What is crista terminalis?

The crista terminalis is a muscular ridge on the interior surface of the right atrium of the heart. It separates the rough, muscular portion of the atrium known as the atrial appendage from the smooth-walled portion of the atrium. The crista terminalis runs from the superior vena cava opening to the inferior vena cava opening, and is often used as a landmark for cardiac procedures.

The crista terminalis is important in the conduction of electrical signals in the heart, as it contains a band of specialized cardiac muscle cells that help to coordinate the contraction of the atria. This area is known as the sinoatrial (SA) node, which serves as the heart's natural pacemaker.

In some individuals, variations in the structure of the crista terminalis can contribute to arrhythmias or other heart conditions. Additionally, when performing cardiac procedures such as catheter ablation or surgery, the crista terminalis must be carefully avoided to prevent damage to the SA node and other vital structures.