Quadripolar left ventricular lead in 20 cases with cardiac resynchronization therapy

Abstract

Objective The purpose of this study was to evaluate the application value of new type of quadripolar left ventricular (LV) lead in patients received cardiac resynchronization therapy(CRT). Methods Retrospective analysis was performed on heart failure patients following successful implantation of a quadripolar LV lead from March 2014 to April 2015 at The Second Affiliated Hospital, Zhejiang University College of Medicine.Clinical data like the anatomy characteristics of coronary vein, location of LV lead and the selected pacing vector were collected intraoperatively.During follow-up, clinical data such as the stability of LV lead, pacing threshold, phrenic nerve stimulation(PNS) and CRT response were collected postoperatively. Results Totally 20 consecutive heart failure patients [15 dilated cardiomyopathy, 3 ischemic cardiomyopathy, 2 others; mean age: (65.6±8.7) years] were selected in our study.All the 20 patients were implanted the quadripolar LV lead, in which 19 succeeded in the first target vein.The average length of LV lead target veins were(71.5±15.2) mm.The pacing sites of LV lead of the 20 cases were all at middle/basal segment(100%). Among them, the tip electrode (D1) of 12 cases were implanted at the apex of heart, 7 at the middle segment and 1 at the basal segment with the proximal fourth electrode (P4) left in the coronary main vein.The tip of LV lead of 19 cases were implanted into small tributary, while in another one case, target vein was lack of tributary, leading to the lead tip simply located in the distal end of lateral vein , and one month later, LV lead was dislocated. During implantation, PNS was occurred in 7 cases and high pacing threshold in 3 cases, which were all overcome by reprogramming pacing vector.After a median follow-up of 6.7 months, the threshold of tip electrode and ring electrode remained stable(P>0.05), LVEF and NYHA improved significantly(P<0.05). Conclusion The Quartet quadripolar LV lead proved to be better at choosing optimal pacing thresholds, avoiding apex pacing and PNS, improving the success of LV lead implantation in chronic heart failure patients receiving CRT.In our opinion, the quadripolar LV lead was suitable to the target vein with small tributary at the branch vein.The threshold of tip electrode and ring electrode remained stable at short-time follow-up. Key words: Cardiac resynchronization therapy; Quadripolar left ventricular lead; Left ventricular pacing site; Complication