NOS3 and Myocardial fibrosis: Moreover, Qishen Yiqi dropping pill may increase the levels of SIRT1 and eNOS to increase the interaction between SIRT1 and eNOS, and improve the bioavailability of NO, thus stabilizing endothelial function, promoting angiogenesis, inhibiting myocardial fibrosis and apoptosis to improve cardiac function [217].