Interference in pacemakers.

We attempt here to outline the different sources of interference and the methods of interference detection and protection with their advantages and disadvantages. A proposal is made as to how a better interference suppression could be established. A comparison of 16 pacemakers from ten manufacturers tested with different interference sources revealed a great variety, which does not allow one to generalize the problem of interference. As an example, an electric steel furnace with its magnetic field is described and how its influence on pacemakers can be estimated. Rules are given as to how pacemaker patients may be treated by electrotherapy. A test procedure for characterizing the specific interference behavior is proposed.