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Flashcards in cardiac output Deck (18)
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1
Q

CO = ?

A

SV x HR

2
Q

normal CO?

A

5 L/min in resting adult

can vary based on metabolism, age, body size

3
Q

what is a better way to measure volume of blood ejected from heart?

A

cardiac index

4
Q

cardiac index =?

A

volume of blood ejected from heart per unit time per unit of body surface area

5
Q

normal cardiac index?

A

3 L/min/sq of S.A

6
Q

what is the SV?

A

volume of blood ejected by ventricle during each contraction

7
Q

determinants of SV

A
  1. end-diastolic volume/ preload
  2. ventricular contractility
  3. afterload
8
Q

tension exerted on cardiac ventricular muscle when it begins to contract

A

preload

9
Q

the pressure that the ventricle has to win to produce a SV?

A

after load

10
Q

what determines after load?

A
  1. ventricular outflow tract
  2. aortic valve fxn
  3. peripheral arterial resistance/ bp
11
Q

intra-ventricular volumer at the end of systole; indicator of systolic fxn

A

end-systolic volume

12
Q

what determines ESV?

A
  1. preload
  2. ventricular contractility
  3. after load
13
Q

what is a length dependent activation of the heart (when the force of ventricular contraction is a fxn of the ventricular end diastolic length of the cardiac muscle_

A

frank starling law of the heart

14
Q

if keep preload & contractility constant, and increase afterload, what happens to SV?

A

SV decreases

15
Q

what is the ANREP effect?

A

when the aortic perssure is elevated abruptly, a positive inotropic effects follows within 1-2 min

16
Q

when you incr the hr (the rate of stimulation), it incr contraction - what is this phenomenon called?

A

bowditch staircase phenomenon

17
Q

effect of HR on CO is ________

A

rate-dependent

18
Q

what is the most commonly used method for measuring CO?

A

pulmonary artery catheterization (PAC) thermodilution w/ blous injxn of cold fluid