Postischemic chronic heart failure was associated with a higher QT variability index across all age groups compared to healthy controls (P<0.0001 for ≤50 years; P<0.05 for >50 years).
Observational (n=128)
Does postischemic chronic heart failure and aging affect the temporal dispersion of myocardial repolarization compared to healthy controls?
QTVI is consistently elevated in patients with chronic heart failure across all age groups, suggesting its utility as a marker for repolarization temporal liability regardless of age.
p-value: p=<0.0001
BACKGROUND AND PURPOSE: QT and T(peak)-T(end) (Te) intervals are associated with sudden cardiac death in patients with chronic heart failure (CHF). We studied age-dependent influence on short-term temporal dispersion of these two variables in patients with postischemic CHF. METHOD: We grouped 75 CHF and 53 healthy control subjects into three age subsets: ≤ 50 years, >50 years and ≤ 65 years, and >65 years. We then calculated the following indices: QT and Te variability index (QTVI and TeVI), the ratio between the short-term variability (STV) of QT or Te, and the STV of resting rate (RR) (QT/RR STV and Te/RR STV). RESULTS: In all different age subgroups, patients with CHF showed a higher level of QTVI than age-matched control subjects (≤ 50 years: P 50 years and ≤ 65 years: P 65 years: P < 0.05). Patients with CHF < 50 years old also had all repolarization variability indices higher than normal age-matched controls (TeVI, P < 0.05; QT/RR STV, P < 0.05; Te/RR STV, P < 0.05), whereas we did not find any difference between the two older classes of subjects. Both QTVI (r²: 0.178, P < 0.05) and TeVI (r²: 0.433, P < 0.001) were positively related to age in normal subjects, even if the first correlation was weaker than the second one. CONCLUSION: Our data showed that QTVI could be used in all ages to evaluate repolarization temporal liability, whereas the other indices are deeply influenced by age. Probably, the age-dependent increase in QTVI was more influenced by a reduction of RR variability reported in older normal subjects.
Piccirillo et al. (Fri,) conducted a observational in Chronic heart failure (n=128). Postischemic chronic heart failure vs. Healthy control subjects was evaluated on QT variability index (QTVI) (p=<0.0001). Postischemic chronic heart failure was associated with a higher QT variability index across all age groups compared to healthy controls (P<0.0001 for ≤50 years; P<0.05 for >50 years).
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