Cardiac Diagnostic Studies by liaoqinmei

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									Cardiac Diagnostic Studies

    Leslie Mickles, RN, MSN
       Cardiac Biomarkers
• Are enzymes, proteins, and hormones
  that are associated with heart function,
  damage or failure.
• Some of the tests are specific for the
  heart while others are also elevated
  with skeletal muscle damage.
     Cardiac Enzymes (Biomarkers)
      Test                 Indication                    Normal Range
CK or CPK        Chest Pain,                     Normal 25-170 U/L
Creatinine       R/O MI
Phosphokinase
                                                 < 5% MB
CK-MB            Release by injured myocardial
                 cells, but found in other
Myoglobin        tissues including muscles       Normal < 85 ng/ml

LDH                                              Normal 100-200 U/L
(Lactate                                         LDH-1 -5
dehydrogenase)                                   LDH- 1 is found primarily in
                                                 heart muscle and red blood
                                                 cells.
Troponin                                         Normal < 0.2 ng/ml
cTnT                                             May be elevated by CRF
Troponin I                                       Normal < 0.6 ng/ml
cTnI                                             Not elevated by CRF
                          Cardiac Enzymes
                          Onset      Peak       Return
CK                        4-6 hr     18-30 hr   3-4 days
CK MB                     4-6 hr     18-30 hr   3-4 days
Myoglobin 2-6 hr                     4-6 hr     24-36 hrs
Troponin I                3-5 hr     14-21 hr   7 days
(most cardiac specific)

LDH                       24-48 hr   3-6 days   14 days
Timing
        Test                    Indication                    Norm Range
C-Reactive Protein    A marker for inflammation and   CRP <1 mg/L lowest risk
                      risk of atherosclerosis, MI,    CRP 1-3 mg/L intermediate
                      CVA, PVD, diabetes.             risk
                      Produced by the liver in        CRP >3 mg/L highest risk
                      response to inflammatory
                      process.
Lipoprotien           Proinflammatory effect causing      Ideally want
Phospholipase A2      reaction with lipids (esp LDLs) and
                      oxidized free fatty acids. These    Lp-PLA2 < 235 ng/mL
(the PLAQ test or     bioactive lipid mediators, which
platelet-activating   are generated in lesion-prone
factor                vasculature are known to elicit
                      several potentially adverse
acetylhydrolase)
                      proinflammatory responses,
                      presumably within the plaque
                      causing atherosclerosis, and
                      plaque rupture

IMA (Ischemia         Chest Pain                      IMA values > 85 U/ml
modified albumin)                                     positive for cardiac
                                                      ischaemia
          Test                    Indication                  Norm Range
Human heart-type fatty   Early marker for MI as it is   Normal <8 ng/mL
acid-binding protein     more specific than
(FABP)                   myoglobin. Pts with
                         elevated FABP are more
                         likely to suffer death,
                         recurrent myocardial
                         infarction or congestive
                         heart failure.
B-Type Natriuretic       Used to diagnosis CHF          Normal cut off
Peptide (BNP)            and severity                   <100 pg/ml
           Electrocardiogram
• Purpose: to graphically record the electrical
  activity of the heart, with regard to
  amplitude, vector and rhythm
• Diagnose:
  •   Rhythm
  •   Vector
  •   Infarction or ischemia
  •   Pericarditis
  •   Electrolyte abnormalities
  •   Hypertrophy
  •   Ventricular aneurysm
  •   Drug effects
                  12 Lead ECG
• Advantage
  • Painless
  • Non-invasive
  • No risk to patient
• Nursing Considerations
   • Patient needs to lie still
   • Reassure patient that no
     electricity passes through
     them
         4 Variations of ECG
• Holter Monitor or Event Recorder

• Stress Electrocardiography –
  some risk

• Thallium Stress - some risk

• Pharmacologic Stress - some risk
            Holter Monitor
• Purpose: noninvasive continous cardiac
  monitoring for 1 or 2 days.
• Diagnose: intermittent cardiac dysrhythmias;
  evaluate effectiveness of antiarrhythmic
  treatment.
• Advantage: noninvasive, no risk, pt can wear at
  home for a few days.
• Nursing Considerations:
  • No risks
  • Instruct patient to resume normal activity and keep
    an activity log.
  • Avoid showers or baths since they will interfer with
    electrodes
Stress Electrocardiography
  Stress Electrocardiography
• Purpose: identify myocardial ischemia
  related to exercise
• Diagnose: coronary artery disease
• Advantages: non-invasive
• Nursing Considerations:
  • Potential risk of angina or MI
  • Must be able to ambulate or peddle bike
                Thallium Stress
• Purpose: identify myocardial infarction and/or ischemia
  related to exercise and assessing cardiac function
• Diagnose:
   •   myocardial ischemia (reperfused cold spot)
   •   myocardial infarction (cold spot)
   •   ventricular dysfunction
   •   ejection fraction
• Advantages: non-invasive
• Nursing Considerations:
   • potential risk of angina or MI
   • must be able to ambulate or peddle bike
   • need an IV access
      Pharmacologic Stress
• Purpose: stress test for those unable to
  exercise
• Diagnose: myocardial ischemia with
  simulated exercise
• Advantage: simulated exercise utilizing
  medications (persantin, dobutamine or
  adneocard) for people who can’t exercise
• Nursing Considerations:
  • Need an IV access
  • Risk from simulated stress
  • Risk of reaction to medication
        Echocardiography
• Utilizes ultrasonic waves that are
  inaudible, to deflect of the heart, and
  provide an image of cardiac structures
  and function - a radar like image.
• Deflected sound waves are called echos
         Echocardiogram
• Purpose: to assess
  • heart chamber size
  • heart valve motion
  • septal wall motion
  • LV wall thickness
  • LV volume
          Echocardiogram
• To Diagnose:
  • valvular disorders (i.e. stenosis,
    insufficiency, prosthetic valve malfunction)
  • pericardial effusion or cardiac tamponade
  • cardiac tumors
  • septal defects
  • chamber enlargement
  • aneurysms
  • thrombi
          Echocardiogram
• Types
  • 2 D Mode
  • M-Mode (ice pick view)
  • Transesophageal
  • Stress Echo
  • Pharmacologic Echo
          Echocardiogram
• No special preparation
• Non-invasive
  • Transducer over 3rd to 5th ICS
  • Monitor rhythm simultaneously
  • Patient supine or in left lateral decubitus
       2 D versus M Mode
• M-Mode (Ice Pick View)
  • Visualizes myocardial layers, thickness and
    fluid accumulation
  • Particularly useful in dx pericardial effusion,
    cardiac tamponade or pericarditis
• 2 D Mode
  • Visualizes ventricular chambers, blood flow,
    and valvular function
  • Particularly use in dx origin of murmur,
    ejection fraction, visualizing VSD, and wall
    motion
M Mode
2 D Mode
          Echocardiogram
• Advantages
  • 2 D and M-Mode are non-invasive and
    entirely painless with no contraindications


