End of block key points

Question 1

NSTEMI vs STEMI

Answer 1

NSTEMI

• plaque ruptures, thrombus, partial occlusion to vessel
• injury to subendocardial myocardium

STEMI
- complete occlusion of BV, transmural injury and infarct to myocardium

Question 2

which symptom will increase the risk of sudden cardiac death in patient with hypertrophic cardiomyopathy?

a) chest pain
b) peripheral oedema
c) oedema
d) headache
e) breathlessness
f) syncope

Answer 2

syncope

Question 3

role of furosemide?

Answer 3

• diuretic

- inhibits [Na+ / K+ / 2Cl-] carrier in thick ascending loop of henle

Question 4

whats open in plateau phase of action potential in cardiomyocytes?

Answer 4

• voltage gated calcium channels

Question 5

what removes calcium from cardiac myocytes to the extracellular space?

Answer 5

• sodium / calcium exchanger

Question 6

what channels plays an important part in repolarising cardiac myocytes?

Answer 6

• voltage gated potassium channel (Delayed rectifier)

Question 7

what ion channel causes the rapid upstroke of the action potential in cardiac myocytes?

Answer 7

• voltage gated sodium channel

Question 8

what channel is blocked by local anaesthetics?

Answer 8

• voltage gated sodium channels

Question 9

what ion channel is blocked by drugs causing pharmacologically acquired long QT syndrome?

Answer 9

• voltage gated potassium channel

Question 10

In adulthood, what are common complications of an untreated atrial septal defect?

Answer 10

• atrial arrhythmias and right heart failure

Question 11

Which phase of the ECG corresponds to beginning of the rapid passive ventricular filling?

Answer 11

• The ST segment

* think after QRS, blood in aorta and PA, blood from RA and LA gonna enter RV and LV

Question 12

Action of bisoprolol?

Answer 12

• heart rate slowed
• acts on beta receptors of heart
• can reduce mortality in HF patients

Question 13

what happens as a result of angiotensin 2 production and where does it act?

Answer 13

• v. constriction

- acts on efferent arterioles

Question 14

23 y/o pregnant female, gripping chest pain on exertion. known to have systolic murmur. ECHO revels severe aortic stenosis. cause of chest pain?

Answer 14

• her circulating volume increased (pregnancy)

- increasing oxygen demand in the myocardium

Question 15

in penetrating chest trauma what chamber of heart most likely to be affected?

Answer 15

right ventricle

Question 16

third heart sound?

Answer 16

• beginning of isometric relaxation

Question 17

what common valvular heart disease would result in systolic crescendo-descrendo murmur?

Answer 17

• aortic stenosis

Question 18

what when activated causes a reduction in circulating volume?

Answer 18

BNP

Question 19

tetralogy of fallot

Answer 19

• aortic override
• pulmonary regurgitation
• atrial septal defect
• right sided aortic arch

Question 20

what would be associated with normal pulmonary artery pressures and large A waves in JVP?

Answer 20

• tricuspid stenosis

Question 21

What happens normally in depolarisation?

Answer 21

• in normal heart

- RV and LV depolarise together, contract simultaneously

Question 22

Describe what occurs in bundle branch block?

Answer 22

• unaffected ventricle depolarises first
• electrical impulses through myocardium to other side
• delayed, slowed depolarisation
• broader QRS complex

Question 23

Describe position of the V1, V6 leads?

Answer 23

V1 - RHS

V6 - LHS

Question 24

Describe what may happen if LHS bundle depolarises first?

Answer 24

• LHS initiated
• signal towards RHS through depolarising the interventricular septum
• away from V6 to V1
• v1 small positive deflection
• small negative in V6
• depolarisation of septum from LHS to RHS
• signals move in both directions however LV larger, so overall net movement to LHS
• thus positive V6 and negative v1

Question 25

What occurs in RBBB?

Answer 25

- initial septal activation is unchanged - LHS depolarises normally, thus positive V6, negative V1 - then reversed to RHS - thus V1 positive, M shaped - V6 negative, broader S shape

Question 26

Describe what occurs in LBBB?

Answer 26

- septal depolarisation reversed from right to left - RV activation 1st, then depolarisation to LHS - V1 negative , v6 positive - V6 characteristic bunny ears

Question 27

Describe significance of right internal jugular vein?

Answer 27

- communicates directly with RA via SVC thus gives indication of central venous pressure

Question 28

Most important points to remember when reading JVP?

Answer 28

1. Blood flows from high to low pressure 2. contraction increases pressure 3. relaxation decreases pressure

Question 29

A wave

Answer 29

atrial contraction, some pressure goes back up to RIJv causing slight distension

Question 30

x descent after A wave

Answer 30

right atrium relaxation

Question 31

C wave

Answer 31

bulging of blood against closed tricuspid valve. rv contracts against closed tricuspid

Question 32

V wave

Answer 32

atrial filling

Question 33

Y descent

Answer 33

opening of tricuspid valve thus allowing ventricular filling

Question 34

no A waves

Answer 34

atrial fibrillation

Question 35

giant regular uniform A waves

Answer 35

- ventricles contract against higher pressure | - RV hypertrophy, tricuspid stenosis, pulmonary hypertension

Question 36

cannon intermittent A wave

Answer 36

- cardiac arrhythmia, RV contracts against closed tricuspid

Question 37

large V wave

Answer 37

- increased ventricular filling - tricuspid regurgitation - often joins with C wave to form CV wave

Question 38

Steep X, Y descent

Answer 38

Friedrich's sign reduced elasticity of pericardial sac e.g. constructive pericarditis

Question 39

S1 and S2 sound

Answer 39

S1 - LUB, AVV closure after blood from atria to ventricles S2 - DUB, aortic and pulmonary valve closes after ventricles eject blood

Question 40

third heart sound

Answer 40

- rapid ventricular filling