nmt432

  1. Reasons to stop a stress test.
    • Severe angina
    • Hypotension
    • Marked arrythmia
    • Severe fatigue, leg pain, or breathlessness
    • ST depression or elevation
    • AV bundle branch block.
  2. Excercise stress test contradictions
    • Unstable Angina
    • Arrythmias
    • Acute illness
    • Critical Aortic Stenosis
    • Advanced AV block
  3. Radiopharmaceuticals that can be used for a First Pass Cardiac Study
    Tc-99m DTPA

    or

    Any non particulate radiopharmaceuticals
  4. Reasons for performing a First Pass Study
    Determine Ejection Fraction

    Evaluate and detect intra cardiac shunts.
  5. Views used in First Pass Study to determing right EF and left EF.
    Right EF = RAO

    Left EF = LAO
  6. What is a MUGA study used to determine?
    Left ventricle EF and Wall motion
  7. What are the techniques for labeling RBC's? also the pros and cons of each ?
    • Invivo-
    • problem--not all pertechnetate tagged to RBC, so accumulates in salvary glads, gastric mucosa and thyroid,

    • Invitro- blood sample collected
    • highest labeling efficiency
    • modified invivo- less blood handeling, better efficiency than invivo.
  8. Normal views for MUGA.
    • Anterior
    • LAO
    • left lateral
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    LAO
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    ANterior
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    lateral
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    right ventricle
  13. kinesis
    movement
  14. Hypokinesis
    Low wall motion
  15. Akinesis
    Motionless
  16. Dyskinesis
    outward motion during Systole
  17. Stroke volume
    The blood ejected by ether ventricle during ventricular systole
  18. Cardiac output
    volume of blood heart pumps per minute
  19. End Disastolic volume
    Capacity of ventricle after it is completely filled with blood. THe largest volume reached by ventricle during the cardiac cycle.
  20. End Systolic Volume
    The residula capacity of the ventricle at the end of contraction. THe smallest volume reached during the cardiac cycle.
  21. Ejection Fraction
    Percent of blood ejected from venticle during each contraction.
  22. LAD supplies
    • The Left Anterior Desending supplies
    • the anterior wall,
    • most of the Septum
    • the distal portin of the Apex
  23. The Left Circumflex supplies
    posterior and lateral walls of the left ventricle.
  24. The RCA supplies
    The Right Coronary Artery supplies the inferior wall of the left ventricle and the right side of the heart
  25. Formula to calculate ejection fraction
    Diastole-systole / diastole * 100%
  26. Drugs that should be discontinued prior to stress
    • caffine
    • beta blockers
    • viagra
    • calcium channel blockers
  27. Patient Prep for Stress test
    • NPO 4-12hrs
    • No caffine, dairy or sugar
    • PAtient should be advised of excersise in advance
    • prepare 10- lead ECG
    • start iv
    • Obtain baseline BP
  28. Target Heart Rate =
    .85 * (220-age) = target heart rate
  29. Risk Factors for CAD
    • high BP
    • high cholestorol
    • smoking
    • obesity
    • diabetes
    • sedentary life style
  30. Perfusion imaging drug that cand determine viability, and has ability to redistribute
    thallum is the only one with the ability to redistribute.
  31. What is Atherosclerosis?
    When fatty substances, like triglycerides, and cholestorol are deposisted in the walls of medium and large diameter arteries.
  32. which ECG wave triggers the camera to aquire counts.
    R wave.
  33. Define stunned myocardium:
    • Abnormal contraction but
    • normal coronary blood flow.

    May persist for days/weeks following angioplasty or thrombolytic therapy, making it difficult to assess the therapy.
  34. Define hybernating myocardium:
    Reduced perfusion and contraction resulting in chronic LV dysfunction.

    in this situation identify viable myocardium to select for revascularization.
  35. "Pacemaker of the heart"
    SA node
  36. Initates contraction
    SA node
  37. generates impulses of 60-100bpm
    SA node
  38. "gate keeper of ventricles"

    allows 40-60bpm
    AV node
  39. Slows impulse transmission
    AV node
  40. carry impulses to tips of both ventricles
    AV bundles
  41. Terminal branch for two bundle branches
    Purkinhe Fibers
  42. ____carry impules to individual myocardial cells resulting in_______
    Purkinje fibers carry impulses to individual myocardial cells resulting in simultaneous contractions of both ventricles.
  43. P wave
    Initated by SA node
  44. P-R interval
    Time from beginning of atrial contraction to beginning of ventricular contraction.

