Atrial Fibrillation

Question 1

Clinical Features

including JVP

Answer 1

Irregularly irregular atrial contractions

Tachycardia

Heart failure due to poor filling of the ventricles during diastole

Absent a waves on JVP

SYMPTOMS
Palpitations
Shortness of breath
Syncope (dizziness or fainting)
Symptoms of associated conditions (e.g. stroke, sepsis or thyrotoxicosis)

Question 2

Atrial Fibrillation

ECG findings

Answer 2

Absent P waves

Narrow QRS Complex Tachycardia

Irregularly irregular ventricular rhythm

Question 3

Atrial Fibrillation

Causes

Answer 3

Ischaemic Heart Disease

Valvular Disease

Infective Endocarditis

Alcohol

Thyrotoxicosis

Question 4

Atrial Fibrillation

Management

4 Questions to ask / 4 step approach

Answer 4

1. Is the patient haemodynamically stable?

Signs of instability are:
- Shock (suggests end organ hypoperfusion)
- Syncope (evidence of brain hypoperfusion)
- Chest pain (evidence of myocardial ischaemia)
- Pulmonary oedema (evidence of heart failure)
If the patient is unstable then they should have IMMEDIATE DC CARDIOVERSION

2. If the patient is stable, then consider reversible causes and appropriate treatments for them:
   - If infection: Antibiotics and fluids
   - If dehydrated: Fluids
   - Replace abnormal electrolytes
3. If AF persists or reversible causes are not present then decisions should be made about rate control, rhythm control or electrical cardioversion.
4. Is long term anticoagulation needed?

Question 5

Atrial fibrillation management

When do you use cardioversion?

Answer 5

DC CARDIOVERSION:
- If the AF is acute (<48 hours) then the patient can be DC cardioverted with sedation.

• If the AF is >48 hours (or onset is uncertain) then the patient must be anticoagulated for 28 days with LMWH before DC cardioversion can be done

OR the patient can have a transoesophageal ECHO to rule out a thrombus in the left atrial appendage before cardioversion.
(NB chronic AF or those who have failed cardioversion before are unlikely to be successfully cardioverted so this would not be considered in most of these cases)

Question 6

Atrial fibrillation management

When do you use rate control?

What do you use - think different situations

Answer 6

RATE CONTROL
- more suitable in elderly patients (>70 years) and those who are more prone to drug interactions and the pro-arrhythmic effects of anti-arrhythmic therapy.

• Achieved by slowing the transmission of electrical transmission through the AV node so to keep heart rate <100bpm.
• Medication choices include:
  1. Beta-blocker (normal bisoprolol) technically contraindicated in COPD and asthma but definitely
  cannot be used in hypotension because it will drop blood pressure.
  (must not use sotalol - only used occasionally for rhythm control)

2. Non-dihydropyridine calcium channel block (diltiazem or verapamil) : Not frequently used in hospital settings because it is negatively ionotropic meaning that it is contraindicated in heart failure
3. Digoxin: for patients who are hypotensive or have co-existent heart failure.
   Should be avoided in younger patients because it increases cardiac mortality.
   Often used second-line in conjunction with beta-blockers if fast AF remains refractory.

Question 7

Atrial Fibrillation Management

When do you use rhythm control?

Answer 7

RHYTHM CONTROL

• Young patients
• Patients with disabling symptoms from the atrial fibrillation
• first episode
• Options include:
  1. Flecainide (Na channel blocker)
  Can be either given regularly or as a “pill in the pocket” when symptoms come on.
  Is preferred in young patients who have structurally normal hearts because it can induce fatal arrhythmias in structurally abnormal hearts.

2. Amiodarone (multi-class action) - if structural heart disease
   Extremely effective drug in controlling both rate and rhythm.
   However it comes with a massive list of significant side-effects so should normally only be given to older, sedentary patients.
3. Sotalol (beta blocker with additional K channel blocker action)
   Used for those that don’t meet the demographics for either flecainide or amiodarone.

Question 8

Atrial Fibrillation

When do you anticoagulate?

Answer 8

Patients should be risk stratified using the CHADS2VASc score:

C: 1 point for congestive cardiac failure.
H: 1 point for hypertension.
A2: 2 points if the patient is aged 75 or over. 1 point if the patient is aged 65-74.
D: 1 point if the patient has diabetes mellitus.
S2: 2 points if the patient has previously had a stroke or transient ischaemic attack (TIA) or VTE
V: 1 point if the patient has known vascular disease (previous MI, peripheral arterial disease)
A
Sc: 1 point if the patient is female.

Males who score 1 or more or females who score 2 or more should be anticoagulated.

Question 9

How would you start anticoagulation?

Answer 9

Start LMWH and Warfarin as bridging?

Question 10

How do you treat atrial flutter?

Answer 10

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