• Disadvantages
  • Sound waves travel poorly through thick
    chest walls, lungs, ribs, and sternum
   Transesophageal Echo
• Transesophageal performed similar to
  brochoscopy with a much smaller
  transducer being placed in the esophageal
• Advantage:
   • Visualizes the atria and AV valves
   • Ribs not in the way
• Risk of:
   • Perforation
   • Bleeding
   • Aspiration
    Stress Echocardiogram
• Same as 2 D mode except exercising
• Risk of myocardia ischemia/infarction
       Pharmacologic Stress
         Echocardiogram
• Advantage: stress simulated with IV
  persantine, dobutamine or adenocard
  for people unable to exercise
• Risk of infarction/ischemia from stress
          For All Stress Tests
• Prep:
   • Informed consent
   • Adequate sleep night before
   • Light meal 1-2 hours prior to test
   • Avoid smoking, alcohol or caffeine prior to procedure
   • Follow MDs instructions regarding meds. Usually hold
     theophylline products 12 hours prior and usually hold
     calcium channel blockers and beta blockers 24 hours prior.
   • Instruct patient to wear nonconstrictive comfortable clothing
     and supportive rubber soled shoes

• During and Post:
   • Notify tech or MD of any chest pain, SOB or dizziness
   • Avoid hot shower or bath for at least 1-2 hours
Nuclear (Radioisotope Scanning)
 • Involves intravenous injection of a
   radioactive isotope. The radioactive
   isotope uptake is then counted over the
   heart by a gamma scintillation camera.
        Nuclear Scanning
• Purpose: supply information about
  myocardial contractility, myocardial
  perfusion and acute cell injury.
  • Evaluate ejection fraction
  • Locate regional aneurysms
  • Evaluate regional wall motion dysfunction
  • Demonstrate pericardial effusion
  • Visualize ventricular hypertrophy, aortic
    aneurysms, or subvalvular obstructions
2 Types of Nuclear Cardiac Scans
• Myocardial Perfusion Imaging “cold
  spots”
  • Uses Thallium 201 (which accumulates in
    regions of the myocardium proportionate
    to the blood flow)
  • Take up by healthy, viable myocardial cells
  • Can do it in conjunction with stress test
• Gated Blood Pool Imaging
            MUGA Scan
• Uses technetium 99m
• Purpose
  • Assess for myocardial ischemia and/or
    necrosis
  • Calculate EF, LVED, and volumes
  • Assess wall motion, chambers size
• Non-invasive & no risks
MUGA Scan
             Chest X-Ray
• Purpose: Identification of cardiac
  borders, and size
• Limited usefulness
  • Visual gross masses
  • Visual cardiac silhouette
      Computer Tomography
• CT, CAT
  • Cardiac wall thickness
  • Pericardial disease
  • Tumors or masses
• Newer EBCT or Ultrafast CT (not widely
  used)
  •   Myocardial perfusion
  •   Graft patency
  •   Ejection fraction
  •   Chamber volume
  •   Cardiac output
  •   Calcium deposits
Normal CT of the Heart
Positron Emission Tomography

• Purpose
  • Visualize cardiac perfusion
  • Visualize coronary artery obstructions
• Disadvantage
  • Limited number of facilities using
    presently
         PET Scan




Normal              Poor Perfusion
      Cardiac Catheterization
• Types
  •   Right heart cath
  •   Left heart cath
  •   Ventriculogram
  •   Angiogram
• Advantages
  • Exact measurement of pressures inside heart
  • Definitive visualization of cardiac structures,
    vessels, chambers, valves and wall motion
      Cardiac Catheterization
• Disadvantages
  • Invasive
  • Multiple risks including:death, infarction,
    coronary artery perforation, myocardial
    perforation, arrhythmias, cardiac tamponade, lose
    of limb, and bleeding.
• Post procedure
  •   Encourage fluids
  •   Monitor circulation to effected limb
  •   Lie flat and don’t bend limb for several hours
  •   Monitor for bleeding
  •   Arrhythmias
   Electrophysiology Study
• Purpose
  • To identify arrhythmias
  • Map ectopic foci
  • Ablate ectopic foci
  • Evaluate effectiveness of antiarrhythmic
    meds
• Similar process to Cardiac Cath
  • Similar complications

								
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