Fig. 5. Ito-mediated J wave and ventricular fibrillation (VF) via phase 2 reentry. (A) VF in a male patient with J wave in lead II, note the larger amplitude of J wave in the beat preceding VF, following a longer R-R interval. (B) Phase 2 reentry predisposing to VF in a canine right ventricular wedge preparation in the presence of the K+ channel opener pinacidil. Loss of AP dome in Epi1 but not Epi2 caused propagation of the dome at Epi2 to Epi1, i.e. phase 2 reentry (solid arrows), which manifested a short-coupled R-on-T beats (open arrows) capable of triggering VF. Reproduced from Yan et al.35) with permission. ECG: electrocardiography.
