title: Influence of aging and chronic heart failure on temporal dispersion of myocardial repolarization.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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 < 0.0001; >50 years and ≤ 65 years: P < 0.05; >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.
  
  
  CONCLUSIONS
  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.
authors: Department of Cardiovascular, Respiratory, Nephrological and Geriatric Sciences, Policlinico Umberto I, "Sapienza" University of Rome, Rome, Italy. gianfranco.piccirillo@uniroma1.it
authors: Gianfranco
authors: G
authors: Piccirillo
authors: Federica
authors: F
authors: Moscucci
authors: Matteo
authors: M
authors: Pascucci
authors: Maria Antonella
authors: MA
authors: Pappadà
authors: Gaetana
authors: G
authors: D'Alessandro
authors: Pietro
authors: P
authors: Rossi
authors: Raffaele
authors: R
authors: Quaglione
authors: Daniele
authors: D
authors: Di Barba
authors: Francesco
authors: F
authors: Barillà
authors: Damiano
authors: D
authors: Magrì
mesh_terms: D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002908:Chronic Disease; D016757:Death, Sudden, Cardiac / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D006321:Heart; D006333:Heart Failure / Q000150:complications* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D012984:Software; D018709:Statistics, Nonparametric
keywords: QT variability; aging; chronic heart failure; heart rate variability; sudden death
references: Eur J Neurol. 2008 Nov;15(11):1216-21
references: 18803652
references: Hypertension. 2003 Jun;41(6):1240-5
references: 12743013
references: Am J Physiol Heart Circ Physiol. 2012 Jun 1;302(11):H2331-40
references: 22467308
references: Circ Arrhythm Electrophysiol. 2012 Aug 1;5(4):719-27
references: 22730411
references: Int J Cardiol. 2012 May 3;156(3):259-64
references: 21112106
references: Circ Arrhythm Electrophysiol. 2012 Oct;5(5):1010-116
references: 22923270
references: Clin Sci (Lond). 2001 Oct;101(4):429-38
references: 11566081
references: J Am Geriatr Soc. 2001 Aug;49(8):1059-65
references: 11555067
references: J Am Coll Cardiol. 2012 Mar 6;59(10):954-61
references: 22381432
references: Am J Physiol Heart Circ Physiol. 2012 Apr 15;302(8):H1625-35
references: 22307668
references: Curr Opin Cardiol. 2010 Jan;25(1):29-36
references: 19907317
references: Clin Sci (Lond). 2001 Mar;100(3):267-74
references: 11222112
references: Heart Rhythm. 2012 Dec;9(12):2044-50
references: 23063868
references: Int J Cardiol. 1995 Jun 30;50(2):117-24
references: 7591322
references: Transl Res. 2008 May;151(5):267-72
references: 18433709
references: Int J Cardiol. 2010 May 28;141(2):122-31
references: 19910061
references: J Electrocardiol. 2009 Nov-Dec;42(6):500-4
references: 19647268
references: Am J Physiol Heart Circ Physiol. 2009 Nov;297(5):H1594-605
references: 19767530
references: Eur J Haematol. 2007 Oct;79(4):322-9
references: 17655692
references: Eur Heart J. 2007 Jun;28(11):1344-50
references: 17101636
references: Front Physiol. 2012 Feb 27;3:41
references: 22375128
references: Eur J Heart Fail. 2006 Nov;8(7):716-22
references: 16513420
references: Transl Res. 2006 Aug;148(2):72-8
references: 16890147
references: Heart Rhythm. 2012 Jun;9(6):943-50
references: 22306617
references: Basic Res Cardiol. 1998 Aug;93(4):241-9
references: 9782365
references: Am J Cardiol. 2004 Mar 1;93(5):650-4
references: 14996603
references: J Am Coll Cardiol. 2003 Feb 19;41(4):633-42
references: 12598076
references: Heart Rhythm. 2012 May;9(5):796-803
references: 22123313
references: Geriatr Gerontol Int. 2010 Jul;10 Suppl 1:S127-36
references: 20590828
references: Heart Rhythm. 2009 Feb;6(2):180-6
references: 19187907
references: Cardiovasc Res. 2011 Aug 1;91(3):437-46
references: 21576131
references: J Cardiol. 2012 Mar;59(2):117-22
references: 22341431
references: Circ Arrhythm Electrophysiol. 2009 Feb;2(1):80-8
references: 19808446
references: Cardiovasc Res. 2007 Feb 1;73(3):521-30
references: 17196569
references: ISRN Cardiol. 2012;2012:912672
references: 22844616
references: Am J Physiol. 1997 Oct;273(4):H1841-7
references: 9362251
references: Neuromolecular Med. 2008;10(3):179-86
references: 18338270
references: Heart Rhythm. 2005 Feb;2(2):162-9
references: 15851290
references: J Am Coll Cardiol. 2009 Aug 25;54(9):840-50
references: 19695465
references: Heart Fail Clin. 2012 Jan;8(1):87-99
references: 22108729
references: Clin Sci (Lond). 2004 Aug;107(2):183-90
references: 15046616
references: Circulation. 1997 Sep 2;96(5):1557-65
references: 9315547
references: Heart Fail Rev. 2010 Sep;15(5):431-45
references: 20419345
references: Acta Pharmacol Sin. 2004 Feb;25(2):137-45
references: 14769199
references: J Am Coll Cardiol. 2004 Oct 6;44(7):1481-7
references: 15464332
references: Heart Rhythm. 2011 Aug;8(8):1237-42
references: 21457791
references: Heart Rhythm. 2009 Apr;6(4):546-52
references: 19324318
references: Int J Cardiol. 1998 Jan 5;63(1):53-61
references: 9482145
references: Ann Noninvasive Electrocardiol. 2013 Mar;18(2):130-9
references: 23530483
references: Circ Arrhythm Electrophysiol. 2011 Aug;4(4):441-7
references: 21593198
references: Heart Rhythm. 2011 Oct;8(10):1584-90
references: 21699842
references: J Cardiovasc Electrophysiol. 1998 Sep;9(9):899-908
references: 9786070
references: Proc Natl Acad Sci U S A. 2007 Mar 6;104(10):3943-8
references: 17360457