then feeds the
  impulses to the vessels based on the information.
  

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Baroreceptors

• The vessels either dilate or constrict based on
  the area of the body.
• In the heart, brain, and skeletal muscles
• ? sympathetic impulses vasodilatation
• ? sympathetic impulses vasoconstriction
• In the rest of the body
• ? sympathetic impulses vasoconstriction
• ? sympathetic impulses vasodilatation

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Baroreceptors

• Normally there is a continuous stream of impulses
  which cause the vessels of the body to always be
  slightly constricted.
• This is called vasomotor tone.
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BLOOD

• Blood is a highly specialized circulating tissue
  consisting of several types of cells suspended in
  a fluid medium known as plasma.
• Responsible for transportation and protection
• The cellular constituents are
• red blood cells (erythrocytes),
• white blood cells (leukocytes),
• platelets (thrombocytes cell fragments),

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Blood Volumes

• Blood volumes
• Whole blood
• 4 to 6 L average
• 7 to 9 of total body weight
• Normal volumes of blood fractions
• Plasma 2.6 L
• Formed elements 2.4 L

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Blood Plasma

• Liquid fraction of whole blood minus formed
  elements.
• 55 of total blood volume
• Composition
• 90 water
• 10 dissolved substances
• Foods Salts
• About 3 O2 carried in plasma
• About 5 CO2 carried in plasma
• Most abundant solutes dissolved in plasma are
  plasma proteins
• Albumins
• Globulins
• Fibrinogen
• Prothrombin

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Blood Plasma

• Plasma minus clotting factors, proteins, is
  called serum.
• Serum is liquid remaining after whole blood
  clots.
• Serum contains antibodies.

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Formed Elements

• Red Blood Cells (erythrocytes)
• White BloodCells (leukocytes)
• Granular leukocytes
• Neutrophils
• Eosinophils
• Basophils
• Nongranular leukocytes
• Lymphocytes
• Monocytes
• Platelets (thrombocytes)

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Erythrocytes (RBCs)

• Characteristics
• Biconcave disk shape (thin center and thicker
  edges) results in large cellular surface area.
• Tough and flexible plasma membrane deforms easily
  allowing RBCs to pass through small diameter
  capillaries.
• Absence of nucleus and cytoplasmic organelles
  limits life span to about 120 days but provides
  more cellular space for iron containing
  hemoglobin.

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Erythrocytes (RBCs)

• Named according to size
• normocytes (normal size about 7-9 µm in diameter)
• microcytic (small size)
• macrocytic (large size)
• Named according to hemoglobin content of cell
• normochromic (normal Hb content)
• hypochromic (low Hb content)
• hyperchromic (high Hb content)

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Erythrocytes
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Erythrocytes (RBCs)

• Hematocrit
• Percentage of RBCs in relation to total blood
  volume
• Normal
• Men 45
• Women 42
• Hemoglobin
• the iron-containing oxygen-transport
  metalloprotein in the red blood cells of the
  blood
• Measured as weight per 100 ml
• Men 14-18 gm/dl
• women 12-16 gm/dl
• Content
• Men 5,000,000 mm3
• Women 4,000,000 mm3

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Erythrocytes (RBCs)

• General functions
• Transportation of O2 and CO2
• Combined with hemoglobin
• Oxyhemoglobin (Hb O2)
• Carbaminohemoglobin (Hb CO2)
• Important role in homeostasis acid base
  balance.

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Leukocytes or WBCs

• General function is protection of body from
  microorganisms by phagocytosis or antibody
  formation.
• WBC normal range is 5,000 to 10,000/mm3 of blood.
  
• Leukopeniatotal numbers below 5,000/mm3 of
  blood.
• Infrequent but may occur with malfunction of
  blood forming tissues or diseases affecting
  immune system, such as AIDS.
• Leukocytosistotal numbers over 10,000/mm3 of
  blood.
• Frequent finding in bacterial infections
• Classic sign in blood cancers (leukemia)
• Differential WBC count is a component test in
  CBC measures proportions of each type of WBC in
  blood sample.

