You could be experiencing angina caused by blocked or narrowed heart arteries. It doesn't sound like GERD. I'm not a health professional, so take anything I share with that in mind, but I had both GERD and angina for a number of years before surgeries for both brought me relief.
GERD can cause chest discomfort more commonly when one is eating or when one has laid down. Stable Angina is often suspected if chest discomfort occurs when one is exercising, often at the very beginning of an activity. Angina occurs when the heart muscle isn't getting the blood flow necessary to continue to function normally. Angina is seldom considered a sharp pain, more like a squeezing pain. As it intensifies, it migrates often toward the left shoulder.
As Selma suggests I would contact your doctor's office. Your doctor is going to get blood tests and sort through your risk factors for GERD, heart disease and other issues. Chest pain/pressure should not be ignored.
Keep us informed.
To be certain what is causing chest pains see ur PCP asap!!!
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