Perflutren-Induced Angioedema To the Editor, Perflutren is used in echocardiography to better delineate the endocardial border and to assess myocardial perfusion and viability.1–3 Final formulation consists of octafluoropropane molecules encapsulated in a lipid shell which create microbubbles in the systemic circulation once injected. It has been well tolerated in clinical trials with common adverse effects reported to be headache, nausea and flushing, occurring in