Introduction
Leadless cardiac pacemakers (PMs) are an alternative to conventional
transvenous PMs designed to avoid the need for transvenous leads and
pockets 1. PM related adverse events remain
substantial; they occur in 1 in 8 patients, despite advancements in
pacing technology over the past six decades 2.
Transvenous PM leads can undergo dislodgment, insulation failure, and
may act as a portal for infection into the vascular space, whereas
pacemaker pockets are susceptible to hematomas and infections3. Thus, the development of a pacing system foregoing
leads and the need for a surgical pocket is a progressive advancement in
pacemaker technology. This has been achieved following advances in
pacemaker battery, component design and chemistry that have led to
leadless pacemakers small enough to be placed directly in the heart;
which may lead to the reduction in complications associated with
conventional transvenous leads and pockets 4.
Leadless cardiac PMs are completely self-contained, encapsulated in a
small unit, and are affixed by nitinol tines to the myocardium in the
right ventricle through a minimally invasive transcatheter approach via
the femoral vein. Reynolds et. Al and Reddy et. Al have reported two
multi-center studies which have found leadless pacemaker implantation to
be a promising alternative to older transvenous systems4,5.
The Micra transcatheter leadless pacing system (Medtronic, Minneapolis,
MN); an example of such a leadless PM, has demonstrated high procedural
success rates 6. However, the procedure may be
associated with complications, these include traumatic cardiac injury
with cardiac perforation and pericardial effusion, high capture
thresholds, and rarely, ventricular arrhythmias 7,8.
While some of these such as traumatic cardiac injury may be attributed
to the learning curve of operators handling this novel technology, other
complications such as arrhythmia may be secondary to implant position of
the device 9.
Few cases of ventricular arrythmias due to Micra have been reported in
the literature. We wish to add to the literature by presenting a case of
ventricular fibrillation arrest temporally related to Micra implant.