Exam 1 Flashcards
Label the following.
See picture
What is Free H2O clearance, what is it regulated by & what does a high number mean?
How much pure H2) is removed from the blood. Regulated by ADH & high # means getting rid of a lot of water.
What is the systemic pulse pressure?
100mmHg
What is the CVP in a healthy person & where is it measured?
It should be 0 & is measured outside the RA.
Where are low & high compliance found?
Low compliance is on arterial side & veins have a high compliance.
What is the meaning of pulse pressure?
It relates to how stiff vessels are. Low PP means more flexible. High PP means stiffer (arteries).
Where is turbulent flow found & what is another function of it?
In the Aorta & acts as a volume reservoir.
What is another word for compliance?
Elasticity. Higher elasticity means higher compliance= more stretch.
What does elastance mean?
How rigid something is. It is the inverse of compliance. High elastance = low compliance.
What kind of compliance is found in the pulmonary system?
High compliance due to low resistance.
What do vasopressors not innervate?
Capillaries & cranial sinuses.
Which has a higher velocity, aorta or vena cavae?
Aorta
MAP Formula
Diastolic + 1/3 (Systolic – Diastolic)
What tells arterioles to relax & increase flow?
Waste products
What are the colloid pressures of Albumin, Globulins, & Fibrinogen?
21.8, 6, & 0.2 (mmHg)
What is normal lymphatic flow & what is max?
2L/day & max is 40L/day
Where does the lymphatic system drain into & what controls the flow?
The subclavian vein. Controlled by skeletal muscles.
Do the lungs have a lymphatic system?
Yes, but it does not work as well as the systemic one.
Where would one encounter negative venous pressures?
In the cranial sinuses
BP at Thigh has how much extra pressure?
40mmHg
BP at the femoral artery bifurcation would be?
142/102 mmHg; + 22mmHg
If a BP is measured on a healthy person’s wrist & it reads 150/110 mmHg, how much arm distance is below the heart?
40.8cm (1.36cm for each 1 mmHg increase.
What is the formula for Vascular compliance?
Compliance= Delta volume / Delta pressure
High volume and low pressure result in ____ compliance?
High
What are normal pulmonary pressure:
Systolic
Diastolic
Mean
25/8 mmHg (16 mmHg)
What is the pulmonary Delta P?
14 mmHg (MPAP= 16 mmHg & LA pressure = 2 mmHg)
What is the normal pressure range for the RA?
0-4 mmHg
What is the normal pressure range for the RV?
0-25 mmHg
What are the normal pressure ranges for LA & LV?
LA= 2-5 mmHg & LV= 2-120 mmHg
When CO is 5L/min, CVP is?
What is CO when CVP is 4?
CVP = 2
CO= 2.5
What is the formula for vessel velocity?
- Velocity= Flow (5L/min) x cross sectional area of vessel
- Cross section: Radius squared x 3.14
What are the beginning pressure, end pressure & Delta P of capillaries?
Beginning= 30 mmHg, end= 10mmHg,
Delta P= 20mmH
What is the capillary colloid pressure?
28mmHg
What is the interstitial fluid pressure?
-3mmHg
What is the average pressure inside a capillary?
17mmHg
What are the πp & g/dL of Albumin, Globulins & fibrinogen?
- Albumin: 21.8 mm Hg & 4.5 g/dL
- Globulins: 6 mm Hg & 2.5 g/dL
- Fibrinogen: 0.2 mm Hg & 0.3 g/dL
Sympathetic vasoconstriction releases _____?
Norepinephrine
What is normal intrathoracic pressure?
-4mmHg or -5cm H2O
What structural pressure is not affected by gravity?
Jugular veins
Veins are ___ times more/less _____ than arteries.
8, more & distensible
What is the formula for vascular distensibility?
Vd= Increase in Volume / (Increase in Pressure x Original volume)
What is the formula for Delta P?
Delta P= F x R (Flow times Resistance)
What is the formula for Flow?
- F= π △Pr4 / 8 η l
- [ (π times Delta P times radius to 4th power) / 8 times viscosity times length) ]
Conductance is proportional to?
Diameter to the 4th power
Small volume to large volume means?
High distensibility
What is the formula for predicting turbulent flow?
