Prenatal Role of the Ductus Arteriosus in Absent Pulmonary Valve Syndrome

Abstract

Absent pulmonary valve with ventricular septal defect is associated with ductal agenesis and markedly dilated main and branch pulmonary arteries. The less common variant with intact ventricular septum generally exhibits a patent ductus and smaller branch pulmonary arteries, and may be associated with tricuspid atresia. We identified 7 patients with the prenatal diagnosis of absent pulmonary valve, 5 with ventricular septal defect (Group 1) and 2 with an intact ventricular septum (Group 2). Imaging, color Doppler, and pulsed-Doppler recordings were analyzed. The branch and main pulmonary arteries were measured and expressed as a ratio with the descending aorta. Pulmonary regurgitation time (PRT) and diastolic acceleration time (DAT) were derived, and DAT/PRT was calculated to characterize diastolic pulmonary flow. Group 1 patients all had a large ventricular septal defect, normal biventricular size and function, and dilated main and branch pulmonary arteries. Group 2 patients had dilated main but smaller branch pulmonary arteries, moderate right ventricular dilation with severe dysfunction, and limited or absent tricuspid inflow. Group 1 demonstrated shorter acceleration time and earlier peak velocity, resulting in a smaller DAT/RT ratio. We speculate that free communication between the fetal aorta and the ventricles may limit atrial inflow and elevate diastolic pressure, affecting cardiac output, ventricular function, and atrioventricular valve development. With an intact ventricular septum, these physiologic and anatomic repercussions are limited to the right ventricle, but with a ventricular septal defect, both ventricles would experience similar consequences and cardiac performance could be critically impaired.

Absent Pulmonary Valve Syndrome with Left Hemitruncus

“…Although TOF is the most commonly associated congenital heart defect (CHD) in APVS, other defects have been described 2,3. Absence of a patent ductus arteriosus (PDA) has been postulated as a cause of APVS 4. The pulmonary valve leaflets are either rudimentary or completely absent, and there is pulmonary valve stenosis and incompetence.…”

Prenatal diagnosis and postnatal outcome in patients with absent pulmonary valve syndrome not associated with tetralogy of Fallot: report of one case and review of the literature

“…The accuracy of prenatal diagnosis in fetuses with APVS, isolated or associated with other cardiovascular malformations, has also been largely reported in the literature [5,6,16]. When diagnosed prenatally, the outcome of APVS seems to be poor; in a series of 24 fetuses with APVS reported by Razavi et al [6] only 15% survived, death occurring mostly in prenatal or neonatal life.…”

“…APVS is usually reported in the setting of tetralogy of Fallot [2,3]. Less commonly, absence or dysplasia of pulmonary leaflets has been described without ventricular septal defect (VSD) [3][4][5].…”

Absent pulmonary valve syndrome with tetralogy of Fallot and associated dextrocardia detected at an early gestational age of 26 weeks

“…As reported by Yeager et al , most of the cases presenting with an intact ventricular septum commonly reveal a patent ductus arteriosus, with relatively small pulmonary arteries and associated tricuspid atresia. [2] According to their study, the free communication between the ventricles and the aorta causes the blood flow to the atria to be reduced, while there is increase in the ventricular end diastolic pressure; this may in turn affect the cardiac function and the development of the atrioventricular valve. Yeager et al also suggest that in the presence of a VSD these changes affect both the ventricles, thereby resulting in a poor prognosis,[2] as seen in our case.…”

“…[1] When APVS is associated with a ventricular septal defect, the physiologic and anatomic repercussions affect both ventricles, and cardiac performance can be critically impaired. [2]…”