Introduction : This study aimed to identify whether shape of appendage ridge assessed by multidetector computed tomography (MDCT) is related to the long-term success of RFCA.MDCT is used to guide RFCA of atrial fibrillation (AF).Method : We analyzed data from 84 consecutive patients referred for RFCA due to drug-refiactory symptomatic paroxysmal AF.Prior to the procedure, all patients underwent ECG-gated 64-MDCT scan for assessment of LA and PV anatomy, LA thrombus evaluation, LA volume estimation, and electroanatomical mapping integration.We classified the shapes of appendage ridge as narrow I-shape (n=56) and broad V-shape (n=28).