Re= [ (v x d x p) / η ]. (velocity x diameter x density / viscosity)
____ pressure & ____ velocity= low compliance.
High & low
Vascular Resistance unit PRU is also equivalent to what?
mmHg/mL/sec
Vascular resistance unit CGS is also equivalent to which two units?
mmHg/L/min = Centimeter Gram Second unit = Dynes x sec / cm⁵
How to convert CGS units to PRU?
1333 x PRU (mmHg/ml/sec)
What kind of sensors are carotid baroreceptors?
Stretch sensors
Aortic baroreceptors are controlled by the ____ thru the ____?
Medulla NTS (nucleus tractus solitarus & Vagus nerve
The carotid & aortic baroreceptors function at the same pressures?
False the aortic receptors function at a BP 20-30mmHg higher.
The carotid baroreceptors receive their signal from the ___, which then sends it thru the ___ & then thru the___?
Hering’s nerve & Glossopharyngeal nerve & Medulla (NTS) vasomotor center.
If someone was to have no baroreceptors, it would result in?
Denervated Neurons lead to increase in _____ of BP.
Higher BP fluctuation.
Increase in variability
If both carotid arteries were to be clamped for short period of time, what happens to the arterial pressure?
What mechanism limits the BP rise when carotids sense low BP
Is will increase 50-60mmHg
Aortic Baroreceptors will sense high BP and limit pressure increase
What is normal ESV?
50cc
What all happens in phase 1?
Filling, ESV=50cc, AV valves open, high atrial pressure, low intraventricular pressure
What is the normal EDV?
120cc
What all happens in phase 2?
Isovolumetric contraction, AV valves close, all 4 valves are closed at the beginning
What all happens in phase 3?
Ejection, peak pressures at 120mmHg, aortic valve closes @100mmHg
What all happens in phase 4?
Isometric relaxation, all 4 valves are closed, ESV= 50cc
What happens during the 1st part of Phase 3?
- 70% (49cc) of SV is ejected,
- LV pressure higher than aortic pressure,
What happens during the 2nd part of Phase 3?
- 30% (21cc) of SV is ejected
- at end aortic pressure > LV pressure
What is the 1st heart sound?
A-V valves (bicuspid and tricuspid) closing
Low pitch
What is the 2nd heart sound?
Semilunar Valves Close (Aortic & Pulmonic)
High Pitch
Why does the 1st heart sound vibrate more than the 2nd?
The aortic valve is meatier & doesn’t vibrate as much
Compare atrial kick in a healthy vs sick heart?
- In a healthy heart it contribute 5-10% &
- In a sick heart it contributes 20-25%
Normal Afterload for LV
80mmHg
A RA pressure of -4 mmHg will results in?
6L venous return
A RA pressure of 7 results in what?
0 CO & VR (Venous return)
System Psf
Another acronym for Psf?
+7 mm Hg
Ppv = Psf
Psf (systemic filling pressure) depends on 2 things
Tone & volume of the system
A Psf of 14 mmHg results in how much venous return?
12L/min
A Psf of 3.5 mmHg results in how much venous return?
4L/min
Effects on CO Curve:
Changing Psf
Changing Resistance
Psf changes size and position of curve.
Resistance changes shape (slope) of graph
Increases Psf:
Effect on RVR
Decreases RVR
Normal Arterial Volume
700cc
What does Pcv stand for?
Thoracic pressure
Maximum CO for Normal Sympathetic Activation
13L/min
Maximum CO for Max Sympathetic Stimulation
25L/min
A left shift of the cardiac output curve results in what?
Increased CO & contractility
What are causes of a right shift of the cardiac output curve? (2)
Parasympathetic stimulation, bad heart
Direct Atrial Stretch Reflex
How is stretch sensed?
MOA
body responds to increased stretch in right atrium by 10-15% increase in HR & SV
Sensor/Mechanism: Already built into the heart
MOA: increase permeability to Na and Ca
Describe Bainbridge Reflex
How is stretch sensed?
Result?
Stretch in Atria sensed by Vagus Nerve transmits to brainstem’s cardioinhibitor.
Brainstem increases SNS activity
Inc HR & SV by 50-60%
What is a normal cardiac index & what is it for an 80y old?
Normal is 3.5 & 80y old is 2.4
Arterial Specific Vasodilator
Hydralazine
What is TPR
Another name for it?
Total peripheral resistance & SVR
Spinal Anesthesia effect on Psf, VR, CO?
Minimal effect on Psf, VR, and CO.
