Open AccessDiurnal variation of frequency domain T‐wave alternans on 24‐hour ambulatory electrocardiogram in subjects without heart disease: Significant effect of autonomic nervous activity of the heart
Author(s) -
Hashimoto Kenichi,
Kasamaki Yuji,
Soma Masayoshi,
Takase Bonpei
Publication year - 2019
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/anec.12620
Subject(s) - medicine , heart rate variability , t wave alternans , ambulatory , cardiology , heart rate , heart rate turbulence , autonomic nervous system , quartile , ambulatory ecg , sudden cardiac death , electrocardiography , diurnal temperature variation , circadian rhythm , blood pressure , confidence interval , atmospheric sciences , geology
Abstract Background T‐wave alternans (TWA) is a risk stratification predictor for sudden cardiac death. However, little is known about the diurnal variation of TWA. Whether TWA are affected by heart rate (HR) or cardiac autonomic nervous activity in the subjects without significant structural heart disease in daily life is not fully understood. Thus, this study was aimed to clarify these issues. Methods Frequency domain (FD)‐TWA analysis was conducted in 47 subjects without significant structural heart disease using 24‐hr ambulatory electrocardiogram (AECG). Measurement of heart rate variability (HRV) was performed in order to evaluate the autonomic activity of the heart. The maximum FD‐TWA value in each period was measured four times per day (A, 00:00–6:00 hr; B, 06:00–12:00 hr; C, 12:00–18:00 hr; D, 18:00–24:00 hr). Correlations between FD‐TWA and either HR or HRV parameters (LF/HF, LFnu, HFnu, SDNN, CVNN, pNN50) were analyzed in each period (A‐D). Results There was diurnal variation of FD‐TWA (median, inter‐quartile range [IQR]: A, 8.2 [6.5, 10.6] μV; B, 10.1 [8.4, 15.0] μV; C, 17.6 [12.3, 25.0] μV: D, 11.9 [9.1, 19.9] μV; p < 0.0001). Maximum FD‐TWA had positive correlations with HR and LF/HF (HR, r = 0.496, p < 0.0001; LF/HF, r = 0.414, p = 0.004), while FD‐TWA had a negative correlation with HFnu ( r = −0.291, p = 0.048). On multiple linear regression analysis, HR had an independent effect on log FD‐TWA amplitude (β = 0.461, p = 0.001). Conclusions FD‐TWA has marked diurnal variation in the daily life of the subjects without significant structural heart disease. This variation could be more strongly affected by HR than the HRV indices.