Application Of Quadripolar Left Ventricular Lead In Cardiac Resynchronization Therapy

Objective:The selection and implantation of left ventricular electrode lead was a key step in cardiac resynchronization therapy(CRT).The purpose of this study was to investigate the application of quadripolar left ventricular lead in CRT.Methods:A total of 40 chronic heart failure patients were admitted into the Affiliated Medicine of Qingdao University from June 2016 to January 2018 and met European Society of Cardiology(ESC)heart failureⅠstandard indication of implanting CRT were selected.According to different left ventricular lead type,they are divided into quadripolar lead group(16 cases)and bipolar lead group(24 cases).The NYHA cardiac function classification of patients in two groups were evaluated in preoperative assessment,as the same time electrocardiography and transthoracic echocardiography were checked.During the operation,left ventricular lead placement time,target vessel distribution,pacing threshold and left ventricular pacing site were recorded.All patients were followed up for at least 12 months after surgery.The differences in left ventricular lead implantation time,pacing threshold,left ventricular pacing site,NYHA cardiac function classification,QRS duration,left ventricular end-diastolic dimension(LVEDD),left ventricular ejection fraction(LVEF),mitral regurgitation area(MRA),complications,and CRT reaction were compared between patients in two groups.SPSS 22.0 statistical software was used to analyze the data,and P<0.05 was considered statistically significant.Results:The left ventricular lead implantation time of the quadripolar lead group was shorter than bipolar lead group[(33.6±4.3)min vs.(37.7±3.7)min,P<0.05 ].The left ventricular pacing sites of the quadripolar lead group were located in the middle orbasal segment,thus apex pacing was completely avoiding.2 cases of phrenic nerve stimulation occurred in the quadripolar lead group during the operation,all of which were solved by adjusting the pacing vector to avoid replacing the target vessel.However,4 cases of phrenic nerve stimulation occurred in the bipolar lead group,2 cases of which were resolved after the adjustment of the original target vessel,and 2 cases of which were resolved by replacing the target vessel.In the quadripolar lead group,there was no dislocation of left ventricular lead,while in the bipolar lead group,there was 1 case of dislocation of lead,and a secondary replacement of left ventricular lead was performed.Compared with pre-operation,twelve months after surgery,QRS duration was shortened,NYHA cardiac functional class was decreased,LVEF was increased,LVEDD was shortened both in the two groups(P<0.05)Twelve months after surgery,no CRT deterioration occurred in the quadripolar lead group,and compared with the bipolar lead group,the response rate of CRT was higher(93.8% vs.66.7%,P<0.05),QRS duration was shorter[(140.1±9.2)ms vs.(149.5±8.3)ms,P<0.05],LVEF was higher [(40.4±2.4)% vs.(35.3±3.2)%,P<0.05] and LVEDD was shorter [(56.9±4.5)mm vs.(66.3±3.9)mm,P<0.05]in the quadripolar left ventricular lead group.Conclusions:Quadripolar left ventricular lead reduces the lead load,which was convenient to implant.It has high safety and low rate of lead dislocation.Quadripolar left ventricular lead increases the selectivity of left ventricular pacing sites,ensure the best pacing sites,effectively avoid the apex of heart,and improve the CRT response rate through the optimization of multiple pacing vectors.