**2. Classification of atrial fibrillation**

The terms used to classify and describe AF categorise it as paroxysmal, persistent, longstanding or permanent (figure 1). Paroxysmal AF is defined as at least two episodes of AF that terminate spontaneously within 7 days. If this is sustained beyond 7 days it is described as persistent. Another category of persistent AF includes longstanding AF, defined by duration of greater than one year. This usually leads to permanent atrial fibrillation in whom cardioversion has either failed or abandoned.15

Fig. 1. Classification of Atrial Fibrillation

Although rate control slows the ventricular response to AF, preventing tachycardia induced cardiomyopathy, it does not reduce the rates of thromboembolism or congestive heart failure. The atria are still in fibrillation and there is loss of the atrial "kick" resulting in worsening of congestive heart failure and requires indefinite anticoagulation with warfarin to counter the risk for developing thromboembolism. Although warfarin reduces the annual risk of ischaemic stroke and systemic thromboembolism to approximately 2%, its use is associated with significant morbidity with a 2% annual risk of drug associated haemorrhage.8,9,10 Anticoagulation may reduce lifetime relative risk of stroke by 60% but

Although the results of the AFFIRM trial demonstrated no long-term benefit of rhythm versus rate control, some patients may still have advantages of being in sinus rhythm. These include freedom from palpitations, increased exercise tolerance and prevention of atrial

Ineffective results with rate and rhythm control strategies have helped to encourage the development of new interventional catheter and surgical treatments. Although catheter ablation is an established therapeutic option, the highest success rates are typically seen in

Therefore it is limited to a small number of patients treated by highly skilled electrophysiologists. On the other hand, almost all cardiac surgeons are capable of

The terms used to classify and describe AF categorise it as paroxysmal, persistent, longstanding or permanent (figure 1). Paroxysmal AF is defined as at least two episodes of AF that terminate spontaneously within 7 days. If this is sustained beyond 7 days it is described as persistent. Another category of persistent AF includes longstanding AF, defined by duration of greater than one year. This usually leads to permanent atrial

*Atrial Fibrillation*

Permanent

Persistent

patients with paroxysmal AF and minimal structural heart disease.14

fibrillation in whom cardioversion has either failed or abandoned.15

does not eliminate it11

performing surgical ablation of AF.

**2. Classification of atrial fibrillation** 

Fig. 1. Classification of Atrial Fibrillation

remodelling. 12,13

Paroxysmal
