Exam 2 – Cardio Ch 20

Question 1

How can you improve heart pumping?

Answer 1

Nervous simulation

Hypertrophy of cardiac muscle secondary to increased work load

Question 2

How can nervous stimulation improve heart pumping?

Answer 2

Sympathetic stimulation (increases heart rate)
Parasympathetic inhibition (decreases heart rate)

Question 3

How does hypertrophy of cardiac muscle secondary to increased work load improve heart pumping?

Answer 3

Increased size

Increased strength

Question 4

What can cause decreased cardiac function?

Answer 4

Damage to cardiac muscle
Inhibition of nervous control
Arrhythmias 
Valvular heart disease
Increased arterial pressure or hypertension
Congenital heart disease
Myocarditis/inflammation

Question 5

What is the cardiac output for a horse? Arterial pressure?

Answer 5

25-40 L/min

115 mmHg

Question 6

What is the cardiac output for a cow? Arterial pressure?

Answer 6

25-39 L/min

150 +/- 27 mmHg

Question 7

What is the cardiac output for a dog? Arterial pressure?

Answer 7

3-5 L/min/m^2

Less than 160 mmHg

Question 8

What is the cardiac output for a cat? Arterial pressure?

Answer 8

100 ml/kg/min

114-137 mmHg

Question 9

What are non-cardiac factors that cause decreased cardiac output?

Answer 9

Decreased blood volume
Acute venous dilation
Obstruction of large vessels
Decreased tissue mass

Question 10

How can cardiac output be measured?

Answer 10

Oxygen Fick method
Indicator dilution method
Echocardiography
Electromagnetic flowmeter

Question 11

What is the Oxygen Fick method?

Answer 11

Measures oxygen levels in right heart and left heart

Measures disappearance of oxygen from inhaled air

Question 12

What is the indicator dilution method?

Answer 12

Dyes

Thermal (cold solution)

Question 13

What is the most used indicator dilution method?

Answer 13

Cold solution

Question 14

What is the most used method of measuring cardiac output?

Answer 14

Echocardiography

Question 15

What is cardiac output influenced by?

Answer 15

Metabolic rate
Fitness
Age
Size

Question 16

What does the cardiac index express?

Answer 16

Cardiac output in relation to body size

Question 17

Does the heart or peripheral circulation control cardiac output?

Answer 17

Peripheral circulation

Question 18

What is cardiac output?

Answer 18

The sum of all tissue flows and is affected by their regulation

Question 19

What is cardiac output proportional to?

Answer 19

Tissue O2 use

1/TPR when arterial pressure is constant

Question 20

Look at cardiac output curves

Answer 20

Look at cardiac output curves

Question 21

What is the plateau of the cardiac output curve determined by?

Answer 21

Heart strength

Question 22

Wha does sympathetics do to the plateau?

Answer 22

Increases it

Question 23

If parasympathetics decrease, what happens plateau?

Answer 23

Increases it

Question 24

What does heart hypertrophy do to the plateau?

Answer 24

Increases it

Question 25

What does myocardial infarction do to the plateau?

Answer 25

Decreases it

Question 26

What does valvular disease do to the plateau?

Answer 26

Decreases it

Question 27

What does myocarditis do to the plateau?

Answer 27

Decreases it

Question 28

What does cardiac tamponade do to the plateau?

Answer 28

Decreases it

Question 29

What does metabolic damage do to the plateau?

Answer 29

Decreases it

Question 30

What does the pericardial sac act as?

Answer 30

A protectant and lubricant so that the heart can be without friction

Question 31

What is tamponade?

Answer 31

When the pericardial sac fills with fluid

Question 32

What does decreased cardiac output cause for tamponade?

Answer 32

Less tamponade

Question 33

What are effects of intrapleural pressure on cardiac output curve?

Answer 33

Changes in thorax which prevent blood from returning to the heart Pressure in right atrium must be less than pressure in the great veins for flow to occur Pressure in veins are slow to rise

Question 34

What happens if the pressure in the right atrium is not less than the great veins?

Answer 34

There will be a back up so that the great veins can get a pressure that is higher than that of the right atrium

Question 35

Look at the effects of intrapleural pressure on cardiac output curve

Answer 35

Look at the effects of intrapleural pressure on cardiac output curve

Question 36

What is the mean systemic filing pressure?

Answer 36

What the pressure is coming from the jugular vein to the right atrium and how it responds as the right atrium pressure goes up

Question 37

If resistance is decreased and blood is left in the periphery, what happens to cardiac return?

Answer 37

It increases

Question 38

If resistance is increased, what happens?

Answer 38

More blood is left to sit on the venous side and pressure will have to be built up enough to overcome the mean systemic filling pressure

Question 39

What happens if cardiac output does not equal venous return?

Answer 39

Blood would either accumulate or be removed from the chest

Question 40

If left ventricle output equals 6 and venous return is equal to 5, what happens to blood?

Answer 40

It would be shifted to the periphery

Question 41

How do you calculate the return of blood to the left heart?

Answer 41

(Mean pulmonic filling pressure – left atrial pressure) / pulmonary vascular resistance

Question 42

If the left heart fails and the right heart keeps pumping, what happens to mean pulmonic filling pressure and mean systemic filling pressure? What does that cause?

Answer 42

Increases MPFP Decreases MSFP (because blood is being removed from systemic circulation) Overloads the pulmonary system

Question 43

What does left atrial pressure have to be less than?

Answer 43

What is coming from the lungs

Question 44

What happens once the left heart starts failing?

Answer 44

Blood starts backing up into the lungs, which will very quickly start backing up into the right heart and cause right heart failure

Question 45

Which is worse clinically, left heart or right heart failure?

Answer 45

Left heart. You can live longer with right heart failure