Mech of the Heart (2) 3

Question 1

What is diastole?

Answer 1

Ventricular relaxation during which they fill with blood?

Question 2

What is systole?

Answer 2

Ventricular contraction during which blood is ejected into the arteries

Question 3

What is End-diastolic volume?

Answer 3

The volume in the ventricles just before contraction starts

Question 4

What is end-systolic volume?

Answer 4

The volume in the ventricles after contraction has occurred and as much blood has been expelled as is going to

Question 5

What is stroke volume (SV)?

Answer 5

SV = EDV - ESV

Question 6

What is the ejection Fraction?

Answer 6

The proportion of the end-diastolic volume that is pumped out of the heart. EF = SV/EDV

Question 7

What is the normal EF and during exercise?

Answer 7

Normal people = 65%

During exercise = maybe 80%

Question 8

What are the 7 phases of the cardiac cycle?

Answer 8

1) Atrial systole
2) isovolumic contraction
3) rapid ejection
4) reduced ejection
5) Isovolumic relaxation
6) rapid ventricular filling
7) reduced ventricular filling

Question 9

What is atrial systole seen as on the ECG?

Answer 9

The P wave

Question 10

What sound may be heard during atrial systole?

Answer 10

Abnormal S4. It is valve incompetency due to PE, heart failure or tricuspid incompetency

Question 11

What is the jugular pulse?

Answer 11

Small pulse on the jugular during atrial systole as some blood is pushed back into the jugular vein.

Question 12

What is isovolumic contraction seen as on the ECG?

Answer 12

QRS complex

Question 13

What sound is heard during isovolumic contraction?

Answer 13

S1, caused by the AV valves closing (lub)

Question 14

What is seen on the ECG during rapid ejection?

Answer 14

Nothing as there is no electrical activity

Question 15

What is seen on the ECG during reduced ejection?

Answer 15

T wave as the cardiac cells begin to repolarise.

T wave = ventricular repolarisation

Question 16

What can be seen on the pressure graph during isovolumic relaxation?

Answer 16

The v wave as the atrial blood pushes the tricuspid valve.

Dichrotic notch which is a small, sharp increase in atrial pressure due to the rebound pressure against the aortic valve as the distended aortic wall relaxes

Question 17

What is heard during isovolumic relaxation?

Answer 17

S2 when the aortic and pulmonary valves close (dub)

Question 18

What can be heard during rapid ventricular filling?

Answer 18

S3 which is abnormal and due to turbulent ventricular filling. May be due to severe hypertension or mitral valve incompetence

Question 19

What is reduced ventricular filling (slow) also known as ?

Answer 19

Diastasis

Question 20

What should systemic blood pressure be?

Answer 20

120/80mmHg

Question 21

What should pulmonary blood Pressure be?

Answer 21

25/5mmHg

Question 22

What happens when the pulmonary valve closes?

Answer 22

The diastolic pressure in the pulmonary artery increases

Question 23

What is Pulmonary Artery Wedge Pressure (PAWP)?

Answer 23

Measuring the preload on the left side of the heart by inserting a balloon into the pulmonary artery and inflating it so no blood can pass

Question 24

What is plotted on a pressure-volume loop?

Answer 24

Ventricular pressure (Y) against ventricular volume (X)

Question 25

What is point 1 on a pressure-volume loop?

Answer 25

End-diastolic volume

Question 26

What is point 2 on a pressure-volume loop?

Answer 26

Isovolumic contraction

Question 27

What is point 3 on a pressure-volume loop?

Answer 27

End systolic Volume (ESV)

Question 28

What point represents preload on a pressure-volume loop?

Answer 28

Point 1

Question 29

What point gives an idea of afterload on a pressure-volume loop?

Answer 29

Just after point 2

Question 30

What is cardiac contractability?

Answer 30

Contractile capability (strength if contraction) of the heart. Simple measure is ejection fraction