Hemodynamics Flashcards

1
Q

What is stroke volume? Cardiac output? Write equation

A

SV» volume of blood pumped out of one ventriclle per beat

CO» amount of blood pumped out of EACH ventricle per minute
Measured by L/min

CO=HR x SV

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2
Q

What is normal CO for a 70kg person at rest

A

cardiac output at rest is about 5 liters/minute.

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3
Q

What is rhe amount of blood flow that should be sent to the brain?

A

maintain a blood flow of 750 ml.min-1 to the brain at all times

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4
Q

The blood flow is controlled via_________

A

Resistance vessels -arterioles and pre capillary sphincters

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5
Q

What is capacitance? In relation to the cvs system? Where is it located?

A

A store of blood that can be called upon when sudden cardiac output changes occur to cope with the amount of blood leavimg and enetering the heart.

This store is in the veins

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6
Q

Pericardial effusion vs pericardial tamponade

A

Pericardial effusion (“fluid around the heart”) is an abnormal accumulation of fluid in the pericardial cavity. Because of the limited amount of space in the pericardial cavity, fluid accumulation leads to an increased intrapericardial pressure which can negatively affect heart function. A pericardial effusion with enough pressure to adversely AFFECT heart function is called cardiac tamponade.

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7
Q

Turbulent flow vs laminar flow

A

Laminar flow is when all the blood moves in strait line in the same direction “STREAM LINES”. Velocity of rbc will be greater in the middle than the periphery, bc in the periphery it comes in contact with the wall and that causes FRICTION
Turbulent flowing in all directions and mixing with the vessels.

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8
Q

What component in blood can increase whole blood viscosity?

What clinical condition is the most common cause of this?

A

If plasma viscosity rise, whole BLood vixcosity rises and causes sludging of blood.

MULTIPLE MYELOMA» cancer if plasma cells, malignant clone of olasma cells produces antibodies in large quantitities which increases the viscosity of the blood.

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9
Q

Term for imcreased RBC, platlets, wbc

A

Polycythemia
Thrombocyathemia
Leukemia

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10
Q

Durin ginflammation what increases in the body? And what do we use to measure inflammation in specific

A

Acute phase protiens! And we use CRP

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11
Q

What is the diacrotic notch?

A

minor extra pressure the aorta gives due to a little backflow of blood that hits the valve when it closes?

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12
Q

What is pulse pressure?

A

Systolic pressure-diastolic pressure=PP

120mmHg-80mmHg=40mmHg

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13
Q

What is MAP? What value if it falls below it, means that organ perfustion is impaired?

A

[(2x diastolic) + systolic]/ 3
=93mmHg
If it falls below 70mmHg, organ perfusion is impaired

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14
Q

Why in some elderly u cannot here a pulse?

A

The artery calcifies and and no complience with aging

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15
Q

What depend on how quick the blood from the aorta travels?

A

Depends om the peripheral resistance

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16
Q

What size should the cuff at leastcwind around the patient’s arm?

A

80%

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17
Q

How does peripheral resistance effect bp

A

The more the peripheral resistance the harder it is for the heart to push put blood, so u get higher bp amd vise versa

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18
Q

If the pressure fall below the normal level of about 100mmHg, what changes occur to compensate this

A

Nervous signals increase force of pumping heart, cause CONTRACTION of venous vreservoirs to provide more blood back to heart and causes genrealised of arterioles in many tissues so that more blood accumalyes in the larger arteries to increase arterial Pressure.
Then after hours and days»kidney takes over.

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19
Q

Blood flow through a blood vessel is determined by 2 factors, what r they

A

Pressure DIFFERENCE of the blood btw the 2 ends of the bv, & vascular resistence

20
Q

What 2 major factors determine pulse pressure? Describe the situation if u were to have high pulse pressure.

A

1) stroke volume output
2) complience of arterial tree

1) This means that the stroke volume increased, increasijg amount of blood in arterial tree, yherefore imcreasing pressure.
2) BUT complience decreases (less stretchable) which gives more pressure

21
Q

What happens to the arteries of those elderly ppl with arteriosclerosis?

A

Their arteries have hardened (less compliemt) so therefore their pulse pressure rises

22
Q

Describe realtionship between compliance and blood velocity

A

The more the compliance» slower the blood velocity

The less the compliance&raquo_space; faster blood velocity

23
Q

What 2 things causes damping of the pressure pulse? &why?

A

1) resistance to movement of blood flow
2) compliance of the bv

Resistence clamps the pulasations bc a small amount of blood can flow forward

Compliamce damps the pulsations bc we need MORE amount of blood to cause an increase in Pressure.

24
Q

What is central venous pressure?

A

Pressure in the right atrium (blood from all systemic veins drain there)

25
Q

How to arterioles effect venous return to heart?

