Utility of local atrial electrogram pattern for predicting left main coronary artery anatomical distance during mapping in the left pulmonary sinus of valsalva

Background Ablation of right ventricular outflow tract (RVOT) ventricular arrhythmia (VA) within the left pulmonary sinus of Valsalva (LPSV) may increase the risk of left main coronary artery (LMCA) injury. Purpose To delineate the anatomical characteristics between LMCA and LPSV and their association with atrial potential (AP) mapping in LPSV. Methods A total of 104 consecutive patients with RVOT‐VA undergoing cardiac‐gated computed tomography coronary angiography (CTCA) after ablation were retrospectively analyzed. Results The LMCA‐LPSV anatomic relationship was classified into three types based on the CTCA measurements. Types 1 and 2 had a shorter LMCA‐LPSV distance than that of type 3 (P < .001). The left atrial appendage (LAA)‐LMCA distance and LAA‐LPSV distance were associated with the incidence of AP in LPSV (odds ratio [OR] = 3.43, 95% confidence interval [CI]: 1.86‐6.34, P < .001; OR = 1.196, 95% CI: 1.09‐1.31, P < .001, respectively). Furthermore, the LMCA‐LPSV distance showed a linear correlation with the LAA‐LPSV distance (r2 = 0.93, P < .001). According to receiver operating characteristic (ROC) analysis, a LMCA‐LPSV distance <5.4 mm could predict the possibility of AP during LPSV mapping (sensitivity 83%, specificity 81%, and area under the ROC curve 0.86). Conclusions The presence of AP in the LPSV may be useful to predict a short distance from the LPSV to the LMCA and to identify patients at higher risk of LMCA injury. This information may contribute to efficient and safe ablation in this area but should be confirmed in future studies.