Case: A Case of Pembrolizumab Induced Myocarditis and Complete Heart Block

Area of Science:

• Cardiology
• Immunology
• Oncology

Background:

• Immune checkpoint inhibitors (ICIs) like pembrolizumab are increasingly used in cancer therapy.
• While effective, ICIs can rarely cause immune-related adverse events affecting various organs.
• Cardiac side effects of ICIs, though uncommon, can be severe.

Observation:

• A patient developed myocarditis and persistent third-degree heart block.
• These cardiac complications occurred during treatment with pembrolizumab.
• The presentation included significant conduction abnormalities.

Findings:

• The case demonstrates a direct link between pembrolizumab and severe cardiac toxicity.
• Myocarditis and complete heart block were confirmed as adverse events.
• This highlights a rare but serious manifestation of ICI therapy.

Implications:

• Clinicians should maintain a high index of suspicion for cardiac adverse events in patients receiving pembrolizumab.
• Cardiac monitoring may be warranted in patients treated with ICIs.
• Understanding these rare toxicities is crucial for patient safety and management in oncology.