RESEARCH PAPER Robust anti-arrhythmic efficacy of verapamil and flunarizine against dofetilide-induced TdP arrhythmias is based upon a shared and a different

Summary of electrophysiological parameters and arrhythmic events in flunarizine suppression and prevention experiments Baseline 1 Dofetilide Flunarizine RR 1181 87 1291 140 1219 251QT 436 44 566 29* 435 36 $ QT C 421 49 553 40* 425 38 $ LV MAPD 355 35 492 53* 367 42 $ RV MAPD 310 32 395 68* 333 30 $ DMAPD 51 28 97 56* 48 32 $ STV LV 1.8 0.5 4.5 1.5* 1.5 0.6 $ TdP 0 011 8* 0 0 $ MEB 0 013 14* 0 0 $ SEB 1 248 58* 1 3 $ Baseline 2 Flunarizine Dofetilide RR 1239 329 1291 390 1410 462QT 422 51 380 50* 494 92* # QT C 413 51 369 41* 476 77* # LV MAPD 299 44 277 36 380 65* # RV MAPD 286 39 275 44 348 73* # DMAPD 42 27 22 16 38 42STV LV 1.5 0.6 1.0 0.5* 1.4 0.5TdP 0 00 00 0MEB 0 10 00 0SEB 3 63 56 10Maximal effects of flunarizine (5 min) in suppression experiments (upper part) and at the end of the infusion (2 min) in preventionexperiments are shown (lower part). Arrhythmias are quantified as average number of events (TdP, MEB, SEB) per 10 min, except for thepretreatment with flunarizine (lower part) where after 5 min dofetilide was added. All electrophysiological parameters are expressed in ms andarrhythmias as average number per time interval.*