Under the circumstances of RHD, there is a potential association among DGX use, CMD, and arrhythmia based on NO as follows: Firstly, RHD is an autoimmune disease, with inflammatory factors upregulated, resulting in the inhibition of eNOS activity and then contributing to the reduction of NO bioavailability, which affected the function of coronary microvascular tissue (40). Here, NOS3 is linked to cardiac arrhythmia.