Ca2+ cycling plays a critical role in heart failure and lethal arrhythmias. As susceptibility to sudden cardiac death is considered to be a heritable trait in general population, we have therefore investigated whether potentially functional variants of genes encoding RyR2 (ryanodine receptor 2) and the L-type Ca2+ channel are related to the risk of ventricular arrhythmias and sudden cardiac death in CHF (chronic heart failure) in a case-control study. We found that the A allele of rs3766871 in RYR2 was associated with an increased risk of ventricular arrhythmias in patients with CHF {odds ratio, 1.66 [95% CI (confidence interval), 1.21-2.26]; P=0.002}. During a median follow-up period of 32 months in 1058 (85.0%) patients, 296 (28.0%) patients died from heart failure, of whom 141 (47.6%) had sudden cardiac death. After adjustment for age, gender and suspected risk factors, patients carrying the A allele of rs3766871 had an increased risk of cardiac death {HR (hazard ratio), 1.53 [95% CI, 1.11-2.12]; P=0.010} and sudden cardiac death [HR, 1.92 (95% CI, 1.25-2.94); P=0.003]. Patients carrying the A allele of rs790896 in RYR2 had a reduced risk of sudden cardiac death [HR, 0.65 (95% CI, 0.45-0.92); P=0.015]. In conclusion, the A allele of rs3766871 in RYR2 not only associates with ventricular arrhythmias, but also serves as an independent predictor of sudden cardiac death, and the A allele of rs790896 in RYR2 is a protective factor against sudden cardiac death in patients with CHF.