Which anatomical structure is commonly involved in atrial flutter?

Which anatomical structure is commonly involved in atrial flutter?

• A. The left ventricle
• B. The right atrial isthmus
• C. The pulmonary veins
• D. The left atrial appendage

Answer: (B)

The right atrial isthmus is commonly involved in atrial flutter, particularly in the typical form known as atrial flutter type I or atrial flutter with a “sawtooth” pattern, often referred to as “F-waves.” This area acts as a critical anatomical substrate for reentrant circuits, facilitating the characteristic electrical activity seen in atrial flutter. The isthmus extends from the inferior vena cava to the eustachian ridge, forming a barrier that helps maintain the reentrant circuit. This area becomes a target for catheter ablation procedures aimed at interrupting the flutter circuit, effectively restoring normal sinus rhythm. As a result, understanding the role of the right atrial isthmus is crucial for both diagnosis and treatment of this arrhythmia.

The right atrial isthmus is commonly involved in atrial flutter, particularly in the typical form known as atrial flutter type I or atrial flutter with a “sawtooth” pattern, often referred to as “F-waves.” This area acts as a critical anatomical substrate for reentrant circuits, facilitating the characteristic electrical activity seen in atrial flutter.

The isthmus extends from the inferior vena cava to the eustachian ridge, forming a barrier that helps maintain the reentrant circuit. This area becomes a target for catheter ablation procedures aimed at interrupting the flutter circuit, effectively restoring normal sinus rhythm. As a result, understanding the role of the right atrial isthmus is crucial for both diagnosis and treatment of this arrhythmia.