Overview
Congenital atrioventricular septal defect (AVSD) involves malformations of both the atrial and ventricular septa, often associated with complex valvular anomalies including double mitral valve orifices. Surgical repair is commonly performed to prevent long-term complications such as heart failure and pulmonary hypertension.Diagnosis
Key Diagnostic Criteria: Characteristic angiographic appearance of the medial border of the left ventricle, double mitral valve orifice visible on echocardiography 2.
Recommended Tests: Echocardiography (M-mode and two-dimensional) for detailed anatomical assessment 2.
Grading: Severity of valvular regurgitation assessed postoperatively via echocardiography 1.Management
First-Line Treatment: Surgical repair, typically involving plastic reconstruction of AV valves 3.
Adjunctive Treatments:
- Early repair (<16 months) may reduce certain risks but increases the risk of significant left AV valve regurgitation in very early repairs (<=4 months) 1.
- Consider prosthetic valve replacement in cases where native valve function is compromised 3.
Specific Considerations: Minor repair or leaving the valve untouched may be sufficient in some cases with double mitral valve orifices 2.Special Populations
Down's Syndrome: Higher mortality rates observed, particularly in early surgical interventions; increased risk of severe left AV valve regurgitation in very early repairs 13.
Pediatrics: Age at repair significantly impacts postoperative outcomes, with younger patients (<=4 months) at higher risk for significant valve regurgitation 1.Key Recommendations
Perform surgical repair of AVSD, ideally after 4 months of age to minimize the risk of significant left AV valve regurgitation 1 (Evidence: Moderate).
Utilize echocardiography for preoperative diagnosis and postoperative assessment of valvular function and regurgitation severity 12 (Evidence: Moderate).
Monitor patients with Down's syndrome closely due to higher risks of mortality and severe postoperative complications, including pulmonary vascular obstructive disease 3 (Evidence: Moderate).References
1 Bonnetts PL, Goldberg SJ, Copeland JG. Frequency of left atrioventricular regurgitation postoperatively after repair of complete atrioventricular defect. The American journal of cardiology 1994. link90471-5)
2 Warnes C, Somerville J. Double mitral valve orifice in atrioventricular defects. British heart journal 1983. link
3 Thiene G, Mazzucco A, Grisolia EF, Bortolotti U, Stellin G, Chioin R et al.. Postoperative pathology of complete atrioventricular defects. The Journal of thoracic and cardiovascular surgery 1982. link