[Polymorphic alele variants of eNOS gene in patients with disorders of cardiac conduction].

We studied the role of endothelial nitric oxide synthase gene polymorphism 4a/4b in development of such disturbances of cardiac conduction as atrioventricular (AV) block and sick sinus node syndrome (SSNS). We examined 69 subjects (36 men, 33 women) with AV block and 90 subjects (33 men and 57 women) with SSNS. They were divided into groups in dependence on type of conduction disorder and sex. Probands with pathologies studied composed separate groups. All participants underwent included clinical-instrumental cardiological examination and molecular genetic study of eNOS gene polymorphisms. In all groups we revealed significant predominance of a rare homozygous genotype 4b/4b and tendency to decreased number of carriers of widely spread 4a/4a allele.