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Leukocytes
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Leukocytes or WBCs

• Leukocyte types and functions
• Granulocytes
• Neutrophils
• Eosinophils
• Basophils
• Agranulocytes
• Monocytes in peripheral blood (macrophages in
  tissues)
• Lymphocytes
• B lymphocytes (Plasma cells)
• T lymphocytes

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Leukocytes or WBCs

• Functions of WBCs
• Neutrophils
• Most numerous type of phagocyte
• Numbers increase in bacterial infections
• Monocytes
• Largest leukocyte
• Aggressive phagocytecapable of engulfing larger
  bacteria and cancer cells
• Develop into much larger cells called macrophages
  after leaving blood entering tissue spaces

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Leukocytes or WBCs

• Eosinophils
• Weak phagocyte
• Active against parasites and parasitic worms
• Involved in allergic reactions
• Basophils
• Related to mast cells in tissue spaces
• Both mast cells and basophils secrete histamine
  (causes inflammation)
• Basophils also secrete heparin (an anticoagulant)

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Leukocytes or WBCs

• Lymphocytes
• B lymphocytes involved in immunity against
  disease by secretion of antibodies
• Mature B lymphocytes are called plasma cells
• T lymphocytes involved in direct attack on
  bacteria or cancer cells (not antibody
  production)

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Platelets and Blood Clotting

• Platelets
• Play essential role in blood clotting
• Normal platelet count 150,000340,000/mm3
• Blood vessel damage causes platelets to become
  sticky and form a platelet plug
• Accumulated platelets release additional clotting
  factors that enter into the clotting mechanism
• Platelets ultimately become a part of the clot
  itself

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Platelets
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Platelets and Blood Clotting

• Clotting in a nutshell
• Damaged tissue cells along with platelets release
  prothrombin activator.
• Prothrombin activator, along with calcium
  converts prothrombin the thrombin
• Thrombin combines with fibrinogen to form fibrin
• Fibrin creates a net that begins to form the
  plug.

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Altering the blood clotting mechanism

• Application of gauze (rough surface) to wound
  causes platelet aggregation and release of
  clotting factors
• Administration of Vitamin K will increase
  synthesis of prothrombin
• Coumadin will delay clotting by inhibiting
  prothrombin synthesis
• Heparin delays clotting by inhibiting conversion
  of prothrombin to thrombin
• A drug called tissue plasminogen activator (TPA)
  is used to dissolve clots that have already
  formed

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Red Blood Cell Disorders

• Most often related to either
• overproduction of RBCs, called polycythemia
• low oxygen carrying capacity of blood,called
  anemia

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Polycythemia

• Cause is generally cancerous transformation of
  red bone marrow
• Dramatic increase in RBC numbersoften in excess
  of 10 million/mm3 of bloodhematocrit may reach
  60
• Signs and symptoms include
• Increased blood viscosity or thickness
• Slow blood flow and coagulation problems
• Frequent hemorrhages
• Distension of blood vessels and hypertension
• Treatment may include
• Blood removal
• Irradiation and chemotherapy to suppress RBC
  production

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Polycythemia
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Anemia

• Caused by either
• low numbers or abnormal RBCs
• low levels or defective types of Hb
• Normal Hb levels 12-14 g/100 ml of blood
• Low Hb level (below 9 g/100 ml of blood)
  classified as anemia
• Majority of clinical signs of anemia related to
  low tissue oxygen levels
• Fatigue skin pallor
• Weakness faintness headache
• Compensation by increasing heart and respiratory
  rates

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Types of Anemia

• Types
• Hemorrhagic anemia
• Aplastic anemia
• Deficiency anemia
• Hemolytic anemia

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Hemorrhagic anemia

• Acute
• Blood loss is either
• immediate
• surgery or trauma
• chronic
• ulcers or cancer

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Aplastic anemia

• Characterized by low RBC numbers and destruction
  of bone marrow
• Often caused by
• toxic chemicals
• irradiation
• certain drugs

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Aplastic anemia
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Deficiency anemia

• Caused by inadequate supply of some substance
  needed for RBC or hemoglobin production.
• Types
• Pernicious anemia
• Iron deficiency anemia
• Folate deficiency anemia

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Iron deficiency anemia

• Caused by deficiency or inability to absorb iron
  needed for Hb synthesis (dietary iron deficiency
  is common worldwide)
• RBCs are microcytic and hypochromic
• Hematocrit is decreased
• Treatment is oral administration of iron
  compounds

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Iron deficiency anemia
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Pernicious anemia

• Caused by Vitamin B12 deficiency
• Genetic related autoimmune disease
• Decreased RBC, WBC, and platelet numbers
• RBCs are macrocytic
• Classic symptoms of anemia coupled with CNS
  impairment
• Treatment is repeated Vitamin B12 injections

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Folate deficiency anemia

• Folate, also called folic acid, is necessary for
  red blood cell formation and growth.
• RBCs are macrocytic.
• Some medications, such as Dilantin (phenytoin),
  interfere with the absorption of this vitamin.
  Because folate is not stored in the body in large
  amounts, a continual dietary supply of this
  vitamin is needed.

