Which structures comprise the Triangle of Koch?

Which structures comprise the Triangle of Koch?

• A. Septal leaflet of TV valve
• B. CS os
• C. Tendon of Todaro
• D. All of the above

Answer: (D)

The Triangle of Koch is the region in the right atrium that contains the AV node and His bundle. It is defined by three boundaries: the tendon of Todaro, the ostium of the coronary sinus, and the septal leaflet of the tricuspid valve. Because each of these structures contributes a boundary, all of the above together form the triangle. The AV node sits at the apex of this area near the coronary sinus ostium, which is why this region is pivotal in mapping and ablation around the AV node.

The Triangle of Koch is the region in the right atrium that contains the AV node and His bundle. It is defined by three boundaries: the tendon of Todaro, the ostium of the coronary sinus, and the septal leaflet of the tricuspid valve. Because each of these structures contributes a boundary, all of the above together form the triangle. The AV node sits at the apex of this area near the coronary sinus ostium, which is why this region is pivotal in mapping and ablation around the AV node.