Anatomic bases of the surgical division of Kent bundles in the posterior septal area of the heart

Abstract

The first part of this paper deals with the general anatomy of the postero-septal area of the heart, with particular emphasis on the relationships between the mitral and tricuspid anuli and the right fibrous trigone, between the conducting system and the interatrial septum, and between the right atrium and the posterior superior process of the left ventricle. In the second part, we describe the operative procedure that has been developed for dividing right and left posteroseptal Kent bundles. The key to this technique is the opening of the right atrium along the tricuspid anulus down to the orifice of the coronary ostium; this offers an excellent exposure on the posterior aspect of the septal area, and allows dissection of the sulcus fat pad from the muscular portion of the interventricular septum and the adjacent posterior superior process of the left ventricle down to the level of the mitral anulus. This planned dissection increases the likelihood of interrupting the anomalous pathways without injury to the normal conducting system which remains encompassed within the interatrial septum and the right fibrous trigone.

Right atrial position of a return electrode for bipolar ablation of the left posterosuperior process ventricular tachycardia

“…The complex anatomy of LV base may play a significant role in effective lesion formation . These anatomical conditions include the presence of very thick myocardium and anatomical surroundings such as myocardial bands, intraventricular septum, coronary vessels, valves, and adjacent RA sites . The use of an irrigated‐tip electrode in a unipolar setting may improve success rate; however, higher energy values may increase risk of complications .…”

“…The fact that we were able to temporarily suppress the arrhythmia from both RA and LV endocardial sites, using unipolar approach, led us to deliver bipolar RFCA between LV endocardium and adjacent RA sites, instead of, that is, entering the epicardial space. The similar approach was used in the very early era of bipolar ablation for treatment of posteroseptal accessory pathway ablation as these pathways appear to be located in close proximity to LV base and PSP …”

Right Atrial Approach for Ablation of Ventricular Arrhythmias Arising From the Left Posterior–Superior Process of the Left Ventricle

“…1,[3][4][5] Because of this, part of the basal inferoseptal aspect of the LV wall is directly apposed to RA tissue rather than RV tissue or epicardium. 4 As described by McAlpine, the PSP-LV is the promontory of LV between the attachment of the septal leaflet of the tricuspid valve to the AV unit, the ostium of the LV, and a line drawn from the latter to the upper end of the posterior interventricular groove. Superiorly, at the apex of the triangle lies the right fibrous trigone and the posterior aspect of the atrio-ventricular membranous septum.…”

“…Superiorly, at the apex of the triangle lies the right fibrous trigone and the posterior aspect of the atrio-ventricular membranous septum. [1][2][3][4][5][6][7] The inferior wall of the RA lies above and lateral to the PSP-LV adjacent to the pyramidal space. The CS orifice is medial to this area.…”

“…The CS orifice is medial to this area. 4 In addition, the atrioventricular node artery and the septal artery ascend onto the PSP-LV crossing within the fat of the pyramidal space. Therefore, a theoretical risk during ablation of the PSP-LV from the adjacent RA tissue is injury to the atrioventricular node or septal artery with resulting AV block.…”