Role of tricuspid regurgitation in fetal echocardiographic diagnosis of pulmonary atresia with intact ventricular septum.

OBJECTIVE

Pulmonary atresia with intact ventricular septum (PAIVS) is a rare cardiac malformation with a broad spectrum of anatomical manifestations, varying from types suitable for biventricular repair to those with diminutive right ventricle and primitive ventriculocoronary connections (VCC), more suitable for single-ventricle palliation or heart transplantation. We sought to test whether tricuspid regurgitation is an easily detectable prenatal criterion with which to identify PAIVS patients at lower risk of needing postnatal single-ventricle palliation.

METHOD

We identified retrospectively patients with both fetal diagnosis and postnatal confirmation of PAIVS who were seen at Bambino Gesù Hospital between January 2000 and December 2006. Tricuspid valve/mitral valve (TV/MV) ratio, presence and severity of tricuspid regurgitation and direct visualization of VCC were evaluated by echocardiography both pre- and postnatally.

RESULTS

We identified 22 patients with a prenatal diagnosis of PAIVS. Four pregnancies were terminated and one fetus was lost to follow-up, leaving 17 patients for the analysis. Based on postnatal cardiac catheterization and/or echocardiography we divided our population in two groups: Group 1 included 10 patients with VCC; Group 2 included seven patients without VCC. At fetal echocardiography, tricuspid regurgitation was absent in all ten Group 1 patients and present in all seven Group 2 patients. VCC were seen directly in 6/10 Group 1 patients and in no Group 2 patients. A cut-off value of 0.56 for the TV/MV ratio was highly predictive of VCC during fetal life, with a sensitivity of 100% and a specificity of 90%.

CONCLUSIONS

The absence of tricuspid regurgitation in fetuses affected by PAIVS is a strong prenatal echocardiographic predictor of VCC, as is a TV/MV ratio < 0.56. Fetuses presenting with tricuspid regurgitation and relatively large right ventricle are at lower risk of needing single-ventricle palliation postnatally. This inforation could be helpful for appropriate prenatal counseling and postnatal decision-making.