Background Chronic heart failure (HF) is a complex syndrome which is increasing in prevalence.The pathogenesis of HF remains unclear.Probably it is a multiple genetic disease.The growing importance of the Natriuretic Peptide (NP) system in HF is well recognized,as an important counter-regulatory system that has generally salutary effects in the HF milieu.NP system also has been shown to be very valuable in the diagnosis and management of patients with HF.Left ventricular ejection fraction (LVEF) must be lower than 35％ for patients with HF who received cardiac resynchronization therapy (CRT),and up to now,there is no report about gene variants for these patients.This study aimed to evaluate the effect of NP system gene single nucleotide polymorphisms (SNPs) on congestive HF with lower LVEF,as well as on CRT efficacy.