Inferior Contours of the Inferior Interventricular Sulcus

Description

Arising on the diaphragmatic surface of the heart, the inferior interventricular sulcus runs in a longitudinal groove between the right and left ventricles, tracking toward the cardiac apex while remaining inferior to the atrioventricular (coronary) sulcus. Along its course, this sulcus typically lodges the posterior interventricular artery and the middle cardiac vein, with epicardial fat filling and softening the contour of the groove. The right ventricle lies more anteriorly even in an inferior projection, while the left ventricle contributes a thicker myocardial mass on the left side of the sulcus. Clear midline geography. Clinically, this is the surface landmark used to teach coronary dominance, because the posterior interventricular artery most often arises from the right coronary artery at the crux cordis, but may originate from the circumflex branch of the left coronary artery in left dominance. That distinction matters when localizing inferior wall myocardial infarction patterns on ECG and when anticipating perfusion to the posterior third of the interventricular septum, including the atrioventricular node artery in many right dominant hearts. Surgeons also reference this groove when orienting the heart in posterior pericardiotomy and during bypass graft planning to the posterior descending artery. Use this inferior perspective in gross anatomy lab manuals, cardiology board review diagrams, and operative atlases that need a clean external correlate for the posterior interventricular septum and its vessels. It also fits well in patient education or hospital teaching files explaining right coronary artery occlusion and inferior ST elevation myocardial infarction. Anatomical accuracy verified by SciePro's Medical Advisory Board.