II. Epidemiology
- 
                          Incidence: 15-25% of Congenital Heart Disease- Most common Congenital Heart Disease cause
- Most common CHD found in chromosomal abnormalities
 
- Gender- More common in males
 
III. Pathophysiology
- Defect in interventricular septal wall- Most often located in membranous ventricular septum
 
- Physiology of VSD changes with time after birth- Newborn initially has a right to left shunt due to increased pulmonary pressures
- By 6 months of age, pulmonary pressures decrease, and shunt is left to right
- Longterm large VSD leads to Eisenmenger Syndrome with right to left shunt- Results from chronic pulmonary overload with Pulmonary Hypertension
 
 
IV. Signs and symptoms
- Severity of symptoms related to:- Defect size
- Pulmonary vascular resistance
- Associated cardiac lesions
 
- Small to moderate VSD- Normal P2 component of the Second Heart Sound
- Pansystolic harsh murmur- Grade II-VI of VI
- Located at lower left sternal border
 
 
- Large VSD with significant shunt- Includes moderate VSD findings
- Mid-diastolic flow rumble at apex
- Congestive Heart Failure signs and symptoms in a pink child (not cyanotic)
 
- Marked Pulmonary Hypertension- Right Ventricular lift
- Loud P2 component of the Second Heart Sound
- Short systolic ejection murmur at left sternal border
 
V. Imaging (large defect findings)
- 
                          Chest XRay
                          - Cardiomegaly
- Increased pulmonary vasculature
- Lungs appear dark in Pulmonary Hypertension (contrast with white of Pulmonary Edema)
 
- 
                          Echocardiogram
                          - Defines position and size of defect
 
VI. Management: Medical
- Small Ventricular Septal Defect- No surgical repair indicated
- SBE Prophylaxis
 
- 
                          Congestive Heart Failure
                          - See Pediatric Congestive Heart Failure
- 
                              Supplemental Oxygen
                              - May worsen Pulmonary Hypertension (increasing left to right shunt)
 
- Positive Pressure Ventilation (BiPAP)
- Diuretics (e.g. Furosemide 1 mg/kg IV)
- Consider Nitroglycerin in flash Pulmonary Edema (Cardiogenic Shock)- However, may worsen left to right shunt
 
- Consider inotropes (Dobutamine or Milrinone)- Indicated in Cardiogenic Shock with Pulmonary Edema (cold and wet)
- Consider Epinephrine if hypotensive
 
- Consider Digoxin
 
VII. Management: Surgical repair indications
- Growth failure refractory to medical therapy
- Pulmonary Hypertension
- Pulmonary to systemic flow ratio > 2:1
VIII. Course
- Spontaneous closure age <6 months: 30-40% related to:- Membranous and muscular defects
- Smaller defects
 
IX. Complications: Without repair
X. Complications: With repair
- Conduction defect: transient Right Bundle Branch Block
XI. References
- Claudius and Strobel (2024) EM:Rap, 9/9/2024
- Cyran (1998) PREP review lecture, October, Phoenix
- Merenstein (1994) Pediatrics, Lange
- Saenz (1999) Am Fam Physician 59(7):1857-66 [PubMed]
