Optimization For Cardiac Resynchronization Therapy With An IEGM Method

Nearly 30%of patients failed to response to cardiac resynchronization therapy(CRT).To decrease the occurrence of nonresponders, besides a careful selection of patients referred for CRT, clinical evidences support the importance of an optimization of the atrioventricular(AV)and interventricular(VV)delays. Intracardiac delay optimization of biventricular pacing devices currently relies on time-consuming echocardiographic measurements. A novel intracardiac electrogram(IEGM)method for atrioventricular(AV)and interventricular(VV)delay optimization was developed, which can be performed during routine device follow-up.Objective Comparing analysis of the optimal AV/VV Delay and AVTI between an IEGM-based and echocardiogram for cardiac resynchronization therapy in heart failure patientsMethods and Results In this trial, patients previously implanted with St.Jude Medical CRT devices underwent standard AV and VV delay optimization guided by Doppler echocardiogram measurements of the maximum aortic velocity time integral(aortic VTI).Aortic VTI measurements applying the IEGM method recommended delays were then obtained in all patients. Twelve patients(age:66±10 years;83% male;)were enrolled for AV and VV delay evaluation. An independent core lab determined the maximum aortic VTIs. Data analysis of the AV and VV delays demonstrated the concordance correlation coefficient (CCC) between the standard method aortic VTI values and the IEGM method aortic VTI values was 93.2%and 92.8%.respectively. All analyses demonstrated that the CCC>90%(P<0.001). Conclusion The automated programmer-based IEGM method provides a reliable alternative to standard techniques for the optimization of AV and VV delay settings in patients with CRT devices.