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Potassium channel KCNH2 K897T polymorphism and cardiac repolarization during exercise test: The Finnish
J Koskela1, J Laiho, M KäHönen
1Internal Medicine, Tampere University Hospital and Tampere University Medical School, Tampere, Finland. Jenni.K.Koskela@uta.fi
Scandinavian Journal of Clinical and Laboratory Investigation
|September 14, 2007
Summary
The K897T polymorphism in the KCNH2 gene did not significantly affect T-wave alternans. However, the CC genotype may influence QT intervals in women, warranting further investigation.
Area of Science:
- Cardiology
- Genetics
- Molecular Biology
Background:
- Cardiac repolarization is crucial for heart function and is influenced by ion channels.
- The KCNH2 gene encodes a potassium channel subunit, and a common polymorphism (K897T) alters its properties.
- Understanding genetic influences on repolarization indices like QT interval and T-wave alternans is important for cardiovascular health.
Purpose of the Study:
- To investigate the association between the KCNH2 K897T polymorphism and repolarization indices (QT interval, T-wave alternans).
- To evaluate these associations during different phases of a physical exercise test in a large patient cohort.
Main Methods:
- Analysis of 1,975 patients undergoing exercise tests with on-line electrocardiographic monitoring.
- Genotyping for the KCNH2 2690A>C variation (K897T polymorphism) using polymerase chain reaction and TaqMan probes.
- Statistical analysis of QT intervals and T-wave alternans across genotype groups, considering potential confounding factors.
Main Results:
- No significant differences in QTc intervals were observed among all subjects across the three genotype groups.
- Women with the CC genotype showed a trend towards longer QT intervals, significantly at rest, even after adjustment for influencing factors.
- The K897T polymorphism did not show statistically significant effects on T-wave alternans in the overall cohort or stratified by sex.
Conclusions:
- The K897T polymorphism of the KCNH2 gene is unlikely to be a primary genetic determinant of T-wave alternans.
- The observed association between the CC genotype and longer QT intervals in women warrants further research.
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