Atrial Fib/Anticoagulants

Question 1

What are the symptoms of atrial fibrillation?

Answer 1

• Irregularly irregular pulse
• Chest pain
• Breathlessness
• Syncope
• Oedema
• Palps
• Dizziness
• Fatigue

Question 2

What are the cardiac causes of atrial fib?

most common at top

Answer 2

• Rheumatic heart disease
• Hypertension
• IHD
• Cardiomyopathy
• Sick sinus syndrome

Question 3

What are the non cardiac causes of atrial fib?

most common at top

Answer 3

• Alcohol excess
• Acute infection
• PE
• Lung cancer
• Pleural effusion
• Thyrotoxicosis

Question 4

How is AF classified?

Answer 4

Acute - first episode, lasting over 30s
Paroxysmal - recurrent, self-limiting episodes within 7 days
Persistent - recurrent episodes over 7 days, need cardioversion
Permanent - ongoing (>1yr) despite treatment

Question 5

What is the pathophysiology of AF?

Answer 5

Impulses from the SAN are overhwlemed by disorganised electrical impulses. This is perpetuated by abnormal fibrous atrial tissue.
The result is a loss of atrial contraction and a rapid, irregular ventricular rate.

Question 6

How is AF diagnosed?

Answer 6

ECG - wandering baseline, absent p waves, irregularly irregular

Question 7

What investigations should be done in someone with suspected AF?

Answer 7

ECG, echo, FBC, TFTs

Question 8

What are the 2 risk assessment scores in AF?

Answer 8

Bleeding risk - HASBLED

Stroke risk - CHA2DS2VAS

Question 9

Which variables does the CHA2DS2VAS score take into account?

Answer 9

Coronary heart disease 1
Hypertension 1
Age >75 2
Diabetes 1
Stroke/TIA 2
Vascular
Age 65-74 1
Sex (female) 1

Question 10

Which variables does the HASBLED score take into account?

Answer 10

Hypertension 1
Abnormal renal/liver function 1 each
Stroke/TIA 1
Bleeding 1
Labile TIA 1
Elderly (age>65) 1
Drugs/alcohol 1 each

Question 11

If a pt with AF has unstable cardiovascular status how should they be managed?

Answer 11

• Rhythm control

- Thromboprophylaxis with heparin

Question 12

If a pt with AF has stable cardiovascular status how should they be managed?

Answer 12

• Rate control
• Symptom assessment for rhythm control
• Stroke awareness and prevent

Question 13

In which cases should rate control be offered?

Answer 13

Offer to everyone EXCEPT:

• reversible cause of AF
• heart failure from AF
• new-onset AF
• if they would benefit more from rhythm

Question 14

What rate control options are available?

Answer 14

1st line - B blocker (atenolol, metoprolol) or CCB (dilitiazem, verapamil)
2nd line - Digoxin

Question 15

When should digoxin be used?

Answer 15

Elderly, sedentary

Question 16

What are the side effects of digoxin?

Answer 16

• Dizziness
• Yellow vision
• Heart block
• Thrombocytopenia

Question 17

In which cases should rhythm control be offered?

Answer 17

Those whose symptoms continue after rate control or are unstable.
If symptoms have been ongoing for 48h, use electrical cardioversion (BUT ANTICOAGULATE BEFORE TO MINIMISE STROK RISK)

Question 18

What pharmacological rhythm control options are available?

Answer 18

Class III - amiodarone
Class IV - flecanide, propafenone
Beta blockers

Question 19

What are the benefits of amiodarone over flecanide?

Answer 19

Reduced risk of hypertension and heart failure. Better for use in anyone with heart disease, be it structural or ischaemic

Question 20

What are the side effects of amiodarone?

Answer 20

Photosensitivity
Thyroid dysfunction
Pulmonary fibrosis

These SEs stay for a while after drug discontinutation

Question 21

What are the benefits of flecanide over amiodarone?

Answer 21

More effective if given within 12h

Effectivity levels out at 24h

Question 22

What should you give 6 wks before and a year after electrical cardioversion?

Answer 22

Amiodarone - maintains sinus rhythm

Question 23

What should be used for long term rhythm control?

Answer 23

1st line - atenolol

2nd line - dronedarone (safer form of amiodarone)

Question 24

How should acute AF be managed?

a) haemodynamically stable
b) unstable

Answer 24

a) <48h - rhythm or rate, >48h - rate

b) electrical cardioversion

Question 25

In which cases should you offer anticoagulation to patients with AF?

Answer 25

Use CHA2DS2VAS score - offer if 2 or above.

Do not offer if <65 with no RF

Question 26

What are the options for AF anticoagulation?

Answer 26

Aim for INR 2-3

Warfarin
Direct thrombin inhibitors - dabigatran
Factor xa inhibitors - apixaban, rivaroxaban

Question 27

What are the advantages and disadvantages of warfarin ?

Answer 27

Adv - cheaper, antidote available (vit K)

Disadv - narrow therapeutic index, interactions, monitoring

Question 28

What are the advantages and disadvantages of NOACs?

Answer 28

Adv - no monitoring

Disadv - expensive, no antidote, GI bleeding

Question 29

Name some inducers of warfarin

Answer 29

Alcohol, rifampicin, st johns wort, phenytoin, carbamazepine

Question 30

Name some inhibitors of warfarin

Answer 30

Amiodarone, cranberry juice, erythromycin, ciprofloxacin, simvastatin, SSRI, tramadol

Question 31

What should be given in a warfarin overdose?

Answer 31

Mild - vitamin K

Severe - beriplex (prothrombin complex concentrate)

Question 32

What are the contraindications for warfarin?

Answer 32

Peptic ulcer, bleeding disorder, HTN, pregnancy

Question 33

What are the complications of AF?

Answer 33

• Stroke/TIA
• Thromboembolism
• Rate related cardiomyopathy - inability of heart to empty and fill properly
• Pulmonary oedema - fluid backs up in the lungs

Question 34

How should you manage a moderately high INR without bleeding?

Answer 34

Omit a dose of warfarin

Question 35

How should you manage a significantly high INR without bleeding?

Answer 35

Omit a dose of warfarin and prescribe oral vitK

Question 36

How should you manage a significantly high INR with bleeding>

Answer 36

Oral/IV vitK and beriplex admin (containts 2, 7, 9, 10)

If beriplex isn’t available, give FFP