Altered dystrophin expression in the right atrium of a patient after Fontan procedure with atrial flutter.

Underlying mechanisms in the development of atrial flutter or intra-atrial re-entry tachycardia in patients with structural cardiac abnormalities remain poorly defined. The right atrial myocardium from two patients with congenital heart disease was evaluated, of whom one presented with severe right atrial dilation and arrhythmia and the other with a normal right atrium, to assess whether increased right atrial pressure and volume overload give rise to sarcolemmal alteration. N-terminus dystrophin staining in the atrium from the patient who had undergone a Fontan procedure showed a normally distributed but significantly reduced staining signal compared with the second patient. This is the first report that patients with severe right atrial dilation and atrial flutter have marked reduction in atrial dystrophin expression.