Formative

Question 1

What forms the left border of the heart?

Answer 1

Left ventricle

Question 2

How do you measure the width of the heart as a proportion to width of the chest?
How do you interpret this?

Answer 2

ratio of widest measurement of heart to width of inner aspect
of rib cage at widest point on a PA (posterior-anterior radiograph)
Anything over 50% suggests cardiac enlargment

Question 3

What are some reasons why the heart shadow might become enlarged on chest xray

Answer 3

dilated left ventricle
ventricular hypertrophy
pericardial effusion

Question 4

What is cardiac tamponade?

Answer 4

Build-up of blood or fluid in the pericardial space which

compresses the heart

Question 5

In a patient with cardiac tamponade, why would cardiac output fall?

What would you do to improve the clinical situation?

Answer 5

fall in cardiac output because the outer fibrous layer of pericardium
is inelastic therefore pressure increases in the pericardial sac
restricts filling of the heart

remove blood or fluid by pericardiocentesis

Question 6

Which artery is the Anterior interventricular artery (Left anterior descending artery) a branch of?

Which area of the heart does it supply?

What would happen if there was a thrombosis in this artery?

Answer 6

Left coronary artery

Supplies the anterior aspect of both ventricles and the
interventricular septum

Myocardial infarction of the anterior aspect of the heart

Question 7

Describe the series of changes that occur in the arterial wall to cause arterial occlusion

Answer 7

atheromatous plaque forms 
rupture of plaque 
thrombus forms 
thrombus occludes artery 
leads to MI if coronary artery involved 

NOTE:
It is the thrombus or embolus (part of thrombus which breaks off) which
occludes the artery, not the atheromatous plaque

Question 8

What are the typical symptoms experienced by a patient with MI?

Answer 8

Central crushing chest pain

which may radiate to arm or neck

Question 9

Explain why a thrombus in the right coronary artery is more likely to cause rhythm disturbance

Answer 9

Right coronary artery supplies SA node (in 60% of people)

or supplies AV node in most people (80%)

Question 10

What is the function of the cordae tendinae

Answer 10

Prevent the mitral valve inverting during systole

Question 11

If the mitral valve is incompetent (failure to close properly), what will happen to the flow of blood in systole?

What would you hear on auscultation of the heart?

Answer 11

Incompetence causes blood to be regurgitated back into left
atrium

pansystolic murmur or systolic murmur

Question 12

If the mitral valve is stenosed (difficult to open), what would happen to the flow of blood in diastole?

What would you hear on auscultation of the heart?

Answer 12

Stenosis would cause turbulent flow across valve

Mid-diastolic murmur

Question 13

Describe how, anatomically, the heart is supported in the mediastinum

Answer 13

The heart is supported within the pericardium which has two
components:
fibrous pericardium
serous pericardium
visceral layer
parietal layer
or double layer of serous pericardium with pericardial cavity

Question 14

What collection of defects are seen in Tetralogy of Fallot

Answer 14

Ventricular septal defect
Right ventricular outflow obstruction
Overriding aorta
Right ventricular hypertrophy

Question 15

Would a patient with Tetralogy of Fallot be cyanosed & why?

Answer 15

Yes, because there is a right to left shunt, bypassing the lungs

Question 16

What forms the right border of the heart?

Answer 16

Right atrium

Question 17

Name the structure in the heart responsible for the initiating electrical
activity in the heart and describe its location.

Answer 17

SAN

RA, where SVC enters

Question 18

Explain why the structure of arterioles makes them high resistance
vessels which can also vary their resistance?

Answer 18

Thick smooth muscle layer
Narrow lumen
= high resistance

Question 19

TheGPwishestoprescribeadrugwhichwilllowerthepatient’sblood
pressure by causing relaxation of vascular smooth muscle cells in
peripheral vessels. Name two possible classes of drugs which could be used.

Answer 19

L-type calcium channel blockers

Alpha 1 adrenoceptor antagonists

(ACE inhibitors also relax vascular smooth muscle, but this in not their main effect of reducing angiotensin II levels)

Question 20

Which statement below best describes the action of α1adrenoreceptors?
A α1adrenoreceptors are present on the heart and activation
increases the force of contraction

B α1adrenoreceptors are present on the heart and activation
increases the force and rate of contraction

C α1adrenoreceptors are present on the heart and activation
decreases the rate of contraction

D α1adrenoreceptors are present on peripheral blood vessels and
activation causes constriction

E α1adrenoreceptors are present on peripheral blood vessels and
activation causes dilatation

Answer 20

D

Question 21

From your knowledge of the nervous system which of the answers below
best describes the role of acetylcholine as a neurotransmitter?

