Spatial and Temporal Non-Uniform Changes in Left Ventricular Myocardial Strain in Dogs with Duchenne Muscular...

Area of Science:

• Cardiology
• Biomedical Engineering
• Animal Models

Background:

• Duchenne muscular dystrophy (DMD) patients have prolonged lifespans, increasing the importance of understanding dystrophin-deficient cardiomyopathy.
• Golden Retriever Muscular Dystrophy (GRMD) dogs serve as a relevant model for studying DMD-related cardiac conditions.

Purpose of the Study:

• To investigate the non-uniformity of myocardial strain within the left ventricle during the progression of cardiomyopathy in GRMD dogs.
• To analyze spatial and temporal alterations in myocardial strain using two-dimensional speckle tracking echocardiography.

Main Methods:

• Two-dimensional speckle tracking echocardiography was used to analyze circumferential strain (CS) and longitudinal strain (LS).
• Strain was assessed in the endocardial, middle, and epicardial layers of the left ventricle (LV) apex, middle-chamber, and base.
• Data were collected from GRMD (n=22) and healthy control dogs (n=7) aged 2 to 24 months.

Main Results:

• GRMD dogs showed reduced systolic CS in all three LV apex layers by 2 months, despite normal global systolic function.
• Spatial heterogeneity in CS progressed with age.
• A decrease in systolic LS was detected in all three LV wall layers by 2 months of age.

Conclusions:

• The study reveals spatial and temporal non-uniform alterations in LV myocardial strain in GRMD dogs.
• These findings provide new insights into the progression of dystrophin-deficient cardiomyopathy in this animal model.
• Early detection of strain abnormalities may aid in understanding and managing cardiac complications in DMD.