Depolarization spatial variance as a cardiac dyssynchrony descriptor

BONOMINI, MARÍA P.; MANGANI, NICOLAS; ORTEGA, DANIEL F.; ARINI, PEDRO D.; BARJA, LUIS D.

BIOMEDICAL SIGNAL PROCESSING AND CONTROL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2019 vol. 49 p. 540 - 545

1746-8094

Ventriculardepolarization dispersion refers mainly to heterogeneity in interlead QRSdurations. Here, we propose the spatial variance (SVd) to describe depolarization dispersion about a mean QRS morphology. We hypothesize that waveform changes can be more accurate than interval changes at measuring QRS heterogeneity,and less sensitive to delineation errors. To prove this, SVd was computed on 36 dyssyn-chrony patients either in sinus rhythm (SVdB) or under nHB (SVdHB), andon 32 control subjects with native conduction (SVdN). In the normal ECG, thereare interlead sets that produce maximal (SVdNmax) and minimal (SVdNmin) spatial variance. In Baseline patients, SVdB significantly increased from controls in the minimal variance situation (p < 0.005), deviating one or more leads from the normal morphology (similar in all the ensemble) and consequently increasing the interlead distance. The opposite held for the maximal variance situation,where it was expected a wide span of morphologies in health, there was atendency to stacking in morphologies at baseline (p<0.005). In both cases nHB induced QRS normalization, demonstrated by the return of SVdHB towards controls SVdN (p = NS). However, QRS narrowing not always accompanied morphological changes. The average rate of QRS normalization was 84% and 89% for SVdNmax and SVdNmin respectively while the rate of QRS narrowing equaled 71% in a multilead approach and performed worse than SVdat baseline-nHB separation. Ensembles withminimal interlead distance produced the best AUC values (aVR-V1, I-aVF-V6, I-II-aVF-V6).In conclusion, SVd may complement QRS width in the electrocardiographic assessment of dyssynchrony.