https://www.mps1disease.com/en/healthcare/diagnosing-mpsi/making-diagnosis/cardiologists.aspx

The cardiac manifestation can present with mitral valve abnormalities, so that position within the valve, it can become thickened, it can cause mitral regurgitation, insufficiency. These are the diseases that can cause this kind of abnormality. Then patients may have deposits within the heart muscle itself causing growth of the muscle tissue, causing fibrosis of the muscle, and this happens mostly in Fabry Disease and Pompe Disease. Lastly there can be narrowing of the blood vessels, that can cause abnormalities in the blood flow to the heart with decreased flow to the muscle that can lead to an equivalent of a heart attack. This can also happen in mucopolysaccharidosis. Therefore it’s very important when these findings are made to think about lysosomal storage disease, and conversely when you have a lysosomal storage disease the pediatrician really has to make sure that any complaint that relates to the heart is checked right away.