Influence of tilt training on activation of the autonomic nervous system in patients with vasovagal syncope.
OBJECTIVE
Tilt training is a new treatment for vasovagal syncope. Its therapeutic efficacy is thought to be the result of the desensitization of cardiopulmonary receptors, but it could be the influence of the tilt training on the activation of the autonomic nervous system as well.


RESULTS
The study group consisted of 24 vasovagal patients (17 women and 7 men) aged 32.5 +/- 11.8 years. The diagnostic head-up tilt test was performed according to the Italian protocol with nitroglycerin if necessary. The monitoring head-up tilt test was performed according to the Westminster protocol without provocation, after 1 to 3 months of tilt training. Holter ECG recordings for HRV parameters (time and frequency domain) were obtained from selected 2-min intervals before, during and after the diagnostic and monitoring tilt test. The diagnostic test was positive in the passive phase in 6 and after provocation in 18 patients. During the training period no syncope occurred. Analysing the HRV parameters we demonstrated the following findings: I. mRR decreases immediately after assumption of a vertical position in both tests (diagnostic and monitoring) but in the diagnostic test its further decrease occurs earlier than in the monitoring test; 2. the absolute power of the HF component is greater in the early phase of tilt after tilt training than in the corresponding period in the diagnostic test.


CONCLUSIONS
After a longer period of tilt training the activation of the sympathetic nervous system in response to the erect position is diminished.
Gajek
Jacek
J
Department of Cardiology, Medical University of Wroclaw, Wroclaw, Poland. gajek33@interia.pl
Zyśko
Dorota
D
Halawa
Bogumił
B
Mazurek
Walentyna
W
D000293:Adolescent; D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin; D011187:Posture; D019462:Syncope, Vasovagal / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D018667:Tilt-Table Test; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D005996:Nitroglycerin