The study aims to compare the results of pulmonary vein isolation (PVI) with a single technology approach in patients suffering from paroxysmal atrial fibrillation (PAF) with patients who have persistent AF of less than 3 months. Many studies have shown that electrical reconnection of the pulmonary veins following the index procedure can occur in up to 40% of targeted veins leading to a recurrence of PAF. Endoscopically guided laser ablation utilising the HeartLight system (CardioFocus Inc., USA) has been shown to be safe and effective and has also shown promising rates of durable isolation compared to point by point radio frequency techniques. However, the impact of employing this technique for patients with persistent AF has not yet been reported. The study hypothesis is that there will be no statistically significant difference between the results of PVI in the two groups of patients.