With the widespread useof immune checkpoint inhibitors(ICIs)in the treatment of various solid tumors,immune-related adverse events have attracted increasing clinical attention.Although ICI-associated myocarditis is rare,it typically has an insidious onset,progresses rapidly,and carries a high mortality rate,making it one of the most severe complications of ICI therapy.Early recognition and management remain challenging due to the absence of standardized diagnostic and therapeutic guidelines.ICI-associated myocarditis is characterized by the following features,with symptom onset commonly occurring within weeks of initiating ICI therapy.Its clinical manifestations are often non-specific and can be misdiagnosed as coronary artery disease or viral myocarditis.Prompt administration of high-dose corticosteroids combined with immunosuppressants,cardiac rhythm and functional support,is crucial for effective management.Although numerous stud-ies highlight the importance of early detection and multidisciplinary collaboration,there is still no consensus on standardized treatment pro-tocols.This report describes a case of acute ICI-associated myocarditis with ovarian cancer who developed symptoms after receiving com-bined apalutamide and toripalimab therapy.The patient responded well to corticosteroid pulse therapy,second-line immunosuppressants,and intensive care support.Due to recurrent ventricular arrhythmias,an implantable cardioverter defibrillator was placed,and cardiac func-tion remained stable during follow-up.Through this case and a review of the relevant literature,we discuss the clinical features,compre-hensive treatment strategies,and long-term management approaches for ICI-associated myocarditis,aiming to raise clinical awareness,pro-mote standardized multidisciplinary team collaboration,and ultimately improve patient outcomes.

With the widespread useof immune checkpoint inhibitors(ICIs)in the treatment of various solid tumors,immune-related adverse events have attracted increasing clinical attention.Although ICI-associated myocarditis is rare,it typically has an insidious onset,progresses rapidly,and carries a high mortality rate,making it one of the most severe complications of ICI therapy.Early recognition and management remain challenging due to the absence of standardized diagnostic and therapeutic guidelines.ICI-associated myocarditis is characterized by the following features,with symptom onset commonly occurring within weeks of initiating ICI therapy.Its clinical manifestations are often non-specific and can be misdiagnosed as coronary artery disease or viral myocarditis.Prompt administration of high-dose corticosteroids combined with immunosuppressants,cardiac rhythm and functional support,is crucial for effective management.Although numerous stud-ies highlight the importance of early detection and multidisciplinary collaboration,there is still no consensus on standardized treatment pro-tocols.This report describes a case of acute ICI-associated myocarditis with ovarian cancer who developed symptoms after receiving com-bined apalutamide and toripalimab therapy.The patient responded well to corticosteroid pulse therapy,second-line immunosuppressants,and intensive care support.Due to recurrent ventricular arrhythmias,an implantable cardioverter defibrillator was placed,and cardiac func-tion remained stable during follow-up.Through this case and a review of the relevant literature,we discuss the clinical features,compre-hensive treatment strategies,and long-term management approaches for ICI-associated myocarditis,aiming to raise clinical awareness,pro-mote standardized multidisciplinary team collaboration,and ultimately improve patient outcomes.