Analysis Of The Predictive Effect Of Fragmented QRS Wave On Cardiac Function Decline After Pacemaker Implantation

Objective: To investigate the predictive role of fragmented QRS(f-QRS)in the decline of left ventricular ejection fraction(LVEF)after pacemaker implantation.Methods:Sick sinus syndrome was diagnosed in Taixing People’s Hospital Affiliated to Bengbu Medical College from January 2017 to December 2019 In 109 cases with sick sinus syndrome or Ⅲ°atrioventricular ventricular block,double-chamber pacemaker(DDDR mode)or single-chamber pacemaker(VVIR mode)was implanted.Each patient received 12-lead ECG and echocardiography on admission,pacing ECG,echocardiography and accumulative ratio of right ventricle pacing at postoperative follow-up,and LVEF decreased by absolute value(ΔLVEF)≥10% at the last follow-up,a total of 46 patients were included in the decreased LVEF group.The patients with ΔLVEF < 10% were divided into the group with no decrease in LVEF,a total of 63 cases.f-QRS(+)was recorded in the ECG of the two groups.None f-QRS is expressed as f-QRS(-).Univariate analysis was used to identify factors that might increase the risk of postoperative LVEF decline,and multivariate COX regression was used to identify independent risk factors associated with postoperative LVEF decline in patients with pacemaker implantation.Results:In all patients with pacemaker implantation,postoperative LVEF decreased as compared with preoperative level(62.79±7.87% VS 65.43±7.17%),the differences were significant(P < 0.01).Kaplan-Meier survival analysis hints: The average time of postoperative LVEF decline in f-QRS(+)patients before pacemaker implantation was earlier than that in f-QRS(-)patients before pacemaker implantation [(30.208±1.218)months VS(53.841±1.364)months](P < 0.01).Multivariate COX analysis suggested that preoperative f-QRS(+)(HR: 4.382,95%CI: 1.13-16.99,P=0.033),the number of pre-operative f-QRS leads(HR: 0.474,95%CI: 0.28-0.802,P=0.005),preoperative intrinsic QRS duration(IQRSd)(HR: 1.051,95%CI: 1.022-1.081,P=0.001),hypertension(HR: 2.217,95%CI: 1.15-4.217,P=0.017)was an independent predictor of LVEF decline after pacemaker implantation.The ROC curve indicated that the preoperative f-QRS lead number >1 and preoperative IQRSd>122ms were the best cut-off values for predicting the decrease of LVEF in patients with pacemaker implantation.Conclusion: Long-term right ventricular pacing increases the risk of postoperative LVEF decline.Preoperative f-QRS(+)patients had earlier postoperative decline in LVEF;f-QRS can be used to predict the decline trend of patients’ LVEF and assess the risk of cardiac function decline earlier.Improving the understanding of f-QRS can help to identify and manage patients at high risk of cardiac function decline in advance.