The manifestations of heart damage after chemotherapy include symptoms, signs and auxiliary examinations, as follows: 1. Symptoms: patients will suddenly feel panic, chest pain or shortness of breath, originally going up to the second floor without shortness of breath, but now they feel chest tightness and shortness of breath when they go up to the second floor, which is a symptom that most patients will have; 2. Signs: they can be manifested as a doctor’s examination and finding that the patient’s heart rate suddenly accelerates, slows down or becomes uneven, premature beats appear, murmurs, 3, auxiliary tests: such as electrocardiogram will appear T-wave changes, ST-segment changes or arrhythmias, low voltage and other manifestations. Such patients also commonly use cardiac ultrasound, which can show a decrease in ejection fraction EF, and laboratory tests find that troponin and BNP are relatively sensitive, etc. Therefore, the clinic repeatedly emphasizes the need to improve the baseline examination when patients are treated with chemotherapy with cardiotoxic drugs. This is because the baseline examination helps to determine whether the cardiotoxicity occurs after chemotherapy, radiotherapy or targeted therapy. Baseline examinations include electrocardiogram, ambulatory electrocardiogram, cardiac ultrasound, and myocardial enzymatic changes, of which troponin and BNP are the more sensitive indicators. If these tests are also abnormal and the ejection fraction EF value decreases by more than 10% or even 5%, it can be judged that the patient has myocardial damage after chemotherapy, radiotherapy or targeted drug therapy.