Clinical and electrocardiographic characteristics of patients with short QT interval in a large hospital-based population

Miyamoto, Akashi; Hayashi, Hideki; Yoshino, Tomohide; Kawaguchi, Tamiro; Taniguchi, Atsushi; Itoh, Hideki; Sugimoto, Yoshihisa; Itoh, Makoto; Makiyama, Takeru; Xue, Joel Q.; Murakami, Yoshitaka; Horie, Minoru

doi:10.1016/j.hrthm.2011.08.016

« Previous Next »Heart Rhythm
Volume 9, Issue 1 , Pages 66-74, January 2012

Clinical and electrocardiographic characteristics of patients with short QT interval in a large hospital-based population

Akashi Miyamoto, MD, PhD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
Hideki Hayashi, MD, PhD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
- Address reprint requests and correspondence: Dr. Hideki Hayashi, Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan
Tomohide Yoshino, MD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
Tamiro Kawaguchi, MD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
Atsushi Taniguchi, MD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
Hideki Itoh, MD, PhD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
Yoshihisa Sugimoto, MD, PhD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
Makoto Itoh, MD, PhD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
Takeru Makiyama, MD, PhD
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Kyoto, Japan
Joel Q. Xue, PhD
- General Electric Healthcare, Milwaukee, Wisconsin
Yoshitaka Murakami, PhD
- Department of Health Science, Shiga University of Medical Science, Otsu, Shiga, Japan
Minoru Horie, MD, PhD
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan

published online 18 August 2011.

Background

Short QT syndrome is one of the underlying disorders associated with ventricular fibrillation. However, the precise prognostic implication of a short QT interval remains unclear.

Objective

The purpose of this study was to investigate the prevalence and long-term prognosis in patients with a shorter-than-normal QT interval in a large hospital-based population.

Methods

We chose patients with a short Bazett QTc interval from a database consisting of 114,334 patients to determine the clinical characteristics and prognostic value of a short QT interval.

Results

A total of 427 patients (mean age 43.4 ± 22.4 years) had a short QT interval with about a 1.2 times higher male predominance (234 men). The QTc interval was significantly longer in female than in male patients (363.8 ± 6.1 ms vs 357.1 ± 5.8 ms, P <.0001). The age-specific prevalence of patients with short QT interval was biphasic, peaking at young and old age. Atrial fibrillation and early repolarization were complicated with short QT interval in 39 (9.1%) and 26 (6.1%) patients, respectively. The prognosis of 327 patients (182 men; mean age, 46.4 ± 27.3 years) with a short QT interval could be assessed (mean follow-up period, 54.0 ± 62.0 months). During the follow-up, 2 patients, 1 of whom had early repolarization, developed life-threatening events, in contrast to 6 patients who died of noncardiac causes and did not have early repolarization.

Conclusion

The prevalence of a short QT interval showed a slight male preponderance and biphasic age-dependent distribution in both genders. The complication rate of atrial fibrillation was higher in those with a short QT interval than in general populations. The long-term outcome suggested that early repolarization in a short QT interval might be associated with potential risk of lethal arrhythmia.

Keywords: Electrocardiography , QT interval , Prevalence , Prognosis , Repolarization

Abbreviations: AF, atrial fibrillation, CI, confidence interval, ECG, electrocardiogram