Catheter ablation for atrial fibrillation (AF) is performed in an increasing number of centres world wide. The recent guidelines on management of AF propose catheter ablation as a reasonable option when first-line antiarrhythmic drugs have failed.1 Several ablation strategies (such as segmental ostial ablation, circumferential ablation) exist, and there is still debate about the optimal ablation strategy. Meanwhile, new ablation strategies targeting fractionated signals,2 or isolation of the coronary sinus3 are being developed. However, in order to be successful and regardless of the ablation strategy applied, knowledge on pulmonary vein (PV) and atrial anatomy is crucial for the cardiologist performing AF ablation procedures.4

PULMONARY VEIN ANATOMY

Previous anatomical studies have demonstrated that PV anatomy is highly variable.5 Variations in its anatomy include “common” ostia of the PVs, additional PVs and anomalous insertion of the PVs. Therefore, accurate visualisation of PV anatomy before and during the ablation procedure is necessary. Different imaging techniques are available for the assessment of PV anatomy, including conventional venography, intracardiac echocardiography, multislice computed tomography (MSCT) and magnetic resonance imaging (MRI).6 Whereas venography and intracardiac echo can provide online information on the anatomy and location of the PVs, MSCT and MRI only provide offline information. However, for the most accurate depiction of PV anatomy and ostial diameters, three-dimensional imaging techniques, such as MSCT, are necessary.7 8 Jongbloed et al demonstrated that MSCT had a higher sensitivity for the detection of additional PVs than intracardiac echo.8 Furthermore, the oval shape of the PVs …