Grade 5 Murmur but normal Echocardiogram

I have been extremely fatigued, my legs have been cramping and feet, ankles and calves swelling, night sweats, weight loss, palpitations, racing heart beat, history of chest pain and syncope off and on since 5years of age, family history of Sudden cardiac death and other cardiac related disease in both maternal and paternal families. All labs such as CBC, TSH w/relflex normal. Went to PCP 3 weeks ago and he found a murmur and graded it at a 5 and thought it was most likely MVP. Past EKG's have shown prolonged QT inverted s and r of 110 ave. I had an Echocardiogram and it was deemed as normal today. I go to see a Cardiologist tomorrow. I have been dealing with this for 21 YEARS! Anyone have any ideas as to what I should ask him or what tests I may have or should have now. BTW my sibling had VSD and Aunt was 40 when deceased from Sudden Death Cardiac Related with no prior history of health problems. I honestly want to give up trying to figure it out.

[Jerry_NJ]

The post and replies in the following seem to be closely related;
http://www.medhelp.org/posts/Heart-Rhythm/Need-advice-ASAP-seriously-sick/show/1891085

Going from (my poor) memory the other post doesn't mention the grade 5 MVP, but I could be wrong on that point - in case I respond to that issue with:
I don't know how MVP is graded, but it many people have MVP, in fact it may be if looked at closely enough most of us have some heart valve faults.