Vagal-induced slowing of the heart rate can be observed temporarily if symptoms are mild, or treated with oral or intravenous atropine if symptoms are significant. The heart rate is controlled by both the sympathetic and vagus nerves. Vagal excitation causes the heart rate to slow down, while sympathetic excitation causes the heart rate to speed up. Mild slowing of the heart rate due to vagus nerve may be temporarily observed for changes in condition, and the symptoms will improve as the vagal tone is gradually reduced. For patients with slow heart rate leading to ejection insufficiency, clinical symptoms such as dizziness may occur, and even cardiogenic syncope may occur, which can be treated with oral atropine, and if the symptoms are particularly serious, intravenous atropine is needed to quickly relieve the patient’s symptoms of slow heart rate and prevent the patient from experiencing a life-threatening condition. The slow heart rate occurs when the vagus nerve is excited, we should pay attention to closely observe the changes in the condition, pay attention to warmth, to prevent the occurrence of syncope.