*   Indywidualna praktyka lekarska Marcin Wiechec, Krakow, Poland;
**  University Hospital in Krakow, Neonatology Department, Krakow, Poland.

Case report

A 27-year-old low risk P0G1 presented in first trimester. Our ultrasound examination revealed:

• Increased nuchal translucency (NT 3 mm, CRL 52 mm);

• Nasal bone was present;

• Ductus venosus waveform with positive a-wave;

• Tricuspid valve without regurgitation.

The risk of trisomy 21 calculated by FMF ASTRAIA software (maternal age, NT, PAPP-A, free-beta-HCG, nasal bone, tricuspid regurgitation) was 1:27.

Image 1: Nuchal translucency 3 mm (CRL 52 mm).

Image 2: Estimated risk for aneuploidies (FMF ASTRAIA).

Considering the findings an amniocentesis was done with normal karyotype 46, XX. Our second trimester examination revealed following findings.

In videos 1 and 2, 4, 5 and 9, a small hypertrophied and hypocontractile right ventricle, intact interventricular septum with bulging towards left ventricle and two atrioventricular valves are seen in the four chamber view.

You can download a 3D volume related to this case here.

Video 1: Four chamber view of the heart at 21 week in B-mode (speed of the video is reduced to 50%). A small hypertrophied and hypocontractile right ventricle, intact interventricular septum with bulging towards left ventricle and two properly moving atrioventricular valves.

Video 2: Vertex sweep, 21 weeks: four-chamber view as above; five-chamber view: normal ascending aorta, intact interventricular septum; in the front of ascending aorta there is coronary fistula seen; more in the front there is no right outflow tract; 3 vessels and trachea view- no pulmonary trunk. Clip speed reduced to 50%.

In color Doppler scan (video 3), some signals with high velocity are visible at the outer wall of the right ventricle.

Video 3: 21 weeks, subcostal view: color Doppler shows coronary fistula starting from right ventricle wall (see attached picture on the right). 

Follow-up 26 weeks.

Video 4: Vertex sweep, 26 weeks: the same observations as in video 2; moreover: fistula is much better seen; beginning of tricuspid valve dysplasia is seen: narrow inlet and hyperechoic leaflets.

Image 3: Pulsed wave Doppler over aliasing signal. In images 3 and 5 flow velocity waveforms of the right ventricle to right coronary artery fistula are seen.

Image 4: Ductus venosus velocimetry.

Video 5: 26 weeks 4C view render: RV hypertrophy, beginning of tricuspid dysplasia.

In video 6A inversion rendering mode shows the right ventricle to right coronary artery fistula (Fis) and lack of right ventricle outflow tract (RVOT). In comparison normal heart is shown in invert mode (video 6B).

Video 6A: 26 weeks Inversion rendering: no RVOT and pulmonary artery; fistula is seen as the connection between right ventricle and aorta. Image on the right explains the structures visible on the video 6A (Fis - fistula, RV - right ventricle, LV - left ventricle).

Video 6B: STIC - inversion mode rendering - normal (video speed reduced to 50%).

Follow-up 31 weeks.

They form a vessel coming from right ventricle wall with aliasing of color (at the level of 100cm/s) aiming towards aorta, which is right ventricle to right coronary artery fistula (Fis) - (video 7).

Video 7: 31 weeks, Tomographic ultrasound imaging: coronary fistula is seen mimicking normal outflow form right ventricle, it begins in the right ventricle wall. Image on the right explains the structures visible on the video 7 (LV - left ventricle, RV - right ventricle, LA - left atrium, RA right atrium, Ao - aorta, Fis - fistula).

Image 5: Pulsed wave Doppler over aliasing signal. In images 3 and 5 flow velocity waveforms of the fistula are seen.

Video 8: Four chamber view.(clip speed reduced to 50%). 31 weeks: the same observation as in video 1 and 5; moreover  progression of tricuspid dysplasia.

