Right margin of LVS – septal margin
The anterior interventricular groove and structures lying inside the left anterior descending artery and anterior interventricular vein determine the right boundary of the LVS. The relation between those vessels in the majority presents a profound intersection of the anterior interventricular vein to the left anterior descending artery (54,4%) [6]. The right margin corresponds with the pulmonary trunk, nevertheless between the right aspect of the anterior interventricular groove and pulmonary trunk, a few millimeters of the septal summit, or the septal aspect of LVS is present. That is why the name of the right margin of LVS should be "septal margin." This term's first usage was in a recent Liao publication describing ventricular arrhythmias with abrupt R-wave transitions in V3[20].The measurement from the bifurcation of the left coronary artery to the first dominant septal perforator denotes the length of the septal margin of the LVS. The annulus of the pulmonary valve and pulmonary trunk, above the septal margin of LVS are present. These structures are overlying the LVS in the most superior aspect. The right ventricle output truck correlates with the lower portion of the septal margin, and various amounts of epicardial adipose tissue between those structures are present [figure2C]. From the septal margin of LVS, the first or sometimes second diagonal branch enters into the LVS region, while toward the ventricular septum, septal perforators are penetrating. The anterior interventricular vein enters from the anterior interventricular groove into the LVS. In some cases, when the most dominant septal perforator is more proximal to the left coronary artery bifurcation, the anterior interventricular vein may not cross the septal margin of LVS. The most uncommon variation is the anterior interventricular vein's right turn, becoming the anterior cardiac vein [7].