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Updated: Aug 29, 2025
Quantification of Mouse Heart Left Ventricular Function, Myocardial Strain, and Hemodynamic Forces by Cardiovascular Magnetic Resonance Imaging
Published on: May 24, 2021
Associations between perfusion defects, tissue changes and myocardial deformation in hypertrophic cardiomyopathy,
Pedro Garcia Brás1, Sílvia Aguiar Rosa2, Boban Thomas3
1Department of Cardiology, Santa Marta Hospital, Lisbon, Portugal.
Insights
Microvascular dysfunction in hypertrophic cardiomyopathy (HCM) is linked to tissue abnormalities and impaired myocardial strain. This dysfunction occurs even in segments without significant wall thickening, highlighting its broad impact.
Area of Science:
- Cardiology
- Cardiovascular Imaging
- Medical Diagnostics
Background:
- Microvascular dysfunction is an underrecognized aspect of hypertrophic cardiomyopathy (HCM).
- Understanding its relationship with myocardial characteristics is crucial for patient management.
Purpose of the Study:
- To assess the association between microvascular dysfunction, wall thickness, tissue characteristics, and myocardial deformation in HCM patients.
- To analyze these associations at the individual myocardial segment level.
Main Methods:
- Prospective cardiac magnetic resonance (CMR) imaging.
- Assessment of wall thickness, T1/T2 mapping, extracellular volume, late gadolinium enhancement (LGE), and stress perfusion.
- Stratification of results by American Heart Association (AHA) segments.
Main Results:
- Perfusion defects were observed in 35% of segments, more frequently in hypertrophied segments but also present in normal-thickness segments.
- Segments with perfusion defects showed higher T1, extracellular volume, T2, and more frequent LGE, independent of wall thickness.
- Impaired circumferential and radial strain was associated with perfusion defects.
Conclusions:
- Microvascular dysfunction is prevalent in HCM segments, both with and without hypertrophy.
- Ischemia is associated with tissue abnormalities (e.g., fibrosis) and impaired myocardial strain, irrespective of segmental wall thickness.
Background:
Microvascular dysfunction is an often overlooked feature of hypertrophic cardiomyopathy (HCM). Our aim was to assess the association between microvascular dysfunction, wall thickness, tissue characteristics and myocardial deformation in HCM patients, by analyzing individual myocardial segments.
Methods:
Prospective assessment including cardiac magnetic resonance to assess wall thickness, T1 and T2 mapping, extracellular volume, late gadolinium enhancement (LGE) and stress perfusion. Results were stratified according to the 16 American Heart Association segments.
Results:
Seventy-five patients were recruited (1200 segments), 63% male, mean age 54.6±14.8 years, maximal wall thickness of 20.22±4.6 mm. Among the 424 segments (35%) with perfusion defects, 24% had defects only in the endocardial layer and 12% in both endocardial and epicardial layers. Perfusion defects were more often detected in hypertrophied segments (64%). Among the 660 segments with normal wall thickness, 19% presented perfusion defects. Independently of wall thickness, segments with perfusion defects had a higher T1 (β-estimate 30.28, p<0.001), extracelluar volume (β-estimate 1.50, p<0.001) and T2 (β-estimate 0.73, p<0.001) and had late gadolinium enhancement more frequently (odds ratio 4.16, p<0.001). Higher values of circumferential strain (lower deformation) and lower values of radial strain were found in segments with perfusion defects (β-estimate 2.76, p<0.001; and β-estimate -10.39, p<0.001, circumferential and radial strain, respectively).
Conclusion:
While microvascular dysfunction was more prevalent in more hypertrophied segments, it also had a major presence in segments without hypertrophy. In this segmental analysis, we found an association between the presence of ischemia and tissue abnormalities, replacement fibrosis as well as impaired strain, independently of the segmental wall thickness.
