Q23.4

Billable

Hypoplastic left heart syndrome

HCC Category Mapping

RxHCCHCC 191 — Congenital Heart/Circulatory Disorders and Fontan Circulation

0.000

What This Code Means

A serious birth defect where the left side of the heart is severely underdeveloped, including a small left ventricle and aortic valve abnormalities.

Coding Tips

•This is a critical congenital condition requiring immediate documentation of associated defects and surgical interventions
•Document any palliative procedures performed (Norwood procedure, Glenn procedure, Fontan procedure)

Clinical Significance

Hypoplastic left heart syndrome is one of the most severe congenital heart defects where the left side of the heart is critically underdeveloped, requiring immediate intervention for survival. This condition necessitates staged surgical palliation (Norwood sequence) and represents one of the highest-risk congenital heart conditions.

Documentation Requirements

✓Echocardiographic confirmation of hypoplastic left ventricle
✓Assessment of mitral and aortic valve atresia or stenosis
✓Evaluation of ascending aorta hypoplasia
✓Staged surgical intervention history (Norwood, Glenn, Fontan)
✓Current single ventricle function and hemodynamics
✓Arrhythmia monitoring and anticoagulation status
✓Exercise tolerance and functional assessment
✓Long-term complications and transplant considerations

Commonly Confused Codes

Q23.0 — congenital stenosis of aortic valve Q20.4 — double inlet ventricle Q22.0 — pulmonary valve atresia I42.0 — dilated cardiomyopathy Q25.1 — coarctation of aorta

Code Hierarchy

└Q23Congenital malformations of aortic and mitral valves └Q23.4Hypoplastic left heart syndrome

└Q23.4Hypoplastic left heart syndrome