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Vitamin B12 and folate deficiency anemia.
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Hemolytic anemia

• Caused by either
• decreased RBC life span
• increased RBC rate of destruction
• Symptoms are related to retention of RBC
  breakdown products
• Jaundice
• Swelling of spleen
• Gallstone formation
• Tissue iron deposits
• Types
• Sickle Cell Anemia
• Thalassemia
• Erythroblastosis fetalis

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Hemolytic anemia
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Sickle Cell Anemia

• Genetic disease resulting in formation of
  abnormal hemoglobin (HbS) primarily in the
  African American race
• RBCs become fragile and assume sickled shape when
  blood oxygen levels decrease
• Sickle cell trait is mild (one defective gene)
• Sickle cell disease more serious (two defective
  genes) causes blood stasis, clotting and
  crises that may be fatal
• Affects 1 in every 600 African American newborns

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Sickle cell anemia
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White Blood Cell Disorders

• Two major types of WBC cancers or neoplasms
• Lymphoid (lymphatic cells) neoplasmsresult from
  B and T lymphocyte precursor cells or their
  descendent cell types
• Myeloid (bone marrow cells) neoplasmsresult from
  the malignant transformation of precursor cells
  of granulocytic WBCs, monocytes, RBCs, and
  platelets

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White Blood Cell Disorders

• Multiple myeloma
• Cancer of B lymphocytes (plasma cells)
• Most deadly blood cancer in people over age 65
• Causes bone marrow disfunction and production of
  defective antibodies
• Characterized by
• Recurrent infections and anemia
• Destruction and fracture of bones
• Treatment includes chemotherapy, drug antibody
  therapy, and marrow and stem cell transplantation

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White Blood Cell Disorders

• LeukemiasWBC related blood cancers
• Characterized by marked leukocytosis
• Identified as
• Acute rapid development of symptoms
• Chronic slow development of symptoms
• Lymphoid lymphatic cells
• Myeloid bone marrow cells

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Chronic Lymphocytic Leukemia (CLL)

• Average age of onset is 65 rare under age 30
• More frequent in men than women
• Often diagnosed unexpectedly in routine physical
  exams with discovery of marked B lymphocytic
  leukocytosis
• Generally mild symptoms include anemia, fatigue,
  and enlarged often painless lymph nodes
• Most patients live many years following diagnosis
• Treatment of severe cases involves chemotherapy
  and radiation

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CLL
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Acute Lymphocytic Leukemia (ALL)

• Primarily a disease of children between 3 and 7
  years of age 80 of children who develop
  leukemia have this form of the disease
• Highly curable in children but less so in adults
• Onset is suddenmarked by fever, leukocytosis,
  bone pain and increased infections
• Lymph node, spleen and liver enlargement is
  common
• Treatment includes chemotherapy, radiation, and
  bone marrow or stem cell transplants

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ALL
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Chronic Myeloid Leukemia (CML)

• Accounts for about 20 of all cases of leukemia
• Occurs most frequently in adults between 25 and
  60 years of age
• Caused by cancerous transformation of
  granulocytic precursor cells in the bone marrow
• Onset and progression of disease is slow with
  symptoms of fatigue, weight loss and weakness
• Diagnosis often made by discovery of marked
  granulocytic leukocytosis and extreme spleen
  enlargement
• Treatment by new designer drug Gleevec or bone
  marrow transplants is curative in over 70 of
  cases

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CML
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Acute myeloid leukemia (AML)

• Accounts for 80 of all cases of acute leukemia
  in adults and 20 of acute leukemia in children
• Characterized by sudden onset and rapid
  progression
• Symptoms include leukocytosis, fatigue, bone and
  joint pain, spongy bleeding gums, anemia and
  recurrent infections
• Prognosis is poor with only about 50 of children
  and 30 of adults achieving long term survival
• Bone marrow and stem cell transplantations have
  increased cure rates in selected patients

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AML
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White Blood Cell Disorders

