Prenatal diagnosis of criss-cross heart with congenitally corrected transposition of the great arteries – detection and fetal echocardiography monitoring with one-year postnatal follow-up

Case report

This was a first pregnancy of a healthy woman. The fetus had routine ultrasound examinations performed at the 6th, 12th, and 20th weeks of gestation, which were determined as ‘normal’. However, at the 27th week of gestation a ventricular septal defect was detected, which resulted in a referral to our centre for targeted echocardiography.
At the 37th week of gestation, the heart area/cardio-thoracic area (HA/CA) ratio was normal. Moreover, levocardia and situs solitus were observed both on the abdominal and atrial level. Both atria were found on their correct sides; however, it was impossible to visualize a tricuspid and mitral valve opening in the same plane. Two ventricles were present, but the morphologically left ventricle was found on the right side, and the hypoplastic morphological right ventricle was located on the left side.
Sequential analysis off-line in slow motion confirmed that blood flows were not parallel within the fetal heart – the blood from the right atrium was directed to the left ventricle, whereas the blood from the left atria was directed to the right ventricle. The position of the hypoplastic right ventricle was superior – above to the left ventricle, which was inferior, and this was clearly confirmed by postnatal computed tomography (CT) angiography (Figure 1). So, there was a superior-inferior relationship between the ventricles. The aorta emerged from the morphological hypoplastic right ventricle and was parallel to the wide pulmonary trunk, which means that there was ventriculo-arterial discordance. The 2 arterial vessels in superior mediastinum had normal blood flow according to Doppler measurements. During subsequent four echo-sonographic exams (Table 1), there were normal umbilical Doppler blood flow parameters and normal heart rate up to the 38th week of gestation. Three weeks before delivery, the size of the pulmonary trunk was 13 mm (Z score +2.47) [1]. The development of the aorta stopped at the same time, and its maximum size was 7 mm (Z score –0.43). The aorta/main pulmonary artery (AO/MPA) ratio was 0.54, which suggested coarctation of the aorta (CoA). There was normal right-left blood flow through the foramen ovale, and the size of the ventricular septal defect (VSD) did not increase. In each fetal exam, the cardio-vascular profile score (CVPS) was 10, so a vaginal delivery was planned in our tertiary centre (prenatal cardiology, obstetrics, paediatric cardiology, and cardiac surgery departments). At the 40th week of gestation a spontaneous delivery occurred, and a male baby was born with a weight of 3000 g and an Apgar score of 10. The Prostin infusion was initiated just after birth to maintain the arterial duct patency. Postnatal echocardiography, chest X-rays, and volume-rendered CT angiography (Figures 1-4) confirmed the prenatal findings and also made it possible to confirm aortic coarctation type A. The aortic arch reconstruction surgery with pulmonary trunk banding was performed on the 8th day of postnatal life, and the child was asymptomatic during his first year of life (our postnatal follow-up).

Discussion

Criss-cross heart (CCH) combined with corrected transposition of the great arteries (cc-TGA) is a cardiac malformation that is very difficult to diagnose both prenatally and postnatally because it is a rare and complex cardiac malformation. In the past, such a malformation was described only in autopsy examinations [2] or was detected by accident in adults [3-5]. In the years 2008-2020 progress in ultrasound technology and experience in fetal echocardiography enabled the diagnosis of CCH or cc-TGA prenatally [6-8]. However, the combination of criss-cross heart and corrected TGA was found only in individual cases (Table 2) [9, 10].
What is unique in our report is not only the diagnosis of abnormal heart anatomy, but also fetal heart monitoring by echocardiography. Besides the diagnosis, fetal echocardiography enabled safe monitoring and preparation of the pregnant woman and medical staff for vaginal delivery at term in the tertiary centre for obstetrics and cardiology. Further cardiological work-up is planned for our patient, but his medical history as well as other cases presented in the literature (Table 2) confirm that despite an abnormal fetal heart looping in early embryogenesis, it does not cause congestive heart failure both prenatally and postnatally and is not related to an abnormal karyotype. These data have crucial value for prenatal consultation purposes for parents-to-be as well as obstetricians, perinatologists, paediatric cardiologists, and adult cardiologists.

Acknowledgements

The cardiac surgery was performed by Prof. Jacek Moll and his team from the Paediatric Cardiac Surgery Department of the Polish Mother’s Memorial Hospital Research Institute. We also would like to thank our colleges from the Obstetrics Department, Neonatology Department, Paediatric Cardiology Department, and Intensive Care Department for their cooperation and appreciation of our input in their daily work.

Conflict of interest

The authors declare no conflict of interest.

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