Clinical Application Of Left Bundle Branch Pacing In Cardiac Resynchronization Therapy Of Patients With Heart Failure

Objective : To observe the effect of cardiac synchronization and the stability of lead pacing parameters in patients with heart failure,the present study was to investigate clinical outcomes and the safety of left bundle branch pacing(LBBP)in cardiac resynchronization therapy(CRT).Method: Twenty-two patients received CRT pacing were enrolled at our hospital from January 2018 to April 2020 in this study.According to the intracardiac electrocardiogram(ECG)and body surface ECG characteristics recorded,it was ensured that all patients underwent LBBP,and the postoperative ventricular pacing was simple left bundle branch pacing.Clinical date,pacing parameters(including threshold,impedance and R wave perception),electrocardiogram,echocardiographic data,NT-pro BNP levels,NYHA function grade and complications were recorded at implantation and follow-up,so as to evaluate the safety and feasibility of LBBP.The QRS duration(QRSd)under different pacing modes at implantation and the changes of QRSd after implantation were evaluated to assess intraventricular synchrony.And left ventricular end-diastolic diameter(LVEDD),left ventricular ejection fraction(LVEF),NT-pro BNP levels and NYHA function grade before and 1 year after operation are compared.Results: Among the 22 enrolled patients,68.1%(15/22)were male,with an average age of(68.45±10.40)years old,including 40.9%(9/22)of complete left bundle branch block,50.0%(11/22)of high atrioventricular block,and 59.1%(13/22)of atrial fibrillation.The pacing parameters were satisfactory during the implantation and stable in medium and long-term follow-up.Impedance during the follow-up period was lower than that in the operation(P<0.05).Compared with right ventricular pacing(RVP)and biventricular pacing(BVP),the QRS duration of LBBP during implantation was significantly narrower than that of RVP and BVP(116.8±10.9)ms vs(158.3±10.0)ms vs(125.8±8.1)ms,P<0.05 ].Left bundle branch block(LBBB)in 9 patients were corrected and the QRS duration was significantly shortened by LBBP(P<0.05).Follow-up for 1 year,there was a significant improvement[(37.9±7.3)vs(45.9±9.7)%,P<0.01] in LVEF in patients with LBBP.LVEDD decreased to 5.67±0.80 cm from baseline 6.24±0.69cm(P<0.05);The level of plasma NT-pro BNP decreased significantly[(4378.9±2149.0)vs(788.9± 463.1),P<0.01].NYHA function grade was improved from the preoperative level[(3.1±0.6)vs(2.1±0.5),P<0.01].No electrode dislocation perforation and other serious complications were found during the follow-up.Conclusion: Left bundle branch pacing threshold is low with good stability.QRSd and achieve favorable cardiac electrical and mechanical synchrony together with improvement in cardiac function.LBBP may be an alternative choice for patients with failure of left ventricular lead implantation or patients with no response of CRT.