Cardiac Conduction System

Description

Rendered in an x-ray style with semi-transparent myocardium, the adult male heart is oriented in anatomical position with the atria superior to the ventricles and the great vessels emerging superiorly, including the ascending aorta and pulmonary trunk. Within the right atrium, the sinoatrial node sits near the junction of the superior vena cava and right atrial appendage, with the atrioventricular node positioned more inferiorly in the interatrial septum near the coronary sinus ostium. The His bundle penetrates the fibrous skeleton and runs anteriorly and inferiorly along the membranous interventricular septum before dividing into right and left bundle branches that course subendocardially toward their respective ventricular apices. Coronary arteries and veins trace the epicardial surface in contrasting colors, framing the conduction pathways against the translucent chamber walls. Clinical correlation is straightforward because conduction tissue and coronary perfusion share real territory: ischemia in the right coronary artery often compromises AV nodal function, while septal infarction can interrupt the bundle branches within the interventricular septum. This view also clarifies why bundle branch block patterns map to specific anatomic tracks, and why septal fibrosis or post-infarct scar can produce infranodal block with wide QRS complexes. Small tissue, big consequence. Use it for electrophysiology teaching when you need to relate an ECG PR interval, QRS morphology, or complete heart block to the actual locations of the SA node, AV node, and Bundle of His, and for cardiology or anatomy texts that pair coronary artery territories with conduction disturbances. It also fits pre-op planning discussions for septal myectomy, valve surgery near the membranous septum, and pacemaker lead placement concepts. Anatomical accuracy verified by SciePro's Medical Advisory Board.