• Infectious mononucleosis
• Noncancerous WBC disorder
• Highest incidence between 15 and 25 years of age
• Caused by virus in saliva
• Leukocytosis of atypical lymphocytes with
  abundant cytoplasm and large nuclei
• Symptoms include fever, severe fatigue, sore
  throat, rash, and enlargement of lymph nodes and
  spleen
• Generally self-limited and resolves without
  complications in about 4 to 6 weeks

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mono
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Leukocytes or WBCs

• Lymphocytes
• B lymphocytes involved in immunity against
  disease by secretion of antibodies
• Mature B lymphocytes are called plasma cells
• T lymphocytes involved in direct attack on
  bacteria or cancer cells (not antibody
  production)

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Clotting disorders

• Hemophilia A
• X-linked inherited disorder results from
  inability to produce Factor VIII (a plasma
  protein) responsible for blood clotting
• In severely affected individuals frequent and
  extensive episodes of bleeding can be life
  threatening
• Characterized by easy bruising, deep muscle
  hemorrhage, blood in urine, and repeated episodes
  of bleeding into joints causing pain and
  deformity
• Treatment includes administration of Factor VIII,
  injury prevention, and avoiding drugs like
  aspirin that alter the clotting mechanism

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hemophilia
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Hemophilia and inheritance
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Clotting disorders

• Thrombocytopeniacaused by reduced platelet
  counts
• Characterized by bleeding from small blood
  vessels, most visibly in the skin and mucous
  membranes
• Platelet count below 20,000/mm3 may cause
  catastrophic bleeding (Normal platelet count
  150,000340,000/mm3)
• Most common cause is bone marrow destruction by
  drugs, chemicals, radiation, and diseases such as
  cancer, lupus, and HIV/AIDS
• Treatment may involve transfusion of platelets,
  corticosteroid type drugs, or removal of the
  spleen.

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Blood Types

• ABO system
• Type A bloodtype A antigens in RBCs anti-B type
  antibodies in plasma
• Type B bloodtype B antigens in RBCs anti-A type
  antibodies in plasma
• Type AB bloodtype A and type B antigens in RBCs
  no anti-A or anti-B antibodies in plasma
• universal recipient blood
• Type O bloodno type A or type B antigens in
  RBCs both anti-A and anti-B antibodies in plasma
• universal donor blood

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Blood Types

• Rh system
• Rh-positive blood
• Rh factor antigen present in RBCs
• Rh-negative blood
• No Rh factor present in RBCs
• No anti-Rh antibodies present naturally in plasma
• Anti-Rh antibodies, however, appear in the plasma
  of Rh-negative persons if Rh-positive RBCs have
  been introduced into their bodies (pregnancy)

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Erythroblastosis Fetalis

• Hemolytic disease of newborn
• Caused by blood ABO or Rh factor incompatibility
  during pregnancy between developing baby and
  mother
• The maternal antibodies fighting against
  foreign fetal RBCs or Rh factor can cross
  placenta, enter the fetal circulation, and
  destroy the unborn babys RBCs
• Symptoms in developing fetus related to decline
  in RBC numbers and Hb levels jaundice,
  intravascular coagulation, and heart and lung
  damage are common
• Treatment may include utero blood transfusions
  and early delivery of the baby
• Prevention of Rh factor incompatibility now
  possible by administration of RhoGAM to Rh
  negative mothers
• xxxxxxxxxxxxxxxxxxxxxxxxxxx

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Rh factor
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Rh factor
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Erythroblastosis fetalis
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Erythroblastosis fetalis
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Blood Pressure

• pressure generated by the blood
• Highest in the arteries
• Lowest in the veins
• Blood pressure gradient difference between two
  blood pressures
• The difference between the beginning pressure and
  the ending pressure within a circuit.
• What two pressures would we look at to compute
  the systemic blood pressure gradient?

160
Blood Pressure

• The maximum pressure generated during ventricular
  contraction is called the systolic pressure.
• The lowest pressure that remains prior to the
  next ventricular contraction is called the
  diastolic pressure.

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Blood Pressure

• Hypertension increased arterial pressure
• Can lead to ruptured vessels stroke
• Hypotension decreased arterial pressure
• Can lead to the loss of circulation life will
  cease.
• Commonly seen with massive hemorrhage.

