Twenty-four hour variability of inverted T-waves in patients with apical hypertrophic cardiomyopathy

Fei Ma; Yating Yang; Jingwen Tao; Xiaoyan Deng; Xufeng Chen; Jingjing Fan; Xuelei Bai; Tongyu Dai; Sheng Li; Xiaoyun Yang; Fan Lin

doi:10.3389/fcvm.2022.1004178

Twenty-four hour variability of inverted T-waves in patients with apical hypertrophic cardiomyopathy

Front Cardiovasc Med. 2022 Sep 21:9:1004178. doi: 10.3389/fcvm.2022.1004178. eCollection 2022.

Authors

Fei Ma^{1

2}, Yating Yang¹, Jingwen Tao¹, Xiaoyan Deng¹, Xufeng Chen¹, Jingjing Fan¹, Xuelei Bai³, Tongyu Dai⁴, Sheng Li¹, Xiaoyun Yang¹, Fan Lin^{1

2}

Affiliations

¹ Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
² Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan, China.
³ Laboratory of Cardiac Physiology, Nanyang Second General Hospital, Nanyang, China.
⁴ Department of Electrophysiology, Changde First People's Hospital, Changde, China.

Abstract

Background: Patients with apical hypertrophic cardiomyopathy (ApHCM) have marked inverted T-waves that vary over several years. Inverted T-waves in ApHCM are unstable, but it is unclear whether this change is due to coronary artery disease (CAD) or if it is a characteristic of ApHCM itself. We aimed to study the characteristics of inverted T-waves in patients with ApHCM over the course of 24 h to improve the diagnostic indices of ApHCM.

Methods: We examined 83 patients with ApHCM and 89 patients with CAD (who served as the control group). All patients underwent a 24-h dynamic electrocardiogram (ECG). We analyzed the average depth of inverted T-waves per minute and sorted them from shallow to deep; the sorted ECG segments at the 10^th, 50^th, and 90^th positions of the T-wave were subsequently analyzed.

Results: The amplitudes of inverted T-waves in ApHCM corresponding to the 10^th, 50^th, and 90^th percentiles were -5.13 ± 4.11, -8.10 ± 4.55, and -10.9 ± 5.04 mm, respectively. Changes in the degree of inverted T-waves were greater in ApHCM than in CAD. T-wave amplitudes in ApHCM were strongly associated with heart rate and circadian rhythm and only weakly associated with CAD and posture. Maximum T-wave amplitudes in the CAD group were <10 mm, while 68% of patients with ApHCM had maximum T-wave amplitudes >10 mm, and all patients with ApHCM aged <50 years had maximum T-wave amplitudes >10 mm.

Conclusion: Notable variations in the T-waves of patients with ApHCM were observed over 24 h. ECG examinations during states of inactivity (comparable to sleep) improved the sensitivity of the diagnosis of ApHCM. Inverted T-wave amplitudes correlated with heart rate and circadian rhythm, where T-wave changes in ApHCM may be due to the normalization of abnormal T-waves effect. Identifying T-wave amplitudes >10 mm can effectively improve the diagnostic rate of ApHCM, especially in patients aged <50 years. The short-term change in T-waves in patients with ApHCM could serve as a novel index that will help in the diagnosis of ApHCM.

Keywords: T-wave amplitudes; apical hypertrophic cardiomyopathy; coronary artery disease; electrocardiogram; normalization of abnormal T-waves.