Hi,
It depends exactly what you mean by an enlarged heart. An enlarged heart can result from a genetic cause, or it can be a response to long-term high blood pressure. You need a proper diagnosis as to what part of the heart is enlarged and if you have any family heart disease. You might have inherited it. If your blood pressure is elevated the first thing is to get it under control with medication.
You can't easily "deal" with an enlarged heart, but in some cases "remodelling" can occur where the heart adjusts itself to a different pumping action, and a lower work load.
Hope this helps.
Cheers, Beefy