%I szte
%J CANADIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY
%A  Orosz Andrea
%A  BaczkĂł IstvĂĄn
%A  Nagy ViktĂłria
%A  GavallĂŠr Edit Henriette
%A  CsanĂĄdy MiklĂłs
%A  Forster TamĂĄs
%A  Papp Gyula
%A  VarrĂł AndrĂĄs
%A  Lengyel Csaba Attila
%A  Sepp RĂłbert
%T Short-term beat-to-beat variability of the QT interval is increased and correlates with parameters of left ventricular hypertrophy in patients with hypertrophic cardiomyopathy
%P 765-772
%N 9
%R 2937124
%O FELTÖLTŐ: Bernátskyné Babus Csilla - csbabus@ek.szte.hu
%L publicatio11594
%X Stratification models for the prediction of sudden cardiac death (SCD) are inappropriate in patients with hypertrophic cardiomyopathy (HCM). We investigated conventional electrocardiogram (ECG) repolarization parameters and the beat-to-beat short-term QT interval variability (QT-STV), a new parameter of proarrhythmic risk, in 37 patients with HCM (21 males, average age 48 +/- 15 years). Resting ECGs were recorded for 5 min and the frequency corrected QT interval (QTc), QT dispersion (QTd), beat-to-beat short-term variability of QT interval (QT-STV), and the duration of terminal part of T waves (Tpeak-Tend) were calculated. While all repolarization parameters were significantly increased in patients with HCM compared with the controls (QTc, 488 +/- 61 vs. 434 +/- 23 ms,  p < 0.0001; QT-STV, 4.5 +/- 2 vs. 3.2 +/- 1 ms, p = 0.0002; Tpeak-Tend duration,  107 +/- 27 vs. 91 +/- 10 ms, p = 0.0015; QTd, 47 +/- 17 vs. 34 +/- 9 ms, p = 0.0002), QT-STV had the highest relative increase (+41%). QT-STV also showed the  best correlation with indices of left ventricular (LV) hypertrophy, i.e., maximal LV wall thickness normalized for body surface area (BSA; r = 0.461, p = 0.004) or LV mass (determined by cardiac magnetic resonance imaging) normalized for BSA (r  = 0.455, p = 0.015). In summary, beat-to-beat QT-STV showed the most marked increase in patients with HCM and may represent a novel marker that merits further testing for increased SCD risk in HCM.
%D 2015
%V 93