Time and Frequency Repolarization Domains in Elderly Candidates to Transcatheter Aortic Valve Replacement.

Background and aim: Aortic valve stenosis (AVS) is a well-known risk factor for sudden cardiac death. Therefore, some non-invasive, electrocardiographic markers are capable to stratify the risk of sudden death at rest and during light mental challenge [mini-mental state examination (MMSE) administration]. Method: We compared short period RR, QT and Te intervals variability in 42 candidates to and 12 age-matched hypertensive control patients at rest and during mental challenge. Results: At rest, AVS patients showed a higher QT standard deviation (sd), QT low frequency power (LF), QT High Frequency (HF), Tpeak-Tend intervals sd (Te sd) and Te HF than the control group. During mental challenge AVS group showed a decrease of RR mean and RR HF, expressed in normalized units (NU), and an increase of RR total power (TP), RR LF, RR LF NU, RR LF, HF ratio (LF/HF). During this same mental test, QT sd, QT LF, QT HF, Te sd, Te LF, Te HF, QT variability index (VI), TeVI, QT normalized variance (VN) were higher in AVS patients than the control group. During mental challenge Te LF (r:0.825, p<0.05) was significantly associated to: serum albumin (ß:-0.473, p<0.001), MMSE (ß:-0.267, p:0.038), diastolic blood pressure (ß:-0.443, p:0.03) and cardiac index (ß:-0.303, p:0.029). Conclusion: AVS patients showed temporal dispersion of ventricular repolarization phase, useful maker to individuate high risk patients. MMSE administration induced a sympathetic sinus activation and vagal deactivation in AVS subjects. Frailty and mental function influenced Te HF and Te LF.

Short-Period Temporal Dispersion Repolarization Markers in Elderly Patients with Decompensated Heart Failure.

Objectives: Aging and chronic heart failure (CHF) are responsible for the temporal inhomogeneity of electrocardiogram (ECG) repolarization phase. In the past, short period repolarization-dispersion parameters were used as makers of mortality risk in different heart diseases, yet. Aim of this work was to evaluate risk of mortality or worsening condition in CHF elderly subjects by mean of these repo-larization variables. Method: An observational, prospective cohort study was performed, collecting 5 minutes ECG recordings to assess the mean and standard deviation (SD) of the following variables: QT end (QTe), QT peak (QTp) and T peak to T end (Te) in 117 decompensated CHF (age range: from 49 to 103 years). 30-day mortality and high levels of NT-pro BNP (<75 percentile) were considered markers of decompensated CHF. Results: A total of 27 patients (23%) died during the 30-day follow-up (overall mortality rate 23%). Te mean (odd ratio (OR): 1.04, 95% confidence limit (Cl 7u): 1.02-1.09, p<0.01), NT-pro BNP (OR: 1.00, 95% cl: 1.00-1.00, p<0.01) and LVMI (OR : 0.98, 95% cl: 0.96-0.10, p<0.05) were associated to risk of mortality at the multivariable logistic analysis. On the contrary, the same statistical analysis selected TeSD (OR: 1.36, 95% cl: 1.16-1.59, p<0.001) and LVEF (OR: 0.91, 95% cl: 0.87-0.95, p<0.001) as marker of decompensated CHF. Conclusion: In decompensated CHF elderly subjects, Te mean seem be associated to mortality and TeSD could be considered a risk factor for CHF worsening and complications. These evidences could provide useful tools for telemonitoring CHF elderly patients, amelio-rating treatments and outcomes.