Abstract 16739: Tricuspid Regurgitation Following Conduction System Pacing Lead Entanglement in Chordae Tendineae

Abstract

Case Description: A 62-year-old male with symptomatic sinus bradycardia presented for pacemaker implantation. Conduction system pacing (CSP) was pursued using the Medtronic 3830 lead. The lead was advanced through a C315His sheath and positioned at the basal-mid ventricular septum. Passive pacing demonstrated V1 notching and aVR/aVL discordance. An attempt was made to fixate the lead but despite rapid clockwise turns at the proximal lead tip, no lead penetration was seen in the LAO projection. The lead was removed and the sheath was repositioned. A second attempt was made with similar results. When attempting to remove the lead however, the lead remained adherent to the tissue despite multiple counter-clockwise turns. Increasing traction was applied at the proximal lead tip which resulted in elongation of the fixation screw and eventual disengagement from the tissue. Upon examination of the lead tip, there was fibrinous tissue suggestive of either chordae tendineae or valve remnant. Further attempts at CSP were aborted and the patient underwent traditional RV septal lead placement. Transthoracic echocardiogram (TTE) performed following the procedure demonstrated mild-moderate eccentric tricuspid regurgitation, likely due to chordae injury. Discussion: Left bundle branch pacing (LBBP) is becoming an increasingly popular form of CSP and requires deep penetration of the septum to engage the left bundle branch. To our knowledge, this is only the second case describing tricuspid valve chordae tendineae entanglement as a result of a CSP attempt. Most often, tricuspid regurgitation due to LBBP is attributed to entrapment of the septal TV leaflet from a basal position of the pacing lead. In our case, we suspect tricuspid valve injury occurred as a direct result of entanglement of the screw into the chordae. Potential ways to mitigate this complication are to pursue a more distal implantation site or to confirm adequate passive injury current prior to fixation to ensure the screw tip engages the myocardial tissue. Most of all, it is important to recognize that when a lead is not advancing into the septum, one should abort the position early and try an alternative site to avoid complications.