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Flashcards in Regulation of Blood Pressure Deck (67)
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1
Q

Define Preload

A

End diastolic volume

Increased preload, increases contractility
Decreased preload, decreases contractility

2
Q

Describe relationship between preload and contractility

A

Increased preload, increased contractility

Decreased preload, decreased contractility

3
Q

What drugs/drug classes decrease preload? (4)

A

ACE
ARB
CCB
Nitro

4
Q

What drugs/drug classes decrease preload? (4)

A

Fluids

5
Q

Define Afterload

A

Pressure that must be overcome by the left ventricle or pulmonary artery pressures that must be overcome by the right ventricle

6
Q

What ‘symptoms’ can develop with a decrease in perload? (2)

A

Reflex Tachycardia

Angina

7
Q

What drugs/drug classes decrease afterload? (4)

A

ACE
ARB
CCB
Nitro

8
Q

What drugs/drug classes increase afterload? (9)

A
Dobutamine
Dopamine
Epi
Ketamine
Norepi
ADHD eds
TCAs
Vasopressin
Effexor (venlafaxine
9
Q

Define baroreceptor reflex.

How does it work?

A

Homeostatic mechanism that helps to maintain nearly constant levels.

Baroreceptors stretch and respond to pressure changes in the arterial wall in vessel they are found in

10
Q

Where are baroreceptors located? (2)

A

Carotid sinus

Aortic Arch

11
Q

What condition can impairment of the baroreceptor reflex cause? (2)

A

Hypertension

Heart Failure

12
Q

Baroreceptors in which location respond to INCREASE in arterial pressures?

A

Aortic arch

13
Q

Baroreceptors in which location respond a DECREASE in arterial pressures?

A

Carotid Sinus

14
Q

Which part of the baroreceptor reflex (carotid sinus or aortic arch) do most anti-hpertensives affect?

A

Carotid Sinus

15
Q

What is the body’s response to activation of the baroreceptor reflex in carotid sinus?

A

Increased HR
Increased Contractility
Vasoconstriction of arterioles and veins (activation of sympathetic NS)

16
Q

Name all 4 Nodal Cells

A

SA
AV
Purkingi Fibers
Bundle of His

17
Q

Define Chronotrophy

A

Changes in heart rate via an increase or decrease in firing of the SA node

18
Q

Define Dromotrophy

A

Speed of Contraction

The speed of movement from the atrium through the AV node (CCB effect) SLOWS pulse and prolongs the PR interval

19
Q

Define Inotrophy

A

Force of Contraction

20
Q

Lusitrophy

A

Relaxation of hearth (diastole)

How fast Ca++ is removed from the cell (no heart contraction)

21
Q

What Drugs/drug classes decrease chronotrophy? (4)

A

BB
Verapamil
Diltiazem
Methyldopa

22
Q

What drugs/drug classes increase chronotrophy? (4)

A

Epi
Nor-epi
CCB
A1 Blockers (doxaxosin, Prazosin, Terazosin

23
Q

What phase of the action potential represents dromotrophy?

A

Phase 0

24
Q

What drugs/class of drugs affect dromotrophy?

A
Antiarrthymics (amioderone, sotalol), phase 4
CCB Class (IV (Diltiazem, verapamil), phase 0
25
Q

The influx of what ion into the cell strengthens inotrophy?

A

Ca++

26
Q

Explain what happens in an Action Potential
Phase 0, SA/AV Node
Phase 0, Ventricular Myocyte
Phase 3 of Both

A

Phase 0 in SA/AV node: influx of ca causing the inside of the cell to become and more (+)

Phase 0 in ventricular myocyte: influx of Na making cell less more (+)

Phase 3 of both: K+ out of the cell making the inside of the cell more (-)

27
Q

Explain what happens in an Action Potential in SA/AV Node
Phase 4
Phase 0
Phase 3

A

Phase 4: NA+ moves inside of the cell causing it to be more (+) (THRESHOLD) THEN FIRES resulting in

Phase 0: influx of Ca++ causing the inside of the cell to be rapidly (+) then has to restart by becoming more (-)

Phase 3: K+ moves outside of the cell causing the inside of the cell to become more (-)

28
Q

Explain what happens in an Action Potential in the Ventricular Myocyte
Phase 0
Phase 1
Phase 2

A

Phase 0: rapid influx of Na+ into cell causing it to be more (+)

Phase 1: initial repolarization; K+ moves out of the cell (via Na/K pump) causing inside of cell more (-)

Phase 2: Ca++ is moving in to cause contraction (systole) QT interval

Phase 3: repolarization; K+ moves out (diastole)

Phase 4: Inward/outward K+

29
Q

Absolute Refractory Period

A

Period where ventricular myocyte cannot receive another action potential

30
Q

Explain the role of Angiotensin II on Blood Pressure

A

Increases Altosterone release (increases Na+/H20 reabsorption and K+ excretion DRT

This increases thirst and H20 consumption
Angiotnesin II is a strong vasoconstrictor, participates in vascular remodeling

31
Q

What phases of the ventricular myocyte action potential represent systole?

