|
|
||||||||||||||
|
|
|||||||||||||||
blockers are associated with a reduction in QT dispersion
a Department of
Clinical Pharmacology and Therapeutics, University of Dundee, Ninewells
Hospital and Medical School, Dundee DD1 9SY, UK, b Department of Epidemiology
and Public Health, Ninewells Hospital and Medical School, c Department of Cardiology, Western
Infirmary, Glasgow, UK, d Department
of Cardiology, Western General Hospital, Edinburgh, UK
Correspondence to: Dr Bonnar. email: c.e.bonnar{at}clinpharm.dundee.ac.uk
Accepted for publication 9 October 1998
OBJECTIVE
To compare
QT dispersion in patients with impaired left ventricular systolic
function and in matched control patients with normal left ventricular
systolic function.
DESIGN
A
retrospective, case-control study with controls matched 4:1 for age,
sex, previous myocardial infarction, and diuretic and
blocker treatment.
SETTING
A regional
cardiology centre and a university teaching hospital.
PATIENTS
25 patients
with impaired left ventricular systolic function and 100 patients with
normal left ventricular systolic function.
MAIN OUTCOME
MEASURES
QT and QTc dispersion measured by three
methods: the difference between maximum and minimum QT and QTc
intervals, the standard deviation of QT and QTc intervals, and the
"lead adjusted" QT and QTc dispersion.
RESULTS
All measures
of QT/QTc dispersion were closely interrelated
(r values 0.86 to 0.99; all p < 0.001).
All measures of QT and QTc dispersion were significantly increased in
the patients with impaired left ventricular systolic function
v controls (p < 0.001): 71.9 (6.5) (mean
(SEM)) v 46.9 (1.7) ms for QT dispersion,
and 83.6 (7.6) v 54.3 (2.1)
ms
1
2
for QTc dispersion. All six dispersion parameters were reduced in
patients taking
blockers (p < 0.05), regardless of whether left
ventricular function was normal or impaired
by 9.4 (4.6) ms for QT
dispersion (p < 0.05) and by 13.8 (6.5)
ms
1
2
for QTc dispersion (p = 0.01).
CONCLUSIONS
QT and QTc
dispersion are increased in patients with systolic heart failure in
comparison with matched controls, regardless of the method of
measurement and independently of possible confounding factors.
Blockers are associated with a reduction in both QT and QTc
dispersion, raising the possibility that a reduction in dispersion of
ventricular repolarisation may be an important antiarrhythmic mechanism
of
blockade.
blockers;
sudden
death
This article has been cited by other articles:
![]() |
F. C. de Carvalho, F. M. Consolim-Colombo, C. A. Pastore, M. C. Rubira, J. C. Meneguetti, E. M. Krieger, and M. Wajngarten Acute reduction of ventricular volume decreases QT interval dispersion in elderly subjects with and without heart failure Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2171 - H2176. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Nakamura, K. Chin, R. Hosokawa, K. Takahashi, K. Sumi, M. Ohi, and M. Mishima Corrected QT Dispersion and Cardiac Sympathetic Function in Patients With Obstructive Sleep Apnea-Hypopnea Syndrome Chest, June 1, 2004; 125(6): 2107 - 2114. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. G. Akar and D. S. Rosenbaum Transmural Electrophysiological Heterogeneities Underlying Arrhythmogenesis in Heart Failure Circ. Res., October 3, 2003; 93(7): 638 - 645. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. D. Demir, K. Senen, Y. Balbay, M. Soylu, H. Tikiz, and S. Korkmaz Effects of Atrial Pacing on QT Dispersion in Patients with Coronary Artery Disease Without Angina Pectoris and ST Segment Depression Angiology, June 1, 2001; 52(6): 393 - 398. [Abstract] [PDF] |
||||
![]() |
H. Tikiz, T. Terzi, Y. Balbay, A. D. Demir, M. Soylu, T. Keles, and E. Kutuk QT Dispersion in Single Coronary Artery Disease: Is There a Relation Between QT Dispersion and Diseased Coronary Artery or Lesion Localization? Angiology, January 1, 2001; 52(1): 43 - 51. [Abstract] [PDF] |
||||
![]() |
M. Malik and V. N. Batchvarov Measurement, interpretation and clinical potential of QT dispersion J. Am. Coll. Cardiol., November 15, 2000; 36(6): 1749 - 1766. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Sahu, P.O. Lim, B.S. Rana, and A.D. Struthers QT dispersion in medicine: electrophysiological Holy Grail or fool's gold? QJM, July 1, 2000; 93(7): 425 - 431. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS | REGISTER |