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Assisting in Cardiology

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					Assisting in Cardiology
        Ch 46/47
Thoracic Cavity
• The heart is a muscular organ that pumps
  blood through the body, circulating a
  continuous supply of O2 and nutrients to the
  cells and picking up the metabolic waste
  products
• The 3 layers of tissue are surrounded by a
  double-membrane sac called the pericardium;
  the epicardium is the 1st layer of the heart; the
  middle muscular layer is the myocardium, the
  endocardium forms the heart valves
Layers of the Heart
                   Blood Flow
• Begins in the right atrium which receives
  deoxygenated blood from the inferior and
  superior vena cava
• R. Atrium contracts and blood passes through
  the tricuspid valve and enters the R. Ventricle
• R. Ventricle contracts and blood passes from
  the R. Ventricle to the lungs via the Pulmonary
  Artery
  – This is the only artery that carries deoxygenated
    blood
             Blood Flow cont..
• Oxygenation occurs in the lungs and the blood
  returns to the L. Atrium through the
  Pulmonary Veins
  – The only veins in the body to carry oxygenated
    blood
• The L. Atrium contracts and blood passes
  through the mitral/bicuspid valve into the L.
  Ventricle
• L. Ventricle contracts and oxygen-rich blood is
  sent out to the body through the Aorta
Coronary Arteries
             Heart Conduction
• Originates in the SA Node (pacemaker of the
  heart) located in the posterior, superior wall of
  the R. Atrium
• Electrical charge crosses both atria, which
  contract and pass blood into the ventricles
• Electrical charge collects in the AV Node, located
  on the septal wall between the R. Atrium and
  Ventricle
• After a slight pause, the AV Node releases the
  charge, sending it through the bundle of His,
  located in the septum between the two
  ventricles.
Conduction System
         Heart Conduction cont..
• The Bundle of His divides into the L. and R. bundle
  branches, which surround the L. and R. Ventricles
• Electrical charge continues through the Purkinje
  Fibers, the most distal part of the heart’s
  conduction system
• The Purkinje Fibers complete ventricular
  stimulation, and the ventricles contract
• Contraction of the heart chambers is
  depolarization
• After contraction, repolarization or electrical
  recovery occurs
• Polarization is the heart at rest
  Diseases and Disorders of the Heart
• Multiple risk factors for cardiac diseases
  include:
  – Genetic Predisposition and family history
  – Hypertension
  – Age
  – Gender
  – Diabetes
  – Elevated blood cholesterol levels
              Cardiac Diseases
• Lifestyle factors include:
  – High fat, high caloric diets
  – Obesity
  – Smoking
  – Lack of exercise
  – Hypertension
  – Stress
   Coronary Artery Disease (CAD)
• Arteries supplying the myocardium become
  narrowed by atherosclerotic plaques
• Platelets stick to the plaque deposits, forming
  thrombi (clots), and lipids continue to build up
  at the site
• The process causes narrowing of the lumen of
  the arteries and inhibits normal blood flow,
  depriving myocardium of adequate blood
                   CAD
• Myocardial ischemia signs and
  symptoms:
   –Angina pectoris (pain behind the
    sternum that can be relieved by rest or
    nitroglycerin) followed by pressure or
    fullness in the chest, syncope, edema,
    unexplained coughing spells and
    fatigue
      Myocardial Infarction (MI)
• Symptoms of MI are very similar to those of
  angina, but MI pain lasts longer than 30
  minutes and is unrelieved by rest or
  nitroglycerin tablets
• An MI is diagnosed by ECG(EKG) changes and
  evaluated cardiac enzymes 6-12 hours after
  the episode
• Enzymes are released by the necrotic
  myocardium and continue to increase for 24-
  48 hours post-MI
       MI Symptoms in Women
• Ischemia over a prolonged period leads to
  necrosis of a portion of the myocardium
  resulting in MI
• Women may exhibit a different clinical picture
  than men:
  – Abdominal or mid-back pain
  – Jaw pain
  – Indigestion
  – Extreme fatigue
  – Aching in both arms
                MI Treatment
• Thrombolytic medications (Streptokinase) to
  dissolve the coronary artery blockage but must
  be started within 24 hours of initial symptoms
• Aspirin
• Beta blockers (Tenormin, Lopressor, Inderal)
• Angiotensin-Converting Enzyme (ACE) inhibitors
  (Lotensin,Capoten)
• Anti-coagulants (Coumadin)
• Anti-cholesterol agents (Lipitor, Zocor, Mevacor)
• Percutaneous Transluminal Coronary Angioplasty
  or open heart surgery may be indicated
     Hypertensive Heart Disease
• Secondary hypertension occurs because of a
  disease process in another body system
• Primary hypertension is idiopathic
• MA responsibility
  – 2 BP readings, 5 minutes apart w/pt sitting; if
    elevated check BP in other arm
• Chronic evaluated BP can result in L. Ventricle
  hypertrophy, angina, MI, heart failure, stroke,
  or nephropathy
           Lifestyle Modifications
•   Weight reduction
•   Diet rich in fruit and veggies and low fat
•   Decrease sodium
•   Aerobic exercise
•   Moderate alcohol intake
                 Risk Factors
• For developing hypertension include:
  – Family history or hypertension or CVA
  – Hypercholesterolemia
  – Smoking
  – High sodium intake
  – Diabetes
  – Excessive alcohol intake
  – Aging
  – Prolonged stress
  – Race
   Congestive Heart Failure (CHF)
• Occurs when myocardium is unable to pump
  enough blood to meet the needs of the body
• Develops over time because of weakness in
  the L. Ventricle because valvular heart disease
  or pulmonary complications
                    Heart Failure
• Typical heart failure initially occurs on one side of
  the heart followed by the other side
• Treatment
   –   Limiting physical activity
   –   Sodium restriction
   –   Weight control
   –   Diuretics
   –   ACE inhibitors and digoxin
   –   Routine monitoring of serum electrolytes, to monitor
       potassium levels
        Left-Sided Heart Failure
• Usually caused by essential hypertension or L.
  Ventricle Disease
• Causes a back-up of blood in the lungs,
  resulting in Pulmonary Edema
• Signs and Symptoms:
  – Dyspnea
  – Orthopnea
  – Non-productive cough
  – Rales
  – Tachycardia
       Right-Sided Heart Failure
• Causes a back-up of blood in the R. Atrium, which
  prevents complete emptying of the vena cava,
  resulting in systemic edema, especially in the legs
  and feet.
• Can develop from lung disease
• Cor pumonale – right sided heart failure caused
  by pulmonary hypertension from COPD
• Both types of heart failure cause fatigue,
  weakness, exercise intolerance, dyspnea, and
  sensitivity to cold temperatures
                  Hypotension
•   Orthostatic or postural hypotension
•   Common problem in elderly
•   May contribute to falls and related injuries
•   Pts need to be evaluated for 2ndry causes and
    encouraged to adjust from a prone position by
    sitting at the side of the bed prior to standing
       Rheumatic Heart Disease
• Develops because of unusual immune reaction
  that occurs approx. 2 weeks after an untreated
  beta-hemolytic streptococcal infection
• Antibodies cause inflammation in the the layers
  of the heart
• Pericarditis – decreases cardiac activity and
  causes pericardial effusion
• Endocarditis – most common heart complication
  – Causes stenosis and scarring
  – Tx – pcn and anti-inflammatory agents, prophylactic
    abx before all invasive procedures
Rheumatic Heart Disease
            Valvular Disease
• Can be caused by a congenital defect or an
  infection, such as endocarditis or RHD.
• The valve can become stenosed, restricting
  the forward flow of blood, or it can be
  incompetent, so blood can leak backward
• The most common valve defect is MVP, an
  incompetence caused by a congenital defect
  or scarring from endocarditis
            Arteries and Veins

