Abstract
Immunotherapy is a potent tool used in cancer treatment, but the occurrence of immune-related adverse events induced by immune checkpoint inhibitors (ICIs) cannot be overlooked. This is particularly true for rare but potentially fatal cardiovascular complications, such as myocarditis; heart muscle inflammation may lead to heart dysfunction and arrhythmia. The present case is a 68-year-old female breast cancer patient who developed palpitations and elevated cardiac enzyme levels after 1 day of ICI therapy, and the patient was eventually diagnosed with immune myocarditis. After receiving hormonal shock therapy, Ctn I, CK, CK-MB and other cardiac enzyme-related markers improved significantly, and electrocardiogram test returned to normal, and the patient recovered during hospitalization without any major adverse cardiac events. Furthermore, the present study reviewed the mechanism of immune myocarditis induced by ICI therapy, with the aim of providing a clinical foundation for the prevention and diagnosis of cardiovascular adverse events in ICI therapy.