A ringing cellular phone in a breast pocket may pose a danger to people with cardiac pacemakers, a researcher at Mount Sinai Medical Center in Miami Beach has found.
The pacemakers temporarily failed when an activated phone was placed very close to where the devices are implanted, near the collarbone.
But talking on the phone poses no danger, Dr. Roger Carrillo concluded.
Carrillo’s work is among the first in a growing body of inquiry into whether cellular phones and similar technology pose any health hazards.
Carrillo’s advice to pacemaker pa tients: Don’t hold or carry a cellular phone close to where the pacemaker is implanted. And consult your physician if you have concerns.
With the help of electrical engi neer Michael Pickels and others at Mount Sinai, Carrillo devised a test that measured heart activity in 59 volunteers with pacemakers while various models of phones were held in two positions: against the collarbone and to the ear.
The phones interfered with the heartbeat only when held close to the pacemakers. In 21 of 170 tests, the pacemaker failed to stimulate the heart, Carrillo and his colleagues said Thursday. When the phones were removed, the heartbeat went back to normal.
He said several types of cellular phones were used in the tests, and the problems appeared to be worse with newer, digital models. The analog models tested were the only ones that did not interfere with the pacemakers, Carrillo said.