However, intraperitoneal administration of FLV, which is known as an extensively used S1R agonist, improved cardiac function, encompassing echocardiographic and hemodynamic indices, serum NT-proBNP concentration (344.70 ± 35.04 vs. 504.20 ± 78.88 pg/ml, P < 0.01), and cardiac hypertrophy, namely, heart weight/tibial length (0.029 ± 0.0013 vs. 0.034 ± 0.0007, P < 0.001), in HF + F group rats, indicating that stimulation of S1R was sufficient to ameliorate the manifestations of PIHF. The gene discussed is NPPB; the disease is hydrops fetalis.