The effects of exercise training on arterial baroreflex sensitivity in neurally mediated syncope patients.
OBJECTIVE
The clinical effects of different modalities of treatment for neurally mediated syncope have been studied for years; however, their influences on its pathophysiological mechanisms still have not been determined. This research aimed to observe the effects of physical training, tilt training, and pharmacological therapy on the arterial baroreflex sensitivity and muscle sympathetic nerve activity in neurally mediated syncope patients.


RESULTS
Seventy patients with recurrent neurally mediated syncope were included in this study. Patients were divided into the following four groups, depending on the treatment proposed: (i) physical training, (ii) tilt training, (iii) pharmacological therapy, and (iv) control group. All patients underwent an autonomic evaluation with microneurography, when the vagal and sympathetic arterial baroreflex gain were tested, using graded infusions of phenylephrine or sodium nitroprusside, before and 4 months after the interventions. The vagal and sympathetic arterial baroreflex gain significantly increased after a 4-month protocol of physical training. Tilt training, pharmacological therapy, and the control group had no significant change in the arterial baroreceptor responses.


CONCLUSIONS
Physical training improves arterial baroreflex sensitivity in neurally mediated syncope patients and could be applied as a non-pharmacological therapeutic alternative for these patients.
Gardenghi
Giulliano
G
Cardiovascular Rehabilitation and Exercise Physiology Unit, Heart Institute (InCor), University of São Paulo Medical School, Av. Dr Enéas de Carvalho Aguiar, 44, Cerqueira César, São Paulo, SP CEP 05403-000, Brazil.
Rondon
Maria Urbana P B
MU
Braga
Ana Maria F W
AM
Scanavacca
Mauricio I
MI
Negrão
Carlos Eduardo
CE
Sosa
Eduardo
E
Hachul
Denise Tessariol
DT
D000293:Adolescent; D000328:Adult; D017704:Baroreflex / Q000502:physiology*; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation; D010101:Oxygen Consumption / Q000502:physiology; D012008:Recurrence; D013564:Sympathetic Nervous System / Q000502:physiology; D019462:Syncope, Vasovagal / Q000503:physiopathology / Q000628:therapy*; D014630:Vagus Nerve / Q000502:physiology