Cardiac involvement in chronic progressive external ophthalmoplegia.

Myocardial involvement has not been extensively investigated in mitochondrial myopathies. The aim of the study was to assess the myocardial morpho-functional changes in patients with chronic progressive external ophthalmoplegia (PEO). Twenty patients with PEO and 20 controls underwent standard echocardiography with tissue Doppler imaging (TDI) and integrated backscatter (IBS) analyses. These techniques are capable of providing non-invasively the early, subtle structural and functional changes of the myocardium. TDI myocardial systolic (Sm) and early (Em) and late (Am) diastolic velocities of left ventricular walls were determined. The systo-diastolic variation of IBS was also determined. Patients with PEO exhibited lower Sm, lower Em, and higher Am, and a reduced Em/Am ratio than controls (p<0.001 for all) at interventricular septum and lateral wall levels. In PEO patients, septal and posterior wall cyclic variations of IBS were significantly lower than those in controls (p<0.001). Patients with PEO showed myocardial wall remodeling characterized by increased fibrosis and early left ventricular systo-diastolic function abnormalities. Although cardiac involvement in PEO is generally considered to be limited to the cardiac conduction system, left ventricular dysfunction may be present and should receive more attention in the management of these patients.