Five-chambered heart: a 20-year story of left atrial appendage aneurysm

Left atrial aneurysm (LAAn) is a rare congenital pathology described by Semans and Taussig in 1938. Most commonly, clinical presentation includes exercise dyspnoea, palpitations, or angina. The condition may be complicated by atrial ectopy or fibrillation, embolism, mitral regurgitation, and, rarely, cardiac tamponade or infarction. To date, approximately 80 case reports on LAAn have been published. This case represents the sole occurrence of the entity in >300 000 echocardiographic examinations performed over 20 years in the laboratories of the authors. A 25-year-old male was admitted to hospital for the first time in 1988 due to exercise intolerance [New York Heart Association (NYHA) functional class II/III]. Chest X-ray suggested cardiac enlargement. Echocardiogram revealed an additional echo-free cavity adjacent to the left ventricle. Preliminary echocardiographic diagnosis was pericardial cyst. Surgery was advised but rejected by the patient. Ten years later, he was reassessed and echocardiography demonstrated a 2 cm wide communication between the left atrium and additional echo-free cavity (measured as 8 × 4 cm in cross-section) located along and modelling anterolateral left ventricular wall. No filling impairment or flow turbulence was detectable. Transoesophageal study revealed the continuity of the apex of left atrial appendage with large blood-filled space consistent with left atrial appendage aneurysm. The patient was still refusing cardiac surgery and remained in NYHA class II. Yearly controls showed unchanged anatomy of the lesion. Five years ago paroxysmal atrial flutter and fibrillation were documented by Holter monitoring, and acenocoumarol was initiated. Thrombi were never visualized inside the aneurysm and no embolic events occurred. In 2006, surgical option was reconsidered due to an increase in palpitations, and multislice cardiac computed tomography and cardiac magnetic resonance were performed. The size of appendage aneurysm is now 11.2 × 9 × 4.8 cm and communication with the left atrial cavity is 3.4 × 2.5 cm wide. According to CT scan, coronaries are normal although a long section of the left coronary artery courses between the left ventricular and aneurysmal appendage cavities. As no additional factors for adverse prognosis were identified in the imaging studies, conservative management with acenocoumarol and β-blockers was continued according to the patient's preference. He is now 45, remaining in functional class NYHA II and occasional supraventricular arrhythmia is well tolerated.