Effect Of Spatial Conformational Changes Of Left Ventricular Quadrupole Pacemaker Electrode On Cardiac Function In Cardiac Resynchronization Therapy

Objective: To explore the effect of left ventricular quadrupole pacemaker on cardiac function in cardiac resynchronization therapy.Methods: From September 2018 to September 2019,30 patients with heart failure who were admitted to the Cardiovascular and Emergency Internal Medicine wards of the affiliated Hospital of Inner Mongolia Medical University in accordance with the indications of ACCF/AHA/HRS implantation of CRT class ? a(NYHA cardiac function class ? or ? a,LVEF ? 35%,with LBBB and QRS ? 150ms)were selected,including 27 cases of dilated cardiomyopathy and 2 cases of ischemic cardiomyopathy.One case of hyperthyroid cardiomyopathy was divided into left ventricular quadrupole lead CRT group(n =10)and conventional three-chamber CRT group(n =20)on the basis of optimal drug treatment.Baseline information was collected,including age,sex,presence of complications,QRS duration,N-terminal pro-brain natriuretic peptide(NT-pro BNP)level,left ventricular end-diastolic diameter(LVEDD),left atrial anterior-posterior diameter(LAD),left ventricular ejection fraction(LVEF),6-minute walking distance(6MWD),complications,medication,New York Heart Association cardiac function classification,etc.,and told them to follow up 3months and 6 months after operation.Improve the cardiac surface echocardiography,cooperate with external program control,adjust the pacemaker parameters of the two groups,and adjust the pacing vector combination of the quadrupole lead group if necessary.Compare the differences of color Doppler echocardiography(LVEDD,LAD,LVEF),QRS wave duration,NT-pro BNP level and 6MWD between the two groups before and after operation,and evaluate whether there are differences in ventricular wall synchrony,CRT reactivity and cardiac function improvement between the two groups.Using SPSS 23.0 statistical software to analyze the data of each group,the difference was statistically significant(P <0.05),and there was no significant difference(P>0.05).Results:1.There was no statistical difference between the two groups.2.In most patients,the left ventricular lead was implanted into the apex of the heart,and the posterior collateral was selected as the target vessel.There was no significant difference between the two groups(P = 1,0.562 > 0.05).3.CRT was implanted successfully in both groups,the success rate was100%.4.The pacing vectors that can be selected in the quadrupole wire group were much more than that in the bipolar wire group,more than three pacing vectors accounted for 80%and 10% respectively,the difference was statistically significant(P = 0.003 < 0.05).5.During the 3-month follow-up,LAD(43.2 ± 4.8vs52.3 ± 8.0)and LVEF(47.9 ± 5.7vs34.8 ±8.6)in the 4-pole wire group and the 2-pole wire group were reversed(P = 0.003,0.0002 <0.05),lved(59.8 ± 10.4)in the 4-pole wire group and lved(69.4 ± 8.8)in the 2-pole wire group were increased.NT pro BNP(827.8 ± 478.5vs3460.0 ± 3851.0)decreased(P =0.042 < 0.05),QRS(135.0 ± 5.4vs144.0 ± 13.3)shortened significantly(P = 0.049 <0.05),6MWD increased(154.0 ± 37.7vs119.2 ± 44.6,P = 0.043 < 0.05),but the former was better than the latter.6.After 6 months of menstruation optimization,LVEDd(58.0 ±10.1 vs 67.3 ± 9.0),LAD(41.0 ± 3.9 vs 50.3 ± 8.1),LVEF(53.7 ± 6.4 vs 38.7 ±10.9)and LVEF(P = 0.017,0.002,0.0004 < 0.05)in the two groups were more significant than those in the former group(P = 0.017,0.002,0.0004 < 0.05)BNP(444.6 ± 324.3)was further decreased,but the difference was not statistically significant(P = 0.199 > 0.05).The QRS time limit(125.4 ± 6.2vs134.5 ± 12.2)was further shortened(P = 0.045 < 0.05),and 6MWD(344.4 ± 117.1vs167.3 ± 50.8)was further improved(P < 0.001),and the improvement was still more obvious in the quadrupole wire group.Six months after the operation,six patients(60.0%)and four patients(20.0%)were assessed for wall synchrony in the four pole lead group.The wall synchrony in the two groups was better than that before the operation(P = 0.045 < 0.05).There were 11 cases of CRT unresponsiveness after operation,1case in quadrupole wire group(10.0%),10 cases in bipolar wire group(50.0%).There were 5cases(55.6%)and 6 cases(60.0%)in the two groups,respectively.There was statistical difference in the incidence of CRT non response(P = 0.048 < 0.05),and there was no statistical difference in the incidence of hyper response(P = 0.425 < 0.05).7.The incidence of left ventricular quadrupole CRT phrenic nerve stimulation is lower,which can avoid the second operation.There was no electrode dislocation and high pacing threshold in both groups,and no death.Conclusions:Implantation of left ventricular quadrupole lead CRT and bipolar lead CRT can benefit patients with chronic heart failure.However,the short-term effect of the former is better than that of the latter in improving acute hemodynamics,restoring mechanical synchronization,improving cardiac function,increasing wall synchronization and increasing CRT response rate,and the above-mentioned functions can be further improved with the extension of implantation time.CRT with left ventricular quadrupole leads has a lower incidence of phrenic nerve stimulation and can avoid secondary operation.There was no electrode dislocation and high pacing threshold in both groups,which needed further follow-up and evaluation.