Multidetector CT (MDCT) visualization of the left atrial pulmonary venous anatomy is becoming increasingly requested prior to radiofrequencey catheter ablation (RFCA) procedures for refractory cardiac arrhythmias. MDCT imaging can define left atrial anatomy including atrial size and venous attachments as well identify complications such as stenoses, dissections or perforations. Proper understanding enables the cardiac imager to be knowledgeable so as to obtain the specific information needed for the interventional cardiologist. This paper reviews the left atrial venous anatomy, the clinical aspects of refractory atrial fibrillation, MDCT imaging protocols, procedural aspects of the ablation, and complications should they arise.