Cardiac involvement in chronic progressive external ophthalmoplegia

Area of Science:

• Cardiology
• Neurology
• Genetics

Background:

• Mitochondrial myopathies are a group of inherited disorders affecting muscle energy production.
• Myocardial involvement in mitochondrial myopathies, particularly chronic progressive external ophthalmoplegia (PEO), is not well understood.
• Previous research suggests cardiac involvement is limited to conduction abnormalities.

Purpose of the Study:

• To investigate myocardial morpho-functional changes in patients with PEO.
• To identify early, subtle structural and functional changes in the myocardium using non-invasive techniques.

Main Methods:

• Twenty patients with PEO and 20 healthy controls underwent standard echocardiography.
• Tissue Doppler imaging (TDI) was used to assess myocardial systolic (Sm) and diastolic (Em, Am) velocities.
• Integrated backscatter (IBS) analysis was employed to evaluate myocardial tissue characteristics and cyclic variations.

Main Results:

• PEO patients showed significantly lower Sm, Em, and Em/Am ratio, and higher Am compared to controls.
• Reduced septal and posterior wall cyclic variations of IBS were observed in PEO patients.
• Findings indicate myocardial wall remodeling with increased fibrosis and early left ventricular systo-diastolic dysfunction in PEO.

Conclusions:

• Chronic progressive external ophthalmoplegia (PEO) is associated with significant myocardial morpho-functional changes.
• Subtle left ventricular dysfunction and fibrosis are present in PEO patients.
• Cardiac involvement in PEO may extend beyond conduction abnormalities and warrants closer attention in patient management.