Slightly decreases
What are causes for increased CO & decreased TPR? (6)
AV shunts, Anemia,
Beriberi, Hyperthyroidism,
Pulmonary disease, Paget’s disease
What are causes for decreased CO & increased TPR? (2)
Remove both arms and legs
Hypothyroidism
Hypothyroidism effect on CO and SVR?
Increased SVR
Decreased CO
What is Beriberi?
-involved in cofactor for what?
S/s (3)
- Vitamin B-1 (thiamine) deficiency (a co-factor for ATP production)
- S/S: High CO, lactic acidosis, right heart failure
Increased O2 consumption & metabolism leads to what?
Increased CO
Explain SVR relationship to VR
- Increasing SVR –> increased resistance to venous return –> decreased venous return (L/min).
- Decreasing SVR –> decreased RVR –> increased venous return (L/min)
Halving & doubling RVR results in how much venous return?
Halving= 12L/min & Doubling= 4L/min
A right shift in the Cardiac Output/ Thoracic Pressure curve is caused by (2)
What is needed to compensate?
- PEEP, tamponade &
- Increasing BP to push blood into chest
Arterial Specific Vasodilator effects:
SVR
RVR
Reduces SVR and RVR
Mixed vasodilator effects:
Psf
RVR
CO
RA pressure?
Psf decreases (venodilation)
RVR decreases (arteriodilation)
CO Slightly decreases
RA moderately decreases
Reduce Compliance or add volume
Effect on Psf and VR
stiff walls –> inc Psf –> inc VR
Constriction effect on Psf and RVR
Increase Psf and RVR
Venular specific vasodilator
Effects on CVP, Psf, VR, CO
Drug Class Example
drop in CVP –> reduce Psf –> reduce VR –> reduce CO
NO Donor
Short-term/acute: constriction of the veins mediated via (2)
- circulating catecholamines
- neural reflex
Phenylephrine Important Effect
Increase Psf & SVR
Long term compensations of cardiac injury is (3)
fluid retention → volume expansion –> Psf increase
Administering 2u of blood effect on
Psf
Vessel size
RVR
Psf inc
Increased volume widens vessel walls
Which decreases RVR
sky high sympathetic tone makes you more prone to ? (2)
Electrical arrhythmias
Myocardial Infarction
Volatile & Spinal Anesthetics considerations for SNS?
What is the safest and why?
Volatile - high doses inhibit the Autonomic NS.
Spinal Anesthetics drifts up the cord.
Epidural is safest because outside the dural sac.
AV Fistula effect on Psf and RVR
AV Fistula - creates easier flow so
NO Psf change
RVR decreases
Label the following
See picture
What does the picture describe?
Increased Preload
Increased Preload results in?
EDV/SV/EF
- Increased EDV & SV.
- Slight EF increase.
Decreased preload will result in?
EDV/SV/EF
- Decreased EDV & SV.
- Slight EF decrease
Increased Afterload will result in?
ESV/SV/EF/ Aortic Pressure
- Increased aortic pressure.
- SV & EF decrease.
- ESV increases
Decreased Afterload will result in?
ESV/SV/EF
- Decreased aortic pressure.
- SV & EF increase.
- ESV decreases.
Increased contractility will result in?
ESV/SV/EF
- SV & EF increase.
- ESV decreases.
Decreased contractility will result in?
- Decreased SV & EF.
- Increased ESV.
Mitral stenosis leads to what & what is the compensation?
- Reduced preload –> lower SV, EDV & EF.
- Compensate via increased preload.
Causes of Mitral Stenosis (3)
Rheumatic Fever (autoimmune reaction)
Strep
Staph infection
What 3 things stick to the cusps of valves?
Calcium, Cholesterol, Scar Tissue
With what kind of valve issue will there be a decreased pulse pressure?
Aortic Valve stenosis
Everyone has aortic stenosis after the age of
60.
With heart failure, expect substantially lower:
To improve SV for CHF patients use:
contractility
use afterload reducer to improve SV
What is DOC afterload reducer for CHF patients?
2 Benefits
ACE Inhibitor
Growth factor inhibitor so less scarring and slower remodeling.
What is normal coronary blood flow?
- 70mL/min/100grams of muscle
- 250mL/min
RCA blood flow during diastole vs systole
Increases with systole
Ok during diastole
LCA blood flow during diastole vs systole
Systole: retrograde at early systole, low
Diastole: Highest!
