Lecture 15 Flashcards
right heart pumps blood to the _______
left heart pumps blood to the _______
lung back to left atrium
the body
Measurement of how much blood is pumped from the heart per min
cardiac output (CO)
formula for cardiac output
Function of stroke volume (SV) X heart rate (HR)
_____ is the amount (mL) of blood leaving heart with each beat
Determined by: _________________
_____ mL**
_____ is the number of beats per minute
70 mL X 80 bpm = 5600 mL = 5.6 L
(SV)
1) preload, 2) afterload and 3) myocardial contractility
70
(HR)
heart rate primarily determines by __________
nerves and hormones
stroke volume from _____________
blood volume
vascular resistance
cardiac output ______ with age.
CO is ____ proportional to overall metabolic demand and overall oxygen demand
CO also controlled by _________
at rest?
with exercise?
declines
directly
local tissue flow
- 4 mL/min/100 g muscle
- 200 mL/min/100 g muscle
Calculate the CO
A 60 year old male has a resting heart rate of 75 beats/min, arterial pressure 130/85 mm Hg, body temperature was normal. Using the pressure volume diagram below.
What is the stroke volume? CO in L/min?
135-65= 70 mL for SV
70 x 75 = 5,250 mL = 5.25 L/min
Cardiac Index
- Output increases in proportion to _________
- Index refers to CO per _________
- Preferred expression of CO
- Calculated by ______________
Normal hemodynamic measures ________ L/min/m2
Average cardiac index _____ L/min/m 2
Minimally accepted level _____ L/min/m2
body surface area
square meter
dividing the CO by the body surface area in meters squared
2.8 to 4.2 L/min/m2
3 L/min/m 2
2 L/min/m2
volume of blood in the ventricles at the end of diastole
preload
resistance left ventricle must overcome to circulate blood
afterload
preload is increased in ________-
hypervolemia
regurgitation of cardiac valves
heart failure
Afterload is increased in __________
hypertension
vasoconstriction
more afterload=more cardiac workload
Mechanisms to compensate for defects which could make the heart’s pumping action ineffective
cardiac reserve
Include hypertrophy, enlargement, increase in heart rate, increase in stroke volume
- A normal heart can pump up to _____ which is about _____ normal venous return
- Normal heart can increase rate to _______ bpm and contractility _____normal strength
13L/min
2.5X
180 to 200
2X