DMD and Duchenne muscular dystrophy: Indeed, at both 6 and 10 months, the heart rate of DMD rats was not significantly different from that of their WT littermates (6 months: DMD = 421 ± 48 bpm, WT = 454 ± 47 bpm and 10 months: DMD = 421 ± 41 bpm, WT = 409 ± 40 bpm; p = 0.400, One-way ANOVA test).