Giant right atrium: an extreme case of idiopathic dilation of the right atrium.

An adult with a grossly dilated right atrium of unknown etiology is presented. The right atrial volume was estimated at more than 1,900 mL, with normal sized left atrium and ventricles. She presented in atrial fibrillation and right ventricular failure. She underwent subsequent reduction atrioplasty of the right atrium and tricuspid valve ring annuloplasty. Atrioplasty alone was unsuccessful in controlling the atrial fibrillation. Postoperatively, her course was complicated by pericardial space problems, eventually requiring a partial pericardiectomy. At her 2-year follow-up she was asymptomatic, although still in atrial fibrillation.