Results presented today from the Atrial Fibrillation Ablation Pilot Study show that almost 40% of patients undergoing a catheter ablation for atrial fibrillation have no underlying disease associated with the arrhythmia, and precipitating factors are rare. The survey, which is a pilot survey from the ESC’s EurObservational registry programme, also confirmed that symptoms are present in 86% of patients but vary considerably; symptoms include palpitations, fatigue, and shortness of breath or dizziness.