Precordial reverse pattern break on ECG: could it be a discriminator endo/epicardial ablation site of left posteroseptal accessory pathways

Abstract Funding Acknowledgements Type of funding sources: None. Backrounds The posteroseptal (PS) region may pose difficulty in WPW ablation due to its complex anatomical structure. require the need for a transeptal puncture, CS venogram or coronary angiography right and left endocardial epicardial proximity. ECG prediction prevent unnecessary procedures. Negative V1 double QRS transition pattern precordial leads is highly specific validated AP Purpose To investigate presence reverse break [V1 (+) V3 (+)] patient compare between endocardial-epicardial localization. Methods We retrospectively included 338 patients into study. 97 them successfully ablated with area. Results Thirty-two total PS (33%) had pattern. A 4 middle cardiac vein (MCV) diverticulum origin were identified. predicts localization 75% time while it 95% time. Conclusion Double are common AP’s ECG. Left also predictive ablation, similar right.