applied anatomy of the heart

Question 1

what are the borders of the heart?

Answer 1

• Upper right: 3rd costal cartilage
• Upper left: left 2nd costal cartilage
• Lower right: 6th costal cartilage
• Lower left: 5th intercostal space midclavicular line

Question 2

what is the cardiac plexus made up of?

Answer 2

vagus nerve
sympathetic nerves
general visceral afferent nerves

Question 3

where does the vagus feed into the heart and what effect does it have on the heart?

Answer 3

feeds into the SAN

parasympathetic - slows down HR

Question 4

where do sympathetic nerves from the heart enter the spinal cord?

Answer 4

T1-T5

Question 5

what effect do sympathetic nerves have on the heart?

Answer 5

increase the rate of firing

Question 6

where do general visceral afferents feed into?

Answer 6

spinal levels T1-T5

Question 7

where is referred heart pain felt and why?

Answer 7

dermatomes T1-T5

brain can’t differentiate between GVA and somatic nerves bc they enter the spinal cord at the same spinal level

Question 8

what are the branches of the right coronary artery?

Answer 8

posterior interventricular/descending artery

marginal branch

Question 9

what are the branches of the left coronary artery?

Answer 9

circumflex branch
left marginal branch of circumflex artery
left anterior descending

Question 10

what artery supplies the SAN?

Answer 10

right coronary artery

Question 11

what artery supplies the AVN?

Answer 11

right coronary artery

Question 12

what arteries supply the bundle branches?

Answer 12

interventricular (descending) arteries

Question 13

what is a right dominant heart?

Answer 13

posterior descending artery is supplied by the RCA which supplies the myocardium of the inferior 1/3 of the interventricular septum

Question 14

what is a left dominant heart?

Answer 14

PDA supplied by the LCA. All of the IV septum supplied by the LCA

Question 15

what is the risk in a left dominant heart?

Answer 15

LCA blockage means both bundle branches have their blood supply cut off

Question 16

what happens as a result of bundle branch block?

Answer 16

• bundle branch becomes ischaemic
• doesnt conduct impulses properly
• use altered pathways for depolarisation (cardiac myocytes conduct the impulses instead of using the bundle branches)
• slows impulse speed
• prolongs QRS
• loss of ventricular synchrony

Question 17

what are the 3 most common places for stenosis of coronary arteries?

Answer 17

left anterior descending
right coronary artery
circumflex artery

Question 18

how long does it take for severe ischaemia to register on an ECG?

Answer 18

minutes

Question 19

how many electrodes and perspectives are there on an ECG?

Answer 19

10 electrodes

12 perspectives

Question 20

how many chest leads are there and how many perspectives do they provide?

Answer 20

6 chest leads
6 perspectives (horizontal plane)

Question 21

how many limb leads are there and how many perspectives do they provide?

Answer 21

4x limb leads

6x perspectives

Question 22

what leads give a lateral view of the heart?

Answer 22

I, aVL, V5 and V6

Question 23

what leads give an anterior view of the heart?

Answer 23

V3, V4

Question 24

what leads give a septal view of the heart?

Answer 24

V1, V2

Question 25

what leads give an inferior view of the heart?

Answer 25

II, III and aVF

Question 26

what leads correspond with the right coronary artery?

Answer 26

main artery on the inferior surface | leads II, III, aVF

Question 27

what leads correspond with the left anterior descending artery?

Answer 27

main artery on the anterior surface | V3, V4

Question 28

what leads correspond with the circumflex?

Answer 28

main artery on the lateral surface | I, aVL, V5, V6

Question 29

where are the heart valves located?

Answer 29

o Aortic – upper right 3rd costal cartilage o Pulmonary – upper left 2nd costal cartilage o Tricuspid – lower right 6th costal cartilage o Mitral – lower left 5th intercostal space midclavicular line

Question 30

where do you auscultate the heart valves?

Answer 30

o Aortic – right 2nd intercostal space o Pulmonary – left 2nd intercostal space o Tricuspid – 6th intercostal space o Mitral – 5th intercostal space midclavicular line

Question 31

what causes the characteristic lub dub noises of the heart?

