II. Epidemiology
- Incidence: 5% of Congenital Heart Disease
- Males affected more often than females by 3:1
III. Pathophysiology
- Aorta and pulmonary arteries are transposed
- Pulmonary and systemic circulation are separate
- Parallel, rather than sequential
IV. Associated Conditions
- Ventricular Septal Defect (30-35%)
- Pulmonic stenosis (5%)
- Pulmonic stenosis with VSD (10%)
- Aortic Coarctation (5%)
V. Signs
- Cyanosis if ventricular septum intact
- Single S2 Heart Sound
VI. Diagnostics: Electrocardiogram
VII. Imaging
-
Chest XRay (Classic triad) - Egg on a string appearance
- Egg shaped cardiac silhoutte
- Narrow mediastinum
- Increased pulmonary markings
- Echocardiogram
VIII. Management: Initial
- Ductus-Dependent
- Keep ductus arteriosus open
- Administer Prostaglandins (PGE1)
- Correct metabolic abnormalities
- Correct severe Hypoxia
IX. Management: Surgical
- Balloon atrial septoplasty
- Temporizing method
- Arterial switch operation
- Procedure of choice
- Most complex surgery of Congenital Heart Disease repairs
- Pulmonary artery and aorta divided and reattached
- Atrial Dysrhythmias are less common with this repair method than with prior methods
X. Prognosis
- Five year survival after arterial switch: 82%
XI. Complications associated with surgical repair
- Pulmonic stenosis
- Aortic Stenosis
- Coronary Artery obstruction
- Ventricular dysfunction
- Arrhythmia
- Mitral Regurgitation
XII. References
- Cyran (1998) PREP review lecture, October, Phoenix
- Merenstein (1994) Pediatrics, Lange
- Saenz (1999) Am Fam Physician 59(7):1857-66 [PubMed]