Complete Heart Block and Myocarditis Related to Immune Checkpoint Inhibitor Therapy

This is a case with metastatic melanoma on combination ipilimumab and nivolumab complicated by developing severe fulminant myocarditis. Patient presented with complete heart block requiring temporary pacemaker insertion that reversed with combination treatment of high dose steroids and abatacept. Patient remained in stable condition with normal LVEF after steroid taper without requirement of permanent pacemaker. Following the steroid taper, patient was started on the next line of therapy for melanoma which included BRAF inhibitors. He has had a durable cancer response but it is unclear whether it is due to early initiation of his next line of melanoma therapy or a lasting response from initiation 2 doses of immunotherapy.