Different Presentations of an Unusual Anomaly
Left Atrial Appendage Aneurysm
Two patients present the same day with an exceedingly unusual diagnosis: (A) a 4-year-old girl referred for a cardiac magnetic resonance imaging for possible pericardial cyst suspected by echocardiography and (B) a 16-year-old girl with headache and atrial flutter. Further cardiac imaging revealed a large aneurysm of the left atrial appendage (LAAA). Although echocardiography showed dense spontaneous contrast inside the saccular aneurysm, no clots were observed in any of the cases. Patient B underwent uneventful surgical resection with immediate resolution of the atrial arrhythmia. Pathologic report was consistent with eosinophilic myocardial inflammation of the LAAA, to the best of our knowledge, not previously reported. In patient A, no surgical procedure has been performed to date.
The first case of LAAA was reported by Parmley et al.1 in 1962 during a surgical procedure. In a review by Aryal et al.,2 40% of the cases (n = 82) were congenital. They can be classified as congenital where the underlying pathology appears to be a dysplasia of the atrial pectinate muscles and acquired in patients with elevated left atrial pressure or myocardial infiltration like in Patient B's case. LAAA can also be extrapericardial due to herniation of the left atrial appendage through a pericardial defect or intrapericardial by focal weakness of the left atrial wall. Only 1/3 of the patients have symptoms before the age of 10. In most patients, the condition is discovered in the second to fourth decades. Early recognition is important because arrhythmias and embolism are the most common complications. Absence of cardiac pathology, normal left atrial anatomy, clear communication between the left atrium and the left atrial appendage, and distortion of the left ventricular free wall by the aneurysm are some of the proposed diagnostic criteria. Aneurysmectomy is the standard treatment.
- Parmley LF Jr. Congenital atriomegaly. Circulation 1962;25:553-8.
- Aryal MR, Hakim FA, Ghimire S, et al. Left atrial appendage aneurysm: a systematic review of 82 cases. Echocardiography 2014;31:1312-8.
Date: April 27, 2018
Source: ACC Media File
Clinical Topics: Arrhythmias and Clinical EP, Congenital Heart Disease and Pediatric Cardiology, Heart Failure and Cardiomyopathies, Noninvasive Imaging, Pericardial Disease, Atrial Fibrillation/Supraventricular Arrhythmias, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Imaging, CHD and Pediatrics and Prevention, Echocardiography/Ultrasound, Magnetic Resonance Imaging
Keywords: Heart Defects, Congenital, Diagnostic Imaging, Aneurysm, Pediatrics, Atrial Function, Left, Atrial Appendage, Atrial Flutter, Mediastinal Cyst, Atrial Pressure, Atrial Fibrillation, Heart Atria, Echocardiography, Thrombosis, Embolism, Magnetic Resonance Imaging, Inflammation