Exam 1 Lecture 3 Flashcards
What is the example cofactor that Dr. S wanted us to know for ATP production
Vitamin B1
Beriberi is a deficiency in what?
How does this impact CO
Vitamin B1 Deficiency
Increase CO from increased metabolism
How many ATP can be made from a normal reaction
36
How does Hyperthyroid increase CO
increase metabolism burns more ATP and burns more O2 causes increase CO
True or false
Pulmonary diseases decrease CO because of a lack of Oxygen delivery to the heart
False
Increase CO because decreased Oxygen levels in blood so CO must increase to compensate
How does AV shunts increase CO
AV shunts cause pressure problems in heart and the blood flow is different than normal heart so heart has to compensate to provide enough oxygen delivery to the tissues
Does LT Dan from forest Gump have increased or decreased CO
Decreased because Heart doesn’t need to provide blood to his non existent extremities
What is the name of the old weight loss drug that we discussed in class?
What is a major side effect of it
Dinitrophenol- weight loss drug, burns glucose inefficient, increase our body temp from increase metabolism
What does PRA stand for
What is this the EXACT same as?
PRA= pressure at right atria
PRA=RAP
What is the normal Intrathoracic pressure
What about the normal value in the pulmonary system
-4mmHg
5cmH2O
How does inspiration impact our intrathoracic pressures
Inspiration makes it more negative
True or false
A more positive pleural pressure will draw blood from the peripheral to the inside of the thoracic cavity
False
A more negative pleural pressure does this
What machine operates on creating a more negative pleural space
Iron lung
A normal lung is under which of the following pressures?
Supratmospheric
Atmospheric
Subatmospheric
Normally under Subatmospheric
How does positive pressure ventilation impact thoracic pressure
Increases pressure
What is a example of an arterial specific vasodilator
Sodium Nitroprusside
(Keep out of light)
How does an arterial Specific vasodilator impact CO
Increases CO
Reduces RVR and SVR
Increase blood return back to heart
What happens to CO when we give a Vein specific vasodilator
What is an example of drug
When we dilate the veins decreases CVP and decrease systemic filling pressure, decrease venous return back to heart and decreased CO
Drug: Nitric Oxide
What happens to CO when we give a mixed vasodilator
Decreased systemic filling pressure from veins dilation
Decreased RVR from arteries dilating so yes easier to get blood back but Psf low
What is happening to the veins if we have decreased compliance
Decreased compliance= constriction
How does a really high SVR impact CO
High SVR usually will decrease CO
Which is more important for Psf arteries or veins
Veins
What does the body do in the acute phase of HF to increase CO
Activates Sympathetic
What do we have to be careful doing to our chronic heart failure patients
Diuresis
Why does the body want to tone down high Sympathetic activity in HF patients
In HF body wants to tone done high sympathetic activity because you need some sympathetic reserve for daily activity like walking stairs
What does the body do to compensate for high Sympathetic activity in HF
Body will retain fluid to increase filling pressure to help the heart
What point is no compensation occurring
Point B
The heart beats best when it is ______ stretched
A little Over stretched
Increased preload does what to
EDV
SV
CVP
Increases them all
Does increased preload increase contractility
No according to Dr. S
by definition contractility doesn’t take into account preload and afterload
How does decreased preload impact
EDV
SV
Decreases them both
How does increased afterload impact
ESV
Aortic Valve timing
SV
SV decreased because we spend less time in ejection
Elevated pressure in aorta will shut aortic valve earlier soon and cuts off ejection
Increased ESV- more left over
How does decreased afterload impact
SV
ESV
Aortic valve timing
Open aortic valve sooner and longer
Spend more time in ejection
Increase SV
Decreased ESV
How does decreased afterload impact
SV
ESV
Aortic valve timing
Open aortic valve sooner and longer
Spend more time in ejection
Increase SV
Decreased ESV
How does increased contractility impact
SV
ESV
Increased SV
Decreased ESV- squeezes harder
How does decreased contractility impact
SV
ESV
Decreased SV
Increased ESV
In mitral valve regurgitation what phases do we have backwards blood movement
Phase 2,3,4
What will the heart do to compensate with a bad mitral valve regurgitation
Increase CVP
Increase EDV
How does mitral stenosis impact
Preload
SV
EDV
Psf
Decreased Preload
Less filling
Decreased SV
Decreased EDV
Increase in Psf long term
In what phase of the cardiac cycle is aortic valve regurgitation very apparent and it can’t be issues with any other valves
Blood leaks back in phase 4, mitral valve would be closed here so only place blood can leak from is aortic
How does aortic valve stenosis impact
Afterload
LV pressure
Pulse pressure
CVP
HR
Increased afterload
Increased LV pressure
Decreased pulse pressure
increased CVP
Increased HR chronic
How does an afterload reducer increase SV
Increases ejection time
Less resistance
How does inspiration effect our Right side of the heart
Inspiration makes chest more negative
increases filling-right side
Decreases afterload- right side
Increase in CO-right side
What happens to systemic MAP during inspiration
Systemic MAP drops early during inspiration because poor filling to left side heart
What is interesting about PPV and thoracic pressure
Positive pressure ventilation increase thoracic pressure and temporarily pushes blood into the heart and increase right and left heart CO
overtime it will impair venous return and reduce CO long term
Is normal breathing positive or negative pressure breathing
Negative pressure
How does Inspiration impact CVP and PAP in the beginning
Decreases CVP and PAP
what two variables effect venous return
Volume and pressure
True or false, increases in SVR will translate to an increase in RVR
TRUE
For this class thus far what are the 2 numbers we need to remember for intrathroacic pressure?
