[Modifications and control of the myocardial threshold with the Vario pacemaker EM 169 (author's transl)].

Measurements of threshold of electrical stimulation were performed in thirty patients with A-V block, at the time of implantation of the pacemaker, after 10 days, 1-2 months and 1 year. The Vario-pacemaker was used for the measurements. An increase in the stimulation threshold of about 260% was noted after 10 days and 1-2 months. One year after the implantation of the pacemaker, the myocardial threshold was about 200% of the initial value. The method is easy to perform. It is very useful to follow the myocardial threshold changes for a long period after the implantation.