Oxygen Extraction Ratio for:
Heart
Regular Tissues
Brain
Heart: 75%, removes 15ml O2
Tissues: 25%, removes 5ml of O2
Brain: 75%, removes 15ml of O2
1dL in ml?
1dL of arterial blood = ? Oxygen Content
O2 in Cardiac Venous Blood?
1dL of arterial blood = 20 mL of O2
Venous Cardiac O2: 5ml
Left Vagus nerve on heart location
Goes over the top of the LA and ends at the AV node
Name the Heart Rates at:
Nodal HR
No Sympathetic Stimulation
No Parasympathetic stimulation
Nodal: 72
No Sym: 60
No Para: 110
What are the 3 pericardial layers?
Serous/visceral= thin & slippery not much connection to other 2
Parietal layer= attached to fibrous layer
Fibrous= doesn’t stretch much
Name the Cusps of the Valves:
Tricuspid
Bicuspid
Aortic
Pulmonic
T: Anterior, Posterior, Septal
B: Anterior, Posterior
A: Left, Right, Posterior
P: Left, Right, Anterior
Commissural Cusp
small, undeveloped on mitral valve but not large enough to count as an independent cusp
Aortic Left Cusp has an opening to the
Aortic Right Cusp has an opening to the
Coronary Perfusion best with open or closed aortic valves?
Left Cusp –> LCA
Right Cusp –> RCA
Coronary Perfusion best with closed valves
Length of 1st heart sound
Length of 2nd heart sound
1st: 0.14s
2nd: 0.11s
3rd Heart sound heard?
Normal in which population?
Beginning of the 2nd/3rd of Diastole OR
-1/3 into diastole
Normal in Kids
What is the 3rd heart sound suggest (4)
-Suggests low LV compliance heart
Mitral regurgitation = restrictive diastolic filling
4th Heart Sound:
Cause
When is sound loudest
Cause: excessive atrial contraction “Atrial Kick” in the beginning of last ⅓ of filling
Human hearing
Hz unit is a sound wave that ?
20 Hz - 20K Hz
Sound wave that oscillates a number of times per second
3 Phases of Diastole
Rapid Inflow - 1/3 of filling
Diastasis - little filling
Atrial Systole - atrial kick
Sympathetic ganglia that affect the heart originate
C-spine to T1
Right Coronary Flow during Systole vs Diastole
Sys: flow increases
Dia: flow is decent
Nutrient levels are low in heart after ejection
Oxygen, fatty acid, glucose concentration
CVP in mechanically ventilated patient will be
high to counteract the PEEP
Loudest of all heart murmurs
Aortic Stenosis
List the murmurs:
Systolic Murmurs (2)
Diastolic Murmurs (2)
Sys: Aortic Stenosis, Mitral Regurgitation
Dia: Mitral Stenosis, Atrial Regurgitation
What shift will be seen on the pressure-volume loop with Mitral stenosis?
Left shift
What EKG changes will be seen with mitral stenosis?
- Prolonged P wave
- right axis deviation.
What results from mitral stenosis?
RV
LA
Arrythmias
Overtime…
- Increased RV afterload
- Dilated LA
Arrhy: A FIb, A Flutter
Overtime failure of the right heart.
Aortic Valves Pressures
Opens at __
Closes at __
Opens: 80
Closes: 100
Inspiration will shift the cardiac output curve to the___?
Left, due to blood being pulled into chest & increasing negative pressure.
What conditions could be deadly for someone with Mitral Stenosis?
A-fib & tachycardia due to decreased filling time.
How is Mitral Regurgitation treated? (2)
- Decrease afterload
- Tachycardia
What shift on the pressure-volume loop would AR cause?
Right shift due to increased intraventricular volume.
When does most aortic regurgitation happen?
At end of phase 4 as LV pressures are low.
What valve issue is the worst for someone with CAD?
Aortic stenosis due to increased wall pressures –> decreased coronary perfusion.
What pulse pressure will be seen with Aortic Stenosis?
Effects of CVP, Psf, and HR
Narrowed pulse pressure.
CVP, Psf, and HR increas
What will ultimately result from MR?
Eccentric hypertrophy –> A-Fib
With a congenital bicuspid aortic valve
75% L and R cusps are tied together.
Pulse pressure is related to___. Higher PP= higher___?
Contractility & contraction
In hemorrhagic shock when do CO & BP start dropping?
