Spectral and cross-spectral analysis of conductance catheter signals - New indexes for quantification of mechanical dyssinchrony

We hereby present novel index to quantify ventricular mechanical dyssynchrony by using spectral and cross-spectral analysis of conductance catheter volume signals. Conductance catheter is a volume measurement technique based on conductance measurement: the intraventricular volume, i.e. the time-varying volume of blood contained within the heart cavity, is estimated by measuring the electrical conductance of the blood employing a multi-pole catheter. Five segmental volume signals (SV_i, i=1,...5) can be acquired; total volume (TV) is estimated as the instantaneous sum of the segmental volumes. We implemented classical time-domain dyssynchrony indexes already utilized in conductance catheter signals analysis, and new frequency-domain indexes. Study population consisted of 15 heart failure (HF) patients with left bundle branch block and 12 patients with preserved left ventricular (LV) function. We found that spectral measures seem to out-perform classical time-domain parameters in differentiating atrial HF patients from no-HF group. These findings encourage the use of spectral analysis to obtain crucial quantitative information from conductance catheter signals.