Seasonal variability of QT dispersion in healthy young males.
BACKGROUND
There are few data related to the seasonal influences on the QT dispersion.


METHODS
We analyzed the effects of seasons on QT dispersion in a large group of healthy young males. We studied the seasonal variability of QT dispersion in 523 healthy male subjects aged 22 +/- 4 years (ranging from 20 to 26). Four seasonal 12-lead resting electrocardiograms (ECGs) recorded at double amplitude were performed at 25 mm/s at intervals of 3 months. Subsequent ECGs were recorded within 1 hour of the reference winter recording. QT dispersion was defined as the difference between the longest and the shortest mean QT intervals.


RESULTS
There was a significant seasonal variation in QT dispersion (P = 0.001), with the largest QT dispersion in winter (71 +/- 18 ms) and the smallest one in spring (43 +/- 19).


CONCLUSIONS
There exists a significant seasonal variation in QT dispersion of healthy subjects and such variability should be taken into consideration in the evaluation process of QT dispersion.
Kose
Sedat
S
Department of Cardiology, Gülhane Military Medical Academy, Ankara, Turkey Department of Cardiology, Hacettepe University School of Medicine, Ankara, Turkey. aiyisoy@hotmail.com
Aytemir
Kudret
K
Can
Ilknur
I
Iyisoy
Atilla
A
Kursaklioglu
Hurkan
H
Amasyali
Basri
B
Kilic
Ayhan
A
Isik
Ersoy
E
Oto
Ali
A
Demirtas
Ertan
E
D000328:Adult; D006329:Heart Conduction System / Q000502:physiology*; D006801:Humans; D008297:Male; D010507:Periodicity; D012621:Seasons