3. Cardiovascular mechanics 2

Question 1

Diastole

Answer 1

Ventricular relaxation

during which ventricles fill with blood

Question 2

Systole

Answer 2

Ventricular contraction

ventricles generate pressure then eject blood into the arteries

Question 3

How many sub phases in diastole?

Answer 3

4

Question 4

How many sub phases in systole

Answer 4

3

Question 5

End diastolic volume (EDV)

Answer 5

volume of blood in ventricles just before ventricles contract

Question 6

End systolic volume (ESV)

Answer 6

residual volume of blood in ventricles after contraction

Question 7

Stroke volume calculation

Answer 7

EDV - ESV

Question 8

Stroke volume

Answer 8

Volume of blood pumped out of heart in 1 beat

Question 9

Ejection fraction calculation

Answer 9

(Stroke volume / EDV) X 100

Question 10

Typical EDV

Answer 10

108 mL

Question 11

Typical ESV

Answer 11

36 mL

Question 12

Typical stroke volume

Answer 12

72 mL

Question 13

Ejection fraction

Answer 13

amount of blood pushed out of heart in relation to amount of blood filling heart

Question 14

Ejection fraction is a clinical sign of

Answer 14

how well ventricles are contracting

Question 15

Ejection fraction values normal vs heart failure

Answer 15

Normal = 60-70%

Heart failure= 30-40%

Question 16

Atrial Systole

Answer 16

Contraction of atria

Question 17

Atrial systole on ECG

Answer 17

P wave

Question 18

Atria already almost full from passive filling driven by pressure gradient. They contract…

Answer 18

to ‘top-up’ volume of blood in ventricle

Question 19

Does atrial systole make a noise?

Answer 19

Not normally, but

4th heart sound – abnormal, occurs with congestive heart failure, pulmonary embolism or tricuspid incompetence

Question 20

Isovolumetric contraction on ECG

Answer 20

QRS complex

Ventricular depolarisation

Question 21

Isovolumetric contraction

Answer 21

Contraction of ventricles with no change in volume, but pressure increases

Question 22

Does Isovolumetric contraction make a noise?

Answer 22

Yes
1st heart sound (‘lub’)
due to closure of AV valves and associated vibrations

Question 23

Rapid ejection

Answer 23

Ventricles contract, pressure within them exceeds pressure in aorta and pulmonary arteries.
Semilunar valves open, blood pumped out and volumes of ventricles decrease

Question 24

Type of contraction in rapid ejection

Answer 24

Isotonic

Question 25

Does rapid ejection make a noise?

Answer 25

No

Question 26

Reduced ejection

Answer 26

End of systole Blood flow from ventricles decreases and ventricular volume decreases more slowly As pressures in ventricles fall below that in arteries, blood begins to flow back causing semilunar valves to close

Question 27

Reduced ejection on ECG

Answer 27

T wave | Ventricles begin to repolarise

Question 28

Isovolumetric relaxation

Answer 28

Aortic and pulmonary valves shut, but AV valves remain closed until ventricular pressure drops below atrial pressure. (No change in volume) Atrial pressure continues to rise

Question 29

Does isovolumetric relaxation make a noise?

Answer 29

Yes 2nd heart sound (‘dub’) due to closure of semilunar and associated vibrations

Question 30

Rapid passive filling

Answer 30

Ventricles start to fill with blood

Question 31

Rapid passive filling on ECG

Answer 31

isoelectric (flat) between cardiac cycles

Question 32

Does rapid passive filling make a noise?

Answer 32

Not normally | 3rd heart sound – usually abnormal, may signify turbulent ventricular filling

Question 33

Reduced passive filling

Answer 33

Ventricular volume fills more slowly | Able to fill considerably without contraction of atria

Question 34

Reduced passive filling AKA

Answer 34

Diastasis

Question 35

Patterns of pressure changes

Answer 35

Are identical in right and left side of heart

Question 36

Why are patterns of pressure changes identical in both sides of the heart?

Answer 36

Both ventricles eject the same volume of blood

Question 37

Which side of the heart pumps blood at a higher pressure?

Answer 37

Left

Question 38

Pressure volume loops: | Increases in preload results in

Answer 38

increased stroke volume

Question 39

Pressure volume loops: | Increases in afterload result in

Answer 39

decreased stroke volume

Question 40

Cardiac output calculation

Answer 40

Heart rate X Stroke volume

Question 41

Can change CO by changing

Answer 41

HR and SV

Question 42

SV can be changed by

Answer 42

preload, afterload and contractility

Question 43

Contractility

Answer 43

Contractile capability (or strength of contraction) of the heart

Question 44

Measure of contractility

Answer 44

Ejection fraction

Question 45

What is contractility increased by?

Answer 45

Sympathetic stimulation