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  1. Antegrade Impulse
    an impulse that travels through the conduction system in the correct direction
  2. Retrograde Impulse
    an impulse that travels through the conduction system in the reverse direction
  3. Ectopy
    a broad term indicating any kind of abnormal impulse
  4. Hyperkalemia
    As potassium levels rise (normal 3.5-5.0 mEq/L) T-waves become higher and more peaked
  5. Anastomosis
    communication between two or more vessels
  6. Poiseulle's Law
    a low of physiology stating that blood flow through a vessel is directly proportional to the radius of the vessel to the 4th power
  7. Cardiac Cycle
    the period of time from the end of one cardiac contraction to the end of the next
  8. Diastole
    Rest - the period of time when the myocardium is relaxed and cardiac filling and coronary perfusion occur
  9. Systole
    Contraction - the period of the cardiac cycle whrn the myocardium is contracting
  10. Ejection Fraction
    ratio of blood pumped from the ventricle to the amount remaining at the end of diastole
  11. Stroke Volume
    the amount of blood ejected by the heart in one cardiac contraction
  12. Preload
    the pressure within the ventricles at the end of diastole, commonly called the end-diastolic volume
  13. Starling's Law of the Heart
    law of physiology stating that the more the myocardium is stretched, up to a certain amount, the more forceful the subsequent contraction will be
  14. Afterload
    the resitance against which the heart must pump
  15. Factors Affecting Stroke Volume
    • Preload
    • Cardiac Contractility
    • Afterload
  16. Cardiac Output
    the amount of blood pumped by the heart in 1 minute (Stroke Volume x heart rate = Cardiac Output)
  17. Chronotropy
    pertaining to heart rate
  18. Inotropy
    pertaining to cardiac contractile force (Strength)
  19. Dromotropy
    pertaining to the speed of impulse transmission (Electrical Conductivity)
  20. Intercolated Discs
    specialized bands of tissue inserted betwen myocardial cells that increase the rate in which the action potential is spread from cell to cell
  21. Syncytium
    group of cardiac muscle cells that physilogically function as a unit
  22. Electrolytes that effect cardiac function
    • Sodium (Na+)-Major role in depolarizing the myocardium
    • Calcium (Ca++) takes part in myocardial depolarization and myocardial contraction,
    • Potassium (K+) influences repolarization
    • Chloride (Cl-)
    • Magnesium (Mg++)
  23. Hypercalcemia
    • increase in serum calcium
    • increased myocardial contractility
    • shortens repolarization, ST segment shortens (sometimes T-wave looks as if it's on QRS)
    • Adrenal insuffciency, hyperthyroidism, Kidney Failure, Lidney Disease
  24. Hypocalcemia
    decrease in serum calcium, decreased myocardial contractility and increased electrical irratibility, prolongs repolarization, prolongs ST segment
  25. Hyperkalemia
    • Normal Potassium 3.5-5.0mEg/L
    • increase in Potassium, decreases automaticity and conduction
    • Tall T-Waves
    • suspect in PT's with Hx of renal failure
  26. Hypokalemia
    decrease in Potassium, increases irritability, Flattened T-waves, Prominent U-waves
  27. Repolarization
    return of a muscle cell to its preexcitation resting state
  28. Action Potential
  29. Excitability
    the ability to be simulated to contract, respond to electrical stimulus
  30. Conductivity
    the ability to transmit(propagate) an electrical impulse from one cell to the another
  31. What are the two types of heart valves?
    Atrio-Ventricular, Semi-Lunar
  32. What are the Atrio-Ventricular valves and where are they?
    • Tricuspid between the Right Atrium and Right Ventricle
    • Bicuspid (Mitral) between the Left Atrium and Left Ventricle.
  33. What are the Semi-Lunar Valves and where are they?
    • Pulmonic between the RV and Pulomary Artery
    • Aortic between the Left Ventricle and Aorta
  34. Where is there not a valve?
    Between the Pulmonary Vein and the Left Atrium. CHF, blood backs up into the lungs from the heart.
