1 — Right ventricle; 2 — Inferior vena cava; 3 — Interventricular septum; 4 — Right atrium; 5 — Interatrial septum; 6 — Sinu-atrial node; 7 — Superior vena cava; 8 — Left atrium; 9 — Atrioventricular node; 10 — Atrioventricular bundle; 11 — Atrioventricular bundle, right crus; 12 — Atrioventricular bundle, left crus; 13 — Left ventricle; 14 — Subendocardial branches
