Telomeres are known to provide genomic stability and telomere length has been associated with cardiovascular diseases. Moreover, a higher telomerase activity has been shown to be associated with ventricular arrhythmias (VA) in ischaemic cardiomyopathy. Increasing evidence suggests that genetic variation in key telomere genes has an impact on telomerase activity. Each copy of the minor allele of SNP rs12696304, at a locus including TERC (telomerase) has been associated with ∼ 75 bp reduction in mean telomere length likely mediated by an effect on TERC expression. We investigated the impact of genetic variation of this SNP on telomerase and its association with VA in ischaemic cardiomyopathy patients.