Improved technique in permanent atrial pacing.

At the present time, the relatively high atrial stimulation threshold and the low and often unstable P wave amplitude are the main concerns in atrial pacing. As a further contribution to the solution of this problem we used a screw-in atrial lead in 16 patients. During the implantation, atrial mapping was performed in order to establish the position with the best electrical performance.

Three-year clinical experience with a new endocardial screw-in lead with introduction protection for use in the atrium and ventricle.

There is still a high incidence of dislodgement, threshold rises, and loss of sensing with permanent transvenous endocardial leads. Atrial leads are an even greater problem and require particularly reliable methods of fixation. In March, 1976 we reported our preliminary results from animal experiments using a new transvenous screw-in lead with introduction protection.

Electromagnetic interference in implantable pacemakers.

The inhibited pacemaker (VVI or AAI) has become the most popular in recent years because of its ability to combine a physiological advantage with economical current consumption in cases with spontaneous activity. One of its disadvantages is its sensitivity to external electromagnetic interference. Though today's pacemakers possess effective protection against most interference signals there may be instances in which patients are subjected to uncomfortable or even life-threatening situations.