Venous Anatomy of the Left Ventricular Summit: Therapeutic Implications for Ethanol Infusion.

Abstract Background Venous ethanol ablation (VEA) is effective for left ventricular summit (LVS) arrhythmias. The LVS venous anatomy is poorly understood and has inconsistent nomenclature. Objective Delineate the LVS venous anatomy by selective venography and 3D mapping during VEA and by venous-phase coronary computed tomographic angiography (vCTA). Methods We analyzed: 1) LVS venograms and 3D maps of 53 patients undergoing VEA, and 3) 3D reconstructions of 52 vCTAs, tracing LVS veins. Results Angiography identified the following LVS veins: 1) LV annular branch of the great cardiac vein (GCV) (19/53), 2) septal (rightward) branches of the anterior ventricular vein (AIV, 53/53), and 3) diagonal branches of the AIV 51/53. Collateral connections between LVS veins and outflow, conus, and retroaortic veins were common. VEA was delivered to target arrhythmias in 38/53 septal, 6/53 annular, and 2/53 diagonal veins. vCTA identified LVS veins (range 1 to 5), in a similar distribution . The GCV-AIV transition could either form an angle close to the left main artery bifurcation (n=16, 88⁰±13⁰) or cut diagonally (n=36, 133⁰±12⁰), p ≤0.001. Twenty-one patients had LV annular vein. In 28 patients only septal LVS veins were visualized in vCTA, in 2 patients only diagonal veins and in 22 patients both septal and diagonal veins were seen. In 39 patients the LVS veins reached the outflow tracts and their vicinity. Conclusion We provide a systematic atlas and nomenclature of LV summit veins related to arrhythymogenic substrates. vCTA can be useful for noninvasive evaluation of LV summit veins prior to ethanol ablation.