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.