-4 mmHg
5cmH2O
Will changes in intrathoracic pressure shift this graph left or right or up and down?
left and right, the height should not increase or decrease.
True or False, positive pressure ventilation will increase venous return to the heart?
False!
What are 3 ways to increase venous return?
1- increase filling pressure
2- decrease right atrial pressure
3- lower RVR
What is the formula for venous return?
Venous return= (systemic filling pressure- Right atrial pressure) / RVR
What does SNP stand for
Sodium nitroprusside apparently….. even though im not convinced this is even a real thing and that he is just making up abbreviations as we go alone
What will cause a shift from A –> B
For this class a shift from A to B can be accomplished with the administration of a Arterial specific Vasodilator (SNP, even though according to Schmiddy its not REALLY arterial specific) this will increase venous return to the heart as well as decrease after load allowing for an increase in cardiac output.
What would cause a shift in this graph from A – > B
a venous specific vasodilator such a Nitro would probably be a good answer for this class.
note here that the drop in CVP will also cause a shift in the PSF
In the chronic phases of heart failure what is the hearts primary compensatory mechanism?
Fluid retention
Why would sympathetic stimulation not be an appropriate compensatory mechanism for chronic heart failure
if you live in a state of constant sympathetic stimulation you might drop dead just walking up a flight of stairs or something because your heart wouldn’t be able to handle even that little increase in workload.
How does Cardiac index compare to cardiac output
Cardiac index takes into account the patients body surface area
CI = CO/ Body surface area (m^2)
What is the normal cardiac index for a middle aged male?
3
What is the cardiac index for lets say an 80 year old
for this class a good answer would probably be 2.4
what is the Cardiac index dependent on? (2 variables)W
TPR, and SVR both of these are controlled by the metabolic rate, so it is fair to say that Cardiac index is also controlled by metabolism.
Why does Beri Beri have constantly high CO and CI?
Because they can’t make enough ATP due to the B1 deficiency, so they increase blood flow to the capillaries to get more o2 and glucose to the cells in an attempt to make more ATP.
would hyperthyroidism have increased or decreased cardiac output?
Hypothyroidism?
Hyper = increased
Hypo = decreased
Explain in crayon what happens with an AV shunt.
Blood moves from high to low pressures in the heart and by doing so bypass the normal circulatory pathway and do not get oxygenated. This decrease in the availability of oxygenated blood will cause an increase in CO and CI to try and get more oxygen to the tissues.
How does dinitorphenol work
“uncouples normal metabolism”
How would an increase in preload change the volume pressure loop?
it would cause an increase in filling which would cause in increase in EDV and eventually in increase in SV
How would a decrease in preload change the volume pressure loop?
it would cause a decrease in filling with would cause in decrease in EDV and eventually a decrease in SV
How does an increase in afterload change the volume pressure loop?
an increase in after load will cause the heart to have to work harder to eject blood this will cause the loop to become taller.
overall this will reduce Stroke volume due to more Time being spent in isovolumetric contraction and relaxation and less time able to be spent in filling and ejection.
How does a decrease in after load change the volume pressure loop?
a decrease in after load will allow the heart to work less to eject blood. Overall the loop will get shorter.
This will allow less time to be spent in isovolumetric contraction and relaxation and more time filling and ejecting.
How does increased contractility change the volume pressure loop
The SV will increase and ESV will decrease due to the heart providing a stronger more efficient squeeze.
How does decreased contractility change the volume pressure loop
The SV will decrease and the ESV will increase due to the heart not pumping efficiently.
How does mitral regurgitation change the volume pressure loop
I have no good words to describe this other than the shape is. “blown out”
essentially we lose ventricular volume into the atria during ventricular contraction when that contraction is supposed to be isovolumetric.
We are also loosing volume in the beginnings of phase 4 because the ventricular pressure is still higher than the atrial pressure, even though we have started the diastolic phase.
What 3 phases do we loose ventricle volume into the atria with Mitra regurgitation?
II, III, IV
How does the body compensate for mitral regurgitation?
we increase our blood volume this will in turn increase the CVP. This will maintain our filling pressures and allow us to keep a CO that is consistent with living.
How does mitral stenosis change the volume pressure loop?
How to we compensate?
Lower stroke volume and decreased EDV due to stenosis
Compensation: increase systemic filling pressures.
How does Aortic Valve insufficiency change the volume pressure loop?
Blood leaks back into the ventricles from the Aorta, this is most likely to occur in the last portion of Phase 4 during isovolumetric relaxation when the ventricle pressure is at its lowest.
Per Schmiddy, this is probably still occurring during phases 1 and 2, but we can’t see it on this graph and he really isnt 100% sure even after 13 years….
How do we compensate for aortic valve insufficiency?
fill the heart with more blood, this will cause ventricular pressure to stay higher and restrict the amount of blood flow that can back flow from the aorta.
Not swell long term hypertrophy of the L Ventricle will occur and you will NOT be most happy.
How does Aortic Valve stenosis change the volume pressure loop?
Aortic stenosis will cause an increase in after load. The shape of the volume pressure curve, will get taller, and shift up.
How do we compensate for Aortic Valve stenosis?
Increase filling pressure.
Increase Heart rate (late compensation)
Increase in left ventricular pressure in required in order to eject the required amount of blood to keep living.
If you have idiopathic tachycardia, what is the most likely cause?
“Its probably a heart problem, usually the aortic valve”
