Short-period temporal repolarization dispersion in subjects with atrial fibrillation and decompensated heart failure

Background/objectives: The association between chronic heart failure (CHF) and permanent atrial fibrillation is very frequent. The repolarization duration was already found predictive for atrial fibrillation. Aim of this study was to evaluate the influence of atrial fibrillation on short period repolarization variables in decompensated CHF patients. Method: We used 5 minutes ECG recordings to assess the mean, standard deviation (SD) and normalized variance (NV) of the following variables: QT end (QTe), QT peak (QTp) and T peak to T end (Te) in 121 decompensated CHF, of whom 40 had permanent atrial fibrillation, too. We reported also the 30-day mortality. Results: QTpSD (p<0.01), TeSD (p<0.01), QTpVN (p<0.01) and TeVN (p<0.01) were higher in the atrial fibrillation than among sinus rhythm CHF subjects. Multivariable logistic analysis selected only TeSD (odd ratio, o.r.: 1.32, 95% confidence interval, c.i.: 1.06-1.65, p: 0.015) associated with atrial fibrillation. A total of 27 patients died during the 30-days follow-up (overall mortality rate 22%), 7 (18%) and 20 (25%) respectively in the atrial fibrillation and sinus rhythm patients. Furthermore, the following variables were associated to the morality risk: NT-pro Brain Natriuretic Peptide (o.r.: 1.00, 95% c.i.: 1.00-1.00, p:0.041), left ventricular end diastolic diameter (o.r.: 0.81, 95% c.i.: 0.67-0.96, p: 0.010) and Te mean (o.r.: 1.04, 95% c.i.: 1.02-1.09, p:0.012). Conclusion: In decompensated CHF subjects, Te mean seems be associated to mortality and TeSD to the permanent atrial fibrillation. We could hypothesize that, during severe CHF, the multi-level ionic CHF channel derangement could be critical in influencing these non-invasive markers. (ClinicalTrials.gov number, NCT04127162) This article is protected by copyright. All rights reserved. Keywords: Chronic heart failure; QT; QTVI; Tpeak-Tend; mortality; permanent atrial fibrillation; temporal dispersion of repolarization phase.