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Triangle of Koch

Surface landmarks around atrioventricular conduction tissue

ThoraxCardiovascular system

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Koch's triangle locates the AV nodal region; its borders do not reveal the precise depth and course of every patient's conduction axis.

Overview

Three right atrial landmarks outline Koch's triangle: the tendon of Todaro, the septal tricuspid leaflet's hinge and the coronary sinus opening. The compact AV node lies near its apex, with the conduction axis continuing into the central fibrous body. Exact tissue positions differ between hearts.

Reference facts

Boundaries
Tendon of Todaro, septal tricuspid leaflet hinge and the coronary sinus ostium
Contents
The AV nodal region near the apex, with neighboring atrial connections and vascular supply
Communications
The conduction axis continues from the apex into the central fibrous body as the His bundle

Clinical correlation

Interventions near this region can damage AV conduction. Its variable anatomy matters when clinicians assess procedures involving the septal tricuspid area or AV nodal pathways.

Frequently asked questions

What are the boundaries of the triangle of Koch?

The triangle of Koch is bounded by the tendon of Todaro, septal tricuspid leaflet hinge and the coronary sinus ostium.

What does the triangle of Koch contain?

The AV nodal region near the apex, with neighboring atrial connections and vascular supply.

What does the triangle of Koch communicate with?

The conduction axis continues from the apex into the central fibrous body as the His bundle.