Idiopathic dilatation of the right atrium is an isolated enlargement of the right atrium in the absence of other cardiac lesions. This rare anomaly has a clinical spectrum ranging from asymptomatic to heart failure or even sudden death. It can be associated with atrial arrhythmias and thrombus formation. Antiplatelet therapy is prescribed in most cases reported in the literature, and reduction plasty is indicated when there is rapid growth of the right atrium, compression of adjacent structures, or refractory arrhythmias. We report four cases of idiopathic dilatation of the right atrium diagnosed during prenatal screening. We describe the intrauterine course and management in postnatal life until early childhood.

A tunnel between the aorta and right atrium in a newborn was occluded with 5×6 Amplatzer Duct Occluder II-Additional Size. Our case is different because of enlarged right atrium and atypical location of tunnel orifice.

Cor triatriatum dexter is an extremely rare congenital anomaly of the right atrium. It occurs because of the persistence of the right sinus venosus valve, resulting in partitioning of the right atrium. Most of the described cases of cor triatriatum dexter in the literature were incidental findings on echocardiogram or at necropsy.

We present a case report of a 7-year-old girl who was referred to us for further assessment, with a possible diagnosis of coarctation of the aorta. Initial investigations confirmed not only the presence of a long segment coarctation of the aorta, but also a large obstructive membrane in the right atrium.

A catheter intervention was performed to stent the coarctation segment, and the fibro-muscular shelf in the right atrium was surgically resected.