A Acetylcholine activates nicotinic receptors but inhibits muscarinic
receptors.

B Acetylcholine acts on muscarinic receptors at the neuromuscular
junction and at the parasympathetic postganglionic to effector cell
synapse.

C Acetylcholine acts on muscarinic receptors at the neuromuscular
junction and at the preganglionic synapse of both branches of the
autonomic nervous system

D Acetylcholine acts on nicotinic receptors at the neuromuscular
junction and muscarinic receptors at the preganglionic synapses of both
branches of the autonomic nervous system

E Acetylcholine acts on nicotinic receptors at the neuromuscular
junction and the preganglionic synapses of both branches of the
autonomic nervous system

Answer 21

E

Question 22

describe the abnormality you would see on

the ECG of an individual with first degree heart block

Answer 22

Elongated P-R interval

Question 23

Where is the conduction problem likely to be located in heart block?

Answer 23

Between atria & ventricles

At AVN or Bundle of His

Question 24

What is the difference between second degree heart block and third
degree heart block (AV block)?

Answer 24

Second degree:
Intermittent failure of conduction between atria & ventricles
Not all P waves followed by QRS complex

Third degree:
Complete failure of conduction between atria & ventricles
No relationship between timing of P waves and QRS complex

Question 25

What would you expect to happen to the heart rate of an individual
with third degree heart block? Explain your answer.

Answer 25

Bradycardia

Ventricles create own rhythm but depolarise much slower

Question 26

Briefly describe how the normal ventricular septum forms

Answer 26

Muscular portion:
Grows up from Ridge from floor of ventricles to meet endocardial cushions

Membranous portion:
Formed by connective tissue of endocardial cushions
Grows down to fill foramen
Most prone to anomalous development

Question 27

Which part of the ventricular septum is Most prone to anomalous development

Answer 27

Membranous part

Question 28

Give some causes of a left to right shunt

Answer 28

Ventricular septal defect
Atrial septal defect
Patent ductus arteriosus

(Not PFO; higher left ventricular pressure pushes it closed: not a true septal defect)

Question 29

Is a patient with a ventricular septal defect likely to be cyanosed? Very briefly explain your reasoning.

Answer 29

No

No mixing of deoxygenated blood with oxygenated circulating around systemic system

Question 30

In a patient with a ventricular septal defect, Howwillthepressureinthepulmonaryarterycomparetothatofnormal (Answer one of lower, higher or same)

Answer 30

Higher
More blood flowing from left to right ventricle
Increases pressure in pulmonary circulation

Question 31

Whatwouldtheheartsoundsbelikeonauscultationofa patient with mitral stenosis and why?

Answer 31

Diastolic murmur

Blood flowing through narrowed valve during diastole

Question 32

Which heart sound is associated with closing of the mitral valve and
when in the cardiac cycle would it close?

Answer 32

S1

Start of ventricular systole

Question 33

Where in the precordium is the mitral valve best heard?

Answer 33

4th or 5th left intercostal space, mid-clavicular line

Question 34

Explain briefly why a patient with mitral stenosis is likely to develop pulmonary oedema.

Answer 34

Increase in LA pressure = increased pressure in pulmonary veins

Increased pulmonary capillary hydrostatic pressure

Excess filtration of fluid out of capillaries

Oedema

Question 35

Briefly state why atrial fibrillation might develop as a result of chronic
mitral valve stenosis and what type of drug might you need to consider if
she develops atrial fibrillation in order to prevent a potentially serious
complication?

Answer 35

Stretch of LA = damage to fibres
Fibrosis = re-entry circuits develop

Anticoagulant: Warfarin
AF = increased risk of thrombosis travelling to systemic circulation

Question 36

What changes in heart function would be seen in a patient with Tetralogy of Fallot of left untreated?

Answer 36

Right heart failure

NOTE:
The outflow tract obstruction makes it harder for the right ventricle
to pump blood to the lungs. This leads to right ventricular
hypertrophy and can ultimately lead to right ventricular heart
failure.