Pacemaker failure due to loss of fluid seal in a patient with a 5/6mm pacemaker header port and a 5mm unipolar lead

Before IS-1 (3.2 mm) standardization of pacemaker leads and connectors, 5/6 mm connector ports accomodated 5mm or 6mm diameter lead connector pins.

A patient with sick sinus syndrome underwent implantation of a 5mm unipolar atrial lead, mated to a 5/6mm connector port Medtronic Spectrax Sx 5985 pacemaker. Pulse generator reached ERI in 2006, with change out to a Medtronic Sigma SSR306 (5/6mm connector port) and preservation of the 5mm lead. She was admitted in 2010 for atrial lead non capture from blood leak and corrosion of the header-connector pin apparatus.

5/6mm pacemaker header ports have a 5mm flexible sealing ring at the port entrance to seal 5mm or 6mm lead connector pins. The inner barrel diameter of the connector port is 6mm and insertion of a 5mm lead results in a 0.5mm tolerance circumferentially. Should the seal be compromised, blood can corrode the apparatus. To minimize this, we can employ (a) a cinching tie to further seal the silicone ring (b) universal adaptor sleeves (c) splice kits (d) lead adaptor kits. Aging leads, adaptor kits or sleeves themselves can result in lead failure. It may be safer to re-implant the entire system.

A 5/6mm configuration pacemaker header connector port allows for significant tolerances when a 5 mm lead is used. Consideration must be made to prevent leaks.