Video 9: STIC four chamber view rendering.(clip speed reduced to 50%). 31 weeks: the same observation as in video 1 and 5; moreover  progression of tricuspid dysplasia.

In video 10 inverted rendering of pulmonary artery branches is shown including tortuous shape of ductus arteriosus.

Video 10: Inverted rendering of pulmonary artery branches.(clip speed reduced to 50%). Tortous shape of ductus arteriosus is seen. Image on the right explains the structures visible on the video 10 (LPA - left pulmonary artery, Ao - aorta, DA - ductus arteriosus, RPA - right pulmonary artery).

Some of the STIC volumetric files can be downloaded here for review.

Our patient decided to continue the pregnancy. She delivered by C section in 38 weeks. At the time her neonate underwent first cardiac surgery. First step of surgical treatment was closure of tricuspid valve, what will result in spontaneous closure of coronary fistula. Further are hemi-Fountain and Fountain procedures.

Neonatal echocardiography videos:

Video 11:  Neonatal four-chamber view. Image on the right explains the structures visible on the video 11 (RA - right atrium, LA - left atrium, RV - right ventricle, LV - left ventricle).

Video 12:  Neonatal echo: short axis view at the level of aortic valve, showing dilated, tortous right coronary artery forming, which forms the fistulaImage on the right explains the structures visible on the video 12 (Ao - aorta, LA - left atrium).

Video 13: Neonatal echocardiography. Simillar as video 12, but shown with color Doppler: aliasing in coronary fistula.

Video 14:  Neonatal echocardiography. Connection between aorta and ductus arteriosus is shown in color Doppler. Image on the right explains the structures visible on the video 14 (Ao - aorta, RPA - right pulmonary artery, DA - ductus arteriosus).

Discussion

In general Pulmonary Atresia (PA) cases reveal various sizes of  right ventricles ranging from a very small to enlarged ones (underdeveloped (80%), normal (6,5%) or enlarged (13%) [1]. Hypoplastic right ventricle caused by PA is associated with presence of small tricuspid valve, usually without regurgitation. In these cases, coronary arterial communications are very common findings. In contrary, such communications are not found in cases with enlarged right ventricles, but here tricuspid regurgitations are quite common [2].
When pulmonary valve atresia is detected, the presence of a fistula should always be taken into account [3]. The earliest diagnosis of this condition was reported by Chaoui et al. [3] in a 13-week fetus. As Chaoui et al. state, the primary etiological factor could be the fistula itself, where deviation of the right ventricular outflow, causes the perfusion in the pulmonary valve to be reduced, thus leading to PA. After some authors, in our opinion all the cases with enlarged NT with normal karyotype has to undergo early first trimester fetal echocardiography, which has to exclude most of CHDs [5].

A video beneath demonstrates our case: 11 weeks fetal heart in adjusted Tomographic Ultrasound Imaging (lower quadrants show 5C and 4C views, upper right 3VT view)

Video 15:

References

1. Freedom RN, Dische MR, Rowe RD. The tricuspid valve in pulmonary atresia and intact ventricular septum: A morphological study of 60 cases. Arch Pathol Lab Med 1978; 102: 28–31.
2. Todros T,et al. Pulmonary stenosis and atresia with intact ventricular septum during prenatal life. Ultrasound Obstet Gynecol 2003; 21: 228–233
3. Chaoui R, Machlitt A, Tennstedt C. Prenatal diagnosis of ventriculo-coronary fistula in a late first-trimester fetus presenting with increased nuchal translucency. Ultrasound Obstet Gynecol 2000; 15: 160–162.
4. R. Chaoui et al. Prenatal diagnosis of ventriculo-coronary communications in second-trimester fetus using transvaginal and transabdominal color Doppler sonography. Ultrasound Obstet Gynecol  1997; 9: 194-197
5. McAuliffe FM, et al Early fetal echocardiography-A reliable prenatal diagnosis tool American Journal of Obstetrics and Gynecology (2005) 193, 1253–9