          • In Class Assignment
• Tell me about them!
  – What are the different arteries and veins?
  – What does size indicate?
  – What type of blood do they carry?
• What is the difference between the
  pulmonary and systemic systems?
                     Shock
• General collapse of circulatory system,
  includes decreased cardiac output,
  hypotension, and hypoxemia
• Initial signs – extreme thirstiness, restlessness,
  and irritability
• Vasoconstriction of peripheral blood vessels
  occurs, causing cool, clammy skin, pallor,
  tachycardia and decreased urinary output
   Signs & Symptoms
        • Thready pulse

          • Tachypnea

• Altered levels of consciousness

 • CNS can become depressed

• Acute renal failure may occur
               Shock cont….
• Cardiogenic – MI, pulmonary embolism, CHF
• Hypovolemic – hemorrhage, burns
• Neurogenic – spinal cord injury, stress, drug
  reaction
• Anaphylaxis – allergic reaction
• Septic - systemic infection
              Varicose Veins
• Are dilated, tortuous, superficial veins that
  develop because the valves do not completely
  close, allowing blood t flow backward
• Vein becomes distended from increased
  pressure
• Caused by congenitally defective valves,
  pregnancy, obesity, prolonged standing or
  sitting, and heavy lifting
                  Treatments
• Aerobic exercise
• Limit heavy lifting
• Elevate legs when
  possible
• Wear support stockings
• Possible surgical
  intervention
        Deep Vein Thrombosis
• Thrombus with inflammatory changes that has
  attached to the deep venous system of the
  lower legs
• Causes partial or complete obstruction of
  vessel
• Symptoms – 50% asymptomatic at first; calf
  pn, swelling, warmth, edema, erythema at site
• Embolus
               DVT cont…..
• Diagnosis – Dopple – measures rate of RBC
  flow
• Tx – IV Heparin, oral Coumadin, bed rest
                    Disorders
Arteriosclerosis           Atherosclerosis
• Thickening and loss of   • Formation of an
  elasticity of arterial     atheroma
  walls associated with
  aging                    • A buildup of
• Can occur in arteries
                             cholesterol, cellular
  throughout the body        debris, and platelets
• Can cause systemic         along the inside
  ischemia and necrosis      vessel wall
                 Aneurysm
• Dilation of a vessel wall
• Diagnosis: bruit, arteriogram, sonography, CT
  scan
• Tx – sx repair
         Diagnostic Procedures
• Vital Signs
• Doppler studies of the patency of blood
  vessels
• Angiography to visualize arterial pathways
• Echocardiography to access the structure and
  movement of the paths of the heart,
  particularly the valves
• Cardiac catheterization to visualize the heart
  chambers, valves, and coronary arteries
  – May be followed by with angioplasty and
    placement of a stent
         MA and Pt Education
• Have some community resource information
  available for your pts
• Remember that pts learn best with the use of
  visual aids
• Make sure to document educational
  interventions

				
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