Discussion
In this report, we presented successful Micra implantation through BTV
in a patient with repaired congenital heart disease. The procedure was
straightforward without any complications. During follow-up, the patient
was asymptomatic and the Micra interrogation showed proper functioning.
Tricuspid valve surgery carries a significant risk of conduction
disorders requiring PPM implantation. The implantation rate decreased
over time from 13-22% before 200013 to 5-11% in the
recent years.14 The PPM implantation after TV surgery
involves technical challenges that must be acknowledged by the
implanters to select the best technical option in each patient.
Several approaches have been reported: epicardial leads, standard
transvenous leads, his-bundle pacing, leadless pacing, or coronary sinus
leads.15
1) Although epicardial PPMs are proven to provide adequate pacing, the
reliability of endocardial leads has been shown to be superior to the
epicardial systems.16 This is especially true if
patients already had multiple cardiac surgeries with resultant
pericardial adhesion, since surgeons may have a tough time to find a
ventricular site with acceptable pacing thresholds.
2) Transvenous leads can interfere with the function of tricuspid
valves, leading to a significant morbidity and mortality through
hemodynamic impairment. The presence of transvenous lead was an
independent predictor of tricuspid regurgitation (TR) during
follow-up.17 Although there is no clear evidence of
increased TR after transvenous lead implantation in the presence of BTV,
most operators prefer to avoid transvenous lead in these patients.
3) His-bundle pacing (HBP) is a more physiologic form of pacing compared
to ventricular pacing. This could be an interesting alternative for
treating AVBs after TV surgeries, especially as the block site is nodal
in most cases. HBP has been described to be feasible in small series
(n=10) of patients after TV repair but none with TV
replacement.18 In these settings, the TV ring may act
as a radiographic marker of the his-bundle and facilitate the
implantation.
4) Since cardiac resynchronization therapy emerged as a cornerstone
treatment for advanced heart failure patients, rare data have been
published in the literature regarding CS pacing after TV surgery. Only
one small series of 17 patients (11 TV repairs and 6 TV replacements)
was published.19 Due to the right atrial dilatation
and resulting malposition of the CS ostium, CS catheterization and lead
placement may be more challenging in this specific situation compared to
typical CRT patients.
5) There are currently no large data about the safety and efficacy of
leadless pacemakers in patients after TV surgery. To date, there is a
few reports on Micra implantation after TV repair and BTV
surgery.10-12, 20, 21 The procedures were performed
successfully with no complications and patients did not have any
valvular dysfunction after the procedure.
.
LLP implantation is an emerging technology validated in clinical studies
and real-world setting with the potential advantage of overcoming some
of the limits of the traditional transvenous pacing lead such as need
for extraction after battery depletion. LLPs overcome this limit and
don’t need extraction after battery depletion; because LLP is
endothelialized into ventricle and according to the existing studies, up
to 3 LLP (with battery longevity of 10-12 years) can be placed inside
the RV. Therefore, there is no need to remove the previous LLP and a new
one can be implanted in the RV22.so it prevents
further open surgeries and the risk of post operation complications .LLP
implantation after BTV might represent an ideal option in this setting
by eliminating the risks connected with the presence of the lead across
the bioprosthetic valve, including valve dysfunction and valvular
endocarditis, 8,23,24. In conclusion, our case
demonstrates that a leadless pacemaker is an ideal option in patients
developing persistent conduction disorders after BTV.