Characteristics of QT Interval Dispersion During Exercise-induced Changes of Heart Rate.
- Author:
Young Joon PARK
1
;
Heon Kil LIM
;
Sook Jin LEE
;
Jae Ung LEE
;
Kyung Soo KIM
;
Soon Kil KIM
;
Jeong Hyun KIM
;
Bang Hun LEE
Author Information
1. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea. limhg@hanyang.ac.kr
- Publication Type:Original Article
- Keywords:
Exercise treadmill test;
Heart rate;
QT Dispersion
- MeSH:
Electrocardiography;
Exercise Test;
Heart Rate*;
Heart*;
Humans;
Hyperventilation;
Male
- From:Korean Journal of Aerospace and Environmental Medicine
2002;12(2):55-59
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: QT interval dispersion (QTD) reflects the regional inhomogeneity of ventricular repolarization, and heart rate variability reflects the autonomic tone of the heart. The relation between QTD and heart rate is not clarified yet. The object of this study was to examine the influence of heart rate on QTD using exercise treadmill test in healthy subjects. METHODS: The influence of heart rate on QTD was studied in 42 young healthy pilots by evaluating the changes in QTD induced by hyperventilation and exercise. QTpeak interval dis-persion (QTp D) was defined as the difference between maximum and minimum QTpeak interval measured on 12 lead ECG at single cardiac beat. Paired t test was used between QTp D at rest, QTp D after hyperventilation and QTp D after exercise to determine the effect of heart rate on QTp D. RESULTS: The QTp D after hyperventilation (37+/-11 msec) was greater compared to QTp D at rest (35 +/-14 msec), but there was no difference (P>0.05). The QTp D after exercise was 31 +/-11 msec at stage 1, 28 +/-13 msec at statge 2 and 31 +/-12 msec at stage 3. and there was the significant difference in QTp D at statge 2 compared to QTp D at rest (P<0.05). CONCLUSION: The QTp D significantly decreased at stage 2 after graded exercise in healthy men. This finding suggests that anti-arrhythmogenic effect associated with decreased QTp D during physiologic exercise is present in apparently healthy men.