- CO @ 15% blood loss
- BP @ 20% blood loss
How much cardiac output is seen with 35% of blood volume loss?
50%
Normal Thoracic Pressure
Thoracic Pressure During Inspiration
Normal -4
Inspiration -6
Inspiration/more Negative Thoracic Pressure effect on CO for:
Left Heart
Right Heart
Left Heart: Decreases CO b/c decreased pulmonary pressures. Pulm pressures like preload for LV
Right Heart: Negative pressure pulls on vena cava walls, reduces afterload–> inc CO –> PAP decrease
In the beginning of respiration, what is the max Systemic BP decrease
If BP drops more than that, pt might be ?
10mmHg
Hypovolemic
What are 3 causes of decreased venous return?
- Low volume
- Low tone
- Obstruction
What does the A wave signify? (2)
Occurs during which phase of cardiac cycle?
- Atrial contraction
- Short increase in CVP
During Atrial Systole of Diastole
What does the C wave signify? (2)
-Isovolumetric Ventricular Contraction
-AV Valves bow backwards into atria
What does the V wave signify?
-End of systole
-Volume builds in atria during all of systole
What is the X descent? (2)
- Atria relaxing
- Filling back up during mid systole
What is the Y descent? (3)
- A-V valves opening
-Dec in atrial pressure during - Early ventricular filling
What is the H wave/plateau?
Diastasis; Middle third of diastole
What affect will A-fib have on the CVP waveform?
- Prominent C wave,
- Loss of A wave
Label the CVP waveform descents & waves in order.
A-wave, C-wave, X-descent, V-wave, Y-descent, H-wave/plateau
What affect will an AV block have on the CVP waveform?
Cannon A wave
What affect will TR have on the CVP waveform?
- Tall systolic C-V wave
- Loss of X descent
What affect will TS have on the CVP waveform?
- Tall A wave
- Attenuation of Y descent
What effect will RV ischemia have on the CVP waveform?
- Tall A & V waves
- Steep X & Y descents
- M or W configuration
What affect will pericardial constriction have on the CVP waveform?
- Tall A & V waves
- Steep X & Y descents
- M or W configuration
What affect will tamponade have on the CVP waveform?
- Dominant X descent,
- Attenuated Y descent
What is the most common shock?
Hypovolemic
During normal breathing, the systemic MAP drops on ____ & LV output drops during___?
On early inspiration for both
What will prolonged positive pressure ventilation lead to?
Decreased venous return & decreased CO
How is SVR calculated?
[ (MAP – CVP) / (CO) ] x80
How is PVR calculated?
[ (MPAP – PAWP) / (CO) ] x80
PAWP normal value
PAWP is an estimate of
10mmHg
- pulmonary capillary pressure.
Miller’s Hemodynamic Values:
SVR Normal / Range
PVR Normal / Range
Oxygen Consumption
SVR: 1200; 800-1600 CGS
PVR: 80; 40-180
O2: 250ml/min
Air in an A-line will lead to an____ waveform?
High Gain on Art Line Amplifier causes
-Over dampened
-Causes artifact
(PDA) Posterior Descending Artery originates from:
RCA in __% of people
LCA in __% of people
RCA - 85%
LCA - 15%
Circumflex Artery anastomosis with which artery?
RCA
Not a lot of blood moves there.
The Great Cardiac Veins turns into _____ & empties into _______
Cardiac Sinus and empties into the Right Atrium
APTM for Valve Auscultation
Aortic Valve
Pulmonic Valve
Tricuspid
Mitral
A: Right 2nd ICS
P: Left 2nd ICS
T: Left 5th ICS
M: Left Lateral to T measurement area (nipple)
Aortic Baroreceptors Setpoint
130-150 mmHg
Kidney reaction to high Right Atrial pressures (4)
What is this called?
Dec SNS –> Relax Afferent Arteriole –> Inc Renal Perfusion –> urine
Atrial stretch Direct Neural Pathway
Why is ANF/ANP produced
An effective diuretic for how long?
High stretch in Right Atrium produces Atrial Natriuretic Factor/Peptide.
2 weeks
ANF/ANP effect on kidney (4)
Which hormone has a similar effect?
increases prostaglandins production →
increased RBF → increases GFR
→ increases UO
Brain Natriuretic Peptide (BNP)
BNP is produced from
Overloaded ventricles
Increased atrial stretch effect on 3 hormones?
