Figure 1.

Prolongation of left ventricular monophasic action potential duration (MAPD₉₀) by Bay K 8644 in the absence and presence of ATX-II. (a) and (b) Representative recordings of MAPs recorded from the epi- (a) and endo- (b) myocardium of the left ventricular wall in serially exposed to no drug (control), ATX-II (3 nM), Bay K 8644 (200 nM), and ATX-II (3 nM) plus Bay K 8644 (200 nM). (c) and (d) Concentration-dependent increases by Bay K 8644 of left ventricular epi- (c) and endo- (d) MAPD₉₀ in absence (n = 11) and presence (n = 7) of ATX-II. ^* P < 0.05 compared with 0 nM Bay K 8644 either in absence or presence of ATX-II; ^# P < 0.05, the increase of MAPD₉₀ by Bay K 8644 alone vs ATX-II plus Bay K 8644 at the same concentration. Arrows indicate ventricular tachycardia (VT) occurred at or above the concentration indicated.