Complications of transvenous and transtboracic electrodes.

Electrode complications in a series of 220 patients are presented. At the primary pacemaker implantation, 114 patients received transvenous and 106 transthoracic electrodes. For the transvenous technique the Elema unipolar electrode (EMT 588 and 588 B) was used exclusively and for the transthoracic technique an epicardial disc electrode (EMT 567) was used in 64 per cent and myocardial electrodes (Vitatron MIP 125, Medtronic 5814 and 6913) in 36 per cent. The material was followed up for an average of three years (from 2 to 10 years). The dislocation frequency of transvenous electrodes was 10.4 per cent/patient-year, as 21 per cent of the electrodes became dislodged. Of the electrode dislocations, forty per cent occurred within the first post-implantation month. Exit block at stimulation with transthoracic electrodes was seen in 8.1 per cent/patient-year. Infections were more common with the transvenous than with the other types of electrodes. The myocardial electrode was significantly (p less than 0.05) more reliable than the transvenous electrode during the follow-up evaluated in terms of uncomplicated function time of the primary electrode. As in Helsinki both endocardial and myocardial-epicardial pacemaker electrodes have been used it seems to be of interest to report the results from our pacemaker material.