The Electrical Remodeling And Mechanical Remodeling After Cardiac Resynchronization Therapy In Heart Failure Patients

Object:To investigate the electrical remodeling and mechanical remodeling after cardiac resynchronization therapy in heart failure patients,and to observe the difference of short-term and long-term effects of cardiac resynchronization therapy in ischemic cardiomyopathy and non-ischemic cardiomyopathy.Method:A total of50patients from January2006to June2011in Tianjin Chest Hospital with an indication for a permanent cardiac resynchronization therapy because of advanced heart failure.Then according to the underlying aetiology of heart disease,the patients are divided into ischemic cardiomyopathy group(11cases) and non-ischemic cardiomyopathy group(39cases).The50patients associated with heart failure and bundle branch block were given cardiac resynchronization therapy. The above group were analysed before CRT,1month after CRT,six months after CRT in terms of electrical remodeling parameters and mechanical remodeling parameters and other parameters.furthermore analyse the long-term survival rate. The electrical remodeling parameters were obtained:P wave duration.PR duration,paced QRS duration,native QRS duration,corrected QT duration(QTc) and QT dispersion(QTd). The mechanical remodeling parameters were obtained:left ventricular ejection fraction(LVEF),left atrial diameter(LAD).left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic volume(LVESV),pulmonary artery pressure(PAP),interventriclar mechanical delay(IVMD),septal-to-posterior wall motion delay(SPWMD).Other parameters were obtained:brain natriuretic peptide(BNP) and NYHA cardiac function classification.Meanwhile.the50patients were divided non-ischemic cardiomyopathy(NICM)group and ischemic cardiomyopathy(ICM)group.the different etiology patients were analysed before CRT, one month after CRT,six months after CRT respectively in terms of electrical remodeling parameters and mechanical remodeling parameters and other parameters.in order to evaluate the difference of short-term and long-term effects after cardiac resynchronization therapy.Reults:CRT were successfully implanted in all50patients with six months to five years of follow-up. The mean follow-up was2.04±1.21years,ten patients died during follow-up.seven of dead patients died of end-stage heart failure,others died of sudden cardiac death. The50patients were follow-up in one month and six months after CRT.compared with the preoperative, the P wave duration,PR duration and QTc of electrical remodeling parameters were no significant change over the previous,and the same of the native QRS duration, but the paced QRS duration and QTd was significantly shorter than the previous.LAD,LVESV,LVEF.LVEDD,PAP,IVMD, SPWMD of mechanical remodeling parameters and BNP,NYHA cardiac function classification of other parameters were improved compared with preoperative in one month and six months after CRT. If according to the definition of response to CRT(more than15%relative decrease in LVESV).64%(32/50) of patients were considered responders;if according to the definition of response to CRT(at least one classification or more improvement in NYHA cardiac function classification),68%(34/50) of patients were considered responders.The electrical remodeling,mechanical remodeling and other parameters were no significant difference of the improvement1month after CRT between the NICM and ICM group, but most of the indicators were significant difference of the improvement6months after CRT between the two groups,the electrical remodeling and mechanical remodeling effect of ICM was significantly lower than the NICM.Meanwhile,the significant difference of the survival estimate at5years was found between the two groups,the long-term survival of the NICM group was better than the ICM group.Conclusion:The implantation of CRT can improve the electrical conduction between the ventricular to a certain extent,reverse the ventricular mechanical remodeling of heart failure patients,improve the cardiac function of heart failure patients.There is no difference in clinical effects after short-term CRT between the NICN and ICM.but significantly different in the long-term follow-up, the electrical remodeling and mechanical remodeling effect of NICM was significantly better than the ICM,the patients who response to CRT in the NICM was significantly better than the ICM too.