Question category: Cardiology
A 50 year old female presents with shortness of breath, fatigue and peripheral oedema. On examination she has a raised JVP, pitting oedema, hepatomegaly and ascites. An echo is organised and reveals globally thickened walls including the interatrial septa with atrial dilatation but the ventricles were not dilated. There is an increased scintillation pattern (granular speckling). There is a normal ejection fraction. An ECG shows low voltage complexes. What is the most likely diagnosis?