[Unusual left-to-right shunt]

Area of Science:

• Cardiology
• Cardiac Imaging
• Pathophysiology

Background:

• Restrictive cardiomyopathy can present with complex intracardiac abnormalities.
• Interatrial shunts, though typically congenital, can manifest acquired forms.

Observation:

• Transthoracic echocardiography initially suggested a coronary artery fistula draining into the right atrium.
• Transesophageal echocardiography identified a patent foramen ovale with a left-to-right shunt.

Findings:

• Elevated pressures in enlarged atria led to patent foramen ovale valve dysfunction.
• This dysfunction resulted in an interatrial leak, mimicking an acquired atrial septal defect.

Implications:

• This case expands the understanding of acquired atrial septal defects.
• It underscores the importance of comprehensive echocardiographic evaluation in complex cardiac conditions.