Healthy diet, great cholesterol reading, ef 50%, workout daily but dypsnea, lv normal size/function, bp 119/63, nuclear -moderate to severe ischemia aterior/apical. is it plaque if not, what??

Be diligent: Sounds like you are in good shape, so keep up the good work. Your Nuclear study as i see it in your question-shows Moderate to Severe ischemia so that may be a clue to your Painful respirations, etc. A cardiac Cath would be definitive for plaque/arterial pathology. Continue with the Cardiologist as maybe medication can be used to treat you. Bet wishes.

Probable: Plaque most likely,option. Discuss options with your cardiologist

That is curious.: That nuclear stress test result suggests that, worst case scenario, you either had a heart attack or are currently at risk for such. It seems by your history that you have a heart history and, quite frankly, your EF is a bit low which might explain the exertional dyspnea. This finding needs to be investigated and managed. Keep in close contact with your heart doctor. Medications? Repeat cath?