Abstract: Objective To analyze the endocardial, myocardial, and epicardial longitudinal systolic strain (LSsys) in the left
ventricle (LV) segments and walls in patients with cardiac involvement due to primary amyloidosis (AL-CA) and hypertrophic
cardiomyopathy (HCM). Methods Twenty patients with biopsy-proven AL-CA, 20 with asymmetric HCM, and 20
age-matched healthy volunteers were analyzed for their clinical characteristics and underwent conventional echocardiography
for evaluating LV wall thickness, left atrial and ventricle size, systolic and diastolic function and 2-dimensional velocity vector
imaging for evaluating the endocardial, myocardial and epicardial LSsys of the LV segments and walls. AL-CA and HCM
patients also underwent cardiac magnetic resonance to evaluate the late gadolinium enhancement (LGE) features. Results
Compared with the control group, AL-CA and HCM groups, with similar clinical symptoms and physical signs, both showed
increased LV wall thickness, left atrial diameter, E/A ratio, septal E/e’ ratio and the prevalence of granular sparkling. LV
segments and walls endocardial LSsys were significantly lower in AL-CA patients than in HCM patients and the control
subjects. The endocardial-epicardial LSsys difference in all the left ventricle walls were significantly smaller in AL-CA group
than in the control group, but this difference appeared variable in HCM group. The LGE also presented with different features
in AL-CA and HCM: AL-CA group showed subendocardial LGE in almost all the LV walls, but HCM group showed patchy
LGE with a regional, multifocal distribution. Conclusion AL-CA is characterized by a significantly reduced endocardial LSsys
in the LV segments and an uniform decrease of the endocardial-epicardial LSsys difference in all the LV walls, but the changes
in HCM appear variable, and 2-dimensional velocity vector imaging is therefore a useful modality to differentiate AL-CA from
HCM.