This research describes a case of a 4 year old female with severe Pectus Excavatum. She was found to have a complication from her PE that has not been previously reported. The severe PE led to marked compression of the right side of her heart. This stress led to a scar, ultimately affecting the blood flow of the heart. The patient developed non-bacterial thrombotic endocarditis, a risky condition in which the heart can produce clots that travel to other parts of the body. This research adds to the body of evidence suggesting that PE is not always a completey cosmetic condition. It can cause serious medical conditions in rare circumstances. For this reason, PE should be followed closely if suspected.