Atrial Fibrillation

Question 1

Definition of atrial fibrilliation

Answer 1

A fib is characterised by irregular uncoordinated atrial contraction.
Usually at rate 300-600.

Question 2

Causes of atrial fibrillation - 7

Answer 2

• Congestive heart failure
• WFW syndrome
• congenital heart disease
• IHD
• Hypertension
• Valvular heart disease
• Hyperthyroidism

Question 3

Complications of AF - 4

Answer 3

1. stroke and VTE
2. Heart failure
3. Tachycardia-induced cardiomyopathy
4. Reduced quality of life

Question 4

Classification of AFib - 4

Answer 4

Acute - lasts less than 48 hours
Paroxysmal - lasts less than 7 days and is intermittent
Persistent - lasts over 7 days and gets better with cardioversion
Permanent - lasts over 7 days and does not get better with cardioversion

Question 5

Causes of AFib - 10

Answer 5

Cardiac:
* IHD
* HTN
* Rheumatic heart disease
* Pericarditis

Non-cardiac:
* Dehydration
* Endocrine (hyperthyroidism)
* Infective causes (sepsis)
* pulmonary causes
* electrolyte disturbance

Question 6

symptoms of Afib - 5

Answer 6

1. palpitations
2. chest pain
3. shortness of breath
4. lightheadedness
5. syncope

Question 7

Signs of afib - 6

Answer 7

• Irregularly irregular pulse rate
• Single waveform on the JVP (a wave is lost which normally represents atrial contraction)
• Apical to radial pulse deficit
• On auscultation may be variable intensity to first heart sound
• features of underlying cause

Question 8

Differentials of Afib - 4

Answer 8

• atrial flutter - sawtooth baseline on ECG (not wavey)
• Supraventricular tachycardia (atrial flutter is a type of SVT)
• Ventricular tachycardia
• Anxiety

Question 9

Investigations of Afib

Answer 9

• 12 lead ECG - irregulary irregular heart rate, absent p waves and wavey baseline
• Bloods - look for signs of infection, hyperthyroidism
• echocardiogram

Question 10

Management of acute Afib

Answer 10

• Follow A-E and treat
• Synchronised DC cardioversion and or amiodarone
  If onset is less than 48hrs - rhythm control with DC cardioversion or anti-arrythmics. Flecanide or amiodarone
  If onset is more than 48hrs - rate control with beta blockers or diltiazem

Question 11

Principals of management of Chronic AF

Answer 11

Focus on rate and rhythm control seperately

Then consider anticoagulation therapy

Question 12

How is rate controlled in chronic AF - 2 lines

Answer 12

Rate is usually managed first

1st line - bisoprolol and diltiazem/verapamil (non-hihydropyrine CCB)
2nd line - dual therapy under guidance

Question 13

How is rhythm controlled in chronic AF -

Answer 13

• electrical cardioversion
• pharmacological cardioversion - flecainide, amiodarone, sotalol (bblocker with K+ blocker action)

Question 14

Which 2 score systems are used to mitigate stroke risk in chronic AF

Answer 14

CHADS2VASc score
males scoring more than 1 and women scoring more than 2 should be anticoagulated.

ORBIT score (previously HASBLED)
little guidance available for what they mean

Question 15

Which anticoagulants are used in chronic AF to reduce stroke risk - 3

Answer 15

• DOACs e.g. apizaban, rivaroxaban
• Warfarin e
• LMWH

Question 16

Complications of Afib - 4

Answer 16

• ischaemic stroke
• HF
• Mesenteric/acute limb ischaemia
• GI or intracranial bleeding

Question 17

how does afib lead to embolus formation

Answer 17

lack of organised atrial contraction can lead to blood stasis in the left atrium. Due to the left atrial appendage, blood clots easily here and if part of this clot embolises it can lead to a stroke.