Two Cases of Immune Checkpoint Inhibitor-Induced Myocarditis With Complete Atrioventricular Block.

Immune checkpoint inhibitor-induced myocarditis (ICIM) has been reported to be complicated by a complete atrioventricular block. Even though steroids are used in the treatment thereof, there is no standard protocol for their use. We report two cases of ICIM with a complete atrioventricular block with different outcomes. In the first case, the complete atrioventricular block did not recover. In contrast, in the second case, the complete atrioventricular block did recover. We discuss the different courses and outcomes of the two cases in relation to steroid use.