On Relation Between Cardiac Resynchronization Therapy On Left Ventricular Reverse Remodeling And Electrical Activity And Of The Optimization Study

Part One Relationship between reverse of left ventricle remodeling and electrical remodeling and ventricular arrhythmias after cardiac resynchronization therapyObjectives To investigate the relationship between reverse of left ventricle remodeling and electrical remodeling and ventricular arrhythmias after cardiac resynchronization therapy in chronic heart failure patients.Methods Patients with heart failure scheduled for implantation of a CRT device were studied. Selection criteria included moderate to severe heart failure(New York Heart Association classesⅢtoⅣ), left ventricular ejection fraction (LVEF)≤35%, and ventricular asynchrony detected by echocardiography. Echocardiographic and Electrocardiogramic data was recorded before, right after and 6 months after CRT implantation, including QRS duration, LVEF, left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume(LVEDV).Ventricular arrhythmia data was obtained through the pacemaker, including PVCs and PVC runs. Anatomical 'responders' were defined as those with a reduction in LVESV of at least 15% by 6 months after implantation. Change of QRS duration in all patients and subgroup were analyzed, and relationship between anatomic remodeling and change of QRS duration and ventricular arrhythmias were assessed.Results 1. A total numbers of 43 patients were enrolled, including 29 as responders and 14 as nonresponders. There were no differences between the two groups in age, etiology, LVEF, QRS duration etc.2. All patients demonstrated an improvement in NYHA class (P<0.01) and 6 minute walk distance (P=0.03).3. All patients demonstrated an increased LVEF, a decreased LVESV and LVEDV, but without any change in QRS duration. Subgroup analysis revealed a similar change in LVEF, LVESV and LVEDV, but obvious decreased QRS duration in responders, while no change in LVEF, LVESV, LVEDV and QRS duration in non-responders. There is a significant difference between the change of QRS duration of the two groups. In all patients reduction of LVESV is positively correlated with change of QRSd(r=0.523, P<0.01).4. Anatomic responders suffered less PVCs and PVC runs than nonresponders (both P<0.01). Multiple regression analysis demonstrated responder status significantly predicts log(PVCs) (β=2.360, P<0.01), and both responder status and gender play a role in predicting log(PVC runs) (β=2.877, P<0.01 andβ=-0.735, P=0.034).Conclusions Effectiveness of CRT consists of reverse of anatomic remodeling, electrical remodeling and reduction of ventricular arrhythmias. Anatomic remodeling is in correlation with electrical remodeling and reduction of ventricular arrhythmias. Both remodeling of left ventricule and gender play a role in ventricular arrhythmias in patients after cardiac resynchronization therapy.Part Two A comparative study of acute hemodynamic effects of interval optimization for cardiac resynchronization therapy patients by echocardiography and QuickOpt functionObjective To investigate the concordance of acute hemodynamic effects of optimization of SAV delay, PAV delay and VV delay between echocardiography and QuickOpt function method.Methods A total number of 19 patients implanted with QuickOpt functioned CRT(D) were enrolled. Echocardiography was used to acquire aortic velocity time integral (aVTI) and optimized SAV, PAV, and VV delay. Also QuickOpt function was used to acquire the optimized SAV, PAV, and VV delay and further measurement of corresponding aVTI was made. Finally, concordance of obtained aVTI is calculated, and the intervals optimized by the two methods were compared.Results Concordance correlation coefficient (CCC) between the maximum aVTI values acquired by the standard method and those by the IEGM method were 95.95%,97.29%,92.45% respectively, by data analysis of the SAV, PAV and VV delays (P< 0.05). The optimal SAV, PAV and VV interval acquired by echocardiography method were not different from those by QuickOpt method (all P>0.05). Optimization of interval with QuickOpt method saves a lot of time compared with echocardiography method (1.28±0.45 minutes vs 43.60±11.07 minutes, P<0.01).Conclusion QuickOpt function is an alternative method for the optimization of AV, PV and VV delay settings in patients with CRT(D) which provides similar effect on acute hemodynamic analysis and saves a lot of time compared with standard echocardiography method.