Unit 4/ CH 20

Question 1

Factors controlling cardiac output - cardiac factors

Answer 1

CO = SV x HR
Stroke Volume = preload, afterload, contractility

Question 2

What is cardiac preload?

Answer 2

the amount the ventricles stretch at the end of diastole

Question 3

Frank-Starling Law of the Heart

Answer 3

the greater the diastolic volume (preload) - the greater the force of contraction

Question 4

Increased venous return results in

Answer 4

increased preload

Question 5

increased preload results in

Answer 5

increased end diastolic volume

Question 6

increased force of contraction leads to

Answer 6

increased stroke volume

Question 7

increased SA node firing leads to

Answer 7

increased stroke volume

Question 8

To estimate preload, atrial pressures equal

Answer 8

ventricular end diastolic pressures

Question 9

Explain the effects of heart failure on preload

Answer 9

CHF engorges the heart = increased preload

Question 9

Afterload includes what three factors?

Answer 9

-ventricle outflow resistance
-clinical indicators
-factors affecting bp and vessels diameter

Question 10

What is afterload?

Answer 10

ventricular outflow resistance

Question 11

What are the stroke volume phases?

Answer 11

-preload: initial stretching of heart muscles, before contraction such as ventricles filling

-afterload: force heart has to contract against to eject blood

-contractility: strength of cardiac muscle

Question 12

clinical indicators of afterload

Answer 12

mean arterial pressure MAP
mean pulmonary arterial pressure MPAP, pulmonary vascular resistance PVR, systemic vascular resistance SVR

Question 13

Factors that affect blood pressure and vessel diameter also affect ______________

Answer 13

afterload

Question 14

What is contractility?

Answer 14

force of contraction

Question 15

What is ejection fraction?

Answer 15

measure of ventricular contractibility

Question 16

What is the normal ejection fraction

Answer 16

60% of EDV at rest
90% of EDV during exercise

Question 17

What are inotropic factors?

Answer 17

factors affecting contractility

Question 18

Most important factors in regulating cardiac output

Answer 18

vascular factors affecting venous blood return

Question 19

What factors affect venous return to the heart?

Answer 19

vascular resistance
blood volume
Right atrial pressure

Question 20

What is the vascular function curve?

Answer 20

relationship between right atrial pressure and venous return

Question 21

Cardiac function curves (Starling curves) are what?

Answer 21

preload versus cardiac output

Question 22

normal blood volume

Answer 22

normovolemia

Question 23

What is to high blood volume?

Answer 23

Hypervolemia

Question 24

What is too low blood volume?

Answer 24

Hypovolemia

Question 25

What is the effect of hypervolemia on the vascular function curve?

Answer 25

right shift

Question 26

What is the effect of hypovolemia on the vascular function curve?

Answer 26

left shift

Question 27

Pressure gradients between systemic capillaries is ___mmHg & RAP ___mmHg

Answer 27

7mmhg, 0mmhg

Question 28

increased contractility causes a ___________ in RAP and ___________ in venous return gradient.

Answer 28

decrease, increase

Question 29

increase in blood volume causes an ____________ in pressure and __________ in CO

Answer 29

increase increase

Question 30

increased afterload causes an ______________ in end systolic volume and an _____________ in preload

Answer 30

increase, increase

Question 31

How to measure hemodynamics

Answer 31

pulmonary artery catheter PAC

Question 32

Pulmonary Artery Catheter (PAC) is inserted where?

Answer 32

IJ, subclavian, femoral, basilic, cubital

Question 33

Ports connected to transducers: Proximal= what two areas? Distal=what areas?

Answer 33

-RA,RV -pulmonary artery

Question 34

Normal PCWP (pulm capillary wedge pressure)

Answer 34

6-12 mmHg

Question 35

Elevated PCWP indicates (>25 mmHg)

Answer 35

pulmonary edema

Question 36

Assuming normal blood volume and valve function, what does increased PCWP imply?

Answer 36

left ventricle is not pumping efficiently

Question 37

Ventricular function curves - Forrester's subsets

Answer 37

I. Normal or hyperdynamic II. Fluid overload - normal contractility III. Hypovolemic IV. Acute Left Heart Failure - decreased contractility

Question 38

Clinical Management principles - Continuous monitoring:

Answer 38

assessment of therapy modification according to patient response effect of drugs, fluids, ventilation

Question 39

clinical management - increased preload

Answer 39

vasodilators, inotropic drugs, increased ventilation pressures

Question 40

clinical management - decreased preload

Answer 40

IV fluid therapy

Question 41

clinical management - abnormal afterload - increased SVR

Answer 41

vasodilators fluid therapy if needed inotropic drugs with caution blood or fluids if hypovolemic

Question 42

clinical management - abnormal afterload - decreased SVR

Answer 42

vasopressors

Question 43

high CI, low pulmonary capillary wedge pressure

Answer 43

Normal or hyperdynamic state

Question 44

high CI, high PCWP

Answer 44

fluid overload - normal contractility

Question 45

low CI, low PCWP

Answer 45

hypovolemic

Question 46

low CI, high PCWP

Answer 46

acute left heart failure

Question 47

arterioles contain only _______% of total blood volume

Answer 47

3

Question 48

In what way would an adrenergic drug affect LV afterload?

Answer 48

If drug vasoconstricts - increase SVR and afterload If drug vasodilates - decrease SVR and afterload -

Question 49

Why would a Ca++ blocker affect the ventricular ejection fraction?

Answer 49

CA++ blockers diminish the force of contraction - decreased afterload

Question 50

What is the heart's response to a sudden loss of contratility?

Answer 50

acute heart failure

Question 51

Adrenergic Drugs

Answer 51

Alpha 1 2 ;Beta 1 2 Increase blood pressure, open airways, constrict blood vessels