So recently (since about 6 weeks ago). I've been experiencing so extremely strange things with my heart. It started with me going to mcdonalds and drinking about 1.5 sweet teas and eating. I then came back and about and hour or so later i drank a Monster Absolutely zero energy drink. After that i started to feel quite odd, like my heart was going to fast. So i went and drank and lot of water to flush out the caffiene but it didn't help. I would wake up in the morning, walk down the hall and i felt as if my heart rate was going to fast, when i checked it, it was up to around 145 to 155 bpm. After i went home, my father took me to a cardiologist who took some EKG and he said it looked very odd so he admitted me to the hospital while suspecting heart failure. I got an echo in the hospital and i had no leaky valves, my heart was "strong" except that the right side looked a little small which they said was probably from dehydration. They released me but didnt do anything. I've been resting for about 4 weeks now, i walk 2 to 3 miles everyday, i drink a lot of water and try to consume more sodium. However my heart still races more than it should. When i sit down my heart rate drops to around 70, which is very normal, however when i stand up my heart will race from 120 to sometimes 140ish. I take a baby aspiring which seems to help a little bit but it still is much to fast for someone of my age. I'm only 19 and have had no problems before this. I go back to the doctor on june 10th for a checkup and i really want to get something done to help me, either more tests or some prescription to help. Any suggestions/ideas of what is causing this?