4.5e Pulmonary Valve Atresia (Q22.0)

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Pulmonary valve atresia is a structural heart anomaly characterized clinically by cyanosis and anatomically by an imperforate pulmonary valve that blocks the flow of blood through the right ventricular outflow tract completely. The imperforate pulmonary valve can look like a membrane, or – because it failed to form altogether – the atresia takes the form of a muscular atretic segment.

Two main forms must be distinguished, based on whether or not a ventricular septal defect is present. These two forms differ in presentation, epidemiology and risk factors.

In most cases, pulmonary valve atresia with a ventricular septal defect is considered as a conotruncal defect – specifically the more severe end of the spectrum of tetralogy of Fallot.
Pulmonary atresia with intact ventricular septum is a different entity (see Fig. 4.18) unrelated to conotruncal heart defects.

Fig. 4.18. Pulmonary valve atresia

Relevant ICD-10 codes

Q22.0 Pulmonary valve atresia
(Q21.0 Ventricular septal defect)

Diagnosis

Prenatal. Pulmonary valve atresiacan be suspected prenatally on a second trimester obstetrican atomic scan, using a combination of four-chamber and outflow tract views, and further characterized by fetal echocardiography. Because of diagnostic challenges, however, postnatal confirmation is necessary for a firm diagnosis.

Postnatal. Infants with pulmonary atresia (with or without ventricular septal defect) typically present early in the neonatal period with cyanosis and hypoxemia that worsens as the ductus closes. Echocardiography is the key diagnostic procedure, although other imaging techniques, including catheterization, might be necessary to better guide management and care.

Clinical and epidemiologic notes

Infants with pulmonary atresia with intact ventricular septum typically present with cyanosis; massive cardiomegaly might also occur.

Pulmonary atresia with ventricular septal defect can be associated with deletion 22q11, unlike the form with an intact ventricular septum.

The overall birth prevalence of pulmonary atresia is estimated to be approximately 1 in 7500 births. The birth prevalence of pulmonary atresia with intact ventricular septum is approximately 1 in 15 000 live births (more frequent among stillbirths).

Inclusions

Q22.0 Pulmonary valve atresia (without ventricular septal defect)
Q22.0 Pulmonary valve atresia with Q21.0 (ventricular septal defect)

Exclusions

Q22.1 Congenital pulmonary valve stenosis

Note:

Some surveillance programmes group together pulmonary valve stenosis (Q22.1) and atresia (Q22.0). This is not recommended. Whereas severe pulmonary stenosis might present similarly to pulmonary atresia, mild forms of pulmonary stenosis are much more common, such that lumping stenosis with atresia generates a heterogeneous group of cardiac defects in which the severe forms cannot be accurately assessed and tracked.
Pulmonary atresia with ventricular septal defect is in most cases a conotruncal defect and should be grouped with tetralogy of Fallot and not with pulmonary atresia with intact ventricular septum.

Checklist for high-quality reporting

Checklist for high-quality reporting
Pulmonary Atresia – Documentation Checklist
Describe in detail the clinical and echocardiographic findings: Specify intracardiac anatomy, including the presence of valve atresia, the involvement of the tricuspid valve, and whether the right ventricle is underdeveloped. Specify whether the ventricular septum is intact or whether a ventricular septal defect is present (if so, note whether a specific type of ventricular septal defect is described in the notes). Specify whether the cardiac findings are from a prenatal or postnatal echocardiogram, or from other investigations (e.g. catheterization, MRI), surgery or autopsy. Document any additional cardiovascular finding, including atrial septal defect, pulmonary collaterals, etc. Look for and document extracardiac birth defects: In deletion 22q11, the heart anomaly can be associated with several internal and external anomalies, including cleft palate, spina bifida, vertebral anomalies or other defects. Report whether specialty consultation(s) were done: Report whether the diagnosis was made by a paediatric cardiologist, and whether the patient was seen by a geneticist. Report any genetic testing and results(e.g. chromosomal studies, genomic microarray, genomic sequencing).

Suggested data quality indicators

Suggested data quality indicators
Category	Suggested Practices and Quality indicators
Description and documentation	Review sample of clinical descriptions for documentation of key elements: Anatomy. How cardiac findings were detected (e.g. echocardiography). Who made the diagnosis (e.g. paediatrician, paediatric cardiologist). Specialists who evaluated the child, in particular, a paediatric cardiologist or geneticist. Key evaluations done, especially genetic testing.
Coding	Track and evaluate cases of pulmonic atresia (Q22.0) with ventricular septal defect (Q21.0). A very low proportion of such cases compared to pulmonary atresia without a ventricular septal defect suggests that ventricular septal defects are either missed or not coded.
Clinical classification	Track proportion of congenital anomalies and syndromes occurring with pulmonary atresia. The expectation is that the proportion is higher for pulmonary atresia with ventricular septal defect compared to pulmonary atresia without ventricular septal defect.
Prevalence	Monitor separately the prevalence of pulmonary atresia with and without ventricular septal defect. If larger monitoring groups are necessary, consider grouping pulmonary atresia with ventricular septal defect with tetralogy of Fallot (part of the same spectrum). Monitor prevalence: If low (< 1 per 10 000 births) it suggests under-ascertainment. Compare prevalence among the smallest site/time units: Statistically significant dissimilar results suggest a possible methodological problem in one or more site/time units.