<p>Pulmonary artery aneurysm (PAA) and dissection are rare and fatal cardiovascular diseases, characterized by insidious clinical manifestations and posing significant challenges in diagnosis and management. This article reports a case of a patient with PAA complicated by dissection, who died within hours of diagnosis. The patient presented with sudden chest pain and dyspnea, which could easily be misdiagnosed as common emergencies such as acute coronary syndrome. Clinicians should maintain a high index of suspicion when managing high-risk populations. CT pulmonary angiography plays a critical role in confirming the diagnosis. This case underscores the importance of multidisciplinary collaboration and timely initiation of cardiac surgical intervention to improve outcomes. Although the generalizability of the conclusions is limited by the small number of cases, this study provides direction for exploring early biomarkers and optimizing diagnostic and treatment strategies. It also offers a theoretical basis for monitoring and intervening in high-risk populations, which may help reduce the mortality rate of such diseases.</p>