Patients experiencing loss of efficacy can experience improvement if alternative pacemaker settings are tested. High-frequency stimulation (31 Hz/210 µs) was preferred by more than half of the patients, and improved treatment outcome was sustained at 3 months.

: Subsensory stimulation as low as 50% of the ST is as effective as stimulation at or above the ST. The study was approved by the Regional Committee on Biomedical Research Ethics, Denmark, and registered at ClinicalTrials.gov (NCT01130870).