A 38-year-old man with progressive dyspnoea and ventricular tachycardia

A previously healthy 38-year-old man presented with a 3-month history of progressive dyspnoea and ventricular tachycardia (VT). He suffered a viral illness 4 months earlier. There was no family history of cardiac disease or sudden cardiac death (SCD). ECG showed left bundle branch block (LBBB). Echocardiography revealed a dilated left ventricle with severely impaired systolic function. Coronary angiogram showed angiographically normal coronary arteries. He was diagnosed as having dilated cardiomyopathy and was referred for further assessment with cardiovascular magnetic resonance (CMR) (figure 1) and subsequently CT thorax.

What is the most likely diagnosis? Dilated cardiomyopathy secondary to HIVGranulomatosis with polyangiitis (GPA)SarcoidosisTuberculosisUnderlying malignancy with lung and cardiac metastases.