Reduces
ADH
ALDO
ANGII
What does the inferior part of the heart rest on?
The central tendon of diaphragm
What all anchors the heart valve cusps?
Chordae tendineae & papillary muscles
What anchors papillary muscles?
Trabecula
What are the parts of heart valves called that touch each other when closed?
Lunule
What connects the pulmonic valve fibrous ring to the rest of the cartilaginous ring?
The tendon of conus
What is another name for the PDA?
Posterior interventricular descending artery
When is a PDA murmur the loudest?
During 2nd part of systole
What does a S3 sound like & when is it?
Rattles during/near end of ventricle filling
When is a S4 heard & what is it?
- In a sick heart
- It’s atrial kick into a full ventricle (end of diastole)
What sound pitch is better heard with a phonocardiogram?
Low pitch
How is coronary perfusion calculated?
Delta P of aortic pressure minus ventricular pressure
Using coronary blood flow, how much does a healthy heart weight?
321 grams (225ml / 70mL= 3.21 x100grams= 321 grams
What drives the low Vascular Resistance of Subendocardial layer during diastole?
High metabolic requirements drive low resistance to promote blood flow
During the normal cardiac cycle, when do forces favor retrograde perfusion?
Early in systole; Hardly any ∆P between LV & Aorta
Aortic stenosis would be heard when, if relating to a specific EKG tracing part?
ST segment & ST interval
MS murmurs will be heard when on an EKG tracing?
TP & PR intervals
In AS the pulse pressure will be___ & in AR pulse pressure will be____?
Narrower & wider
Pulse pressure is related to___ & increased SV___ pulse pressure?
Contractility & increases
MR can be heard when on an EKG tracing?
QRS, ST segment & ST interval
Hearing S2 splitting would be when & due to what?
During inspiration due to increasing negative pressure, reducing pulmonic valve afterload, keeping valve open a bit longer.
Which area of the heart is hardest to perfuse & why?
- Subendocardial arterial plexi.
- Subject to high wall pressures & sustained pressure due to inner cells depolarizing first & repolarizing last.
Thyroid Gland blood flow per minute is ___ its mass.
5x its mass
Concentric LVH is___ heart failure caused by___ &
Eccentric LVH is___ heart failure caused by__.
- Diastolic & AS
- Systolic & AR
What is the BP pressure difference at the phlebostatic axis?
+ 6 mm Hg
At what Reynolds’ number is flow turbulent?
> 2,000
_____ velocity & _____ diameter lead to turbulent flow.
High & large
How does conductance & resistance relate?
Conductance= ( 1 / resistance )
What is another name for dicrotic notch?
Incisura (Lecture 1 slide 31)
Max sympathetic stimulation for CO is also called ____ & will shift the curve ____?
Hypereffect & left
Type of shock generated during anesthesia
Form of neurogenic shock
Loss of Psf
When is S-4 heard?
Shortly before S1. Means increased ventricular diastolic stiffness
When is stroke work is increased?
With increased SV & increased afterload
What will cause shifts in the end-systolic pressure-volume relationship
Only contractility alterations will cause shifts in end-systolic pressure-volume relationship
How does AR affect BP, PP, EDV & LV pressures?
Aortic regurgitation: Aortic pressures fall faster & further than normal during diastole –> a low diastolic pressure & large pulse pressure. EDV & pressure are higher. Often it is stenotic & insufficient.
Decreased arterial compliance leads to ___ pulse pressure & ___systolic pressure?
Increased & increased
Increased SV leads to___ pulse pressure & ___systolic pressure?
Increased & increased
Aortic regurgitation has ___ SV & ___ diastolic pressure?
Increased & decreased
Aortic stenosis leads to ___SV, ___ pulse pressure & ___systolic pressure?
Decreased, decreased & increased
A decreased diastolic pressure means Resistance is ___ & conductance is ___?
High & low
Increased plasma osmotic pressure means filtration is ____?
decreased
What happens to the SNS, PSNS, HR, BP, & TPR in cushing’s reaction?
- SNS increases
- PSNS decreases
- HR increases
- BP increases
- TPR increases
At beginning of exercise the CVP ____ & RVR ____?
Both increase. At max output the CVP > RVR
Examples that cause a right shift on the cardiac curve?
- open chest Sx
- tamponade
- blowing(trumpet)
- positive pressure ventilation
Examples causing a left shift on the cardiac curve?
