Pulmonary Atresia With Ventricular Septal Defect

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Often associated with velocardiofacial syndrome or DiGeorge’s syndrome

• Neonate or infant with cyanosis and hypoxia (or congestive heart failure in 25%) and single accentuated S₂, holosystolic murmur along the left lower sternal border

  • – Continuous murmurs in the presence of patent ductus arteriosus (PDA) and/or systemic to pulmonary collateral arteries

• Cardiac imaging:

  • – Large aortic valve overriding a malaligned large membranous or infundibular ventricular septal defect (VSD) and a blind hypoplastic right ventricular infundibulum

  • – Atrial septal defects (ASDs) and muscular VSDs may be present

  • – PDA may be identified; right aortic arch in 50%

GENERAL CONSIDERATIONS

• Sometimes pulmonary atresia with VSD is considered the most severe in the spectrum of tetralogy of Fallot

• Clinical presentation and surgical options depend on the amount of pulmonary blood flow

• Pulmonary circulation is supplied by a PDA, systemic to pulmonary collateral arteries, or plexuses of bronchial and pleural arteries

• Other associated congenital conditions: tricuspid atresia or stenosis, complete atrioventricular canal defects, complete or corrected transposition of the great arteries, left superior vena cava, anomalies of the coronary sinus, dextrocardia, and asplenia or polysplenia syndromes

• Surgical options depend on the anatomy of the individual

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Most patients present with cyanosis and hypoxia, which becomes severe when the ductus arteriosus closes

• Rarely patients present around ages 4–6 weeks with heart failure, increased blood flow, and minimal cyanosis in the setting of a large PDA or well-developed systemic to pulmonary collateral arteries

• Hemoptysis may occur owing to rupture of collateral arteries

• Infections may occur, especially with DiGeorge’s syndrome

PHYSICAL EXAM FINDINGS

• Cyanosis

• Normal S₁; single, often accentuated S₂ (aortic valve closure)

• Holosystolic murmur along the left lower sternal border; some with severe cyanosis do not have a detectable murmur

• Continuous murmurs in the presence of a PDA or systemic to pulmonary collateral arteries

• An early diastolic murmur of aortic regurgitation may be present

DIFFERENTIAL DIAGNOSIS

• Tetralogy of Fallot

• PDA

• Truncus arteriosus

• Other causes of cyanosis and heart failure

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Arterial blood gases: show hypoxemia and hypocarbia

• CBC: reactive polycythemia

ELECTROCARDIOGRAPHY

• Right ventricular hypertrophy and right-axis deviation

• Right atrial enlargement

• Sometimes left ventricular hypertrophy and left atrial enlargement

IMAGING STUDIES

• Chest x-ray: normal or mildly enlarged, boot-shaped heart; absent main pulmonary arterial shadow; heterogeneous reticular pattern in lung fields from systemic to pulmonary artery collateral vessels; enlarged, right-sided aortic arch in 50% of cases; variable pulmonary vascular markings

• Echocardiography: large aortic valve overriding a large membranous or infundibular VSD and a ...