Mitro-Aortic Fibrosa Pseudoaneurysm: Case Report and the Role of Echocardiography

The mitro-aortic fibrosa is a rigid, avascular structure located between the anterior cusp of the mitral valve and the non-coronary cusp of the aortic valve.Throughout the cardiac cycle, it ensures anatomical and functional integrity between the aortic and mitral annuli.Being relatively avascular, this region is more susceptible to infectious processes, favoring the development of pseudoaneurysms.Although rare, mitro-aortic fibrosa pseudoaneurysms are increasingly recognized, especially due to advances in cardiac imaging techniques.We report the case of a 33-year-old male patient admitted to the emergency department of the Complexo Hospitalar de Doenas Cardio-Pulmonares Cardeal Dom Alexandre do Nascimento with a two-month history of progressive dyspnea (initially on moderate to large exertion, later on minimal exertion), associated with oppressive chest pain, non-radiating, and lasting over one hour.Transthoracic echocardiography revealed a partial and extensive discontinuity at the level of the mitro-aortic fibrosa, with aneurysmal bulging into the left atrium, suggestive of a pseudoaneurysm.Transesophageal echocardiography confirmed the diagnosis, showing an anechoic structure in this region, with cord-like motion and no signs of rupture.The case was reviewed by the heart team and considered complex and high-risk.The patient remains under hospital follow-up, preoperatively stable under medical therapy.Mitro-aortic fibrosa pseudoaneurysm is a rare entity, whose early recognition depends primarily on echocardiography.This case highlights the importance of imaging techniques in evaluating chest pain and dyspnea in young patients, allowing timely diagnosis, multidisciplinary discussion, and the formulation of strategies to improve prognosis and reduce potentially fatal complications.