These electron micrographic observation indicates that the chronic HF condition provokes increased basal SDCV (possibly containing PACAP and VIP) in splanchnic–adrenal synapse of HF rats promoting toward the maintenance of long-term catecholamine secretion, increased ER and Golgi lumen width to accommodate the enhanced demand for increased catecholamine synthesis and release, and more mitochondria with dilated cristae and glycogen to adapt to the increased energy demand for the increased biogenesis and exocytosis of catecholamines from the adrenal medulla. Here, VIP is linked to hydrops fetalis.