CCP Fall 2013 - Week 5

  1. What is the formula for determining cardiac output (CO)?
    • Cardiac Output = Heart Rate x Stroke Volume
    • CO = HR x SV
    • Normal CO is 4-8 liters/minute
  2. What is the formula for determining cardiac index (CI)?
    • Cardiac Index = Cardiac Output / Body Surface Area
    • CI = CO/BSA
    • Normal CI is 2.5 - 4.2 liters/minute
  3. What are the components of Stroke Volume (SV)?
    • Preload
    • Afterload
    • Contractility
  4. Declare the impact Preload has on SV
    ⇧ Preload = ⇧ SV
  5. Declare the impact Afterload has on SV
    ⇧ Afterload = ⇩ SV
  6. Declare the impact Contractility has on SV
    ⇧ Contractility = ⇧ SV
  7. Compare SV to Ejection Fraction (EF)
    SV ~ ⅔ End Diastolic Volume ∴ normal Ejection Fraction (EF) ~ 67%
  8. What is the lowest acceptable EF?
  9. What ways can we ⇩ preload & what is the ~ rate of onset for each?
    • Vasodilators (immediate)
    • Morphine (immediate)
    • Diuretics (fast)
    • ACE inhibitors (slow)
  10. What ways can we ⇧ preload & what is the ~ rate of onset for each?
    • Fluids (immediate)
    • Vasonconstrictors (onset is agent dependent,
    • typically fast)
  11. Define afterload
    The resistance the heart must pump against to eject blood from the ventricles
  12. Describe Pulmonary Vascular Resistance (PVR)
    • Measures afterload for the right heart
    • Normal PVR is 50-250 dynes
    • ⇩ w/dehydration & RV Failure
    • ⇧ w/anything that causes pulmonary HTN
  13. Describe Systemic Vascular Resistance (SVR)
    • Measures afterload for the left heart
    • Normal SVR is 800-1200 dynes
    • ⇩ in dehydration, distributive shock states & w/vasodilators
    • ⇧ w/IHSS, aortic stenosis, any cause of HTN & w/vasoconstrictors
  14. What vasodilators can be used to ⇩ afterload (SVR)?
    • nitroprusside (Nitropress®) nitrate donor *metabolite concern: thiocyanate
    • fenoldopam (Corlopam®) [dopamine agonist]
    • nifedipine (Procardia®), nicardia (Cardene®) [Ca++ channel blocker]
    • dobutamine (Dobutrex®) [β2 agonist]
    • nesiritide (Natrecor®) [RAA inhibitor]
  15. What vasopressors can be used to ⇧ afterload (SVR)?
    • dopamine (Intropin®) [α1 agonist]
    • phenylephrine (Neo-Synephrine®) [αagonist]
    • norepinephrine (Levophed®) [αagonist]
    • epinephrine [αagonist]
  16. What will ⇧ contractility?
    • SNS stimulation
    • ⇧ Ca++ levels
    • Cardiac glycosides
    • β1 agonists (dobutamine, epinephrine, etc)
  17. What will ⇩ contractility?
    • Electrolyte imbalances
    • Hypoxia
    • Acidosis
  18. What is the # 1 cause of a dampened waveform?
    Air in the line
  19. What does IABP stand for?
    Intra Aortic Balloon Pump
  20. What are the goals of IABP therapy?
    • ⇩ work of the heart by ⇩ afterload
    •   ⇩ myocardial O2 demand
    • Augment diastolic coronary perfusion pressure
    • Improve CO
    • Limits myocardial ischemia
    • Prevent cardiogenic shock, limit size of infarctions
    •   The SHOCK trial concluded w/recommendations that emergency revascularization in conjunction w/intra-aortic balloon counterpulsation should be used in patients w/AMI complicated by cardiogenic shock.
