Interference of transcutaneous electrical nerve stimulation with permanent ventricular stimulation: a new clinical problem?

To assess the compatibility of thoracic TENS and permanent PM treatment and to identify any signs of interference of TENS with the PM function. Twenty-seven patients treated with PM were tested. Transcutaneous electric nerve stimulation electrodes were placed above each mamilla, and the stimulation intensity was increased to the maximum level tolerated for 30 s or until electrocardiogram revealed signs of interference. Transcutaneous electric nerve stimulation of 2 and 80 Hz was tested with the PM ventricular sensing level set to the clinically chosen level as well as to maximal sensitivity. Interference was detected in 22 of 27 patients (81%). Low-frequency (2 Hz) stimulation was more associated with PM interference (52% at normal vs. 81% at maximal ventricular sensitivity) than high-frequency (80 Hz) stimulation (33% at normal vs. 63% at maximal ventricular sensitivity); although the differences were not statistically significant. Transcutaneous electric nerve stimulation frequently induces inhibition of the PM function already at the clinically set ventricular sensitivity. Therefore, individual testing is warranted before TENS treatment is considered in patients with a PM. A test protocol for TENS and PM interaction is proposed.