Overall, chemotherapy decreases the function of the heart, which can manifest as heart enlargement or valve damage. There is also coronary artery damage, which can cause unstable angina, myocardial infarction, valvular disease, and cardiomyopathy, all of which can lead to decreased systolic or diastolic function of the heart. These problems can usually be detected by patient symptoms, signs and ancillary examinations. For the structural examination of the heart, ultrasound is definitely inseparable, then there is enzymatic judgment, and there is also a good way to do ECT and perform nuclear myocardial imaging, which can also be more accurate to show these injuries. For targeted therapy after radiotherapy, especially immunotherapy in recent years, once cardiotoxicity occurs, the mortality rate is very high, and the mortality rate of fulminant myocarditis is also very high. Therefore, when using such drugs, doctors should communicate well with patients and families. If immunosuppressant use causes heart damage, it can also cause skeletal muscle damage. Patients will feel weakness and myalgia, and when these symptoms occur, they should be alert to the presence of myocardial damage. Moreover, cardiac enzymes, myoglobin and troponin are sensitive to cardiac injury caused by immunotherapy.