Clinical Study Of Cardiac Resynchronization Therapy In Patients With Heart Failure And Different Left Bundle Branch Block Morphology

Aims To analyse if newly proposed criteria for LBBB identify chronic congestive heart failure patients with a better clinical outcome from Cardiac Resynchronization Therapy(CRT).Methods Between May2007and June2012, chronic congestive heart failure patients met the traditional LBBB criteria and received CRT implantation were enrolled in this study. All patients were divided into"true"LBBB group and"false" LBBB group according to QRS morphology:"true"LBBB group (definition:QS or rS in leads V1and V2, mid-QRS notching or slurring in2of leads V1, V2, V5, V6,I, and aVL, and QRS duration>140ms (men) or130ms (women)and "false" LBBB group (definition: met the traditional criteria of LBBB, but has yet to reach of true"LBBB, including mid-QRS notching or slurring in less than2of leads V1,V2, V5, V6,I,or QRS duration<140ms (men) or130ms (women). During follow-up,QRS duration,LVEDD,LVEF and NYHA class were recorded.Results32patients (23in"true"LBBB group and9in"false" LBBB group) were enrolled. The base-line clinical characteristics were similar in two groups. At the end of follow-up, reverse remodeling was achieved better in "true"LBBB group than "false" LBBB group, with significant reduction of LVEDD((6.3±1.0cm vs7.6±1.0cm, P=0.003) and the increased of LVEF (38.9±11.3%vs27.1±6.6%,P=0.006).Conclusion New LBBB criteria is related to a better clinic outcome in chronic congestive heart failure patients with CRT...