Effects of DHA on regional APD and AP triangulation ex vivo. (A). Effects of DHA on APD₇₅ in apex, mid lateral wall, lateral basis, and medial basis in WT, LQT1, LQT2, LQT2–5, and LQT5 rabbits. (B) AP triangulation before (fully coloured columns) and after (dotted columns) administration of DHA in WT, LQT1, LQT2, LQT2–5, and LQT5 rabbits. (C) Comparison between APD₇₅ in LQTS rabbit hearts after administration of DHA and AP triangulation in WT rabbit hearts before administration of DHA. In contrast to QTc and APD_75, a normalization of AP triangulation cannot be observed in LQT2 after DHA administration; sample numbers: LQT1 (green) n = 7, LQT2 (red) n = 6, LQT2–5 (violet) n = 9, LQT5 (blue) n = 9, and WT rabbits (grey) n = 7. Differences are indicated as * for P-value < 0.050, ** for P-value < 0.010, and *** for P-value < 0.001. All data are presented as mean ± SEM. AP, action potential; APD, action potential duration; DHA, docosahexaenoic acid; LQTS, long QT syndrome; LQT1, long QT Type 1; LQT2, long QT Type 2; LQT5, long QT Type 5; LQT2–5, combined form of long QT Types 2 and 5; MAP, monophasic action potential; SEM, standard error of the mean; WT, wild type.