Giant Left Atrial Aneurysm Complicated by Multiple Thrombi and Cardiogenic Shock: A Fatal Case.

A giant left atrial aneurysm is an exceptionally rare but clinically significant cardiac abnormality, most commonly associated with rheumatic mitral valve disease, long-standing atrial fibrillation, and progressive atrial remodeling related to aging. Its clinical relevance lies in the high risk of thromboembolic events, compression of adjacent structures, malignant arrhythmias, and advanced heart failure. We report the case of a 72-year-old woman with a history of persistent atrial fibrillation, chronic heart failure, chronic kidney disease, and a non-reperfused acute myocardial infarction, who presented with progressive dyspnea, precordial chest pain, and peripheral edema. Contrast-enhanced computed tomography of the chest revealed a giant aneurysmal dilation of the left atrium complicated by multiple intracavitary mural thrombi, severe cardiomegaly, and displacement of adjacent cardiac and extracardiac structures. Despite aggressive medical management, the patient rapidly deteriorated and developed refractory cardiogenic shock, culminating in cardiorespiratory arrest. This case highlights the catastrophic potential of giant left atrial aneurysms and underscores the importance of early diagnosis and timely intervention to prevent fatal complications.