Ventricular Septal Defect Common Locations

Ventricular septal defects (VSDs) most commonly occur in the perimembranous region. These types of defects typically include subcrestal and subvalvular varieties, and are generally located around the membranous portion of the septum. The ventricular septum is usually divided into four distinct areas: the perimembranous, inlet, outlet, and muscular regions.

Types of Ventricular Septal Defects

One of the most common types is the perimembranous VSD, which accounts for approximately 60% to 70% of all cases, making it the most frequently diagnosed form. This type is often associated with defects located just beneath the aortic valve.

Outlet Region VSDs

Another significant category is the outlet VSD, also referred to as a supracristal or high VSD. This includes defects beneath the pulmonary valve, known as subpulmonary or juxta-arterial defects. These are less common than perimembranous defects but still represent a significant portion of diagnosed VSDs.

Inlet Region VSDs

The inlet VSD, sometimes called the atrioventricular canal type, occurs in the area of the septum near the tricuspid and mitral valves. This type is often associated with congenital heart conditions that affect the alignment of the heart's chambers and valves.

Muscular VSDs

Finally, muscular VSDs are typically found in the apex of the heart, although they can occur anywhere within the muscular portion of the septum. These defects are surrounded by muscle tissue and are generally considered to be less complex than other types of VSDs.