Introduction: The rupture of the ventricular free wall is a complication of STEMI in the fi rst 24 hours or at 3-5 days, maximum 2 weeks. Subacute rupture appears when the formation of thrombus and adhesions closes the solution of continuity. The pseudoaneurysm, another complication of myocardial infarction, represents a localised rupture of the myocardium, limited by adhesions of the pericardium, by the organised thrombus and local haematoma which prevent the formation of haemopericardium. In both cases, the solution is the emergency surgical intervention. We will present the case of a 74 year old patient, ex-smoker, with medical history of rheumatoid arthritis, who was urgently sent in our hospital with the diagnosis of pericardial effusion with signs of cardiac tamponade for pericardiocentesis. Methods: The electrocardiogram at admission revealed necrosis and ST elevation in the inferior leads, identical recording as 3 months before. Transthoracic ecography illustrated a pericardial effusion compressing the RV. At the level of the inferior wall of the LV, a pseudoaneurysm was seen, the external wall being formed by pericardium stuff ed with thrombotic material. The transoesophageal ecography suggested the sanguineous consistency of the pericardial eff usion. The cardiac MRI confi rmed the presence of the sanguineous effusion compressing the RV and the pseudoaneurysm of the LV with a thrombus inside. The effusion extended inferiorly near the pseudoaneurysm, being only delimited by thrombotic material. The coronary angiography showed chronic occlusion of the RC artery. Results: After all investigations, the indication of emergency surgical intervention was established. During surgery, the pericardial effusion compressing the RV was evacuated, not obtaining the distension of the RV. The pericardium presented multiple adhesions suggesting constrictive pericarditis, thus partial right pericardectomy was performed. The cure of the pseudoaneurysm and CABG was done. The postoperative evolution was marked by diff use haemorrhage at the level of the pericardectomy and consequently, reintervention for the control of the haemostasis was necessary. Because of the haemodinamic instability, inotropic and vasopressor support and an intraaortic ballon pump were needed. Aft erwards, the patient developed multiple organ failure, the exitus by PEA happening 2 days postoperatively. Conclusions: The singularity of the case is represented by the fact that pericardial adhesions, determined by the rheumatoid arthritis, determined the formation of the pseudoaneurysm and limited the extension of the initial hemorrhagic effusion. Furthermore, the cardiac tamponade limited to the right side of the heart appeared more than 3 months aft er the major coronary event. Last, but not least, it has to be highlighted that a late diagnosis involves multiple complications with a fatal outcome.