The Effects Of QRS Characteristics Of True Left Bundle Branch Block On CRT Reactivity

According to data published by the ?Chinese cardiovascular disease report 2016?[1],the number of cardiovascular diseases in China is 290 million,among which heart failure is 4 million 500 thousand.The data show that the 5 year mortality rate of heart failure is as high as 50%.There are two main methods for the treatment of heart failure: drug therapy and non drug therapy.Cardiac resynchronization therapy(CRT)as a non drug treatment,It plays an important role in improving cardiac function and prognosis in patients with chronic congestive heart failure with complete left bundle branch block(CLBBB),the efficacy and safety of this treatment have been widely recognized in clinical.In 2012 and 2016,the ESC guidelines for the diagnosis and treatment of acute and chronic heart failure[2-3] were recommended as first class indications for patients with preoperative cardiac failure of CLBBB.But the current diagnostic criteria of left bundle branch block needs to be further explored,many clinical studies[4-6] have confirmed about 1/3 according to the traditional standard of CLBBB patients is not really CLBBB.Some clinical studies have also confirmed that the cases based on traditional CLBBB criteria,about 30% of patients do not benefit or rarely benefit from CRT[7-9].In 2011,Strauss et al[10] proposed the concept and diagnostic criteria of true CLBBB(t-CLBBB)for the first time.Subsequently,some clinical trials further demonstrated that the CRT reactivity in patients with t-CLBBB were better than patients with f-CLBBB[11-15].However,there is no specific quantitative requirement for the amplitude of V1 lead R wave in the new standard,and the independent influence factors of R-V1 amplitude on the reactivity of CRT to CRT are still lack of relevant reports.At the same time CRT perioperative and postoperative management is a long-term and complicated system engineering,in the management process of pacemaker perioperative and postoperative,effective left ventricular pacing is important for improving cardiac function,and it is a simple,cheap and cheap method to measure whether the left ventricular pacing is effective by pacing ECG,and it is easy to implement in clinic.To further clarify the effect of t-CLBBB amplitude of Initial R wave in lead V1 on cardiac resynchronization therapy,this study was designed to retrospectively analyze CRT reactivity to investigate the effect of preoperative t-LBBB V1 lead R wave amplitude on CRT reactivity and its significance.At the same time,retrospectively analyze the relationship between the morphology of QRS after operation and the CRT response.Method This study is divided into two parts,all of which are retrospe ctive analysis.All data were from our hospital's CRT patients with true left bundle branch block.Collected patients with CRT from October 2012 to December 2016 in our hospital.By the designated doctor to register all the patients' ECG and ultrasound echocardiography,etc.then record cardiac function in patients(NYHA grade)change,measuring QRS duration and every ventricular diastolic diameter(left and right ventricle,left atrium and right atrium),left ventricular ejection fraction(LVEF),fractional shortening(FS),etc.All cases required a minimum follow-up of 6 months.1.The effect of preoperative R-V1 amplitude to the CRT reactivity in patients with true left bundle branch block 1.1 All the selected patients completed three routine examinations,ECG,myocardial enzymes,liver and kidney function,coagulation function,etc.,in order to determine the absence of surgical contraindications.1.2 Coronary vein angiography,left ventricular electrode implantation,right ventricular and right atrial electrode implantation,threshold test and capsular suture were performed according to the routine operation of catheterization room in our hospital.1.3 After the operation,all patients need to had the twelve lead electrocardiogram,24 hour ambulatory electrocardiogram and ambulatory blood pressure monitoring and inspection.on the seventh day All patients need to undergo pacemaker programmed examinations under the guidance of echocardiography.1.4 Routine oral administration of ACEI,beta-blocker,CCB and diuretics,as well as other recommended drugs in guidelines,and according to the actual situation of patients to adjust drug treatment program.1.5 Regular follow-up(1 moth,2 moths,6 moths,12 moths,18 moths,24moths……), each follow-up need to undergo pacemaker programmed examinations under the guidance of echocardiography to optimize the left ventricular ejection fraction(LVEF)improvement,FS,etc.at the same time need to observe new arrhythmia.also,according to the clinical manifestations of patientsto adjust the drug treatment program.1.6 According to the initial R wave amplitude in lead V1 before CRT divided into study group(R-V1 ?0.1m V)and control group(R-V1 < 