In contrast, the trigon of Brocq and Mouchet base is marked by the point where the anterior interventricular vein crosses the anterior interventricular groove. The Brocq and Mouchet trigon has five main variations dependent on vessel crossings and their relations in heart groves, while the LVS area is independent of such variants [63,64]. The inaccessible area is almost triangular, closed at the bottom by the venous system. Usually, the superior aspect dominates in size over the accessible area, and frequently, the LVS may be constituted only by inaccessible area (Figures 1, 2B, and 3A). The inaccessible area contents include proximal branches from coronary vessels, small veins and a thick layer of epicardial adipose tissue covered by the left atrial appendage and pulmonary trunk.