As already stated, it is difficult without other information to establish the right course of action. However, with a dilated left atrium and moderate mitral valve leakage, there may be a clue here. Perhaps, and I say perhaps because it is only based on the information provided, the leakage in the mitral valve is the cause. Back pressure into the left atrium can cause it to dilate and the left ventricle will thicken the muscle wall to try and compensate, to get more blood into circulation. I would guess that the pressure in the left side of your heart is too high, causing damage. Perhaps a TEE would be wise to establish more accurately how well your mitral valve is performing. There are a number of reasons why your mitral valve can be leaking, one is damaged heart tissue from a previous heart attack. Have you had any heart attacks?
Unfortunately, it is impossible to make any recommendations just on an echocardiogram report alone. A thorough history and physical needs to be taken into account with this report in order to dictate a specific treatment. However, the findings of your echo suggest that there are structural issues with your heart that should be addressed. Further testing might be warranted to find not only the cause of these problems, but also if there are specific treatment strategies that should be initiated.