Indexes of Temporal Myocardial Repolarization Dispersion and Sudden Cardiac Death in Heart Failure: Any Difference?. Issue 2 (22nd November 2012)

• Record Type: Journal Article
• Authors: Piccirillo, Gianfranco; Rossi, Pietro; Mitra, Marilena; Quaglione, Raffaele; Dell'Armi, Annalaura; Di, Daniele; Maisto, Damiana; Lizio, Andrea; Barillà, Francesco; Magrì, Damiano
• Is Part Of: Annals of noninvasive electrocardiology. Volume 18:Issue 2(2013:Mar.)
• Page Start: 130
• Page End: 139
• Publication Date: 2012-11-22
• Subjects: Electrocardiography -- Periodicals; Arrhythmia -- Periodicals; 616.1207547
• DOI: 10.1111/anec.12005
• Languages: English
• ISSNs: 1082-720X

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="anec12005-sec-0010" sec-type="section"> <title>Background</title> <p>The QT variability index, calculated between Q‐ and the T‐wave end (QT<sub>end</sub>VI), is an index of temporal myocardial repolarization lability associated with sudden cardiac death (SCD) in chronic heart failure (CHF). Little is known about temporal variability in the other two temporal myocardial repolarization descriptors obtained from Q–T<sub>peak</sub> and T<sub>peak</sub>–T<sub>end</sub> intervals. We therefore investigated differences between these indexes in patients with CHF who died suddenly and in those who survived with a left ventricular ejection fraction (LVEF) ≤35% or >35%.</p> </sec> <sec id="anec12005-sec-0020" sec-type="section"> <title>Methods and Results</title> <p>We selected 127 ECG and systolic blood pressure (SPB) recordings from outpatients with CHF all of whom had been followed up for 30 months. We calculated RR and SPB variability by power spectral analysis and QT<sub>end</sub>VI, QT<sub>peak</sub>VI, T<sub>peak</sub>T<sub>end</sub>VI. We then subdivided data patients into three groups SCD, LVEF ≤ 35%, and LVEF > 35%. The LVEF was higher in the SCD than in the LVEF ≤ 35% group, whereas no difference was found between the SCD and LVEF > 35% groups. QT<sub>end</sub>VI, QT<sub>peak</sub>VI, and T<sub>peak</sub>T<sub>end</sub>VI were higher in the SCD and LVEF ≤ 35% groups than in the LVEF > 35% group. Multivariate analysis detected a negative relationship between all repolarization variability indexes, low frequency obtained from RR intervals and LVEF.</p> </sec> <sec id="anec12005-sec-0030" sec-type="section"> <title>Conclusions</title> <p>Our data show that variability in the first (QT<sub>peak</sub>VI) and second halves of the QT interval (T<sub>peak</sub>–T<sub>end</sub>VI) significantly contributes to the QT<sub>end</sub>VI in patients with CHF. Further studies should investigate whether these indexes might help stratify the risk of SCD in patients with a moderately depressed LVEF.</p> </sec> </abstract>