Radiation associated coronary occlusion: Overlooked as trastuzumab-induced cardiomyopathy

Trastuzumab is an agent used for receptor-positive breast cancer. Up to a third of patients treated with trastuzumab might develop cardiomyopathy. Many patients with breast cancer have taken pre- or co-administration of mediastinal radiotherapy. Both of treatment modalities have toxic effects on myocardium. It may result with diagnostic confusion between radiation-induced CAD (riCAD) and trastuzumab cardiomyopathy in the case with dilated cardiomyopathy. TTE may offer clues of differential diagnosis.