Clinical significance of the dispersion of the activation--recovery interval and recovery time as markers for ventricular fibrillation susceptibility in patients with Brugada syndrome.

Brugada syndrome (BS) is associated with sudden cardiac death and the markers for ventricular fibrillation (VF) remain unclear, so the activation-recovery interval (ARI) dispersion and recovery time (RT) dispersion were investigated as possible markers in 20 subjects with BS (BS group) and 22 healthy individuals (H group). The 20 BS subjects were divided into 8 cases with documented VF (BS-VF group), 3 of which had recurrences, and 12 without (BS-N group). The corrected dispersion measurements from the standard 12-lead ECG of the QT interval (QTcd), ARI (ARIcd) and RT (RTcd) were compared among the groups. There were significant differences noted between the BS-VF and BS-N groups for the ARIcd and the RTcd, but not for the QTcd. Further, there were critical differences, 150 ms(1/2), observed for the ARIcd and RTcd, and these were associated with a prolongation of the maximum ARI or RT, shortening of the minimum ARI or RT, and prolongation only of the maximum QT for the QTcd. Susceptibility to VF may be predicted by the ARIcd or RTcd in BS.