MPO and hydrops fetalis: It has been shown that patients with HF have elevated levels of pro-inflammatory cytokines and increased levels of circulating proteolytic enzymes such as myeloperoxidase, acid phosphatase and elastase.11 12 Regardless of the aetiology of myocardial injury, there is the same inflammatory response: capillary dilatation and hyperaemia of the vascular bed; increased vascular permeability with capillary leak and oedema; subsequent myocyte cell injury and death; expansion of the extracellular space; and ultimately collagen deposition with scar formation.