2 METHODS
The VTs per episode, recorded using an ICD or CRT-D device, were
classified as regular or irregular VTs according to the RR interval
variability of the cycle length. Based on this variability, we evaluated
the rates of VT termination using ATP or shock therapy, and spontaneous
termination, and acceleration. Additionally, the reproducibility of the
RR interval variability of VTs (regular or irregular) in both an episode
and an individual was evaluated.