From the Guidelines
The most common type of ventricular septal defect (VSD) is the perimembranous VSD, accounting for approximately 80% of all VSDs. This defect occurs in the upper portion of the ventricular septum, just below the aortic valve, and is located in the membranous septum, a thin area of tissue that separates the left and right ventricles near the heart valves 1. Perimembranous VSDs vary in size, which determines their clinical significance, with small defects often closing spontaneously during early childhood, while larger ones may require surgical or catheter-based intervention if they cause significant left-to-right shunting, pulmonary hypertension, or heart failure symptoms.
The prevalence of perimembranous VSDs is due to the complex embryological development of this region of the heart, where multiple components of the developing heart must fuse precisely to form a complete septum. Other less common types of VSDs include:
- Muscular VSDs, which account for 5% to 20% of all defects
- Inlet VSDs, which occur in the lower part of the right ventricle and adjacent to the tricuspid valve
- Outlet (supracristal) VSDs, which are rare, accounting for fewer than 5% of all defects, except in the Asian population, where the incidence is as high as 15% to 20% 1.
Given the high incidence of perimembranous VSDs, it is essential to prioritize their diagnosis and treatment to prevent potential complications and improve patient outcomes. Transthoracic echocardiography is the best diagnostic imaging tool to characterize the type, size, and number of defects and estimate the pulmonary artery pressure 1. Surgical closure for patients with perimembranous VSD is safe and effective and is considered the therapeutic option of choice in neonates, infants, and children 3 years of age 1.
From the Research
Types of Ventricular Septal Defects (VSDs)
- Perimembranous VSD: This type of VSD is located in the membranous part of the ventricular septum and is the most common type of VSD 2, 3, 4.
- Muscular VSD: This type of VSD is located in the muscular part of the ventricular septum 2.
- AV type VSD: Not mentioned as the most common type in the provided studies.
Prevalence of Perimembranous VSD
- Perimembranous VSD is the most common congenital heart defect, accounting for the majority of VSD cases 2, 3, 4.
- In a study of 256 patients with VSD, perimembranous VSD was the most frequent type, accounting for 62% of cases 4.
Conclusion is not allowed, so the response will continue with more information
Association with Other Conditions
- Perimembranous VSD may be associated with aortic regurgitation and ascending aortic aneurysm 5.
- Perimembranous VSD may also be associated with aneurysm of the membranous septum, which can affect the natural history of the defect 3.