Atrial Fibrillation

Question 1

What are the symptoms of atrial fibrillation?

Answer 1

• Palpitations,
• Dyspnoea,
• Chest pain, syncope (rare)
• Complications eg, stroke
• No symptoms at all

Question 2

How is the diagnosis of AF made and what are the different types

Answer 2

• Irregularly irregular pulse confirmed by 12 lead ECG
• AF can be paroxysmal (intermittent - may require ambulatory ECG recordings), persistent (requires intervention to be stopped) or permanent

Question 3

Describe the appearence of AF on ECG

Answer 3

• Variable rate with irregular, narrow QRS and no P waves

Question 4

Describe the appearence of atrial flutter on ECG

Answer 4

Variable rate but regular narrow QRS with sawtooth atrial activity of 300bpm so difficult to identify P waves (best seen in inferior leads)

Question 5

What are conditions which predispose to AF?

Answer 5

• Hypertension,
• Symptomatic heart failure,
• Valvular heart disease,
• Cardiomyopathies,
• ASD/other congenital heart disease,
• Coronary artery disease,
• Thyroid dysfunction,
• Obesity,
• Diabetes mellitus,
• COPD and sleep apnoea,
• Chronic renal disease

Question 6

What are the objectives of treatment for AF?

Answer 6

• Prevention of stroke,
• Symptom relief,
• Optimum management of CVD,
• Rate control,
• With or without rhythm control

Question 7

What are the essential investigations for AF

Answer 7

• ECG,
• Echocardiogram,
• TFT,
• LFTs

Question 8

Describe the guidelines for rate control in AF

Answer 8

• Target HR of <110 bpm but is still symptomatic then aim for HR <80bpm
• 1st line treatment for patients without HF is a BB (bisoprolol or atenolol) or rate limiting calcium channel antagonist (verapamil)
• 2nd line is digoxin.

Question 9

What is the risk factor based scoring system for risk of stroke inAF?

Answer 9

CHADS-VASc
C = congestive heart failure
H = Hypertension (BP >140/90)
A = Age over 72 (2)
D = Diabetes
S = Stroke or TIA previously (2)
V = vascular disease
A = Age 65+
S = Female sex.
Any score >1 is high risk. A score of 1 is moderate risk

Question 10

What is the anti coagulant therapy for AF?

Answer 10

• NOAC
• Warfarin if patient has a mechanical heart valve or severe mitral stenosis

Question 11

When do patients with AF require specialist referall?

Answer 11

• Patients under 60,
• Patients who are still symptomatic despire rate control,
• Inadequate rate control despite beta blocker/calcium antagonist and digoxin
• Structural heart disease,
• AF and HF

Question 12

When should you opt for rhythm control and what are the methods

Answer 12

• Younger patients and symptomatic patients despite good rate control.
• Options include direct current cardioversion (persistent AF), antiarrhythmic drugs or cardiac ablation

Question 13

What are some of the antiarrhythmic drugs used in AF

Answer 13

• Class 1: Na channel blockers eg, flecanide.
• Class 2: Potassium channel blockers eg, sotalol or amiodarone.
• Multichannel blockers, eg, dronedarone
• Used in combination with Beta blocker

Question 14

Describe features of catheter ablation

Answer 14

• Triggers for AF in pulmonary veins so pulmonary vein electrical isolation using radiofrequency current of cyro-ablation can be curative
• More effective in patients with structurally normal hearts
• Patients with highly symptomatic paroxysmal AF resistant to 1+ antiarrhythmic should be referred for ablation.

Question 15

What are the causes of atrial flutter?

Answer 15

Similar to AF but more likely to occur with pulmonary disease such as COPD, obstructive sleep apnoea, pulmonary emboli or pulmonary hypertension

Question 16

What is the treatment for atrial flutter

Answer 16

If haemodynamically unstable - Cardioversion
If haemodynamically stable then treat reversible cause and rate control using BB or CCB

Question 17

What are signs of haemodynamic instability?

Answer 17

• Shock,
• Syncope,
• Chest pain,
• Pulmonary oedema