A 17-year-old female with Kearns Sayre syndrome, complete heart block,
and an implanted single chamber (VVIR) pacemaker, underwent testing w
ith a GSM cellular phone that was placed directly over the pacemaker s
ite. The pacemaker was immediately inhibited when the phone began to o
perate. A 6.5-second period of complete heart block with asystole occu
rred until the phone was switched off.