Can transcutaneous electrical nerve stimulation be safely used in patients with permanent cardiac pacemakers?

In 51 patients who had 20 different models of permanent cardiac pacemakers, we conducted transcutaneous electrical nerve stimulation studies at four anatomic sites--the lumbar area, cervical spine, left leg, and lower arm area ipsilateral to the pacemaker. With a mean stimulation of 24.7 Hz, no episodes of interference, inhibition, or reprogramming of the pacemakers occurred. The proximity of the stimulation site to the pulse generator had no effect. We did not study electrodes placed parallel to the pacemaker electrode vector, a position that has been of concern to others and that should probably be avoided until proved safe. On the basis of our findings, we believe that most patients with permanent cardiac pacemakers can safely undergo transcutaneous nerve stimulation.