[Structural features of cardiomyocytes in the atrialized right ventricle in patients with Ebstein anomaly].

Intraoperative biopsy specimens were used to analyze the sizes and ultrastructure of cardiomyocytes (CMC) in the atrialized right ventricle (ARV) versus those in the right ventricle (RV) and right atrium (RA) in 32 patients aged 9 months to 57 years with Ebstein anomaly. The mean CMC diameter in ARV, RV, and RA did not differ significantly in patients less than 10 years; that was equal in ARV and RV, but higher in RA in patients over 10 years of age. No specific atrial granules were found in the CMC of ARV, RV, and RA; but T system channels and multiple intercalated disks were encountered significantly more frequently than in the RA cells.