Pulmonary Atresia with Intact Ventricular

SeptumAli Sepahdari, MD

University of Illinois at Chicago

Background

Rare lesion accounting for 1-1.5% of all congenital heart disease

Complex disease with commonly associated abnormalities of the tricuspid valve, RV, coronary arteries, and left heart.

Treatment options vary depending on severity of disease

A more familiar abnormal....

Hypoplastic right heart...

Components of PA.IVSPulmonic atresia

Variable degree of right ventricular hypoplasia

Interatrial communication always present

Varying degrees of tricuspid valve abnormality

Coronary artery abnormalities

Pulmonic atresia

Exact cause unknown, but occurs late in development

Inflammatory/infectious insult speculated

Subtle hemodynamic alterations causing left heart loading is another proposed mechanism

Varying degrees of abnormality

RV Hypoplasia

Hypertrophied wall

Reduced cavity size in 90% of cases

5-10% of cases have enlarged right heart and Ebstein’s anomaly

Unipartite, bipartite, or tripartite RV (controversial)

Tricuspid abnormality

Typically expressed as Z score

85% are -2 to -5 SD below mean

Average Z = -2.2

Correlated with RV size

Functionally regurgitant (severe in 25%)

Interatrial connection

True secundum ASD in 20%

Patent PFO in the rest

Can be restrictive 5-10% of the time

Coronary artery abnormalities

Persistent right ventricular sinusoids, which may have fistulae to the coronary arteries

Presence inversely related to TV diameter, RV cavity size, and degree of TI; correlates directly with RV systolic pressure

Coronary circulation can be dependent on these communications, due to coronary artery stenoses (20%)

Pathophysiology

Natural history is hypoxia, acidosis, early death (weeks to months)

Maintenance of PDA critical initial step

LV is overloaded, and pumps mixed blood

Can have myocardial ischemia, depending on degree of coronary artery anomaly

Management

Cardiac cath to assess coronary arteries

If complete myocardial dependence on RV, consensus to avoid decompression

Management algorithm is complicated beyond that

Possible repairs

“two ventricle repair” – repaired RVOT, conventional physiology

“one ventricle repair” (Fontan circulation) -- passive systemic venous return to pulmonary arteries, bypassing the heart

“one and a half ventricle repair” – RVOT repair + bidirectional Glenn

Management Strategy

• After stabilization, initial procedure will be RVOT procedure and/or BT shunt – reassess at 3-6 mo.

• Subsequent procedures may include bidirectional Glenn +/- ASD modification

• Fontan at 1-4 years if single ventricle repair is planned

Radiology’s role

All available literature describes combination of echo and angiography in workup of PA.IVS -- CT and MR may have future role

TV annular size, coronary arteries are most important

TV regurgitant fraction, RV chamber size, morphology, growth

Post procedure flow dynamics?

References

• Reddy VM and Hanley FL. “Pulmonary Atresia with Intact Ventricular Septum.” Glenn’s Thoracic and Cardiovascular Surgery. Baue AE (ed). Appleton and Lange, 1996: 1315-1332.

• Mi YP et al. Evolution of the management approach for pulmonary atresia with intact ventricular septum. Heart 2005; 91:657-663

• Salvin JW et al. Fetal tricuspid valve size and growth as predictors of outcome in pulmonary atresia with intact ventricular septum. Pediatrics 2006 118(2):e415-e420

• Bichell DP. Evaluation and management of pulmonary atresia with intact ventricular septum. Current Opinion in Cardiology. 1999; 14(1):60-66

• Humpl T et al. Percutaneous balloon valvotomy in pulmonary atresia with intact ventricular setpum: impact on patient care. Circulation 2003; 108(7):826-832

• Jahangiri M et al. Improved results with selective management in pulmonary atresia with intact ventricular septum. J of Thoracic and Cardiovascular Surgery. 1999; 118:1046-1052

• Rychik J et al. Outcome after operations for pulmonary atresia with intact ventricular septum. J of Thoracic and Cardiovascular Surgery. 1998; 116:924-931