Cardiac resynchronization efficiency estimation by new ultra-high-frequency ECG dyssynchrony descriptor

The biventricular implantable pacemaker (BiV) is usually recommended for heart failure patients with LVEF ≤ 35% and QRS duration > 120ms. We introduce promising marker evaluating suitability and efficiency of the Cardiac Resynchronization Therapy (CRT) recipients. Data: 12-lead UHF-ECG, 25 kHz sampling, 10 minute resting measurement, 28 CRT subjects, each before BiV and with BiV on, VV delay o. Methods: A new parameter D YS was computed as the time diference between two maxima of UHF envelopes computed from VI and V6 leads in QRS complex in 500-1000Hz frequency band. The values of DYS and QRS width before and after BiV implantation are analysed. The assumption for being responder for BiV is high value of DYS before CRT and significant DYS decrease during biventricular pacing. Subjects with no response on BiV stimulation are under the borderline of DYS = 30ms before stimulation. Thus the D YS parameter can serve as a new marker for the prediction of Bi V pacemaker efficiency. This information cannot be derived from standard QRS width values prior BiV implantation.