Giant aneurysm of the left atrial appendage: a case report.

Background: Left atrial appendage aneurysm (LAAA) is a rare condition mostly due to congenital malformations or secondary causes (i.e. mitral regurgitation). Case summary: We present a case of a 47-year-old male with a history of atrial fibrillation treated with propafenone presented to our emergency department for palpitation and epigastric pain. The electrocardiogram showed atrial fibrillation at high ventricular rate and a new-onset left bundle branch block. Urgent coronary angiogram excluded coronary artery disease. Echocardiography and cardiac magnetic resonance revealed a giant LAAA. The electrocardiogram alterations were deemed secondary to aberrancy and treatment with class IC antiarrhythmic. The patient was discussed in the heart team, and considering his will to avoid surgery, he was managed conservatively with closed follow-up, anticoagulant and antiarrhythmic therapy, and internal loop recorder. At 1-year follow-up, he showed asymptomatic and without arrhythmias. Discussion: Few cases are described in the literature; therefore, there is uncertainty in treatment and prognosis. Diagnosis is achieved with multimodality imaging. Treatment can be surgical with aneurysmectomy or conservative with regular follow-up by imaging examinations and pharmacological therapy aimed to prevent complications such as thrombosis and arrhythmias. Since high-quality scientific data are lacking, shared decision-making is essential for the management of patients affected by LAAA. In our clinical case, our patient's will to not undergo surgery was considered, and therefore, a conservative management with strict follow-up and medications was chosen.