Double left atrial appendage: A diagnostic dilemma.

Area of Science:

• Cardiology
• Pediatric Cardiac Surgery
• Congenital Heart Disease

Background:

• Anatomic variations in cardiac structures can present diagnostic challenges.
• The left atrial appendage (LAA) is a common site for thrombus formation, often mimicking other masses.

Purpose of the Study:

• To report a unique intraoperative finding of a double left atrial appendage (LAA).
• To highlight the diagnostic dilemma posed by an invaginated LAA mimicking a cardiac mass or thrombus.

Main Methods:

• Intraoperative transesophageal echocardiography.
• Surgical exploration following cardiopulmonary bypass and cardiac arrest.

Main Results:

• An additional, previously undetected left atrial appendage (LAA) was identified.
• The accessory LAA was found invaginated into the left atrium (LA), presenting as a prolapsing mass.
• The mass was confirmed to be a double LAA, not a thrombus.

Conclusions:

• Double atrial appendages are rare and can lead to misdiagnosis.
• Careful intraoperative assessment is crucial for identifying unusual cardiac anatomy and avoiding diagnostic errors.