Mutual abrasion of endocardial leads: analysis of explanted leads

Abrasion of the outer insulation in crush syndrome and in the pocket region is a common cause of endocardial lead failure. Lead fracture at the level of the tricuspid valve has also been described.

We examined 1,212 endocardial leads removed percutaneously from 700 patients. The average time the leads had been in place was 77.3 ± 55.9 months. Macroscopic examination revealed abrasion of the outer insulation with exposure of the metal conductor in the intracardiac parts of 199 leads removed from 177 patients. Lead abrasion was confirmed by examination with an optical microscope. Multivariate analysis showed that the phenomenon was associated with the number of extracted leads, the time the leads had been in place, infections of the cardiovascular electronic device, location of the lead in the coronary sinus, and excessive lead length.

We conclude that the described mechanical abrasion of the outer lead insulation in the heart chambers could result from mutual friction. It is highly likely that intracardiac lead abrasion might play a role in the formation of intracardiac vegetation and lead-dependent endocarditis.