  21. What is the # 1 reason for using IABP?
    To prevent cardiogenic shock
  22. What are the uses of IABP?
    • Support in AMI w/cardiogenic shock
    • Circulatory support in post-CABG pts
    • Support in high risk catheterizations
    • In severe ischemia as a bridge to revascularization
  23. Where should the IABP be placed?
    • West Zone 3
    • 2cm below aortic arch
    • 4th/5th intercostal space
  24. What are contraindications to the use of IABP?
    • Aortic Valve Insufficiency
    • Severe Aortic Disease
    • Sever peripheral vascular disease
  25. What are the complications of IABP therapy?
    • #1 - Ischemia of limb distal to insertion site
    • Aortic dissection
    • Thrombocytopenia
    • Renal complications
    • Gas emboli - Rare
  26. Describe the timing error of Early Inflation in IABP therapy
    • Inflation before aortic valve closure
    • Leads to reflux into Left Ventricle
    • Decreases CO, Increases SVR
    • Harmful
  27. Describe the timing error of Late Inflation in IABP therapy
    Results in suboptimal augmentation because there is minimal displacement of blood back toward coronary arteries
  28. Describe the timing error of Early Deflation in IABP therapy
    Vacuum effect & afterload reduction is lost because by the time the aortic valve opens, the pressures in the aorta have equalized.
  29. Describe the timing error of Late Deflation in IABP therapy
    The balloon is deflated during the beginning of ventricular systole. This increases the work load of the left ventricle. Very harmful for the patient.
  30. What mode can you NOT be in when timing an IABP?
    1 : 1
  31. What is the primary trigger for the IABP?
    Usually the ECG.
  32. Describe changes in triggering required by air transport
    The primary trigger is usually the ECG. D/t aircraft vibration, the trigger mode may need to be the arterial pressure line. The ECG may have too much artifact to effectively trigger the balloon inflation/deflation.
  33. Describe the impact increasing altitude will have on IABP therapy
    Balloon will purge on ascent d/t Boyle's law & gas expansion
  34. Describe the impact decreasing altitude will have on IABP therapy
    Balloon will purge on descent d/t gas contraction w/decreasing altitude
  35. Describe another reason to evac all air out of an art line
    Minimize dampening of the waveform since this may be a trigger source in the event of ECG trigger failure
  36. What must you change w/IABP therapy in the event of the patient goes into cardiopulmonary arrest?
    Place the trigger mode on arterial pressure or on internal trigger mode
  37. What must be done with IABP in the event of power failure?
    The balloon needs to be manually pumped q 30 min to prevent thrombus formation on the balloon - TAKE THE SYRINGE!
  38. Before leaving the facility with a pt on IABP, what should you do?
    Assure ballon placement by verifying the distal tip of the balloon is 2 cm distal to the aortic arch (left subclavian), commonly between the 2nd & 3rd intercostal spaces, & the proximal end of the balloon does not occlude the renal arteries. Get a RECENT CXR!
  39. What additional parameters must be monitored during transport of the IABP pt?
    • Urinary output
    • Distal pulses
  40. Describe the significance of "rust colored flakes" in the IABP line. What actions, if any, should be taken?
    • Balloon rupture.
    • STOP the balloon, place pt in trendelenburg.
  41. What is the respective orientation of the sciatic nerve, femoral artery & femoral vein in the body?
    • Nerve, Artery, Vein; Lateral to medial
    • NAVEL: Nerve, Artery, Vein, Empty Space, Lymphatics; Peripheral to medial
  42. What is the Q wave?
    1st downward deflection after the P wave & before the R wave
  43. What is the S wave?
    1st downward deflection AFTER the R wave
  44. What is the J Point?
    The transition point delineating the end of the QRS segment & the beginning of the S-T segment
