Ventricular Arrhythmias Linked to the Left Ventricular Summit Communicating Veins

Abstract

HomeCirculation: Arrhythmia and ElectrophysiologyVol. 11, No. 1Ventricular Arrhythmias Linked to the Left Ventricular Summit Communicating Veins Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBVentricular Arrhythmias Linked to the Left Ventricular Summit Communicating VeinsA New Mapping Approach for an Old Ablation Problem Daniele Muser, MD and Pasquale Santangeli, MD, PhD Daniele MuserDaniele Muser From the Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia. and Pasquale SantangeliPasquale Santangeli From the Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia. Originally published11 Jan 2018https://doi.org/10.1161/CIRCEP.117.006105Circulation: Arrhythmia and Electrophysiology. 2018;11:e006105See Article by Komatsu et alThe left ventricular summit (LVS) is the most superior portion of the epicardial LV outflow tract and is a common site of origin of idiopathic ventricular arrhythmias (VAs).1,2 The LVS is anatomically bounded septally by the bifurcation between the left anterior descending and the left circumflex coronary arteries, and transected laterally by the great cardiac vein at the junction with the anterior interventricular vein.3 A proper knowledge of the specific anatomic boundaries within the LVS has substantial clinical relevance with respect to the mapping and ablation approach. The junction between the great cardiac vein and the anterior interventricular vein separates the LVS into an accessible region, lateral to the venous junction and remote from the bifurcation of the left main coronary artery and the epicardial fat around the atrioventricular groove, and an inaccessible region septal to the venous junction and in close proximity to the proximal left coronary arteries and epicardial fat. Although VAs arising from the accessible LVS are rarely problematic and usually can be mapped and ablated from the distal coronary venous system or directly via a percutaneous pericardial approach,2,4 VAs from the inaccessible region represent a major clinical challenge.Direct epicardial mapping of the inaccessible LVS via a percutaneous epicardial access is limited mainly by the presence of a thick layer of epicardial fat which effectively insulates the underlying epicardium and prevents adequate electrogram recordings; in many cases catheter manipulation is challenging because of the anatomic proximity of the left atrial appendage. Furthermore, direct epicardial radiofrequency application to the inaccessible LVS is rarely possible because of the close proximity to the proximal left coronary system and, occasionally, to the left phrenic nerve. When ablation is possible it may be ineffective because of poor energy penetration through fat.2,5To overcome these challenges, an ablation approach targeting sites anatomically adjacent to the inaccessible LVS has been proposed by several authors, with success rates ranging from 25% to ≈75%.6–8 The choice of the optimal ablation site among different adjacent regions is usually based on a multiparametric assessment that takes into consideration activation mapping results (second best site), pacemapping data and the anatomic distance between the adjacent sites. When standard ablation approaches are not effective, alternative ablation strategies have been proposed including use of simultaneous unipolar radiofrequency ablation,9 bipolar radiofrequency ablation,10 alcohol arterial/venous ablation,11 or surgical epicardial ablation with direct visualization of the coronary vessels and dissection of the epicardial fat.5In this context, Komatsu et al12 describe a new technique to obtain direct recordings from the inaccessible LVS via a 2F multipolar microcatheter introduced into the summit communicating veins (CV) which runs between the aortic and the pulmonary annulus. T