Long-term outcome of variety of techniques used to stabilize left ventricular lead in difficult coronary sinus anatomy- A single centre experience.

Introduction: Difficult coronary sinus (CS) anatomy may lead to difficulty in optimal left ventricular (LV) lead placement and lead displacements leading to nonresponse to cardiac resynchronization therapy (CRT).

Methods: In this retrospective study, we studied the CRT parameters of devices implanted by single operator during the time period from January 2014 till December 2021, where different off-label techniques were used to place/stabilize LV lead. The technique used to stabilize LV lead, CRT parameters at baseline and follow up were noted for each patient.

Results: Out of 133 CRTs implanted during the study period, 23 patients (17.29 %) required off-label techniques. Stylet and guidewire retaining techniques were used in 11/23 (47.82 %) and 7/23 (30.43 %) patients respectively. In two patients, LV lead was jailed using coronary stent to prevent displacement. Two patients had CS stenosis and required balloon dilation while one patient had tortuous posterolateral vein which was straightened using a coronary stent. There was technical failure of 6/23 LV leads (26.08 %) with loss of capture, at a median follow up of 44 months (Range: 06-114 months). Out of these 6 patients, stylet and guidewire retaining techniques were used in 4 and 2 patients respectively.

Conclusion: Despite having acceptable parameters at implantation, these techniques particularly stylet and guidewire retention, may lead to non-capture of LV lead on long term follow ups. Better LV leads like active fixation leads and conduction system pacing (His Bundle/left bundle branch pacing) should be preferred in difficult CS anatomy.