Rehabilitation: Periodic somatosensory stimulation increases arterial baroreflex sensitivity in chronic heart failure patients

Background

One of the beneficial effects of exercise training in chronic heart failure (CHF) is an improvement in baroreflex sensitivity (BRS), a prognostic index in CHF. In our hypothesis-generating study we propose that at least part of this effect is mediated by neural afferent information, and more specifically, by exercise-induced somatosensory nerve traffic.

Objective

To compare the effects of periodic electrical somatosensory stimulation on BRS in patients with CHF with the effects of exercise training and with usual care.

Methods

We compared in stable CHF patients the effect of transcutaneous electrical nerve stimulation (TENS, N = 23, LVEF 30 ± 9%) with the effects of bicycle exercise training (EXTR, N = 20, LVEF 32 ± 7%). To mimic exercise-associated somatosensory ergoreceptor stimulation, we applied periodic (2/s, marching pace) burst TENS to both feet. TENS and EXTR sessions were held during two successive days.

Results

BRS, measured prior to the first intervention session and one day after the second intervention session, increased by 28% from 3.07 ± 2.06 to 4.24 ± 2.61 ms/mm Hg in the TENS group, but did not change in the EXTR group (baseline: 3.37 ± 2.53 ms/mm Hg; effect: 3.26 ± 2.54 ms/mm Hg) (P(TENS vs EXTR) = 0.02). Heart rate and systolic blood pressure did not change in either group.

Conclusions

We demonstrated that periodic somatosensory input alone is sufficient and efficient in increasing BRS in CHF patients. This concept constitutes a basis for studies towards more effective exercise training regimens in the diseased/impaired, in whom training aimed at BRS improvement should possibly focus more on the somatosensory aspect.