Korean Circ J.  1994 Oct;24(5):664-671. 10.4070/kcj.1994.24.5.664.

Circadian Variation of Non-Sustained Ventricular Tachycardia

• Kim YN
• Park KA
• Bae JH
• Lee JH
• Kim KS
• Kwon CH

• KMID: 2229312
• DOI: http://doi.org/10.4070/kcj.1994.24.5.664

Abstract

BACKGROUND
Circadian rhythms have been described for many cardiovascular phenomenon, both physiologic and pathologic. However, its frequency of onset in nonsustained ventricular tachycardia(NVT) has rarely been studied. Hence, this study was performed to examine the occurence of circardian rhythm in patients with NVT and to access underlying factors affecting it. METHOD: Among about 2000 patients who had undergone 24-hour Holter recordings between 1988 and August 1992, 46 patients with one or more ventricular tachyardia(VT) episode were selected. In this group, subjects receiving antiarrhythmic drug, including beta blockers were excluded.
RESULTS
The frequency of onset of circadian rhythm in NVT peaked between 10 to 11AM and 6 to 7PM. In patiens younger than 60 years, its frequency was highest between 9 AM to 12 noon and 6 to 8 PM, whereas peak occurred around 9 AM in the morning in other age groups. In addition, circadian rhythm was more frequent in female NVT patients between 9 to 11 AM, while peaking between 6 to 8 PM in male patients. Moreover, higher frequency was shown during the day in patients with underlying heart disease, although the peak occurred in 9 AM and 8 PM in patients without any heart disease.
CONCLUSION
In NVT patients, the frequency of onset of circadian rhythm varied with time of the day, showing nearly equal peaks in the morning and in the evening. This is similar to rnythms described for acute myocardial infarction and sudden death. Furthmore, the occurrence was affected by age, sex and presence of underlying disease.

MeSH Terms

Circadian Rhythm
Death, Sudden
Female
Heart Diseases
Humans
Male
Myocardial Infarction
Tachycardia, Ventricular*