Hello, I have shortness of breath and heart palpitations on a regular basis. Sometimes, the shortness of breath can last up to 2 weeks. Actually, I am not sure if its shortness of breath but it feels like i have to work to breath or that the air is warm. It s hard to explain. The heart palpitations started about 4 years ago and come about twice a month. I was a smoker for 6 years but stopped about 2 years ago at age 28. Once i quit, i started to use e-cigs for 1 year and eventually stopped smoking e-cigs and have been on nicotine gum ever since. I am 30, not in bad shape, i am muscular. No one would describe me as fat. I was scared I was going to have a heart attack and the doctor checked my heart but said there was nothing wrong with it. He did an ultrasound and made me ride a bike. Could it be nicotine causing my palpitations and shortness of breath? My dad has cardiomyopathy and recently had to have surgery. When i went to the doctor he said i did not have it. So i have narrowed it down to nicotine. It s scary to be honest. It should be noted that i was diagnosed with sleep apnea at 22. I snore alot while sleeping and always have. Sometimes, even while awake, i notice that i have been holding my breath. They said in the sleep study that I stop breathing and now i notice that i even stop breathing while awake without realizing it.