HRH2 and hydrops fetalis: For several decades, it has long been suggested that histamine H2 receptor (H2R) was highly related to occurrence and development of HF and, as a result, might be a novel promising anti-HF target (Hara et al., 2002; Leary et al., 2014; Leary et al., 2016; Saheera et al., 2022).