conduction system disorder AE endocardial fibrosis AE 10014664 http://en.volupedia.org/wiki/Cardiac_fibrosis This is an AE which refers to the excess deposition of extracellular matrix in the cardiac muscle, but the term may also refer to an abnormal thickening of the heart valves due to inappropriate proliferation of cardiac fibroblasts. QY, JX, HY 心内膜心肌纤维化