I am 34 year old man 5'6 115 lbs and in good shape. I exercise regularly through the practice of judo. during hard cardio training my heart will go from beating very hard, to beating so soft it feels as if it has stopped. i will get light headed and my vision will darken and i get tingling sensation in my face and hands. this will be followed by adrenaline rush and a return to very hard beating. however the hard beating is slow and it is several minutes before i feel normal again. this has also occured during other activites that do not involve strenous physical activity. years ago i had test done due to chest wall pain (inconclusive) i think the test was call a TCE? the doctor found that my left ventricle was malformed, enlarged i think. my mother had a heart murmur when she was younger. these events scare me a lot but without heath care i dont know what steps to take, i am afraid of haveing a heart attack. i feel i s hould add that i have very low blood pressure and have participated in 5 in house pharmacutical research studies with drugs previously not tested on humans.