A fast heartbeat does not necessarily lead to death. However, it depends on which type of arrhythmia this fast heartbeat is, such as ventricular flutter or ventricular fibrillation, which may cause sudden death. Therefore, if you want to clarify whether this fast heartbeat of the patient can threaten the patient’s life, you should still perform an electrocardiogram in time. If it is a simple sinus tachycardia and is transient, it will not usually lead to death. Patients may experience rapid heartbeat when they are agitated, after drinking alcohol, when they are anemic, when they have ionic disorders, or when they have hyperthyroidism. If a patient has ventricular fibrillation, prompt electrical defibrillation treatment is required because ventricular fibrillation can cause death at any time.