Reference values for a novel ambulatory-based frequency domain T-wave alternans in subjects without structural heart disease

• Published in: Journal of cardiology Vol. 76; no. 5; pp. 506 - 513
• Main Authors: Hashimoto, Kenichi, Harada, Naomi, Kasamaki, Yuji
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.11.2020
• Subjects: Frequency domain T wave alternans; Holter electrocardiogram; Lethal arrhythmias; Sudden cardiac death; Ventricular tachyarrhythmias; Lethal arrhythmias; Holter electrocardiogram; Ventricular tachyarrhythmias; Sudden cardiac death; Frequency domain T wave alternans
• ISSN: 0914-5087; 1876-4738; 1876-4738
• DOI: 10.1016/j.jjcc.2020.06.002

•The reference values for ambulatory-based frequency domain T wave alternans (FD-TWA) were established.•Ambulatory-based FD-TWA values were mostly influenced by heart rate.•Also, ambulatory-based FD-TWA values related to age.•Maximum FD-TWA was observed mostly in the Z lead regardless of the age group and position. Conventional frequency domain T wave alternans (FD-TWA) is a noninvasive risk stratification marker for identifying arrhythmic sudden cardiac death, but the conventional FD-TWA device that was considered the gold standard device has been discontinued commercially. Recently, a newly developed ambulatory electrocardiogram (AECG) device that can detect FD-TWA continuously for 24 hours is available in clinical settings. However, information on the normal values using the novel AECG-based frequency domain TWA (FD-TWA) is lacking. FD-TWA for AECG was examined in 312 subjects without heart disease (Sb-wHD) (range 20-89 years, 146 men) and 30 heart disease patients (HD-P) (mean age 57±17 years, 24 men). The maximum FD-TWA amplitude over 24 hours was measured with manual editing. The upper limit of local noise levels for measurement of FD-TWA was set to both <10 μV and <20 μV (acceptable noise level <10 μV and <20 μV). The reference values (95th percentiles) of FD-TWA in Sb-wHD were 19.9 μV for the acceptable noise level <10 μV and 23.6 μV for the acceptable noise level <20 μV. The 75th percentile of FD-TWA amplitude in HD-P was 19.5 µV at an acceptable noise level <10 µV and 21.5 µV at an acceptable noise level <20 µV. FD-TWA amplitude without heart disease was significantly affected by heart rate when the maximum FD-TWA was measured (β = 0.274 p < 0.001 for the acceptable noise level <10 μV; β = 0.263, p < 0.001 for the acceptable noise level <20 μV) and age (β = 0.204, p = 0.004 for the acceptable noise level <10 μV; β = 0.149, p = 0.034 for the acceptable noise level <20 μV). In the present study, the reference values for a novel FD-TWA in Sb-wHD and the distribution of TWA values in HD-P were established. In future research, the cut-off values of FD-TWA in HD-P will need to be examined.