Centrifugal wave-front propagation speed for localizing the atrial tachycardia origin

Background: The earliest activation site (EAS) on a centrifugally-propagated atrial tachycardia (AT) map may represent the true AT origin (true-focal pattern), or the earliest site resulting from passive activation of AT originating from neighboring tissue (pseudo-focal pattern). We assessed the benefits of using the wave-front propagation speed to distinguish between the true- and the pseudo-focal pattern.

Methods: AT mapping was performed using a novel ultra-high resolution mapping system with a 64-electrode mini-basket catheter. The true AT origin was defined as the site where radiofrequency application eliminated AT. The wave-front propagation speed was estimated from the area surrounded by the centrifugally-propagated wave front over a specific time interval.

Results: Total of 46 centrifugally propagated AT maps from 34 patients were analyzed, including 18 true-focal and 28 pseudo-focal pattern. The area surrounded by the propagated wave front was significantly smaller for the true-focal pattern than for the pseudo-focal pattern, 1-20 msec after the earliest activation. The true-focal pattern was identified by the area 13 msec after the earliest activation, with the best cut-off area value of <4.5 cm².

Conclusion: The presence or absence of a true origin of AT at the EAS on centrifugally-propagated AT maps can be distinguished using a wave-front propagation speed.