CONGRESS ABSTRACT

A 66-year-old hypertensive male called emergency services for respiratory distress. Upon arrival, he was diaphoretic and hypotensive. A FAST ultrasound revealed a large pericardial effusion, and the ECG showed ST-segment elevation in V5-V6. The patient was transferred to the emergency department, where severe pericardial effusion with early haemodynamic compromise was confirmed. Due to persistent hypotension and elevated lactate, inotropic therapy was initiated. A transoesophageal echocardiogram showed a severely reduced ejection fraction but excluded aortic dissection and myocardial wall breach. Despite this, a chest-abdominal CT angiography was planned to rule out aortic dissection. However, the patient's rapid hemodynamic deterioration, despite maximal inotropic therapy, led to the emergency placement of a percutaneous femoral-femoral veno-arterial ECMO. Once stabilized, a contrast-enhanced CT angiography confirmed the pericardial effusion and showed large endoluminal clots in the left ventricle. Most importantly, it revealed an aortic dissection flap in the ascending aorta, involving the ostium of the coronary arteries. The patient was urgently taken to the operating room, where no dissection was found. Instead, a myocardial wall breach was identified at the lateral wall of the left ventricle and was promptly repaired with surgical suturing. After surgery, hemodynamics rapidly improved, and ECMO was removed after 48 hours. Diagnostic coronary angiography revealed a recanalized occlusion of the MO1 branch, supplied by collateral coronary circulation, and medical therapy was recommended. The patient was discharged asymptomatic and hemodynamically stable. This case highlights the challenge of distinguishing between aortic dissection and myocardial rupture as causes of pericardial tamponade in ECMO patients. ECMO-induced hemodynamic changes can cause contrast stratification in the aorta, mimicking aortic dissection. Specifically, the opposing flows from the left ventricle (antegrade) and ECMO (retrograde) can lead to false positives on CT angiography. Given the potential for such diagnostic errors, alternative approaches, such as delayed venous phase CT angiography, transoesophageal echocardiography, or direct transfer to the operating room, may be required.