Immune checkpoint inhibitor-associated sick sinus syndrome and cardiogenic shock.

Immune checkpoint inhibitors (ICI) represent a major advance in the treatment of cancer. Most studies of ICI have underestimated their cardiotoxicity; however, an increasing number of cases of cardiotoxicity are being reported. Herein we discussed a 67-year-old, male, Japanese patient who presented with cardiogenic shock accompanied by sick sinus syndrome 4 days into his second course of ipilimumab plus nivolumab combination therapy. A temporary transvenous pacemaker was subsequently placed, and a permanent pacemaker was implanted for persistent, symptomatic, intermittent bradycardia. The permanent implantation of the pacemaker improved his symptoms and allowed him to continue his ICI therapy.