Cardiac and autonomic adaptations to a wheelchair hockey match in athletes with muscular dystrophy

Muscular dystrophies (MD), such as Duchenne’s MD (DMD), appear in childhood and progressively lead to respiratory and/or heart failure. Exercise-based therapy may be helpful, but the cardiac and autonomic adaptations to sport activities are poorly studied in MD patients. Heart rate (HR) was measured in 30 players (all males, 28±6 [m±SD] years) with different forms of MD (divided into 2 groups according to pathology severity): (a) before, (b) during and (c) immediately after a wheelchair hockey match. In addition, HR variability (HRV) indexes RMSSD, SD1, LF, HF and LF/HF ratio were measured before and during the game in a subgroup of 9 DMD athletes. A sinus tachycardia was found in all MD athletes before the game (114±13 bpm in DMD, 113±18 bpm in other muscular dystrophies, OMD). In both DMD and OMD groups HR increased significantly from pre-game to game and decreased during recovery. During the game, HR was higher in the OMD compared to the DMD group. The subgroup of DMD athletes evidenced an almost normal parasympathetic withdrawal and altered sympathetic adaptations to exercise. Sinus tachycardia affects MD patients independently from MD form. However, the residual autonomic modulation allows the athletes to adapt to the energetic demands of wheelchair hockey.