Cardio. system lecture 1

  1. Outermost Pericardium

    Innermost Pericardium

    Visceral (epicardium)
  2. Pericardial space holds how much fluid?
  3. Surface of heart =
  4. Middle layer of heart=

    contracting muscle of the heart--conduction system here
  5. Inner layer of the heart=
    lines inside heart's chambers and great vessels
  6. What prevents blackflow during contraction--flaps
    Chordae tendineae
  7. faster heart rate=
    • less time for filling
    • cardiac output decreases
    • increase in O2 consumption
  8. Intrinsic rates
    • SA node= 60-100 bpm
    • AV node= 40-60 bpm
    • Ventricles= 20-40 bpm
  9. Diastole
    ventricular filling and ventricles relaxed
  10. Atrial Kick
    toward end of diastole, atria contract--pumping additional blood to ventricle
  11. Ventricular systole
    • ventricles contract==blood ejected pulmonary and systemic
    • 60-100 x/min
  12. Cardiac output
    amt bl pumped by left ventricle in 1 min
  13. Stroke volume
    • amt bl ejected from heart with each contraction
    • 70mL adult

    Calculation CO: multiply stroke vol X HR
  14. P wave
    SA node inpulse and atrial contraction/depolarization
  15. PR interval
    Time for impulse travel from SA to AV and bundle branches

    Time: 0.12-0.20 sec
  16. QRS:
    • ventricular depolarization
    • 0.06-0.10
  17. ST segment
    period from end QRS to begin T wave and norm isoelectric
  18. T wave
    ventricular repolarization
  19. QT interval
    beginning QRS to end of T wave; time for ventricular depolarization and repolarization

    Time: 0.32- 0.44 sec

    A lot of drugs affect QT interval
  20. Cardiac Output AVE adult
  21. Cardiac output determined by 4 factors
    • HR
    • Preload (affected by venous return)-- Hypervolemia and fluid overload increases preload
    • Afterload (htn, vasocontriction)-- overtime hypertrophy of left ventricle
    • Contractility-- poor contractility= decreased stroke vol
  22. Election fraction
    • % bl in ventricle ejected with each contraction
    • affected by preload, afterload, and contractility
    • norm is 65%
    • (measure w/ cardiac cath)
  23. Lipid Profile: total cholesterol
    • <200
    • <200
    • 60
    • <100

    • evaluate risk for atherosclerosis and coronary heart disease
    • must be fasting for 12 hours
  24. C-reactive protein
    • <0.5
    • measure inflammation and help predict CHF
  25. Serum cardiac markers: Creatine phosphokinase (CK or CPK): male--female
    • male-30-180
    • female-10-70
    • ck mb- 0-6%
    • ctnt- <0.2
    • ctn1-<0.5
    • sensitive indicators of heart damage
  26. serum cardiac hormones: atrial cardiac factor or hormone
    B-type natiuretic peptide(BNP)
    • 20-27
    • <100
    • Increase bl levels indicate heart failure
    • must fast
  27. Transthoracic echocardiogram (TTE)
    computer converts impulses to an image of heart walls, chambers, and their movements
  28. Transesophageal echocardiogram (TEE)
    gives more direct view of heart by avoiding chest wall
  29. stress echocardiogram
    combines resting, TTE, exercise on a treadmill or bike and ECG monitoring, and a TTE after exercise to evaluate effect of exercise on cardiac function
  30. Multigated Acuisition (MUGA) scan
    • eval ht sixe, vent wall motion, and ejection fraction--eject isotope IV
    • (more in notes)
  31. Exercise perfusion imaging or stress test
    • eval myocardial perfusion during exercise
    • (more in notes)
  32. tunica intima
    innermost, slick surface, assist bl flow
  33. tinica media/middle
    • smooth muscle, thicker and more elastic in arteries than veins
    • allows arteries to expand and contract-maintain bl flow to capillaries between ht beats
    • major factor in BP
  34. tunica adventitia
    • outermost
    • connective tissue protects and anchors vessel
    • thicker in veins than arteries
  35. Blood pressure regulated by:
    cardiac output and HR
  36. When CBC is down:
    rheumatic ht disease and contitions char by inadequate tissue oxygenation
  37. When HCT is up
    vascular volume depletion
  38. hypokalemia
    • cardiac electrical instability goes up, ventricular dysrythmias and higher risk or dig toxicity
    • higher risk for asystole (flat line) and vent dystrhythmias
  39. Na+
    decrease in HF=h2o excess
  40. Ca+
    • decrease with vent dysrhythmias, prolonged QT and cardiac arrest
    • decrease with cardiac arrest
  41. Mg+
    • low: v tach or v fib
    • high: muscle weakness, hypotension, brady and prolonged PR
  42. Ankle-brachial index
    • non invasive- highly indicative atherosclerosis
    • BP cuffs placed at intervals on extremity
    • divide systolic pressure at ankle by brachal systolic pressure
  43. each small box=
    5 small boxes=
    5 large boxes=
    30 large boxes=
    • 0.04 sec
    • 0.2 sec
    • 1 full sec
    • 60 sec
  44. PR less than 0.12
    impulse did not follow normal conduction pathway; rapis atrial rate
  45. PR more than 0.2 sec
    disease process may be affecting cardiac conduction pathway- slowing it down/blocking; heart block
  46. ST segment

    • ischemia
    • injury
  47. NSR (normal sinus rhythm) usually 60-100--changes from normal affect:
    pumping ability and tissue perfusion
  48. Dysthythmia can affect two things:
    cardiac output and tissue perfusion
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Cardio. system lecture 1
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