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... Show moreBACKGROUND: 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+/-2.61ms/mmHg in the TENS group, but did not change in the EXTR group (baseline: 3.37+/-2.53ms/mmHg; effect: 3.26+/-2.54ms/mmHg) (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. Show less