A

If arterioles dilate, peripheral resistence decreases and allows rapid flow from arteries into veins

26
Q

Large veins do sometime offer resistemce to blood flow, how?

A

Most large veins entering thorax r compressed at many point from the surrounding tissues, bein from arm r compressed by their sharp angulations over first rib, veins moving through abdomenare often compressed by diff organs by the intrabdominal pressure, so they r at least “partially” collapsed

27
Q

What effect would high atrial pressure have on peripheral resistance? And what is the normal right atrial pressure?

A

RAP» 0mmHg, if pressure rises above this, blood begin to back up in the large veins cause them to enlarge (distended veins).
Even the collapsed veins ( mentioned earlier) start to open up when RAP rise above 4 to 6 mmHg. If this rising continues, it can lead to increase venous pressure in the limbs!

28
Q

How does blood move through aorta and describe what the aorta does to acheive this

A

During systole, at first, only the proximal portion of the aorta is distended, to prevents SUDDEN blood flow all the way to the periphery,nunthen rising pressures jn the aorta overcome this and the wave soreads further and further.»

29
Q

A strong pulse is often describes as ________

A weak pulse is often describes as_________

A

bounding

Thready

30
Q

What is a pulse?

A

It is the ‘shock wave’ we feel before the blood itself arives

31
Q

What 2 conditions in the heart cause a bounding pulse?

A

Bradycardia, heartblock
Heart slows down> more time to fill with blood, although the heart is beating less fast, ita pumping put more blood with each beat.

32
Q

What is the measurements for pressure?

A

Psi» punds per square inch

33
Q

If u get a stenosis in an artery, what would happen to BLood flow after that point? What about the velocity of the blood after that point?

A

Blood flow would decrease, but velocity would increase (like the hose example)

34
Q

***IN HEMODYNAMICS, JUST BECAUSE VELOCITY INCREASED THAT DOESNT MEAN FLOW IMCREASES AS WELL, IT DECREASES ACTUALLY

A

Just a reminder hehe :p

35
Q

What is a post stenotic dilatation?

A

When u get a stenosis at a point, the blood rushing beyond g point has a high velocity and causing a high pressure, this high speed can cause a dialtion (anuerysm) of the that vessel after the stenotic point!

36
Q

What is a bruit sound?

A

or vascular murmur,[1] is the abnormal sound generated by turbulent flow of blood in an artery due to either an area of partial obstruction; or a localized high rate of blood flow through an unobstructed artery.

[2] The bruit may be heard (“auscultated”) by pressing a stethoscope to the skin over the turbulent flow and listening. Most bruits occur only in systole,

37
Q

During a stenosis in an artery, if u can feel the turbulence at that point it is called a __________. If u can hear it with a stethescope we call it a ________. If u can hear that in the heart it is called a ________

A

Thrill
Bruit
Murmur

38
Q

What does blood consist of?

A

Plasma
Rbc
Wbc and platlets

39
Q

When can u get low peripheral resistance?

A

When ur taking a hot bath, excersise, pregnant

40
Q

Why do u get low peripheral resistance when your pregnant?

A

Uve got a boiler in ur uterus which js producing heat, and so u need to vaodialte to release this heat

41
Q

Why in aortic regurgiatation do u get a bounding pulse?

A

In aortic regurgitation, aortic valves dont close well, causing back flow of blood back into the heart, (diastolic pressure is maintained when the aortic valve closes, but bc the valve doesn’t close, blood falls too much back into the heart causing the diastolic pressure in the major arteries to fall toooooo dangerously low! 20mmHg…, while the sytolic is too high! 220mmHg bc the ventricles r overfilled with the back leak of blood from the aorta, causing the ventricles to stretch more, cause it to contract more!

IN THIS CASE pulse pressure will now increase
Normal»pp=120-80= 40mmHg
Abnormal»pp=220-20=200mmHg

42
Q

What has pulse pressure got to do with a bounding pulse?

A

Iany time u get a bounding oulse, it mean oulse pressure has widened

43
Q

What accumalates in pathological hypertrophy?

A

Myocardial scarring occurs (collamgen) stiff heart and leads to ineffective

44
Q

The fluid collected from unclotted blood is called________

The fluif collected from clotted blood is called________

A

Plasma

Serum

45
Q

Define what a serum is?

A

When blood CLOTTS, the fibrin that precipitates out is called serum

SERUM= Plasma-clotting factors

46
Q

What is multiple myeloma?

A

Myeloma is a cancer that affects cells in the bone marrow, called PLASMA CELLS. As the cancerous plasma cells fill the bone marrow, you are not able to make enough normal blood cells. This can lead to anaemia, bleeding problems and infections.