A

0
1
2

32
Q

What phases of the ventricular myocyte action potential represent diastole?

A

3

4

33
Q

If age 40-70 years with baseline BP of 75/115-115/185 and SBP raises 20mmHG and/or DBP increases by 10mmHG, what happens to the risk of CVD?

A

It doubles with each increase of 20 or 10, respectively.

34
Q

What are the hemodynamic and pathophysiologic factors that contribute to blood pressure? (5)

A
Autonomic NS
Heart
Blood Vessel Anatomy
Distribution and Movement of Blood
Hormonal Influences and Plasma Volume
35
Q

Define systolic Blood Pressure

A

HIGHEST arterial pressure during the cardiac cycle

Pressure generated during systole/ventricular contraction where blood being ejected out of arterial system

36
Q

Define Diastolic Blood Pressure

A

LOWEST arterial pressure during the cardiac cycle.

Pressure generated during diastole/relaxation phase

‘Resting Pressure”

37
Q

Define Mean Arterial Pressure (MAP)

A

‘Average Pressure’ in vascular system with respect to time

38
Q

What is the clinical application of understanding MAP?

A

Vasomotor center in brain usually maintains a MAP of 100mmHG

Goal in sepsis, spinal cord injury less

39
Q

Define Pulse Pressure

A

Difference between SBP & DBP

40
Q

Formula for Cardiac Output?

A

SVxHR

41
Q

Define Stroke Volume

A

Volume of blood ejected with each ventricular beat

Influences pulse pressure
Influenced by: preload, afterload & inotrophy

42
Q

Define Ejection Fraction

A

Fraction of end diastolic volume (EDV) ejected out of heart with a ventricular bat and related to contractility

43
Q

Formula for ejection fraction?

A

EF=SV/EDV

44
Q

Normal percentage for Ejection Fraction?

A

60%

45
Q

Formula for MAP?

A

CO x SVR

46
Q

What happens to the aorta during systole and diastole?

A

expands during systole, recoils in diastole

47
Q

What part of the Nodal Action Potential is a primary influence on chronotrophy?

A

Primarily influenced by rate of rice in Phase 4 (pacemaker cells & inward Ca++ current

48
Q

What drug classes decrease chronotropy? (4)

A

a2 agonists
Beta Blockers
Digoxin
Non-DHP CCB

49
Q

What a2 Agonists decrease chronotrophy? (3)

A

Clonidine
Guanfacine
Methyldopa

50
Q

What Beta Blockers decrease chronotrophy (3)

A

atenolol
esmolol
metoprolol

51
Q

What non-DHP CCBs decrease chronotropy? @)

A

Diltiazem

Verapamil

52
Q

Activation of what receptor increases Chronotropy?

A

Beta 2

53
Q

What specific drugs increase chronotropy directly? (4)

A

Dobutamine
Dopamine (high dose)
Epi
NorEpi

54
Q

What classes of drugs increase chronotroy by affecting baroreceptor reflex? (7)
(decrease TPR/preload)

A
a1 Blockers
DHP CCB
Diuretics
Fenoldopam
Hydralazine
Nitroprusside
Phentolamine
55
Q

What classes of drugs decrease dromotropy? (3)

A

Beta Blockers
Class 1 Antiarrthymics
Non-DHP CCB

56
Q

What Beta Blockers decrease dromotropy? (3)

A

Atenolol
Esmolol
Metoprolol

57
Q

What Class I Antiarrthymics decrease dromotropy? (4)

A

Procanamide
Lidocaine
Flecainide
Propafenone

58
Q

What non-DHP CCB decrease dromotropy?(1)

A

Diltiazem

59
Q

What drugs increase dromotropy?

A

NONE

60
Q

What drug lasses decrease inotropy?(4)

A

a2 Agonists
beta blockers
Non-DHP ccB
Class III Anti-arrhythmics

61
Q

What a2 agonists are used to decrease inotropy? (3)

A

Clonidine
Guanfacine
Methyldopa

62
Q

What Beta Blockers are used to decrease inotrophy? (3)

A

Atenolol
Esmolol
Metoprolol

63
Q

What Non-DHP CCB are used to decrease inotropy? (2)

A

Diltiazem

Verapamil

64
Q

What Class III Antiarrhymics are used to decrease inotropy? (2)

A

Amiodarone

Sotolol

65
Q

What classes of drugs increase Lusitropy? (3)

A

Beta agonists
Catecholamines
Dobutamine

66
Q

What classes of drugs decrease lusitropy? (4)

A

beta blockers
Non-DHP CCB
+/- Digoxin

67
Q

What factors influence increase of MAP? (4)

A

Increase heart rate
Increase contractility and SV
Increase vasoconstriction of arterioles (Increases TPR)
Increase Vasoconstriction of veins