A-V nodal artery anatomy and relations to the posterior septal space and its contents

Background and aim: Radiofrequency catheter ablation treats resistant nodal re-entrant tachycardia but carries a risk to AV conduction system and its vessels. We aimed to study the origin of the A-V nodal artery (AVNA) and its course within the posterior septal space (PSS). Methods: Twenty embalmed human hearts of both sexes (16 males) age, 25-60 years, were dissected to study the PPS and its arteries down to their destination. Results: The PSS is a four sided pyramidal space, at the crux of the heart, with its base made of the pericardium. It is made of four; right upper and lower and left upper and lower walls corresponding to the right atrium and ventricle and left atrium and ventricle, respectively. The right coronary artery (RCA) crossed the base from the right to the left angle, to lie inferior and adherent to the terminal part of the coronary sinus (CS). The posterior interventricular artery, the ventricular branches of the RCA, the middle cardiac vein and the ventricular veins, all crossed the base of the space to their final destination. AVNA originated from either the RCA itself or one of its branches. Double AVNA was encountered in 14 specimens with the upper artery larger and passed between the right and left atria and the lower artery smaller and crossed the space adjacent to the right ventricle. Conclusions: These findings highlight the importance of the PSS and its structural relations, in particular to the AVNA, that should be considered during various interventional procedures. (C) 2009 Elsevier Ireland Ltd. All rights reserved.