  45. What is aVR?
    • augmented Vector Right
    • Combines Leads III & I
  46. What is aVL?
    • augmented Vector Left
    • Combines Leads II & I
  47. What is aVF?
    • augmented Vector Foot
    • Combines Leads II & III
  48. What does MCL stand for?
    Modified Chest Left
  49. What does MCR stand for?
    Modifed Chest Right
  50. What is meant by the term "R-Wave Progression"?
    • How quickly the R-Wave becomes > 50% of the QRS complex in amplitude
    • Measured in Precordial Leads V1-V6
    • Between V3 & V4 is considered normal
    • Before V3 & V4 is called "Aggressive" or "Progressive" R-Wave progression
  51. What is concordance
    The overall polarity of the complex in question
  52. What is the standard ECG paper speed?
    25 mm/s
  53. Describe the precordial lead locations
    • V1: 4th Intercostal, just Right of the sternal border
    • V2: 4th Intercostal, just Left of the sternal border
    • V3: At midpoint of line drawn from V2 to V4 (May be on top of rib)
    • V4: 5th Intercostal, Left side, midclavicular
    • V5: {Even laterally w/V4}, 5th Intercostal @ anterior axillary line
    • V6: {Even laterally w/V4 + V5}, 5th Intercostal @ midaxillary line
  54. Describe correct lead placement
    • Should form 3 lines:
    • V1⇨V2
    • V2⇨V3⇨V4
    • V4⇨V5⇨V6
  55. How do the right sided leads differ from standard precordial lead locations?
    Same landmarks only opposite side of chest
  56. Are all right sided leads required to examine for RVI?
    • No, V4R/MCR4 is most specific (90%) & most accurate (90%)
    • Remember to label as V4R/MCR4
  57. In terms of MI, what is necrosis?
    Dead tissue
  58. In terms of MI, where is Injury found?
    Immediately surrounds the necrosed tissue
  59. In terms of MI, where is Ischemia found?
    Immediately surrounds the injured tissue
  60. Describe T-Wave Enlargement
    T-wave enlargement with more symmetry is typical. Represents hyper-acute phase which typically occurs in the 1st few minutes of infarction. Transient enough you may miss this.
  61. Describe the importance of ST Segment Elevation
    This is the primary indicator of myocardial INJURY. Typically presents w/i the 1st hour or few hours after damage begins. This represents an acute situation. Reversible in theory.
  62. Describe the importance of T-Wave Inversion
    This change suggests myocardial ISCHEMIA. T-wave inversion may precede ST elevation or occur simultaneously. Again, this represents an acute finding.
  63. Describe the importance of Q-Wave Development
    Development of a pathological Q wave indicates myocardial INFARCTION. This typically presents 2-10 hrs after initial onset of infarct. There is irreversible tissue death.
  64. Describe 'Recovery' ECG changes
    • ST changes have returned to baseline
    • T-waves will return to normal size & deflection
    • Q-wave remains
  65. Describe a physiologic Q-wave
    Q wave that is < 0.04 sec wide (40 ms)
  66. Describe a pathologic Q-wave
    • Q-wave > 0.04 sec (40 ms) wide or
    • 1/3 total QRS
  67. What leads reveal septal infarction?
    V1 & V2
  68. What leads reveal anterior infarction?
    V3 & V4
  69. What leads reveal lateral infarction?
    V5, V6, I & aVL
  70. What leads reveal inferior infarction?
    II, III & aVF
  71. What leads reveal posterior infarction?
    • V1, V2, V3 & V4
    • [Reciprocal rs, perform mirror test]
  72. What lead reveals right ventrical infarction?
    • V4R
    • [Look 4 inferior & posterior wall involvement w/clinical sxs]
  73. Describe Bundle Branch Block criteria
    • QRS ≥ 120 ms
    • Supraventricular Rhythm

    Any lead, Any QRS
  74. Describe BBB identification
    • 1.   Go to V1
    • 2.   Locate the J Point
    • 3.   Go backwards
    • 4.   If tracing goes up: The turn signal goes up = RIGHT turn = RIGHT BUNDLE BRANCH BLOCK
    • 5.   If tracing goes down: The turn signal goes down = LEFT turn = LEFT BUNDLE BRANCH BLOCK
  75. What is the significance of LARGE amplitude complexes in the precordial leads
    Left Ventricular Hypertrophy (LVH)
  76. Describe the rules for Left Anterior Hemi-Block
    • Pathological Left Axis Deviation
    • Small Q in I and small R in III
  77. Describe the rules for Left Posterior Hemi-Block
    • Right Axis Deviation or a witnessed rightward shift
    • Small R in I and a small Q in III
    • VERY common to have RBBB
Card Set
CCP Fall 2013 - Week 5
Cardiac and Hemodynamics, Part V; ECG Parts I-III