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Blood Pressure

• Factors that affect blood pressure
• Blood volume
• Directly related to BP
• Force of heart contractions
• Affects cardiac output directly, unless there is
  a noted decrease in blood volume i.e. hemorrhage
• Heart rate
• Affects cardiac output directly. This is only
  true if the stroke volume does not decrease
  sharply when the heart rate increases, due to
  less fill time.
• Blood viscosity
• Directly related to BP

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Pulse and Pulse points

• Temporal
• Facial
• Carotid
• Brachial
• Radial
• Femoral
• Popliteal
• Posterior tibial
• Dorsal pedal

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Circulatory Shock

• Failure of the circulatory system to deliver
  oxygen to the tissues adequately, resulting in
  cell impairment.
• Types
• Cardiogenic Shock
• Hypovolemic Shock
• Neurogenic Shock
• Anaphylactic Shock
• Septic Shock

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Neural Control of Vascular System

• Vasomotor center (medulla) coordinates
  vasodilatation vasoconstriction by controlling
  the of sympathetic impulses.
• Systemic increased impulses will vasoconstrict
• Systemic decreased impulses will vasodilate
• HOWEVER
• Heart, brain, skeletal muscle increased
  impulses will vasodilate
• Heart, brain, skeletal muscle decreased
  impulses will vasoconstrict

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Baroreceptor Reflex

• Baroreceptors regulate the arterial BP by
  initiating reflex adjustments.
• stretch receptors
• Found in
• Walls of the aortic arch
• Impulses travel along the vagus nerve
• Walls of the carotid artery
• Impulses travel along the glossopharyngeal nerve

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Effects of cardiac cycle on BP

• BP rises falls in a pattern like the phases of
  cardiac cycle.
• When ventricles contract blood is forced into
  pulmonary trunk aorta. At this point the
  pressure in the arteries increases sharply.

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Pulmonary Blood Flow

• Distribution of pulmonary blood flow
• Progressively decreases from the base to the
  apex.
• Factors affecting distribution
• Gravity
• Cardiac output
• Pulmonary vascular resistance

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Pulmonary Blood Flow

• Blood is gravity dependant because it is
  relatively heavy.
• Average lung is 30cm from the base to the apex.
• If blood was to fill the lung form the base to
  the apex it would need 30cmH2O of pressure
  (22mmHg) to over come the gravitational force.
• The pulmonary artery enters in the middle (hilum)
  so the blood that reaches the apex needs at least
  11mmHg to over come the gravitational force.

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Pulmonary Blood Flow

• The vessels _at_ the base have greater pressure than
  those _at_ the apex.
• The increased pressure in the vessels of the
  bases cause the vessels to widen, which decreases
  pulmonary vascular resistance.
• These factors change based on lung position.

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Zones of Pulmonary CirculationThese factors due
change based on lung position

• Zone 1
• Least gravity dependant
• Worst perfusion
• Best aeration
• Zone 2
• Good perfusion
• Good aeration
• Zone 3
• Most gravity dependant
• Best perfusion
• Worst aeration
• xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

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Lung zones
176
Hemodynamics

• The study of the forces that influence the
  circulation of blood.
• Consist of measurements and calculations.
• A pulmonary artery catheter (Swan-ganz catheter)
  is used to collect hemodynamic measurements in
  critically ill patients.

177
Hemodynamics

• Units used in hemodynamics
• mmHg
• Dyne
• A unit of force which accelerates a mass of 1
  gram _at_ a rate of 1cm/sec.

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Hemodynamics

• Hemodynamics are either measured or calculated.
• Measured an instrument is used to collect
  information.
• Calculated measurements are used in formulas to
  compute additional information
• Because hemodynamic parameters will vary with the
  size of the patient, some hemodynamic values are
  indexed by body surface area (BSA)

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Hemodynamics

• Calculation for BSA (m2)
• Centimeters Kilograms
• (Height (cm) X Weight (kg) /3600) .5
• Inches Pounds
• (Height (in) X Weight (lb) /3131) .5

180

• For example
• Me!
• I weigh about 100 kg, and my height is about 188
  cm (1in 2.54 cm).
• So, my BSA is (188X100)/3600, then take the
  square root of this
• Answer is approximately 2.3m squared

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Swan-ganz catheter
182
Swan-ganz catheter

• Inserted into the internal jugular or the
  subclavian vein
• Very invasive procedure only used in critically
  ill patients under constant observation.
• Complications include
• Pneumothorax / Hemothorax
• Air emboli
• Infection
• Pulmonary artery rupture

