Cardio 2

Question 1

What does the PR interval represent?

Answer 1

Delay in conduction at the AV node

Question 2

Mx of Mobitz II?

Answer 2

Pacemaker

Question 3

What infectious disease can cause 3rd degree heart block?

Answer 3

Lyme disease

Question 4

What medications can cause heart block?

Answer 4

• beta blockers
• CCBs
• adenosine
• amiodarone
• digoxin

Question 5

What condition can cause congenital heart block?

Answer 5

Neonatal lupus (anti-Ro and anti-La Abs attack the conduction system).

Question 6

Give some causes of RBBB

Answer 6

1) PE

2) RVH

3) RHF

Question 7

What is the main ECG feature of BBB?

Answer 7

Widening of the QRS

Question 8

What condition are those with 1st degree AV block at an increased risk of?

Answer 8

AF

Question 9

Define preload & afterload

Answer 9

Preload - amount of blood that returns to the heart

Afterload - peripheral resistance

Question 10

Mechanism of digoxin?

Answer 10

Inhibits Na+/K+ ATPase pump at the cell membrane of the cardiomyocyte.

Question 11

What is a ‘black triangle’ medication?

Answer 11

Black triangle drugs are medicines that are under intensive monitoring because they are either new to the market or have very limited post-marketing exposure data.

ALL suspected adverse drug reactions (even diarrhoea) must be reported using the Yellow Card scheme.

Question 12

What is the yellow card scheme?

Answer 12

Has become the standard way to report adverse reactions to medications.

It is run by the Medicines and Healthcare products Regulatory Agency (MHRA).

Question 13

What should be reported under the yellow card scheme?

Answer 13

1) all suspected adverse drug reactions for new medicines (identified by the black triangle symbol)

2) all suspected adverse drug reactions occurring in children, even if a medicine

Question 14

What dose of the following drugs is given in peri-arrest rhythms:

1) atropine (in bradycardia)

2) amiodarone (in VT)

3) adenosine (in SVT)

Answer 14

1) 500 micrograms (up to 6x i.e. 3mg)

2) 300mg IV

3) 6mg then 12mg then 18mg

Question 15

What are the investigations of choice for narcolepsy?

Answer 15

Multiple sleep latency EEG, along with polysomnography.

Question 16

Common contraindication for adenosine?

Answer 16

Asthma/COPD - as causes bronchospasm

Question 17

PR interval on an ECG?

Answer 17

From start of P wave to start of QRS complex (i.e. NOT to R)

Question 18

What falls under ‘risk of asystole’ when mx bradycardia?

Answer 18

1) recent asystole

2) Mobitz type II block

3) complete heart block with broad QRS

4) ventricular pause >3s

Question 19

What are the 2 options for temporary cardiac pacing in bradycardia?

Answer 19

1) Transcutaneous pacing

2) Transvenous pacing

Question 20

What are the 3 types of SVT?

Answer 20

1) Paroxysmal

2) AVNRT –> the re-entry point is through the AV node

3) AVRT –> the re-entry point is an accessory pathway (e.g. WPW syndrome)

Question 21

Give 4 conditions that atrial flutter can be associated with?

Answer 21

1) HTN

2) IHD

3) Cardiomyopathy

4) Thyrotoxicosis

Question 22

Mx of tachycardia with life threatening features?

Answer 22

1) Synchronised DC cardioversion (up to 3 attempts) - sedation or anaesthesia if conscious

If unsuccessful:

2) Amiodarone 300mg IV over 10-20 mins

3) Repeat synchronised DC shock

Question 23

Mechanism of adenosine?

Answer 23

Slows cardiac conduction through the AV node

Question 24

Give some key contraindications for adenosine?

Answer 24

1) Asthma/COPD

2) HF

3) Heart block

4) Hypotension

Give verapamil instead

Question 25

Mx of atrial flutter?

Answer 25

Similar to AF

1) Rate control w/ beta blockers

2) Treat underlying cause e.g. HTN, thyrotoxicosis

3) Radiofrequency ablation (permanent)

4) Anticoagulate

Question 26

2 types of VT?

Answer 26

1) Monomorphic i.e. each QRS is identical

2) Polymorphic (torsades de pointes) i.e. each QRS is different

Question 27

Who does torsades de pointes occur in?

Answer 27

Patinets with a prolonged QR interval:

1) Long QT syndrome (inherited)

2) Medications:
- antipsychotics
- citalopram
- flecainide
- sotalol
- amiodarone
- macrolides

3) Electrolyte disturbances:
- hypokalaemia
- hypomagnesaemia
- hypocalcaemia

Question 28

Mx of torsades de pointes?

Answer 28

IV magnesium sulphate

Stop causative meds/correct electrolytes

Question 29

what beta blocker can cause a prolonged QT interval?

Answer 29

sotalol

Question 30

What 3 electrolyte abnormalities can lead to a long QT interval?

Answer 30

1) Hypokalaemia

2) Hypocalcaemia

3) Hypomagnesaemia

Question 31

What is monomorphic VT most commonly caused by?

Answer 31

MI

Question 32

Mx of torsades de pointes?

Answer 32

IV magnesium sulphate

Question 33

What does a prolonged QT interval represent?

Answer 33

Prolonged repolarisation of the myocytes after a contraction.

Question 34

What class of medication is atropine?

Answer 34

Antimuscarinic –> inhibits parasympathetic nervous system

Question 35

Side effects of atropine?

Answer 35

Antimuscarinic:
- dry mouth
- dry eyes
- constipation
- urinary retention
- pupil dilation

Question 36

What is a key class of Abx that can cause long QT?

Answer 36

Macrolides

Question 37

Which macrolide carries that greatest risk of QT prolongation?

Answer 37

Erythromycin

Question 38

What is the QT interval on an ECG?

Answer 38

From beginning of QRS complex to the END of the T wave.