Low prenatal detection rate of valvar pulmonary stenosis: What are we missing?
Ronai C, Freud LR, Brown DW, Tworetzky W.
Prenat Diagn. 2020 Apr 20. doi: 10.1002/pd.5715. [Epub ahead of print]
Take Home Points
- Despite routine prenatal cardiac screening ultrasounds, congenital heart disease lesions with normal four chamber view has low sensitivity in prenatal detection.
- Prenatal diagnosis of pulmonary valve stenosis maybe improved with the use of cine clips to define the valve mobility and color flow Doppler to detect valvar flow acceleration.
- Unlike pulmonary atresia and intact ventricular septum, fetuses with pulmonary stenosis has near normal appearing tricuspid valve and pulmonary valve size making the diagnosis of pulmonary stenosis without cine clips and Doppler imaging challenging.
Comment from Dr. Jennifer Johnson (Pittsburgh, PA), Section Editor of Pediatric Cardiology Journal Watch: This is a single center retrospective chart review of all neonates who underwent cardiac catherization for critical pulmonary valve stenosis or pulmonary atresia intact ventricular septum. The cohort was evaluated for prenatal diagnosis of congenital heart disease and those patient’s fetal echocardiograms were reviewed.
Methods: Data was collected on all neonates who underwent cardiac catheterization from 2000-2014 at Boston Children’s Hospital with the diagnosis of critical pulmonary valve stenosis or pulmonary atresia intact ventricular septum.
Results: A total of 178 patients met inclusion criteria with 91 patients having critical pulmonary valve stenosis and 87 patients have pulmonary atresia intact ventricular septum. Prenatal diagnosis was significant lower in those neonates with critical pulmonary valve stenosis at 37% compared to those with pulmonary atresia intact ventricular septum 60% (p=0.003).
Tricuspid and pulmonary valve measurements were evaluated for those patients with fetal echocardiograms and all patients with postnatal transthoracic echocardiograms. The tricuspid and pulmonary valve z score was significantly higher in those patients with critical pulmonary stenosis compared to those with pulmonary atresia intact ventricular septum (p = <0.001 and p =0.004). Comparison of the transthoracic tricuspid and pulmonary valve z score of those patients prenatally and postnatally diagnosed showed no statically significance.
Discussion: In this cohort, as the authors proposed the prenatal detection of critical pulmonary valve stenosis would be significantly lower than those patients with pulmonary atresia intact ventricular septum. The decreased detection for those patients with critical pulmonary valve stenosis was thought to be linked to a normal appearing tricuspid valve and right ventricular on the obstetric screening four chamber view, obstetric imaging of the right ventricular outflow tract was not routinely recommended until 2013 and the decreased obstetric use of cine/color flow mapping imaging. Lastly, critical pulmonary valve stenosis may progress in severity over pregnancy therefore being undetected in routine obstetric ultrasound.
Limitations: Single center, retrospective study.
Next Steps: It would be of interest to see how many of the critical pulmonary valve stenosis patients had progressive pulmonary valve disease with a normal screening obstetric ultrasound at 18-20 weeks of gestation.