Common Types of Ventricular Septal Defects in Clinical Practice

Ventricular septal defects (VSDs) are among the most common congenital heart defects, and they are classified based on their location within the ventricular septum. There are multiple classification systems, but in clinical practice, especially in pediatric cardiology, the following types are most frequently encountered.

1. Perimembranous Ventricular Septal Defect

This is the most common type of VSD, accounting for more than 50% of all cases. It occurs just below the aortic valve and is often adjacent to the tricuspid valve. Due to its proximity to the heart valves, this type of defect may be associated with other structural abnormalities and can sometimes lead to complications such as aortic regurgitation if not treated timely.

2. Subarterial (Supracristal) Ventricular Septal Defect

Also known as supracristal VSD, this type is located beneath the pulmonary valve and is often referred to as a "ridges-up" type in echocardiographic reports. It is important for parents and caregivers to understand that this terminology refers to the same anatomical location as the subpulmonary VSD. This type is less common but may require surgical intervention due to its potential to cause significant left-to-right shunting.

3. Muscular Ventricular Septal Defect

This type of VSD is found within the muscular portion of the interventricular septum. It can vary in size and may be single or multiple. Muscular VSDs have a higher chance of spontaneous closure during early childhood, especially if they are small or moderate in size. However, larger defects may require medical or surgical management to prevent complications such as heart failure or growth delays.

4. Malalignment Ventricular Septal Defect

This type of VSD arises due to abnormal rotation or alignment between the great arteries and the ventricles during heart development. Malalignment VSDs are often associated with more complex congenital heart diseases such as tetralogy of Fallot or double outlet right ventricle. These defects typically require surgical correction to restore normal blood flow and prevent long-term complications.