- breathing against negative pressure
- taking someone off the ventilator
- decreasing intrathoracic pressure
Decreased venous compliance leads to ____ CVP?
increased
Anemia leads to ___ RVR & arteriolar ____, which leads to ___venous return?
- Decreased
- vasodilation
- increased
Examples of what increases RVR
- Increased venous return
- increased arterial resistance
- increased SNS activity
- obstructions
Beriberi is a deficiency in ____ leading to ____ & ____ cardiac output?
- thiamine
- vasodilation
- increased
How does adenosine affect the heart?
Increases coronary blood flow
In compensated heart failure, alodisterone & angiotensin 2 are?
Increased
A blowing sounding murmur means?
Insufficiency
If your patient’s mean systemic arterial pressure changes, it must be because of changes in?
Cardiac output and/or TPR
Getting up after days in bed results in hypotension & dizziness, why?
Lying down results in increased CVP & baroreceptor firing –> increased renal activity –> fluid loss. When standing up there is decreased cerebral blood flow & the respiratory & skeletal pumps cannot compensate enough.
Why can BP rise very high during static exercises?
Muscles compression –> decreased blood flow
How does giving someone phenylephrine affect BP, SNS activity, contractility, TPR, HR?
- BP, TPR would increase.
- HR would decrease.
- Phenylephrine stimulates alpha-adrenergic –> increased BP –> increased baroreceptor firing –> decreased SNS activity & increased PSNS activity.
What would decreased renal & splanchnic blood flow despite an increase in MAP mean?
Increased sympathetic activity
Acute increases in arterial pulse pressure usually result from increases in stroke volume. True or false?
- True.
- Pp= SV/Ca (Pulse pressure= stroke volume / arterial compliance
An increase in TPR increases diastolic pressure more than systolic pressure. True or false?
False
At rest the patient has a pulse rate of 70 beats/min and an arterial blood pressure of 119/80 mm Hg. During exercise on a treadmill, pulse rate is 140 beats/min and blood pressure is 135/90 mm Hg. Use this information to estimate the exercise¬ related changes in the following variables: SV, CO & TPR?
- SV=Pp -> SV rest= 39cc. SV exercise= 45cc –> 6cc difference=15% increase.
- CO: CO rest= 70 x 39cc= 2.73L/min. CO exercise= 140 x 45cc= 6.3L/min. CO increased 2.3 times.
- TPR: MAP rest= 93, MAP exercise= 105. TPR= Pa/CO TPR rest= 93/2.73= 34mmHg. TPR exercise= 105/6.3= 16.7mmHg. TPR= 16.7mmHg / 34mmHg= 0.49= 49% decrease during exercise.
What is indicated by a normal MAP but very high arterial pulse pressure?
Increased arterial stiffness.
How would a stenotic aortic valve influence coronary blood flow?
- Increased LV pressures –> increased O2 use –> increased coronary flow. But high LV intraventricular pressures decrease flow.
- Resting O2 may be enough but cardiac reserve for exercise is not adequate
Which of the following will decrease the mean circulatory filling pressure?
- Increased circulating blood volume.
- Decreased arteriolar tone.
- Increased venous tone.
None
Severe dehydration would cause what kind of shift in the venous function curve?
Left shift
Which of the following would directly decrease CVP?
A) increased SNS activity
B) increased PSNS activity
C) Increased blood volume
D) Decreased TPR
Increased SNS activity
Consider the various components of the arterial baroreceptor reflex and predict whether the following variables will increase or decrease in response to a rise in arterial pressure?
– baroreceptor firing
– PSNS activity on the heart
– SNS activity on the heart
– Arteriolar tone
– Venous tone
– Peripheral venous tone
– TPR
– Cardiac output?
- Increase= baroreceptor firing rate, PSNS activity.
- Decrease= the rest.
Carotid massage in PSVT would do what?
Increased baroreceptor firing –> increased PSNS –> decreased HR &/or establishing normal rhythm
- Describe the immediate direct and reflex cardiovascular consequences of giving a healthy person a drug that blocks a,-adrenergic receptors.
- Describe the possible changes in mean arterial pressure, sympathetic nerve activity, cardiac output, total peripheral resistance, and shifts in the cardiac function and venous return curves?
- CO increases.
- TPR decreases.
- MAP decreases
- SNS activity increases(HR)
- Cardiac curve goes up
- Venous curve has no shift.
