You're crazy......... No, just kidding Ross
although this is not a funny subject. I know lots of people with cardiomyopathy that do not have the left side of their chest larger than their right. I have never heard of this. I would suspect a tumor or some type of other growth if you are not imagining it.
Angina, which I have had plenty of, can by and of itself make it seem like the left side of your chest is at a higher pressure, or more full than the ever innocent right side. I have never looked in the mirror though. I know that it is the angina. You can have angina in your back for sure, I know that. You need to see a doctor and explain these pains soon. You could have coronary artery disease (CAD), which causes chest pain, or angina.