The heartburn is isosorbide nitrate tablets, which are the more commonly used nitrate drugs in clinical practice. The method of taking cardiac pain can be roughly divided into two categories: one is similar to the application method of nitroglycerin and quick-acting heart pills, taking sublingual or swallowing method when angina attack, temporary oral 5mg of cardiac pain, which helps to relieve angina and improve the symptoms. In another category, because of the relatively short half-life of the anti-cardiac pain, if the anti-cardiac pain is used to prevent angina and improve the blood supply to the heart muscle, it is generally recommended to take 3 times/day orally, 1-2 tablets/time, or for patients with recurrent attacks of angina, you can also take 4 times/day orally anti-cardiac pain, 2-3 tablets/time, to prevent the attack of severe angina by increasing the dose.