Hello, 1m 25 y/o, male and i am smoking for 8 years. Ive had chest pains, palpitations and shortness of breath for about a month now. I had chest xray, 2-d echo, ecg and stress test and the results were all negative though my 2-d echo states that i have a slightly dilated left atrium . My doctor prescribed Vastarel MD 35mg twice a day. I do feel better now but there are times when i smoke or even if i dont that my lungs would feel heavy especially when i wake up in the morning but there are times when it feels normal. Is slightly dilated left atrium a serious ailment? is that the reason why sometimes my chest feels heavy while/after i smoke? And there are times that I feel like Im choking and out of breath especially when that tought comes in my mind