AF

Question 1

Causes of AF

Answer 1

• Pulmonary - PE, COPD
• Idiopathic/Isolated
• Rheumatic heart disease (i.e. Mitral Regurgitation)
• Alcohol dependence/binging
• Thyrotoxicosis
• Endocarditis / Echocardiographic changes (ie. Cardiomyopathy)
• Sick Sinus Syndrome
• Hypertension
• Ischaemic
• Valvular disease

Question 2

What is CHADS 2 VASC?

Answer 2

calculates stroke risk for patients with AF

• Age
  
  • <65 0
  • 65-74 +1
  • ≥75 +2
• Sex
  
  • Female +1
  • Male 0
• CHF history
  
  • No 0
  • Yes +1
• Hypertension history
  
  • No 0
  • Yes +1
• Stroke/TIA/Thromboembolism history
  
  • No 0
  • Yes +2
• Vascular disease history
  
  • No 0
  • Yes +1
• Diabetes history
  
  • No 0
  • Yes +1

0 = low = no therapy or aspirin

1 = moderate = oral anticoagulant or aspirin

2 or more = high = oral anticoagulant

Question 3

What are the 3 clinical patterns of AF?

Answer 3

• paroxysmal atrial fibrillation
  
  • ​where episodes come on suddenly and generally revert spontaneously within the next 24 to 48 hours without any intervention
• persistent atrial fibrillation
  
  • ​with similar abrupt onset but episodes persist for days or weeks unless active measures are taken to revert the patient to sinus rhythm
• permanent (or chronic) atrial fibrillation
  
  • where the patient has demonstrated inability to sustain sinus rhythm for any length of time, or a decision has been made not to attempt cardioversion because of longstanding atrial fibrillation, giant atria or other factors.

Question 4

Treatment for AF?

Answer 4

The treatment of atrial flutter and atrial fibrillation needs to be considered under three separate headings:

• rate control
  
  • atenolol (1st line)
  • metoprolol (1st line)
  • diltiazem (2nd line)
  • verapamil (2nd line)
• rhythm control
  
  • flecainide (1st line)
  • sotalol (1st line)
  • amiodarone (2nd line)
• prophylaxis against thromboembolic complications
  
  • warfarin (1st line)
  • dabigatran (2nd line)

When using warfarin, heparin should be continued concurrently for a minimum of 5 days and until the international normalised ratio (INR) has been above 2 on 2 consecutive days. When using dabigatran, cease heparin at the time of starting dabigatran.

Question 6

When to do cardioversion in AF?

Answer 6

• >48hrs, or unsure of duration - DO NOT CARDIOVERT unless pt is haemodynamically unstable
• anticoagulation for 3 weeks
  
  • dalteparin 120 units/kg up to 10 000 units SC, twice daily
  • enoxaparin 1mg/kg SC bd
  • unfractionated heparin
• symptomatic or haemodynamically unstable = cardiovert
• drugs = amiodarone or flecainide, oral or IV