Figure 7

Ventricular arrhythmias (A) Illustration of the programmed electrical stimulation protocol. In the ECG tracing shown, ramp pacing elicits a NSVT episode of 7 beats. (B) Arrhythmia inducibility in the continued EEX study. Four stimulation steps were performed prior and after isoprenaline administration. No significant differences in inducibility were observed between the groups (logrank (Mantel-Cox) test P = 0.204). (C) Arrhythmia burden in the continued EEX study. The cumulative length of the induced arrhythmia episodes is expressed as the number of beats or duration in milliseconds. There was no significant difference between the CVB groups as evaluated by means of the Mann–Whitney U test. Three animals (2 from the CVB-EEX group and 1 from PBS-EEX) were excluded from the analysis because of periprocedural death, impeding completion of the stimulation protocol. Group size: PBS-SED: n = 5; PBS-EEX: n = 3; CVB-SED: n = 10; CVB-EEX: n = 7. (C) Arrhythmia inducibility in the pretrained EEX study. No significant differences with regard to inducibility were observed between the groups (logrank (Mantel-Cox) test P = 0.798). (D) Cumulative arrhythmia burden in the pretrained EEX study. The Mann–Whitney U test did not demonstrate significant CVB group differences. Animals not completing the entire stimulation protocol because of periprocedural death, were excluded from analysis (preSED-PBS: n = 1; preEEX-PBS: n = 1; preEEX-CVB: n = 1). Group size: preSED-PBS: n = 4; preEEX-PBS: n = 3; preSED-CVB: n = 6; preEEX-CVB: n = 6.