What is Atrial fibrillation?

Atrial fibrillation is an abnormal heart rhythm characterized by rapid and irregular beating of the atrial chambers of the heart

What are the "types" of atrial fibrillation?

• first detected episode (irrespective of whether it is symptomatic or self-terminating)
• paroxysmal AF (Such episodes last less than 7 days ,typically < 24 hours).
• persistent AF (for recurrent episodes that do not self-terminate)
• permanent AF

What is meant by paroxysmal AF?

When a patient has 2 or more episodes of AF and the episodes of AF terminate spontaneously then the term paroxysmal AF is used. Such episodes last less than 7 days (typically < 24 hours)

What is meant by persistent AF?

When a patient has 2 or more episodes of AF and the episodes of AF do not terminate spontaneously then the term persistent AF is used. Such episodes last more than 7 days

What are the two key parts of managing patients with AF?

1. Rate/rhythm control
2. Reducing stroke risk

What is first line for rate control in AF?

A beta-blocker or a rate-limiting calcium channel blocker (e.g. diltiazem)

Which patient groups are candidates for rhythm control in AF? (cardioversion)

• coexistent heart failure
• first onset AF
• where there is an obvious reversible cause
• where rate control has failed

When is the highest risk of stroke in cardioversion?

the moment a patient switches from AF to sinus rhythm

How do you manage the stroke risk when cardioverting patients?

patients must either have had a short duration of symptoms (less than 48 hours) or be anticoagulated for a period of time prior to attempting cardioversion.

Which AF patients should be considered for anti coagulation?

• symptomatic or asymptomatic paroxysmal, persistent or permanent atrial fibrillation
• atrial flutter
• a continuing risk of arrhythmia recurrence after cardioversion back to sinus rhythm or catheter ablation

How can you risk satisfy AF patients who are considered for anticoagulation?

CHA2DS2-VASc score for stroke risk

ORBIT scoring system for bleeding risk

When is Catheter ablation used in AF?

considered for those with AF who have not responded to or wish to avoid, antiarrhythmic medication

How does Catheter ablation work in AF?

the aim is to ablate the faulty electrical pathways that are resulting in atrial fibrillation. This is typically due to aberrant electrical activity between the pulmonary veins and left atrium

Whats the stroke risk post Catheter ablation for AF?

catheter ablation controls the rhythm but does not reduce the stroke risk

What's the success rate of Catheter ablation for AF?

• around 50% of patients experience an early recurrence (within 3 months) of AF that often resolves spontaneously
• longer term, after 3 years, around 55% of patients who've had a single procedure remain in sinus rhythm. Of patients who've undergone multiple procedures around 80% are in sinus rhythm

When is cardioversion considered in atrial fibrillation?

• electrical cardioversion as an emergency if the patient is haemodynamically unstable
• electrical or pharmacological cardioversion as an elective procedure where a rhythm control strategy is preferred.

How does electrical cardioversion work?

A synchronizing function (either manually operated or automatic) allows the cardioverter to deliver a reversion shock, by way of the pads, of a selected amount of electric current over a predefined number of milliseconds at the optimal moment in the cardiac cycle which corresponds to the R wave of the QRS complex on the ECG.

If the atrial fibrillation (AF) is definitely of less than 48 hours onset patients should be {{c1::heparinised}}. Patients who have risk factors for ischaemic stroke should be {{c2::put on lifelong oral anticoagulation}}. Otherwise, patients may be {{c3::cardioverted using either: electrical, pharmacology}}

What steps need to be taken before cardioverting someone who has been in AF for > 48 hours?

• anticoagulation should be given for at least 3 weeks prior to cardioversion
• alternative is to perform a transoesophageal echo (TOE) to exclude a left atrial appendage (LAA) thrombus

What medication can be given to increase to changes of cardiovertion being successful?

it is recommend to have at least 4 weeks amiodarone or sotalol prior to electrical cardioversion

How long should patients with AF be anticoagulated for following cardioversion?

for at least 4 weeks

What are the two first line medication for pharmacological cardioversion?

• amiodarone
• flecainide (if no structural heart disease)

In pharmacological cardioversion when must you use amiodarone over flecainide?

if there's structural heart disease