Patient: Female, 58Final Diagnosis: Acute hear failureSymptoms: Dispnoea • edema • fatigueMedication: —Clinical Procedure: Bone marrow biopsy • endomyocardial biopsy • abdominal subcutaneous fat biopsy under ECMO supportSpecialty: CardiologyObjective:Rare diseaseBackground:Cardiac amyloidosis results from the amyloid deposition in heart tissue, either in the context of a systemic disease or as a localized form. Several pro-amyloid proteins can produce amyloid deposits in the heart. Each of these amyloidoses has characteristic clinical (cardiac and extracardiac) features, and a specific diagnosis and treatment.Case Report:A 58-year-old woman who presented with acute heart failure and echocardiographic findings strongly suggestive of infiltrative cardiomyopathy needed percutaneous veno-arterial extracorporeal membrane oxygenation (ECMO) as bridge-to-decision. Amyloid deposition was found on endomyocardial and bone marrow biopsies. Bone marrow plasma cell infiltrate with acute renal lesion and hypercalcemia confirmed the diagnosis of multiple myeloma-associated systemic light-chain amyloidosis (AL). Refractory shock with multi-organic failure syndrome persisted and no improvements in left ventricular function and structure were seen. After extensive discussion by a multidisciplinary team, and with the patients’ family, she was not considered eligible for high-dose chemotherapy and/or autologous stem cell transplantation, heart transplantation, or sequential heart with autologous stem cell transplantation. The patient died a few hours after ECMO withdrawal. During the 14 days of ECMO support no major bleeding or thrombotic complications occurred.Conclusions:The clinician must consider a diagnosis of cardiac amyloidosis in patients with heart failure, a restrictive type of cardiomyopathy with ventricular hypertrophy in the absence of valve abnormalities, or uncontrolled arterial hypertension. Although developments in chemotherapy have greatly improved the outcomes in AL amyloidosis, the prognosis of patients with severe cardiac involvement remains very poor. ECMO is potentially a reliable bridge-to-diagnosis and bridge-to-decision in these patients. An experienced ECMO team, careful patient selection, and rigorous management protocols with objective criteria to wean or stop ECMO are needed.