Transvenous pacemaker leads in the dog: an experimental study

Tined transvenous pacing leads were inserted into nine healthy large-breed dogs as part of an experimental study evaluating an implantable defibrillator. The pacing leads were used to induce ventricular fibrillation on the day of insertion, two and four weeks after insertion and then monthly. Despite daily running exercise on and off a leash, the tined leads remained firmly anchored to the right ventricular apex for the full experimental period of up to 12 months. Apart from mechanical endocarditis of the tricuspid valve, and partial penetration of the ventricular wall in one dog, problems associated with the pacing leads were not encountered. The use of tined leads and careful technique may minimise the likelihood of transvenous lead displacement.