My son is 14 and he plays basketball and baseball. During basketball season only he complains of being dizzy to the point of his vision blackening and he also feels palpitations. I took him to a pediatrician last year. She listened to his heart, took his blood pressure and pulse standing and squatting. She stated that everything appeared to be normal and he was probably overexerting himself. She said she would order and EKG and a pediatric cardiologist would read it. We did this and were told everything was normal. Well, he is continuing to have the same symptoms this year. He has never actually pasted out. He says it happens a couple times a week. The coach is aware and my son tells him when he feels dizzy so coach has him rest a little bit. I asked the coach if he has any other kids that do this and he said no, not unless tnhey are sick. I am concerned that this is a cardiac issue. I am worried about sudden cardiac death.He had hypertrophic tonsils until he was three, snored ( and had sleep apnea I believe) and had a T&A at the age of 4. Could this be caused by a pulmonary problem? Is is just puberty? Should I continue to worry. HELP!