Blunted cardiovascular responses to exercise by inhibiting afferent feedback via spinal cord stimulation in heart failure

Abstract

This case study investigated the impact of SCS on alterations in blood pressure during constant-load exercise in a female patient with heart failure. Three different SCS frequencies [No SCS (~0 Hz), Low SCS (~100 Hz), and High SCS (~1000 Hz)] with and without ischaemic stimulation of the legs (cuffs) were randomly applied during constant-load exercise. To determine cardiovascular and ventilatory responses to exercise following SCS frequencies, BP, heart rate (HR), and respiratory gas exchange were measured. This experiment was duplicated in visit 1 and visit 2 with a random application of SCS frequency order and the data were averaged. There were no significant differences among three frequencies with no leg ischaemia. However, High SCS demonstrated lower BP, HR, and respiratory gas exchange relative to No SCS and Low SCS. SCS may be effective in improving cardiovascular and ventilatory responses in HF and high-frequency stimulation provides more clinical benefit; however, further studies are needed.