DISCUSSION
The present study retrospectively analyzed the characteristics of pseudo-focal ATs. The main findings are as follows: (1) the breakthrough site is close to a low-voltage area that contains the collision site and masks a well-identified epicardial bundle supporting the concealed part of the circuit; (2) a short PPI at the site opposite to the breakthrough site demonstrates a macroreentrant mechanism despite centrifugal propagation in the activation map; and (3) the distinction from true focal ATs is crucial, since ablating the breakthrough site is not the best therapeutic option in pseudo-focal ATs.