Applied anatomy of the heart

Question 1

What 3 types of fibres make up the cardiac plexus?

Answer 1

1) General visceral afferent
2) Parasympathetic via vagus
3) Sympathetic via sympathetic trunk

Question 2

Effect of parasympathetic nervous system on the heart

Answer 2

Reduces heart rate and reduces force of contractability

Stimulates cardioinhibitory centre

Question 3

Effect of sympathetic nervous system on the heart

Answer 3

Increases heart rate and increases force of contractibility

Stimulates cardioaccelaratory centre

Question 4

Where does cardioinhibitory centre send axons to?

Answer 4

SAN and AVN

Question 5

Where do you find pre and post ganglionic axons from cardioaccelaratory centre

Answer 5

Pre= thoracic spinal cord
Post= Neurons to AVN and SAN

Question 6

Where do you find cardioinhibitory and cardioacceleratory centres

Answer 6

In the reticular formation of the medulla

Question 7

Describe the anatomical position of the cardiac plexus

Answer 7

Anterior to bifurcation of the trachea

Posterior to arch of the aorta

Question 8

What causes cardiac pain

Answer 8

Ischaemia which stimulates sensory nerve endings in myocardium

Question 9

Where is cardiac pain usually referred to

Answer 9

T1-T4

Somtimes T5-T9

Question 10

Why is cardiac pain referred?

Answer 10

Somatic afferents from skins ascend in the same spinal segment as visceral sensory fibres- brain confuses the signals

Question 11

From where is coronary circulation derived?

Answer 11

Ascending aorta

Question 12

What does the left coronary artery divide into

Answer 12

Left marginal
Left anterior descending/ anterior interventricular
Circumflex

Question 13

What does the right coronary artery divide into

Answer 13

Right marginal

Question 14

Which vessel supplies the SAN

Answer 14

right coronary artery

Question 15

Which vessel ‘decides’ the dominance of the heart- how

Answer 15

Posterior interventricular
If it comes mainly from right coronary artery= right dominance
If it comes mainly from circumflex= left dominance

Question 16

Where are conducting fibres of the heart found

Answer 16

Interventricular septum

Question 17

Describe distribution of blood supply to interventricular septum

Answer 17

LAD provides anterior 2/3

PDA provides posterior 1/3

Question 18

What is bundle branch block

Answer 18

Ischaemic bundle branch ceases to properly conduct so uses altered pathways for depolorisation eg through myocytes

Question 19

Effect of bundle branch block

Answer 19

Depolarisation is slower
Prolonged QRS
Loss of ventricular synchrony

Question 20

Define atrial remodelling

Answer 20

Any persistent change in atrium structure

Question 21

Define cardiac remodelling

Answer 21

Structural changes associated with cardiac dynsfunction (increased myocyte mass)

Question 22

Define cardiac dysfunction

Answer 22

Altered relationship between preload and stroke volume

Question 23

3 main causes of pathological remodelling

Answer 23

Pressure overload, volume overload and cardiac injury

Question 24

What can causes pressure overload

Answer 24

hypertension and aortic stenosis

Question 25

What can cause volume overload

Answer 25

Caused by valvular regurgitation or hypervolaemia

Question 26

Define valvular regurgitation

Answer 26

Backward flow so increased volume in the first chamber

Question 27

Define hypervolaemia

Answer 27

Increased fluid levels in the blood

Question 28

5 molecular changes that occur during ventricular hypertrophy

Answer 28

- Increased sarcomeres - Synthesis of abnormal proteins - Decreased capillary: myocyte - Apoptosis of myocytes - Increased fibrous tissue

Question 29

What is concentric hypertrophy

Answer 29

Thickening of the ventricular wall due to the paralell addition of sarcomeres

Question 30

What is eccentrial hypertrophy

Answer 30

Dilation of the ventricular wall due to the addition of sarcomeres in sequence

Question 31

Main causes of each type of ventricular hypertrophy

Answer 31

``` Concentric= aortic stenosis, chronic hypertention Eccentric= aortic and mitral regurgitation, systolic dysfunction, hypervolaemia ```

Question 32

Effect of concentric hypertrophy

Answer 32

Increased afterload, less compliant, compromised ventricular filling

Question 33

Effect of eccentric hypetrophy

Answer 33

Increased oxygen demands, decreased mechanial effects

Question 34

What happens to cusps and cordae tendonies during rheumatic disease

Answer 34

Cusps fibrose | Cordae tendinae soften

Question 35

What is mitral regurgitation and its two most common causes

Answer 35

Abnormal regurgitation in left atrium | MItral valve prolapse, rheumatic heart disease

Question 36

Effect of mitral regurgitation

Answer 36

Reduced CO, pulmonary oedema

Question 37

Describe murmur heard for mitral regurgitation

Answer 37

Mitral closed throughout Pansystolic (louder at late systole) Heard at apex

Question 38

Why does aortic stenosis lead to concentric ventricular hypertrophy

Answer 38

Left ventricle has to generate increased pressure in order to overcome increased afterload. INcreased muscle mass allows ventricle to generate increased force necessary to propel blood past obstruction

Question 39

Describe murmur heard with aortic stenosis

Answer 39

Turbulence as blood pushing through stenotic aortic valve Mid systolic typically Heard at tight intercostal space

Question 40

Is aortic stenosis murmur more or less severe if heard early or late

Answer 40

Late- time taken to generate pressure to pass through stenotic valve

Question 41

Effect of mitral valve stenosis (4)

Answer 41

- L atrium needs higher pressure to overcome stenosis - Atrial kick larger leading to atrial enlargement and increased pressure leading to oedema - Reduced ventricular filling, reduced CO - Can lead to AF

Question 42

Describe murmur of mitral stenosis

Answer 42

Diastolic murmur | Soft and rumbling

Question 43

Effect of aortic regurgitation

Answer 43

Blood goes back into the LV during diastole Chronic volume overload--> stretching and elongation of myocardial fibres LV dilation Decreased CO Increased preload

Question 44

Describe murmur of aortic regurgitation

Answer 44

Rheumatic | Complex and absent

Question 45

Where does the cardiac plexus of nerves flie

Answer 45

Anterior to bifurcation of the trachea | Posterior to arch of the aorta

Question 46

What makes up the anterior and posterior/ base surface of heart

Answer 46

``` Anterior= mainly right ventricle Posterior= Left atrium (some right atrium) ```

Question 47

What makes up the diaphgramatic surface of heart

Answer 47

RV/LV | Mainly LV

Question 48

Which coronary artery is most commonly occluded

Answer 48

LAD

Question 49

Which ECG leads give information about LAD

Answer 49

V1, V2, V3, V4`

Question 50

What ECGS leads give information about the diagonal branch of LAD

Answer 50

1, avL, V5, V6

Question 51

What ECG leads give info about RCA

Answer 51

2,3 avF

Question 52

Name 4 leads that give lateral view of the heart

Answer 52

1, aVL | v5, v6

Question 53

Name 3 leads that give inferior view of the heart

Answer 53

2, 3, aVF

Question 54

Name 2 leads that give view of the septum

Answer 54

V1. V2

Question 55

Name 2 leads that give anterior view of the heart

Answer 55

V3, V4