One of the main symptoms of a heart attack is a sensation of heaviness, tightness, squeezing, or pressure in the chest or upper back. This pain may not be sudden or severe. It may last for a few minutes, then go away and come back. Some people mistake heart attack pain for heartburn or indigestion. If this pain does not start soon after eating, if you do not usually have heartburn, or if it is accompanied by nausea (feeling like you are going to vomit), you need to visit the emergency room. Women suffering from a heart attack may experience sharp pain that resembles a toothache or earache in the jaw, neck, shoulder or back. This pain occurs because the nerves supplying these areas are also supplying the heart. This pain may come and go for a while before it becomes more intense. It may even be so intense that it wakes you up during the night.  These pains may be felt in each location at once, or in only some of the locations listed. Women often don't experience pain in their arm or shoulder men often report when they have a heart attack. If you suddenly feel faint, your heart may not be getting the blood it needs. If shortness of breath or a cold sweat accompanies the dizziness (feeling as if the room is spinning) or lightheadedness (feeling like you may faint), you could be having a heart attack. Decreased blood flow to the brain causes these symptoms. If you feel winded all of a sudden, this could be a sign of a heart attack. Feeling winded means that you feel as if you cannot catch your breath. If you are feeling short of breath, try breathing through pursed lips (as if you are going to whistle). You use less energy when you breathe this way. This method of breathing may also help you feel more relaxed and lessen the "shortness of breath" feeling. When you have a heart attack, the blood pressure in your lungs and heart rise while the pumping function of the heart decreases. Gastrointestinal symptoms are more common symptoms of a heart attack for women than for men. These symptoms are often overlooked by...

TL;DR in Vietnamese:
Lưu ý cảm giác khó chịu ở ngực hoặc lưng. Xác định cảm giác khó chịu ở phần lưng trên. Lưu ý hiện tượng chóng mặt và/hoặc đau đầu. Lưu ý triệu chứng khó thở. Lưu ý triệu chứng tiêu hóa, chẳng hạn như buồn nôn, khó tiêu, và nôn mửa. Lưu ý hiện tượng khó thở khi thức dậy. Lưu ý cảm giác lo âu. Cảnh giác với triệu chứng suy nhược và mệt mỏi.