Increased orthostatic tolerance following moderate exercise training in patients with unexplained syncope (original) (raw)
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Physical Training as Non-Pharmacological Treatment of Neurocardiogenic Syncope
Arquivos Brasileiros de Cardiologia, 2014
Background: Characterized as a sudden and temporary loss of consciousness and postural tone, with quick and spontaneous recovery, syncope is caused by an acute reduction of systemic arterial pressure and, therefore, of cerebral blood flow. Unsatisfactory results with the use of drugs allowed the nonpharmacological treatment of neurocardiogenic syncope was contemplated as the first therapeutic option. Objectives: To compare, in patients with neurocardiogenic syncope, the impact of a moderate intensity aerobic physical training (AFT) and a control intervention on the positivity of head-up tilting test (HUT) and orthostatic tolerance time. Methods: Were studied 21 patients with a history of recurrent neurocardiogenic syncope and HUT. The patients were randomized into: trained group (TG), n = 11, and control group (CG), n = 10. The TG was submitted to 12 weeks of AFT supervised, in cycle ergometer, and the CG to a control procedure that consisted in 15 minutes of stretching and 15 minutes of light walk. Results: The TG had a positive effect to physical training, with a significant increase in peak oxygen consumption. The CG did not show any statistically significant change before and after the intervention. After the intervention period, 72.7% of the TG sample had negative results to the HUT, not having syncope in the revaluation. Conclusion: The program of supervised aerobic physical training for 12 weeks was able to reduce the number of positive HUT, as it was able to increase tolerance time in orthostatic position during the HUT after the intervention period. (Arq Bras Cardiol. 2014; 102(3):288-294
European Heart Journal, 2007
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. Methods and 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. Conclusion Physical training improves arterial baroreflex sensitivity in neurally mediated syncope patients and could be applied as a non-pharmacological therapeutic alternative for these patients.
Epidemiology and prognostic implications of syncope in young competing athletes
European Heart Journal, 2004
Aims This study was undertaken to evaluate the epidemiological features and the prognostic implications of syncope in young athletes. Methods and results A cohort of 7568 young athletes (5132 males, 2436 females, aged 16.2 ± 2.4) underwent a pre-participation evaluation. A syncopal spell in the last 5 years was reported by 474 athletes (6.2%). Syncope was unrelated with exercise in 411 athletes (86.7%), post-exertional in 57 (12.0%) and exertional in 6 (1.3%). All episodes of non-exertional or post-exertional syncope had the typical features of neurallymediated fainting. The 6 athletes with exertional syncope underwent further testing allowing the diagnosis of hypertrophic cardiomyopathy in one case, and of right ventricular outflow tract tachycardia in another. The remaining 4 athletes only showed a positive response to tilt-testing. All athletes were followed for 6.4 ± 3.1 years, during 48 066.6 person-years of follow-up. The recurrence rate was 20.3 per 1000 subjectyears in athletes with non-exertional, and 19.2 per 1000 subject-years in athletes with post-exertional syncope. The incidence of first report of syncope was 2.2 per 1000 subject-years for non-exertional and 0.26 per 1000 subjects-years for post-exertional spells. No other adverse event was noted during follow-up. Conclusions In young athletes, syncope occurring before the initial pre-participation screening has a neurally-mediated origin in most cases and shows a low recurrence rate. Exercise-related syncope is infrequent and is not associated with an adverse outcome in subjects without cardiovascular abnormalities. The incidence of new syncope during competitive activity is particularly low.
Delaying orthostatic syncope with mental challenge: A pilot study
Physiology & Behavior, 2012
At orthostatic vasovagal syncope there appears to be a sudden decline of sympathetic activity. As mental challenge activates the sympathetic system, we hypothesized that doing mental arithmetic in volunteers driven to the end point of their cardiovascular stability may delay the onset of orthostatic syncope. We investigated this in healthy male subjects. Each subject underwent a head up tilt (HUT)+ graded lower body negative pressure (LBNP) up to presyncope session (control) to determine the orthostatic tolerance time, OTT (Time from HUT commencement to development of presyncopal symptoms/signs). Once the tolerance time was known, a randomized crossover protocol was used: either 1) Repeat HUT + LBNP to ensure reproducibility of repeated run or 2) HUT + LBNP run but with added mental challenge (2 min before the expected presyncope time). Test protocols were separated by 2 weeks. Our studies on five male test subjects indicate that mental challenge improves orthostatic tolerance significantly. Additional mental loading could be a useful countermeasure to alleviate the orthostatic responses of persons, particularly in those with histories of dizziness on standing up, or to alleviate hypotension that frequently occurs during hemodialysis or on return to earth from the spaceflight environment of microgravity.
1996
IX Results. Blood volume decreased an average of 14.9 (± 22.1) ml in the calf segment; increased an average of 64.1 (± 7.9) ml in the thigh segment, and decreased an average of 80.1 (± 29.7) ml in the abdominal segment. The mean net change in volume of the three combined regions was not significantly different from zero. Presyncope was induced in subjects by a progressive exposure to upright tilt, and then addition of LBNP at-20 mm Hg and-40 mm Hg. In the tilt/LBNP group, there was a net increase of 1022 (±269.8) ml for the combined segments. Changes in all 3 segments were significantly different than the mean segmental volume changes seen in centrifuge subjects at G-LOC endpoints. Significant changes from baseline mean arterial pressure, but not heart rate were also seen within, but not between the 2 groups, with mean eye level blood pressures (ELBP) falling an average of 45.6 (±7.7) mm Hg in the tilt/LBNP group at syncope and 105.1 (±15.5) mm Hg in the centrifuge subjects at G-LOC. Conclusions: These differences suggest that G-LOC may be due entirely to hydrostatic effects, with venous pooling being prevented by the wearing of an anti-G garment, even when it remains uninflated.
Efficacy of Orthostatic Self‐Training in Medically Refractory Neurocardiogenic Syncope
Clinical and Experimental Hypertension, 2003
Background. Orthostatic self-training is effective in the prevention of neurocardiogenic syncope, though the success of this method in drug refractory patients has not been reported. Study objective and methods. This study examined the effectiveness of orthostatic self-training in 15 patients with head-up tilt testing (HUT)-inducible neurocardiogenic syncope, who were intolerant of, or refractory to standard drug therapy. They were enrolled in a home orthostatic self-training program for up to 30 min=session, twice daily. Head-up tilt testing was repeated within 4 weeks after onset of the training program, using the same protocol as at baseline. Orthostatic self-training was continued once daily, for up to 30 min, for a mean follow-up period of 11 months, in the drug-free state. Results. Syncope was not reinducible by follow-up HUT, and spontaneous syncope occurred in no patient during the follow-up period. Conclusions. Home orthostatic self-training, up to 30 min once daily following an initial twice daily program, was highly effective in the suppression of recurrent neurocardiogenic syncope in patients intolerant of, or refractory to standard drug therapy.