When your heart is beating fast and it is firing with great rapid around the sinoatrial also known as the sinus nodes you have sinus tachycardia.

The reason why the sinoatrial node is vital is because it's located around your heart at the right of your atrium and known as the pacemaker. The impulses from cardiacs can be transmitted all the way down to your atria and ventricles.

Sinus tachycardia happens when you are in pain, exertion, fever, exercise, excessive thyroids, stimulate drugs and even low blood oxygen. There are lots of other things that could also cause this to happen. You should contact your doctor if you are having pains and feeling your heart beat fast often.

When you're not careful and don't get treatment it might be warnings of heart failure and other diseases such as the heart valve. You should always pay attention to your body when you're in pain and not feeling good.