Segmental myocardial tissue remodeling and atrial arrhythmias in hypertrophic cardiomyopathy: Findings from
Danqing Liu1, Hong Luo2, Changjing Feng1
1Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
Insights
Myocardial fibrosis in the basal septal and anterior left ventricle is linked to atrial arrhythmias in hypertrophic cardiomyopathy (HCM). Elevated native T1 values in the basal anteroseptal segment may predict arrhythmia development in HCM patients.
Area of Science:
- Cardiovascular Imaging
- Cardiac MRI
- Hypertrophic Cardiomyopathy Research
Background:
- Left ventricular (LV) myocardial fibrosis is associated with atrial fibrillation in hypertrophic cardiomyopathy (HCM).
- Quantitative assessment of LV fibrosis and atrial arrhythmias in HCM using T1 mapping and extracellular volume fraction (ECV) is limited.
- Understanding the relationship between fibrosis and arrhythmias is crucial for managing HCM.
Purpose of the Study:
- To explore the segmental relationship between diffuse LV fibrosis and atrial arrhythmias in HCM.
- To investigate the utility of T1 mapping and ECV in identifying fibrosis patterns associated with arrhythmias.
- To provide imaging insights into the pathophysiology of HCM with atrial arrhythmia.
Main Methods:
- 38 HCM patients were divided into groups with and without atrial arrhythmias based on ECG and Holter monitoring.
- T1 mapping parameters were compared between groups using covariance analysis, adjusting for wall thickness.
- Analysis included all 16 myocardial segments collectively and individually.
Main Results:
- Elevated native T1 values were observed in the entire LV and specific segments (S1-3) in HCM patients with arrhythmias.
- Basal anterior (S1) and inferoseptal (S3) segments showed prolonged ECV and elevated native T1 values in patients with arrhythmias.
- Myocardial native T1 values in the basal anteroseptal segment (S2) predicted atrial arrhythmia presence, with values >1350 ms increasing likelihood.
Conclusions:
- Basal septal and anterior LV fibrosis significantly contributes to myocardial remodeling and atrial arrhythmia development in HCM.
- Elevated native T1 values in the basal anteroseptal segment serve as a potential marker for concurrent atrial arrhythmias in HCM.
- T1 mapping offers valuable insights into the substrate underlying atrial arrhythmias in HCM.
Background:
Myocardial fibrosis of the left ventricle (LV) has been associated with atrial fibrillation and other arrhythmias in individuals with hypertrophic cardiomyopathy (HCM). However, few studies have quantitatively examined the segmental relationship between diffuse LV fibrosis and atrial arrhythmias in HCM using T1 mapping and extracellular volume fraction (ECV). The aim of this study is to explore this relationship through T1 mapping, offering imaging insights into the pathophysiology of HCM with atrial arrhythmia.
Methods:
A total of 38 patients with HCM were classified into two groups-those with atrial arrhythmia and those without-based on electrocardiographic and Holter monitor recordings. A covariance analysis was conducted to compare T1 mapping parameters between the two groups, adjusting for wall thickness (WT) as a covariate. Analysis was performed collectively for all 16 myocardial segments, as well as for each segment individually.
Results:
Native T1 values were elevated in the entire LV myocardium and in segments S1-3 in patients with HCM with atrial arrhythmias compared to those without (P < 0.001; P < 0.05, 1316.0 ms ± 15.9 vs 1263.1 ms ± 13.6, 1350.5 ms ± 14.2 vs 1311.9 ms ± 11.7, 1305.7 ms ± 2.5 vs 1271.5 ms ± 10.6, respectively). Notably, the basal anterior segment (S1) and basal inferotseptal segment (S3) exhibited prolonged ECV and elevated native T1 values in patients with HCM and atrial arrhythmia (P < 0.05). Multivariable binary logistic regression analysis identified myocardial native T1 values in the basal anteroseptal segment (S2) as a predictor of atrial arrhythmia presence in HCM, with values exceeding 1350 ms correlating with an increased likelihood of arrhythmia development. No significant difference in WT was observed between the groups in hypertrophic myocardial regions (P > 0.05), while non-hypertrophic myocardium in individuals with HCM and atrial arrhythmias exhibited reduced wall thickness (7.7 mm ± 3.0 vs 9 mm ± 3.0, P < 0.001) compared to those without arrhythmias.
Conclusion:
Fibrosis in the basal septal and anterior regions of the left ventricle plays a crucial role in myocardial tissue remodeling, contributing to the development of atrial arrhythmia in HCM. Elevated native T1 values in the basal anteroseptal segment may may serve as a significant marker for the concurrent occurrence of atrial arrhythmias in individuals with HCM.
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