  35. Route of Blood Flow starting with the body?
    Body > RA > Tricuspid > RV > Pulmonary Valve > Pulomary Artery > Lungs > Pulmonary Vein > LA > Mitral (Bicuspid) Valve > LV > Aortic Valve > Aorta
  36. Peripheral Circulation
    Arterial, Venous, Capillary, Circuits
  37. Arterial Layers
    • Tunica Intima, Inner layer, one cell thick, smooth, reduces friction
    • Tunica Media, middle layer, elastic fibers/ muscle for strength and recoil, thickest in arteries
    • Tunica Adventicia, outer fibrous covering, withstands high pressure
  38. Automaticity
    pacemaker cells capability to self-depolarize, the ability to selfgenerate an impulse
  39. Contractility
    the ability of the muscle fibers to contract, shortening of the muscle fibers (mechanical property)
  40. Internodal Atrial Pathways
    Connect the SA node to the AV node
  41. artifact
    deflection on the ECG produced by factors other than the hearts electrical activity, such as muscle tremors, shivering, patient movement, loose electrodes, 60 hertz interference, machine malfuntion
  42. Bipolar Limb Leads
    ECG leads applied to the arms and legs that contain 2 electrodes of opposite (+ & -) polarity. Leads I, II and III
  43. Einthoven's Triangle
    the triangle around the heart formed by the bipolar limb leads
  44. Refractory Period
    the period of time when myocardial cells have not yet completely repolarized and cannot be stimulated again.
  45. Absolute Refractory Period
    the period of the cardiac cycle when stimulation will not produce any depolarization whatever.
  46. Relative Refractory Period
    The period of the cardiac cycle when a sufficiently strong stimulus may produce depolarization.
  47. Resting Potential
    The normal electrical state of the cardiac cells
  48. Cardiac Depolarization
    A reversal of charges at a cell membrane so that the inside of the cell becomes positive in relation to the outside; the opposite of the cells resting state in which the inside of the cell is negative in relation to the outside.
  49. Mycardial Infarction's usual sequence
    Ischemia (lack of O2), Injury, Necrosis (cell death, infarction)
  50. Ischemia
    Lack of O2
  51. Necrosis
    Cell Death
  52. Infarction
    area of dead tissue caused by lack of blood
  53. Precordial Leads
    V1-V6 (Chest) Horizontal Plane of the Heart
  54. Unipolar Leads
    aVR, aVL, aVF (Augmented)
  55. Bipolar leads
    I, II, III(LA) (Limb Leads)
  56. Physiologic Q waves
    considered normal (<.04 sec)
  57. Patholigic Q-waves
    shows previous MI, permanent damage (>.40)
  58. Atherosclerosis
    a progressive, degenerative disease of the midsize and large arteries
  59. Arteriosclerosis
    a thickening, loss of elasticity, and hardening of the walls of the ateries from calcium deposits
  60. aneurysm
    the ballooning of an arterial wall
  61. "J" Point
    the junction between the end of the QRS and the beginning of the ST segment
  62. 12-Lead Basics - Progression
    ST depression - ischemia, ST elevation - injury, T-wave inversion - late ischemia, Pathologic Q-waves - infarct
  63. Hyperacute (12 - Lead)
    ST segment on baseline, t-wave = large tomb stone
  64. Acute (12-lead)
    ST Segment more than 1 small box elevation, t-wave = large tomb stone
  65. Acute + (12-lead)
    ST segment more than 1 small box elevation, t-wave = large tomb stone, negative deflection q-wave normal
  66. Old (12-lead)
    ST segment on baseline, pathologic Q-wave (>.04)
  67. Hypertrophy
    stretching; enlargement without any additional cells
  68. Bundle Branch Block
    V1(right hand) & V6(left hand), If terminal deflection is positive in V1 with negative in V6 its a RBBB and vice-versa
  69. WPW - Wolfe parkingson's white
    Lead I or V6(usually), short p wave (2 small boxes), no pr interval,R-wave starts immediately after P-Wave with a Delta wave (slurred beginning) on R wave, wide qrs (almost 3 boxes) in the R
Card Set
Cards based on lecture and reading from the EMS-153 Introduction to Cardiology class at northern VA Community College MEC
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