Okay. I will try to make this as short as possible. I am a 27 yr. old male, 190 lbs. Last summer I had an "episode" in which the right side of my face and the inside of my mouth became numb. My heart rate increased to ~200 bpm, then depersonalization, chest pain, sweating, severe confusion, and both arms "shook." Afterward, I was so tired that I fell asleep immediately. The episode lasted about 5-10 min. When I woke, I went to ER and checked for infarction w/ neg. results. Went to a physician and was diagnosed with panic attacks. Now, for my concern: I began reasonable exercise regimen at the beginning of this year, and noticed, on more than one occasion, that I become extremely lightheaded, the world "dims," and my heartrate increases to 200 (no anxiety, though). I went to my physician and he placed a stethoscope over my left carotid and heard a "murmur" and said, "We need to get you to a cardiologist." Echo revealed "prominent" LVH with normal systolic diameter and good ejection fraction. After visiting with cardiologist, he said "LVH--don't worry about it," and prescribed Toprol XL: "Only take if your Holter monitor comes back with anamolies." Holter was fine. Doc says don't worry; other general physician is very worried about my "serious" pathologies and doesn't want me to exercise. I have two doctors in conflict about my problem. I am unsure what happened in the summer-- transient ischemic attack (mini-stroke) or just a panic attack? Does this all connect, and should I seek other medical opinions, given that, when I exercise, I feel like something's wrong?