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Hemodynamics

• Directly measured
• Central Venous Pressure CVP
• Right Atrial Pressure RAP
• Mean Pulmonary Artery Pressure PA
• Pulmonary Capillary Wedge Pressure PCWP
• Cardiac Output CO

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Hemodynamics

• Computed
• Stroke Volume SV
• Stroke Volume Index SVI
• Cardiac Index CI
• Pulmonary Vascular Resistance PVR
• Systemic Vascular Resistance SVR
• p.459 Des Jardins

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Central Venous Pressure Right Atrial Pressure
(measured)

• RAP is very close to CVP
• CVP is a measure of atrial preload.
• Atrial preload is determined
• distribution of blood within the body
• total blood volume
• presence and force of atrial contraction

188
Mean Pulmonary Artery Pressure Pulmonary
Capillary Artery Wedge Pressure (measured)
189
PCWP

• End-diastole represents the moment in the cardiac
  cycle when the ventricle contains the greatest
  volume of blood, just before it contracts and
  ejects its volume.
• The wedged pulmonary artery catheter reflects
  LVEDP because at end-diastole, the mitral valve
  is open and this creates communication between
  the left atria, left ventricle, and pulmonary
  vascular bed. In other words, the doors are all
  open from the LV to the pulmonary capillary.
• The window into the left heart

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Cardiac Output

• A bolus of sterile solution that is colder than
  the patients blood is injected into the proximal
  port of a pulmonary artery catheter located in
  the right atrium.
• In the atrium, the solution mixes with the blood
  and passes through the tricuspid valve into the
  right ventricle.
• A thermistor within the catheter senses the
  change in blood temperature as the blood passes
  the catheter tip located in the pulmonary artery.
  
• The change in temperature over time is calculated
  by a computer and converted into a measurement of
  cardiac output.

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Cardiac Output (measured)
193
Stroke Volume (computed)

• Volume of blood ejected by ventricle with each
  contraction.
• Normal 40-80 mL
• Stroke volume is derived by dividing the cardiac
  output by the heart rate
• Determinants of stroke volume
• Preload
• Afterload
• Myocardial contractility

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Determinants of stroke volume

• Preload how much blood is returning to the
  heart, and how well can the heart muscle
  accommodate it
• rubber band
• Afterload the forces past the heart which the
  ventricles must fight against
• Viscosity volume Pulling/pushing ketchup vs.
  water through a straw
• Vascular cross-sectional surface area Long
  straw vs. short straw
• Vascular resistance Coffee straw vs. Slurpee
  straw
• Myocardial contractility
• Contractility inotropism

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Stroke Volume Index (computed)

• A patient has a stroke volume of 40mL
• This patient is 65 280lb
• Is this a good value for this patient?
• NO!
• How do we know if a stroke volume is appropriate?
• Stroke Volume Index

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Stroke Volume Index (computed)

• SVI SV/BSA
• Normal 30 65 Ml/beat/m2

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Cardiac Index (computed)

• Normalizes Cardiac Output (measured) to body
  surface area.
• CI CO/BSA
• Normal 2.5-4.2 L/min/m2

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Vascular resistance

• Pulmonary system
• low resistance system short straw
• Systemic system
• high resistance long straw

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Vascular resistance (computed)

• Blood pressure is directly related to vascular
  resistance.
• When vascular resistance increases this will
  cause BP to increase.
• When the straw diameter gets smaller, you have to
  pull/push harder!

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Vascular resistance

• Vascular resistance blood pressure
• cardiac
  output
• You are looking at what pressure it takes to
• eject a liter of blood.

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Pulmonary vascular resistance

• The PVR reflects the afterload of the right
  ventricle.
• When looking at PVR, you must have your pressures
  represent the beginning to the end of the
  pulmonary circuit.
• What is the beginning of the pulmonary circuit?
• What is the end of the circuit?

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Pulmonary vascular resistance

• PVR (PA PCWP/CO) X 80
• The constant 80 is a conversion factor for
  adjusting to the unit of dyne/sec/cm-5

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Systemic Vascular Resistance

• The SVR reflects the afterload of the left
  ventricle.
• When looking at SVR, you must have your pressures
  represent the beginning to the end of the
  systemic circuit.
• What is the beginning of the systemic circuit?
• What is the end of the circuit?

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Systemic Vascular Resistance

• SVR (MAP CVP/CO) X 80
• The constant 80 is a conversion factor for
  adjusting to the unit of dyne/sec/cm-5