Cardiovascular autonomic control in Becker muscular dystrophy

Although autonomic symptoms are not prominent in dystrophinopathies, a redu ced vagal activity and an enhanced sympathetic tone have been found in Duch enne muscular dystrophy. Twenty patients with Becker muscular dystrophy (BM D) were investigated by a battery of six cardiovascular autonomic tests (be at-to-beat variability during quiet breathing and deep breathing, heart rat e responses to Valsalva maneuver and standing, blood pressure responses to standing and sustained handgrip) and power spectral analysis (PSA) of heart rate variability. Although 11 patients revealed abnormal findings at some cardiovascular tests, none of them had a definite autonomic damage, as indi cated by two or more abnormal tests. The mean results of the single tests d id not differ from normal controls, except for the beat-to-beat variability during quiet breathing, which was significantly higher in BMD (p < 0.05). Such finding was confirmed by a significantly higher total variance (p < 0. 05), indicating an increased parasympathetic activity. Spectral components were not significantly different from normal controls. PSA values were not influenced by age, functional ability score or presence of heart abnormalit ies. Our data suggest that autonomic involvement does not represent a major finding in BMD. (C) 2001 Elsevier Science B.V. All rights Our reserved.