The most common point of failure in a pacemaker is lead dislodgement from the cardiac wall occurring in 5-10% of patients. Currently, the only way to fix lead dislodgement is through corrective surgery which increases patient discomfort and overall cost of a pacemaker. Displacement is caused by exceeding the maximum tensile force on the lead. The main causes of lead displacement include Twiddler’s syndrome, Reel’s syndrome, and direct trauma to the device. Twiddler’s syndrome occurs when the patient rotates the pulse generator along it long axis causing tension and in severe enough cases lead displacement. Reel’s syndrome is almost identical to Twiddler’s syndrome however the pulse generator is rolled along its transverse axis. Direct trauma to the system comes from a variety of sources, the most common of those being intense respiratory therapies like CPR.
We are proposing a new design for bioactive pacemaker lead attachment. The
new design combines the current PtIr screw lead attachment with a bioactive, contractile Nitinol mesh. A bioactive scaffold made out of PLLA and Nitinol would be coated with an extracellular matrix derived hydrogel and pre-seeded with the patient’s own cardiac stem cells. This would encourage integration with the native host tissue and encourage differentiation of the implanted cells to replicate that of their microenvironment.

This mesh would back the screw and the NiTi “umbrella” will contract upon implantation, anchoring itself into the cardiac muscle. Over a period of a few weeks, the scaffold would be fully differentiated and integrated into the patient’s tissue. Over the course of a few months, the PLLA will safely degrade inside of the implant, ensuring the new cells are truly a part of the new tissue.

The tradeoff for this effectiveness is difficulty in removing the lead later. This still needs to be addressed.