0.1m V).Two groups of patients were futher divided into two groups: control group I(R-V1=0.0m V),control group II(0.0m V < R-V1 < 0.1m V),study group I(0.1m V < R-V1 < 0.3m V),study group II(R-V1 = 0.3m V).The left ventricular ejection fraction(LVEF),Fractional shortening(FS),QRS duration,cardiac chamber size,NYHY classification and clinical symptoms were analyzed retrospectively.2.Study on the characteristics of QRS after operation to the reactivity of CRT in patients with left bundle branch block 2.1 Preoperative examinations,surgical procedures and follow-up procedures were the same as in the first part.2.2 These cases were divided into two groups by RV1 SI morphology according to the postoperative QRS wave group(R/S?1 in lead V1 and/or R/S?1 in lead I): RV1 SI group and non RV1 SI group were retrospectively analyzed to comprehensive evaluate the response by left ventricular ejection fraction(LVEF),fractional shortening(FS),QRS duration,the heart of the cavity chamber size,NYHY classification,and so on.Result 1.The effect of preoperative R-V1 amplitude to the CRT reactivity in patients with true left bundle branch block 1.1 From October 2012 to December 2016,a total of 108 patients with CRT were enrolled in our hospital.There were 55 patients with complete left bundle branch block,and the data were complete,all patients were followed up for a minimum of 6 months,the average follow-up time was 13.64±6.52(6-36)months.1.2 The study group was enrolled in 26 patients(n=26),includin g 9 patients in the study group I(0.1m V < R-V1 < 0.3m V)and 17 patients in the study group II(R-V1? 0.3m V);The control group was selected in 29 cases(n=29),in which the control group I a total of 19 cases(R-V1=0.0m V),the control group II(0.0m V < R-V1 < 0.1m V),a total of 10 cases.1.3 Before CRT,there were no significant differences in myocardial ischemia ratio,hypertension ratio,BNP value and other related clinical data between the study group and the control group.After CRT,NYHA grading,QRS time limit,LVEF,FS,LVEDD and so on were improved in all patients(P < 0.05).There was no significan t difference in the QRS interval between the two groups after the CRT(P > 0.05),but the ? LVEF control group increased more significantly than the study group(P < 0.01).1.4 After CRT,there was no statistical significance in four groups on ?QRS duration.?LVEF had no statistical difference between two subgroups in the control group,also in the study group.But the ?LVEF of the two subgroups in the control group was obviously higher than that of the two subgroups in the study group,the difference was statistically significant(P < 0.05).The results indicated that,when the R-V1 ?0.1mv,the ?LVEF had no statistical difference after CRT.this provides a clinical study evidence that 0.1mv can be used as a dividing line for optimizing CRT indications,but the standard is subject to further investigation because of the small number of cases and the single center study.2.Study on the characteristics of QRS after operation to the reactivity of CRT in patients with left bundle branch block 2.1 RV1 SI group was selected in 35 cases,of whom R-V1< 0.1mv was 19 cases(54.28%);non RV1 SI group of 20 cases,including 10 cases of R-V1< 0.1mv(50%).2.2 There was no significant differences between the preoperative clinical data of the two groups including the ratio of R-V1 < 0.1mv.But the LVEF,FS,LVEDD improvement in group RV1 SI were significantly higher than those in non RV1 SI group(P < 0.01),and the other data were not statistically significant.conclusion 1.True left bundle branch block can achieve a definite CRT response after CRT,but not every patient can achieve the same clinical treatment effect.2.Preoperative R-V1 amplitude had a marked effect on the CRT reactivity in patients with t-CLBBB.control group(R-V1 < 0.1mv)can get a better response after CRT,including 5 patients received CRT super-response,but there was no super responsor in study group.R-V1 amplitude is expected to be an independent factor to effect CRT reactivity in patients with true left bundle branch block; 3.Retrospective follow-up results confirmed the improvement of LVEF after operation in the two groups had significant differences,but there is no significant difference between the duration of QRS.Therefore,when we make pacemaker program,we can not only pursue the reduction of QRS duration,but also combine the other ultrasonic indicators and clinical symptoms to optimize the related parameters of pacemaker.4.The CRT response in RV1 SI group after operation was higher than non RV1 SI group.Because the form can reflect the effective pacing biventricular,the RV1 SI morphology can provide a reference standard for the operator to determine whether the electrode position of the left ventricular pacing is reasonable during Perioperative period.It can also provide important ECG reference value for the CRT managers to improve CRT reactivity.