Ventricular Septal Defect (VSD) in Babies
The short answer
A ventricular septal defect (VSD) is a hole in the wall between the heart's lower chambers and is the most common congenital heart defect, occurring in about 1 in 240 to 500 babies. Small VSDs often cause no symptoms and close on their own within the first few years of life. Larger VSDs may cause heart failure symptoms and require surgical repair. With appropriate management, the long-term outlook is excellent.
By Age
What to expect by age
A VSD is usually detected by a heart murmur heard during a newborn exam or early well-child visit. Paradoxically, the murmur of a small VSD is often louder than a large one. Small VSDs typically cause no symptoms. Larger VSDs may not cause symptoms right away because pulmonary pressure is still high in the first weeks of life, but as pressure drops, excess blood flow to the lungs increases and symptoms begin to appear — rapid breathing, difficulty feeding, and poor weight gain.
This is when moderate to large VSDs often become symptomatic. Babies may breathe rapidly (especially during feeding), sweat on the forehead while eating, tire before finishing feedings, and gain weight slowly. Medications such as diuretics may be used to manage symptoms. If the VSD is large and the baby is struggling despite medication, surgical repair is typically planned during this period.
Small VSDs continue to be monitored and many show signs of getting smaller. Babies with large VSDs that have been surgically repaired typically show dramatic improvement in feeding and growth after surgery. The murmur may change or get quieter as a small VSD shrinks. Regular echocardiograms track the size of the defect.
Many small VSDs close completely by age 2-5, though some persist as tiny, hemodynamically insignificant holes. Children with closed or small VSDs typically have no restrictions or long-term effects. Children who had surgical repair usually lead completely normal lives with periodic cardiac check-ups. The repair is considered a long-term success in the vast majority of cases.
What Should You Do?
When to take action
- Your baby has a small VSD detected by murmur, but is feeding well, gaining weight normally, and has no symptoms
- Your baby's VSD is getting smaller on follow-up echocardiograms
- Your baby had VSD repair and is growing and developing well
- Your pediatrician describes the murmur as loud but the echocardiogram shows only a tiny hole
- Your baby has a heart murmur that has not been evaluated with an echocardiogram
- Your baby with a known VSD is starting to breathe faster, sweat during feedings, or gain weight slowly
- Your baby's murmur has changed in character or you have noticed new symptoms
- Your baby is breathing very rapidly (more than 60 breaths per minute at rest), refusing to eat, or appears gray or blue
- Your baby who had VSD surgery develops fever, wound redness, or drainage from the surgical site
Sources
Related Resources
Related Medical Concerns
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Achondroplasia (Dwarfism) in Babies
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Adenoid Hypertrophy and Breathing
Adenoids are lymphoid tissue located behind the nose that help fight infection in young children. When adenoids become enlarged (adenoid hypertrophy), they can block the nasal airway, causing chronic mouth breathing, snoring, nasal speech, and sleep-disordered breathing. Enlarged adenoids are most common between ages 2-7 and are a leading cause of obstructive sleep apnea in young children. Treatment ranges from watchful waiting and nasal steroids to surgical removal (adenoidectomy) if breathing or sleep is significantly affected.
Air Quality and Baby Health
Babies and young children are more vulnerable to air pollution than adults because they breathe faster, their lungs are still developing, and they spend more time close to the ground where some pollutants concentrate. The EPA recommends keeping babies indoors when the Air Quality Index (AQI) exceeds 100 (orange level). During wildfire smoke events, keep windows closed, use air purifiers with HEPA filters, and monitor your child for coughing, wheezing, or difficulty breathing. Long-term exposure to air pollution can affect lung development.
Altitude Sickness in Babies
Babies and toddlers can experience altitude sickness when traveling above 5,000-8,000 feet (1,500-2,500 meters). Symptoms are harder to recognize in infants because they cannot describe how they feel. Watch for unusual fussiness, poor feeding, disrupted sleep, vomiting, and fast breathing. Gradual ascent is the best prevention. Most pediatricians recommend avoiding sleeping at very high altitudes (above 8,000 feet) with infants when possible, and descending immediately if symptoms appear.
Amblyopia (Lazy Eye) Treatment Timing
Amblyopia (lazy eye) is the most common cause of vision loss in children, affecting 2-3% of the population. It occurs when one eye develops weaker vision because the brain favors the other eye. Early detection and treatment are critical because the visual system is most responsive to treatment during early childhood. Treatment is most effective when started before age 7, though improvement is possible at older ages. Treatment options include patching the stronger eye, atropine eye drops, glasses, or a combination.