Cardiac Def & Numbers

Card Set Information

Cardiac Def & Numbers
2014-03-23 15:47:53
LCCC nursing cardiac medsurg

for exam 2
Show Answers:

  1. Mean Arterial Pressure (MAP)
    Normal MAP is between 60-70mm Hg

  2. Cardiac Output
    • The amount of blood pumped from the left ventricle every minute
    • Normal range is 4-7L/min

  3. Stroke Volume
    the amount of blood ejected by the left ventricle during each contractino
  4. Preload
    the degree of myocardial fiber stretch at the end of diastole and just before contraction
  5. Afterload
    • The pressure or resistance that the ventricles must overcome to eject blood through the semi-lunar valves into the peripheral blood vessels
  6. Impedance
    the peripheral component of afterload, its the pressure that he heart must overcome to open the aortic valve
  7. Myocardial contraction
    force of the cardiac contraction independent of preload, it effects the CO and SV
  8. What is the equation for BP? What three mechanisms regulate BP?

    BP is regulated by the ANS (fight or flight), the kidneys which detect changes, endocrine system which send hormones to stimulate the sympathetic nervous sytem
  9. Paroxysmal nocturnal dyspnea (PND)
    After laying down for several hours, blood pools in the venous system.  For the diseased heart, the increase in preload causes pulmonary congestion.  The patient awakens abruptly from sleep feeling as if they are suffocating
  10. Paradoxial blood pressure
    an exaggerated decrease in systolic pressure by more than 10 mm Hg during inhalation.
  11. Ankle Brachial Index (ABI)
    • Asses the vascular status of the lower extremities
    • Obtain brachial pulses. Place BP cuff on leg just above maleous. Measure systolic by doppler at both the tibial and pedal.  Divide the higher number by the higher brachial pulse.
    • BP in the legs is usually higher due to gravity, therefore it should be equal to or greater than 1
  12. What is the difference between a hypokinetic and a hyperkinetic pulse?
    • Hypokinetic: weak pulse indicitive of a narrow pulse pressure
    • Hyperkinetic: bounding pulse caused by increased ejection of blood
  13. Automaticity
    the self excitable pacing function of the heart
  14. Excitability
    the non pacemaker heart cells respond to the electrical impulses from cell to cell
  15. Contractility
    the ability of the atrial and ventricular muscle cells to shorten their fiber lengths in response to electrical stimulation
  16. PR segment
    • isoelectric line from the P wave to the beginning of the QRS complex
    • The pulse is slowed down as it travels through the AV node
  17. PR interval
    from the beginning of the P wave until the end of the R.  Time required for atrial repolarization and the impulse delay in the AV node for the pulse to reach the perkinji fibers
  18. QRS complex
    Ventricular depolarization
  19. P Wave
    represents atrial depolarization. In atrial fib, it is indistinguishable.  In Atrial flutter, it looks like a saw tooth
  20. ST Segment
    represents early ventricular polarization. May be elevated in MI or angina
  21. T wave
    represents ventricular repolarization