Discussion
The use of a single ventricular lead placed in the coronary sinus in
patients with prosthetic tricuspid valves is well established.[1-5] Data shows that ventricular sensing by an LV
lead placed in the coronary veins is feasible and reliable[7]. When compared to the unipolar leads,
quadripolar leads have the advantage of having more pacing sites which
can optimize the pacing threshold, [6] but the
disadvantage of not allowing to perform conventional ventricular
sensing, as it is usually achieved by the RV lead in patients with
CRT-P. Among device manufacturers, Biotronikresynchronization devices have independently RV and LV pacing and
sensing. While RV sensing is used for RV-based timing and RV pacing
inhibition, LV sensing is only used to prevent a pacemaker-induced
arrhythmia, as it inhibits a scheduled pace event for 300 to 500ms to
avoid LV pacing during de vulnerable recovery period (T wave) but does
not reset the lower rate timer – this feature is referred to as LV
T-wave protection. [8] Here, we describe a patient
with a mechanical tricuspid valve and a previous malfunctioning CS
unipolar lead that as submitted to a second lead implantation in the CS.
It was decided to a quadripolar lead due to the several pacing options
allowing the optimization of the pacing threshold. Due to the presence
of patient’s heart rhythm for periods, a BiotronikCRT-P generator was chosen to perform LV sensing using de LV T-wave
protection algorithm. The chosen endocardial approach avoided a fourth
surgical intervention to place an epicardial lead, that would have been
associated with increased morbidity. As far as we know, it is the first
described case of a patient with prosthetic tricuspid valve and a
previous CS malfunctioning lead that was submitted to a single
ventricular quadripolar lead placement in the CS, programmed at VVI-BiV
and using only the LV T-wave protection algorithm as sensing mechanism.
ACKNOWLEDGMENTS
No acknowledgments to report.
CONFLICT OF INTEREST
The authors have no conflict of interest to declare.
AUTHOR CONTRIBUTIONS
PSC and MMO: designed and directed the project. AG and PSC: collected
the data. AG: wrote the manuscript with support from PSC and MMO.
ETHICAL APPROVAL
Written informed consent was obtained from the patient for the
publication of this case report.