Twenty-four hour variability of inverted T-waves in patients with apical hypertrophic cardiomyopathy
Fei Ma1,2, Yating Yang1, Jingwen Tao1
1Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Insights
Inverted T-waves in apical hypertrophic cardiomyopathy (ApHCM) vary significantly over 24 hours. Measuring T-wave amplitude, especially >10 mm, improves ApHCM diagnosis, particularly in younger patients.
Area of Science:
- Cardiology
- Electrocardiography
- Cardiovascular Diseases
Background:
- Apical hypertrophic cardiomyopathy (ApHCM) is characterized by significant inverted T-waves.
- The dynamic nature of these T-wave changes and their association with coronary artery disease (CAD) versus ApHCM itself remain unclear.
Purpose of the Study:
- To investigate the 24-hour characteristics of inverted T-waves in ApHCM patients.
- To differentiate T-wave changes in ApHCM from those in CAD.
- To enhance diagnostic indices for ApHCM using T-wave analysis.
Main Methods:
- A 24-hour dynamic electrocardiogram (ECG) was performed on 83 ApHCM patients and 89 CAD patients.
- Analysis focused on the average depth of inverted T-waves per minute.
- T-wave segments at the 10th, 50th, and 90th percentiles were analyzed.
Main Results:
- ApHCM patients exhibited greater T-wave variability compared to CAD patients.
- T-wave amplitudes in ApHCM were associated with heart rate and circadian rhythm.
- Maximum T-wave amplitudes exceeded 10 mm in 68% of ApHCM patients, and all ApHCM patients under 50 years old.
Conclusions:
- Significant 24-hour T-wave variations are characteristic of ApHCM.
- ECG during inactivity enhances ApHCM diagnostic sensitivity.
- Identifying T-wave amplitudes >10 mm is a valuable diagnostic index for ApHCM, especially in younger individuals.
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 10th, 50th, and 90th positions of the T-wave were subsequently analyzed.
Results:
The amplitudes of inverted T-waves in ApHCM corresponding to the 10th, 50th, and 90th 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.
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