Reverse Electrical Remodeling Assessed by High-Frequency QRS Dyssynchrony and QRS Duration

Abstract

Reverse electrical remodeling (RER) is usually assessed by measuring the QRS duration (QRSd) before and after cardiac resynchronization therapy (CRT) during the stimulator off. The ventricular electrical depolarization dyssynchrony (DYS) can be assessed directly from ECG by high-frequency QRS analysis. The purpose of the study was to compare the RER assessment by the DYS and QRSd changes in CRT patients. Echocardiography and 12-lead ECG were conducted in 26 CRT recipients. The averaged V1-V6 QRS envelopes were calculated through frequency ranges from 150 to 950Hz. The DYS was assessed from the envelopes, and the QRSd was measured. All the ECG parameters were assessed before, after, and 6 months after the CRT during CRT off. Patients were divided to CRT responders/non-responders by the change of end-systolic volume of the left ventricle in a 6-month follow-up. Mean values of the DYS and QRSd parameters evince significantly shorter values in non-responders before CRT. When compared changes of DYS and QRSd, only DYS parameter is significantly shorter after 6-month follow-up compared with baseline DYS prior CRT. The DYS parameter change as a marker of RER corresponds with reverse structural remodeling assessed by echo cardiography.