How can one distinguish cardiac chest pain from non-cardiac chest pain?

Usually, the main symptom of a heart attack is a heavy, squeezing, constricting, burning pain or discomfort occurring in the center of the chest.
This pain may sometimes radiate down the left arm, across the left shoulder and upper back, or up to the neck and to the lower jaw. Anxiety, profuse sweating, nausea and vomiting, shortness of breath, and fainting may also be present. Fortunately, in most cases, the pain or discomfort is severe enough to cause an individual to seek medical attention.
In some instances, however, the pain lasts for only an hour or less and the individual mistakenly believes that the chest pain is simply due to indigestion or skeletal muscle spasms.
The following questions can be useful in helping individuals to differentiate cardiac chest pain from non-cardiac chest pain:

Does the pain/discomfort get better or worse when changing body position?
Cardiac chest pain is not influenced by changes in body position.

Is the pain/discomfort better or worse with respirations?
Cardiac chest pain is not exacerbated by respiration.

Is the pain/discomfort intense, dull, or knifelike?
Cardiac chest pain is usually described as a dull ache or heaviness; it is seldom characterized as being sharp or stabbing.

Is the pain/discomfort deep or close to the surface?
Cardiac chest pain is deep, not superficial.