At 9 a.m. on April 18, a 120 ambulance team received a task. A 72-year-old male patient, with 2 stents placed 1 month ago due to myocardial infarction, felt chest pain and chest tightness 20 minutes ago when going out to take the bus. His family helped him to take 4 nitroglycerin under the tongue, which has relieved the chest pain, but dizziness, fatigue, sweating and paleness appeared. The family called 120 for help. When the team arrived at the scene, the medical staff immediately carried out various examinations for the patient. The results showed that the blood pressure was at 60/29mmHg, heart rate at 40 beats / minute, and ECG with no obvious ST-T changes. The patients said that his basal blood pressure was 130-140/80mmHg and basal heart rate was 60-70 beats/minute. Doctor Yang Yi considered that the patient's hypotension was caused by excessive nitroglycerin, so he immediately treated the patient and established a green channel for him to go to a nearby hospital rapidly. How to take nitroglycerin correctly?

For patients with angina pectoris and those with confirmed coronary heart disease, it is necessary to carry nitroglycerin. It is recommended to choose a sitting position or a semi-recumbent position, instead of standing, to avoid dizziness, syncope, and fall injuries that may be caused by orthostatic hypotension. The supine position should also be avoided, as this may increase the burden on the heart due to increased blood volume returning to the heart. It is necessary to take nitroglycerin sublingually, for 1 tablet, taking about 1-3 minutes to take effect. If the symptoms are not relieved after 5 minutes, you make take another tablet. If the symptoms still exists after 5 minutes, you may use 1 tablet again. The limit is 3 tablets. If the symptoms such as chest pain still not relieved, acute myocardial infarction may occur, and it is necessary to call 120 in time. If there are appropriate conditions, blood pressure and heart rate can be monitored during medication. If the blood pressure is too low, it is necessary to stop taking in time. There are contraindications of nitroglycerin and some patients should avoid taking it. Before taking any medication, please follow the doctor's advice for safety.