Overriding aorta

An anatomical defect in the heart associated with congenital heart disease

Overview

Diagram of an overriding aorta

The overriding aorta is a congenital heart defect where the aorta is positioned directly over a ventricular septal defect (VSD), instead of arising solely from the left ventricle. This anatomical anomaly is one of the four components of Tetralogy of Fallot, a condition that leads to cyanosis and other complications due to the mixing of oxygenated and deoxygenated blood.

Anatomy and Pathophysiology

In a normal heart, the aorta arises from the left ventricle, carrying oxygen-rich blood to the body. However, in the case of an overriding aorta, the aorta straddles the interventricular septum and receives blood from both the left and right ventricles. This results in the mixing of oxygenated and deoxygenated blood, leading to reduced oxygen levels in the systemic circulation.

Clinical Presentation

Patients with an overriding aorta often present with symptoms associated with Tetralogy of Fallot, including:

• Cyanosis
• Difficulty breathing
• Fatigue
• Heart murmurs

Diagnosis

The diagnosis of an overriding aorta is typically made using imaging techniques such as:

• Echocardiography
• MRI
• CT scan

These imaging modalities help visualize the position of the aorta and the presence of a ventricular septal defect.

Treatment

Illustration showing the position of the aorta in relation to the ventricles

Treatment for an overriding aorta often involves surgical intervention to correct the defect. The primary goal is to repair the ventricular septal defect and reposition the aorta to ensure it arises solely from the left ventricle. This is typically done as part of the surgical repair for Tetralogy of Fallot.

Prognosis

With early diagnosis and appropriate surgical treatment, the prognosis for patients with an overriding aorta can be significantly improved. Long-term outcomes depend on the severity of the defect and the presence of any associated cardiac anomalies.

Related pages

• Tetralogy of Fallot
• Congenital heart defect
• Ventricular septal defect
• Cyanosis