Idiopathic dilatation of the right atrium revealed in childhood by dysrhythmias.

A 7-year-old male presented with apparently banal but repetitive episodes of paroxysmal supraventricular tachycardia, along with other manifestations of atrial hyperexcitability. Isolated dilatation of the right atrium was discovered. This disorder is usually latent or benign, but sometimes it is serious because of conduction defects. Lack of relevant studies means the basis of the disorder is not understood.