Atrial Fibrillation

Question 1

Define the following types of AF

1. paroxysmal
2. persistent
3. permanent

Answer 1

1. episodes of AF lasting <7 days (often <24hrs)
2. episodes of AF lasting >7 days
3. AF which is resistant to cardio version or cardio version deemed inappropriate

Question 2

What are the symptoms and signs of AF?

Answer 2

symptoms

• chest pain
• palpitations
• dyspnoea

sign: irregularly irregular pulse

Question 3

Rate and Rhythm Control

1. Rate control generally method of choice. When is this not the case?
2. Describe the rate control guidance.
3. When can cardioversion be attempted?

Answer 3

1. • coexistent heart failure
   • first onset AF within 48hrs
   • obvious reversible cause
2. beta blocker or rate-limiting CCB (diltiazem)

if rate still not adequately controlled use 2 of:

• beta blocker
• diltiazem
• digoxin

3. • within 48 hrs of onset of AF
   • anticoagulation 3 weeks prior to attempt

THINK: this is because atrium suddenly returning to normal beat could dislodge embolus and cause stroke

Question 4

Anticoagulation

1. What score is used to decide if anti-coagulation should be offered in AF?
2. When should anti-coagulation be offered?
3. What must be done if patients do not qualify for anticoagulation via this score?

Answer 4

1. CHA2DS2VASc score
2. if score 2 or more
   (consider in males if 1)
3. must have echo to exclude valvular disease

(valvular disease would mean anticoagulation required for patient)

Question 5

Cardioversion

1. When is cardioversion indicated?
2. At what point of the cardiac cycle is cardioversion synchronised to and why?
3. Onset <48hrs
   Can be electrical or pharmacological.
   How could this be done pharmalogically?

4.

a) How could cardioversion be carried out if patient has not been coagulated 3 weeks prior?
b) If this is the case what cardioversion should be carried out?

5. a) When is there a high risk of failure?
   b) What should be done in these cases?
6. How long should patients be anti coagulated for following electrical cardioversion?

Answer 5

1. • patient haemodynamically unstable
   • elective procedure when rhythm control has been preferred
2. R wave - because cardioversion at T wave (during depolarisation) can cause VF
3. amiodarone (flecainide is an alternative if there is no structural heart disease)
4. a) transoesophageal to exclude left atrial appendage thrombus
   - > if not present can be and cardioverted immediately

b) electrical

5. a)
   - previous failure
   - AF recurrence
   b) 4 weeks of amiodarone or sotalol prior to electrical cardioversion
6. at least 4 weeks

Question 6

What should be given prior to electrical cardioversion

Answer 6

heparin

Question 7

When should anticoagulation be given to patients with AF who have suffered a stroke?

Answer 7

begin after 2 weeks

unless very large cerebral infarction in which case delayed further

Question 8

Catheter Ablation

1. When is this indicated?
2. What can be used to ablate the tissue?
3. What tissue is typically causing the aberrant electrical pathway and hence is ablated?
4. What can be the complications from the procedure?
5. How many patients remain in sinus rhythm?
6. What anticoagulation should be given following treatment?

Answer 8

1. patients who have not responded to or do not wish for anti-arrhythmic medication
2. cryotherapy or radiofrequency (heat generated from medium frequency alternating current)
3. tissue between pulmonary veins and left atrium
4. • pulmonary vein stenosis
   • tamponade
   • stroke
5. 55% at 3 years
   (80% who’ve had multiple procedures)
6. score 0 or 1: 2 months
   (remember if cha2ds2vasc 2 or more lifelong)

Question 9

1. How is the bleeding risk in anticoagulation assessed?

2. What variables does this involve?

Answer 9

1. ORBIT score
2. Old - age >74

R - red cells - haemoglobin <130 in males or <120 in females OR haemocrit <40% in males, <36% in females

B - bleeding history (GI, intracranial bleed, haemorrhagic stroke)

I - renal Impairment: GFR <60

Treatment with anti platelet agents