Thoracic Key

1.9 The Isthmus Region Size/form: Variable expansion of the area Location: Between the tricuspid valve, inferior vena cava, and the opening of the coronary sinus

1.8 The Fast Pathway Region Size/form: Variable expansion of the fibers Location: In the region of the intraatrial septum anterosuperior to the KOCH triangle

1.7 The Slow Pathway Region Size/form: Variable expansion of the fibers Location: Between the opening of the coronary sinus and the compact AV node (posteroinferior to the compact AV node)

1.4 The Compact AV Node Size/form: ca. 1×3×5mm Location: Base of the right atrium at the point of the so-called Koch triangle (between the tricuspid annulus and the eustachian valve),…

1.2 Anatomy of the Conduction System

1.6 The Bundle Branches Right bundle branch: Extension of the bundle of His coursing along the right aspect of interventricular septum

1.5 The Bundle of His Size/form: 10–20mm Location: Continuation of the compact AV node, penetrates the annulus fibrosus, subendocardial course in the pars membranacea of the interventricular septum

1.1 Basic Anatomy

1.3 The Sinus Node Size/form: 10–20 mm, spindle-shaped Location: In the first third of the sulcus terminalis along the axis between the opening of the superior vena cava and the…