    impulse from AV node to purkinje fibers.
  45. QRS complex
    Depolarization of both ventricles immediately precedes their contraction
  46. ST segment
    Represents early repolariztion (recovery) of ventricles.
  47. T Wave
    Ventricular repolariztion
  48. Repolarization of Atria
    Not seen on ECG!! because it is obsured by QRS complex
  49. Wave that is present in hypokalemia?
    U WAVE!
  50. Normal P-R interval
    .12-.20 sec (3-5 small squares)
  51. normal duration of QT interval
    .36-.44
  52. Sinus arrythmia
    all is normal except R-R intervals
  53. Sinus Bradycardia
    everything normal except slowed rate, less than 60bpm
  54. Premature Atrial contractions
    • P waves early, may look smaller, or peaked,
    • P-R interval usually shorter.
    • R-R varied
  55. No P-wave before, unusally tall and wide QRS, T-wave may be below baseline.
    Premature Ventricular Contractions.
  56. Fast constant firing of ectopic focus, F-waves instead of P-waves.
    Atrial Flutter
  57. Irregular R-R interval, and F waves instead P-waves
    Atrial Fibrillation
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    supraventricular tachycardia
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    ventricular tachycardia
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    Ventricular fibrillation
  61. P-R interval greater than .20 sec
    Heart block
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    First degree heart block
  63. Some P-waves not followed by QRS or T-wave because
    impulse was blocked.

    P-R interval become longer and longer until no QRS. than will be normal.

    second degree heart block

    • (wenckebach) MOBITZ type 1
  64. everything normal except some P-waves are not followed by QRS or T-wave?
    • Second Degree Heart Block
    • (MOBITZ TYPE2)
  65. AV node is completly blocked, so no relationship between P wave and QRS complex/ t-wave.
    3rd Degree AV Heart BLock
  66. Image Upload 18
    2nd degree heart block

    Morbitz type 1

    WENCKEBACH
  67. Image Upload 20
    2nd degree heart block

    MOBITZ TYPE2
  68. Image Upload 22
    3rd Degree Heart Block

    complete heart block
  69. Image Upload 24
    Pace maker
  70. define ischemia
    A deficency of blood resulting from ablockage or constriction of a blood vessel
  71. 4 characteristic of ideal myocardial perfusion agent
    • 1. High first pass extraction proportional to blood flow
    • 2. High target to non target ratio
    • 3. Must remain in myocardium long enough to image.
    • 4. able to complete stress and rest on same day.
  72. Tl-201 mech of action
    High extraction efficency by myocardial cells. by active transport Na-K pump

    slower clearance from under perfused areas.
  73. Tc-99m mibi
    high liver uptake, clears from hepatobiliary system faster than myocardium.

    passive diffusion into mitochondrial membranes.
  74. Adenosine;
    -mech of action
    -plasma half life
    Activates adenosine receptors on cell membranes of endothelium and smooth muscle of coronary arteries.

    mediator of vasodiator action

    half life <10sec
  75. Dipyridamole:
    mech of action
    half life
    counter
    Inhibits clearnce pathway of adenosine into cells. Extracellular adenosine taken up by receptors on cell membrane of endothelium and smooth muscle of coronary arteries.

    coronary arteries dilate and blood flow increases to normal arteries.

    half life 15-30 min.

    counter: IV aminophylline, blocks adenosine receptors.
  76. Lexiscan:
    mech of action
    half life
    Produces coronary vasodilation and increases coronary blood flow by activating the A2 adenosine receptors.

    Half life: 2hrs
  77. Dobutamine:
    mech of action
    half life
    counter
    Increases force of mycardial contraction and oxygen demand by stimulating beta receptors in the heart.

    half life: 2 min

    counter: Beta blockers.
Author
certifiedfly
ID
90251
Card Set
nmt432
Description
EXAM1
Updated