Question: I have a question. First i will admit that i can be a hypochondriac. However there is something that is just not right. I have had episodes of palps for 6 years. I am starting to get at peace with them however, and they have been lease frequent lately. Just to inform you on my overall health i think its great. I have had ekgs nearly every year since 09. They are always good, i have worn a 24 hour holter twice. Once in 09 and once in april of this year. Both showed pacs but otherwise great. And two echos. One in 09 and one in april of this year. Both good. Only thing both showed was a minimal leak in one valve. Also went to er in january for palps they did a chest xray it was clear also. I am 36 years old, 5'6 and 155 lbs. My bp runs 110/65. And my trigs and cholesterol levels are all good. So i think i have a healthy heart. But here is my issue. When i exercise, and it doesnt even have to be real strenuous my heart begins to beat real hard. Not fast per say but hard. And i get a strange feeling in my chest. No palps. More of a straining feeling. And i get pain in the center of my chest that shoots to my back. And also on my chin. And i get out of breath. And my pulse feels normal for my activity level rate wise and its regular not sporadic but it feels really hard. This doesnt happen everytime i work out but has been more frequent lately. It usually happens after about 20-30 minutes of exercising. And my exercising is mostly walking 4mph for 30 - 45 minutes. Its jut different than in the past. I know how it feels to have an increase in heartrate when exercising. In the past my heart speeds up and all but no pain or strain feeling. I am wondering if it is being caused by a rhythm problem because i really doubt i have blockage. My cardiologist says im a picture of health but im really afraid. It really XXXXXXX like aomething is not right but i have had numerous tests that say im healthy