Whenever cardiac output is increased, mean arterial pressure must also be increased. True or false?
False. Increased CO usually decreased TPR but MAP could be same, lower or higher
Chronic elevation of arterial pressure requires that either cardiac output or TPR (or both) be chronically elevated. True or false?
True. Pa= CO x TPR
If resistance through an organ decreases what happens to TPR?
TPR decreases
Calculate TPR. MAP= 100mmHg, CVP= 0mmHg, CO= 6L/min?
1) R= △P/Q => TPR= (Pa – Pcv) / CO
2) TPR= (100-0) / 6L/min= 16.7mmHg x L/min
Determine Flow. Cap pressure= 28mmHg, Plasma oncotic= 24mmHg, tissue hydrostatic= -4mmHg, tissue oncotic= 0mmHg?
F= [28 – (-4) – 24 + 0]= +8mmHg
Increased Pulse pressure is related to which valve disease?
Aortic insufficiency
Calculate resistance to flow across this stenotic valve.
BP= 150/100mmHg,
LV pressures= 150/2mmHg,
LA pressures= 50/32mmHg,
HR= 60bpm,
SV= 50cc?
1) CO= 60bpm x 50cc= 3L/min.
2) R= △P/Q R= 30mmHg/3l/min= 10mmHg x L/min
What alteration in jugular venous pulsations might accompany third-degree heart block?
Irregular giant a-waves also called cannon waves
When is tricuspid regurgitation heard on an ECG tracing?
Right after S-1 –> close to S-2
Does 3rd degree HB cause an increased or decreased SV?
Increased SV due to lower HR= longer filling time
Pulmonic stenosis will cause what kind of axis shift?
Right axis shift
What is the definition of ejection fraction?
Ration of SV to EDV
P-wave in normal aVR lead will have what deflection?
Downward deflection
Decreased AV node conduction velocity will?
- Decreased HR,
- increase P-wave
- Increase PR interval
- widen QRS
Increase PR interval
Calculate CO.
- Male 70kg,
- SAO2= 200cc/L
- PAO2= 140cc/L
- VO2= 600cc/L
1) CO= 10L/min. Q= [ VO2 / (SAO2 – PAO2) ]
With all other factors equal, myocardial oxygen demands will be increased to the greatest extent by which of the following?
- increases in the heart rate
- increases in coronary flow
- increases in end-diastolic volume
- decreases in arterial pressure
- decreases in cardiac contractility
- Isovolumetric contraction uses most energy.
- Increased EDV will also increase O2 use but less than increased HR.
Four of these conditions exist during the same phase of the cardiac cycle and one does not. Which one is the odd one?
- The mitral valve is open.
- The ST segment of the ECG is occurring.
- The “v” wave of thejugular venous pulse hasjust occurred.
- Ventricular volume is increasing.
- Aortic pressure is falling.
ST segment occurs during systole
Increases in sympathetic neural activity to the heart will result in an increase in stroke volume by causing a decrease in end-systolic volume for any given end¬ diastolic volume. True or false?
True. Increased SNS activity –> increased contractility & EF
In which direction will cardiac output change if central venous pressure is lowered while cardiac sympathetic tone is increased?
- Need more info to properly answer question.
- Decreased preload decreases SV.
- Increased SNS will increase SV & HR.
Which of the following interventions will increase cardiac stroke volume?
- Increased ventricular filling pressure.
- decreased arterial pressure.
- Increased activity of cardiac sympathetic nerves.
- Increased circulating catecholamine levels?
All are correct.
How does a stenotic valve affect EDV, ESV, CO, flow?
- Flow is low due to high resistance.
- EDV is reduced.
-ESV is increased due to decreased CO.
A common Side effect of beta-blocker therapy is decreased exercise tolerance. Why is this not surprising?
Block the ability to increase HR & CO
Individuals with high arterial blood pressure (hypertension) are often treated with drugs that block beta-adrenergic receptors. What is a rationale for such treatment?
- Reduce HR & contractility –> decrease CO.
- Less flow through a constant = smaller pressure difference.
What direct cardiovascular consequences would you expect from an intravenous injection of norepinephrine?
Increased HR, contraction, arteriolar & venous constriction
How would a 10% diameter increase affect resistance?
- Resistance decreases by 32%.
- (R=1/r4th) R= 1/1.1 to the 4th –> 1/1.46 = 0.68%
