Base of the Heart Isolated from Vessels, Posterior View

Description

Posteriorly, the cardiac base is formed mainly by the left atrium, with the right atrium contributing on the right, and the atrioventricular (coronary) sulcus marking the junction with the ventricles inferiorly. With the great vessels removed, the ostia of the pulmonary veins are appreciated entering the left atrial wall laterally and superiorly, while the superior and inferior vena cava entry points sit on the right atrium. Inferior to the atria, the posterior surfaces of the left ventricle and a smaller portion of the right ventricle occupy the diaphragmatic aspect, separated by the posterior interventricular sulcus. This posterior perspective is the one clinicians map mentally when correlating atrial anatomy with esophageal proximity and posterior mediastinal relationships, because the esophagus lies directly posterior to the left atrium and is the structure at risk during left atrial radiofrequency ablation for atrial fibrillation. Clear delineation of the venous entry sites also supports teaching of atrial remodeling and pulmonary vein sleeve arrhythmogenicity, a key concept in electrophysiology. Landmarks matter. Use this illustration in gross anatomy and cardiothoracic modules when you want a clean view of chamber morphology without the visual noise of the pulmonary trunk, aorta, or caval vessels, and in EP education materials to orient catheter approaches around the posterior left atrium and pulmonary vein ostia. It also fits atlases, journal figures, and patient-facing explanations of AF ablation risks involving the posterior left atrial wall. Anatomical accuracy verified by SciePro's Medical Advisory Board.