Answer 31

``` o Lub (S1) when mitral valves and tricuspid close (systole) o Dub (S2) when aortic and pulmonary valves close (diastole) ```

Question 32

what 2 things can go wrong with the heart valves?

Answer 32

stenosis | regurgitation

Question 33

what is stenosis?

Answer 33

when the valves dont open properly

Question 34

what is regurgitation?

Answer 34

when the valves dont close properly

Question 35

what type of murmur is mitral regurgitation?

Answer 35

systolic murmur

Question 36

what causes mitral regurgitation?

Answer 36

Mitral valve doesn’t close properly – can hear when blood passes back through valve into the atria

Question 37

what does mitral regurgitation sound like?

Answer 37

pansystolic | often louder in late systole

Question 38

where is mitral regurgitation heard?

Answer 38

heard at the apex

Question 39

what is the most common form of valvular heart disease?

Answer 39

mitral regurgitation

Question 40

what type of murmur is aortic stenosis?

Answer 40

systolic murmur

Question 41

why do you hear turbulence in aortic stenosis?

Answer 41

as blood has to be pushed through stenotic aortic valve

Question 42

describe the different severities of aortic stenosis throughout systole and why this occurs

Answer 42

less severe in early systole more severe in late systole bc time taken to generate pressure to pass through stenotic valves

Question 43

where is aortic stenosis heard?

Answer 43

right second intercostal space

Question 44

what does mitral stenosis sound like?

Answer 44

rarely produces a soft rumbling diastolic murmur

Question 45

what does aortic regurgitation sound like?

Answer 45

complex and often absent

Question 46

what are the further complications of aortic regurgitation?

Answer 46

decreased cardiac output bc of regurgitation elevates preload and afterload LVH - typically very dilated

Question 47

what causes change in heart size

Answer 47

- changes based on workload | - workload can be physiological (athletes, pregnancy) or pathological (valvular disease, atrial fibrillation)

Question 48

define preload

Answer 48

volume of blood in ventricles at the end of diastole

Question 49

define afterload

Answer 49

resistance ventricle must overcome to circulate blood

Question 50

what does preload increase in?

Answer 50

hypervolemia, valve regurgitation, heart failure

Question 51

what does afterload increase in?

Answer 51

(chronic) hypertension, vasoconstriction, valve (aortic) stenosis, outflow stenosis

Question 52

what is concentric hypertrophy?

Answer 52

hypertrophic growth of a hollow organ without overall enlargement – walls thicken, and capacity/volume are reduced

Question 53

how does concentric hypertrophy occur?

Answer 53

increased afterload bc of aortic stenosis or chronic hypertension increased resistance wall thickness increases to overcome resistance - new sarcomeres

Question 54

what are the disadvantages of wall thickness increasing?

Answer 54

compliance is reduced (stiff) | ventricular filling is compromised (diastolic dysfunction)

Question 55

what is eccentric hypertrophy?

Answer 55

dilation of the left ventricular chamber (normal response to healthy exercise)

Question 56

what causes eccentric hypertrophy?

Answer 56

o Aortic and mitral regurgitation o Systolic dysfunction (loss of cardiac inotrophy) o Volume overload (hypervolaemia due to ventricular or renal failure) o Others eg alcohol cocaine

Question 57

what causes atrial enlargement?

Answer 57

in response to mitral or tricuspid valve pathology

Question 58

what is atrial remodelling?

Answer 58

any persistent change in atrial structure

Question 59

what is the link between atrium size and the risk of atrial fibrillation and why?

Answer 59

larger the atrium the higher the risk of AF bc you're disrupting the electrical conduction pathways

Question 60

how is atrial fibrillation diagnosed?

Answer 60

absent P waves on an ECG reduced cardiac output thrombi and syncope

Question 61

how is left atrium enlargement seen on an x-ray?

Answer 61

seen as a double density over the right atrium

Question 62

how is left ventricular enlargement seen on an x-ray?

Answer 62

heart looks like a boot