Hi Toneishastuht, Thanks for visiting HCM. Both acid reflux and ischemic heart disease causing angina are fairly common in COPD patients. While pain of reflux presents like heartburn, usually follow a pattern of before meal or after meal, increases on lying down, the pain of angina occurs in central chest, is squeezing in character, radiates left shoulder, jaws, neck and usually occurs on exertion and relieves on rest. In my opinion it is better to go for electrocardiography. If it is negative go for stress cardiography. If both are negative then it is probably due to acid reflux which can be relieved on taking antacids like proton pump inhibitors like pantoprazole for 2-3 weeks. Meet your doctor for these stuffs. Best wishes