Chest pain like a squeezing or heavy pressing sensation in the center of the chest cavity behind the breast bone, with a sense of heaviness or numbness in the arm, shoulder, elbow or hand, usually on the left side, can be suspected for angina pectoris.
If the ECG wasn't done during the pain episode, just after it has ended, the diagnosis of angina pectoris can't be done.
ECG changes can be noticed only if the test is done during episode of angina pectoris.
In addition, you may be given an ECG exercise test on a treadmill or exercise bike (a stress test) to determine if the heart muscle is the source of the pain.
Angina is often brought on by stress, extreme cold, physical exercise, a heavy meal.
Hypertension, smoking, obesity, high levels of cholesterol, family history of atherosclerosis, diabetes are risk factors for angina pectoris.
Chest pain due to severe coughing is more like muscle soreness in the chest wall, upper abdomen or diaphragm.
This type of muscle soreness often increases with movement of the shoulders.

Best wishes!
Marija