When analyzing the polymorphic variants Ser49Gly (rs1801252) and Gly389Arg (rs1801253) of β1-AR in patients with dilated cardiomyopathy, it was found that the frequency of the Gly389 allele was significantly higher in patients with dilated cardiomyopathy without ventricular tachycardia than in those with ventricular tachycardia[146]. This evidence concerns the gene ADRB1 and ventricular tachycardia.