Diurnal variation in QT dispersion in patients with chronic heart failure.
QT dispersion is defined as the difference in QT interval among the different leads of the standard 12-lead electrocardiogram and reflects inhomogeneity of myocardial repolarization. Dispersion of repolarization is an important electrophysiologic feature that is considered fundamental for the initiation of ventricular fibrillation. However, no data exist regarding the diurnal variation of QT dispersion measured from simultaneous 12-lead recording in chronic heart failure patients. The aim of this study was to identify diurnal variation in QT dispersion in patients with chronic heart failure. QT dispersion was measured in the 12-lead standard electrocardiogram in 11 patients with chronic heart failure. QT dispersion in these patients was increased in the afternoon compared to the morning. It is concluded that QT dispersion has a clear diurnal variation in patients with chronic heart failure. These findings have potentially significant implications for therapy and prevention of sudden cardiac death in patients with chronic heart failure.
Kinoshita
Osamu
O
Division of Cardiovascular Medicine, Shinshu University School of Medicine, Matsumoto, Japan. kinos@hsp.md.shinshu-u.ac.jp
Wakamatsu
Masaomi
M
Tomita
Takeshi
T
Aizawa
Kazunori
K
Kasai
Hiroki
H
Kumazaki
Setsuo
S
Tsutsui
Hiroshi
H
Koyama
Jun
J
Yazaki
Yoshikazu
Y
Watanabe
Noboru
N
Hongo
Minoru
M
Ikeda
Uichi
U
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D002940:Circadian Rhythm; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged