Development of autonomic innervation at the venous pole of the heart: bridging the gap from mice to human.

Background: Prenatal development of autonomic innervation of sinus venosus-related structures might be related to atrial arrhythmias later in life. Most of the pioneering studies providing embryological background are conducted in animal models. To date, a detailed comparison with the human cardiac autonomic nervous system (cANS) is lacking.

30 Years' Experience in Percutaneous Pulmonary Artery Interventions in Transposition of the Great Arteries.

Background: Pulmonary artery (PA) stenosis is common after arterial switch operation (ASO) for transposition of the great arteries (TGA). Differences between balloon angioplasty (BA) and stents on right ventricular (RV) and PA pressures are not well studied.

Objectives: The purpose of this study was to analyze percutaneous PA interventions' frequency after ASO, complications, and the effects of BA and stents on RV and PA pressures.

Balloon atrial septostomy for transposition of the great arteries: Safety and experience with the Z-5 balloon catheter.

Background: Balloon atrial septostomy (BAS) is an emergent and essential cardiac intervention to enhance intercirculatory mixing at atrial level in deoxygenated patients diagnosed with transposition of the great arteries (TGA) and restrictive foramen ovale. The recent recall of several BAS catheters and the changes in the European legal framework for medical devices (MDR 2017/745), has led to an overall scarcity of BAS catheters and raised questions about the use, safety, and experience of the remaining NuMED Z-5 BAS catheter.

Aims: To evaluate and describe the practice and safety of the Z-5 BAS catheter, and to compare it to the performance of other BAS catheters.

Ductal Flow Ratio as Measure of Transition in Preterm Infants After Birth: A Pilot Study.

Cardiovascular changes during the transition from intra- to extrauterine life, alters the pressure gradient across the ductus arteriosus (DA). DA flow ratio (R-L/L-R) has been suggested to reflect the infant's transitional status and could potentially predict neonatal outcomes after preterm birth. Determine whether DA flow ratio correlates with oxygenation parameters in preterm infants at 1 h after birth.

Abnormal sinoatrial node development resulting from disturbed vascular endothelial growth factor signaling.

Background: Sinus node dysfunction is frequently observed in patients with congenital heart disease (CHD). Variants in the Vascular Endothelial Growth Factor-A (VEGF) pathway are associated with CHD. In Vegf(120/120) mice, over-expressing VEGF120, a reduced sinoatrial node (SAN) volume was suggested.

Echocardiographic assessment of embryonic and fetal mouse heart development: a focus on haemodynamics and morphology.

Background: Heart development is a complex process, and abnormal development may result in congenital heart disease (CHD). Currently, studies on animal models mainly focus on cardiac morphology and the availability of hemodynamic data, especially of the right heart half, is limited. Here we aimed to assess the morphological and hemodynamic parameters of normal developing mouse embryos/fetuses by using a high-frequency ultrasound system.

Normal and abnormal development of the cardiac conduction system; implications for conduction and rhythm disorders in the child and adult.

The cardiac conduction system is a specialized network that initiates and closely coordinates the heart beat. Cardiac conduction system development is intricately related to the development and maturation of the embryonic heart towards its four-chambered form, as is indicated by the fact that disturbed development of cardiac structures is often accompanied by a disturbed formation of the CCS. Electrophysiological studies have shown that selected conduction disturbances and cardiac arrhythmias do not take place randomly in the heart but rather at anatomical predilection sites.

Accessory atrioventricular myocardial pathways in mouse heart development: substrate for supraventricular tachycardias.

Atrioventricular reentry tachycardia (AVRT) requiring an accessory atrioventricular pathway (AP) is the most common type of arrhythmia in the perinatal period. The etiology of these arrhythmias is not fully understood as well as their capability to dissipate spontaneously in the first year of life. Temporary presence of APs during annulus fibrosus development might cause this specific type of arrhythmias.

Perinatal management and long-term cardiac outcome in fetal arrhythmia.

Background: cardiac arrhythmias are commonly observed in the fetus, however, may have major consequences for fetal development and post natal life.

Aims: to evaluate the perinatal management and cardiac outcome of fetuses with tachy- or bradyarrhythmia.

Study Design: perinatal management, outcome and long-term cardiac follow-up were evaluated retrospectively in consecutive fetuses with cardiac arrhythmias.

Podoplanin deficient mice show a RhoA-related hypoplasia of the sinus venosus myocardium including the sinoatrial node.

We investigated the role of podoplanin in development of the sinus venosus myocardium comprising the sinoatrial node, dorsal atrial wall, and primary atrial septum as well as the myocardium of the cardinal and pulmonary veins. We analyzed podoplanin wild-type and knockout mouse embryos between embryonic day 9.5-15.

Accessory atrioventricular myocardial connections in the developing human heart: relevance for perinatal supraventricular tachycardias.

Background: Fetal and neonatal atrioventricular (AV) reentrant tachycardias can be life-threatening but resolve in most cases during the first year of life. The transient presence of accessory AV myocardial connections during annulus fibrosus development may explain this phenomenon.

Methods And Results: A total of 45 human embryonic, fetal, and neonatal sectioned hearts (4 to 36 weeks of development) were studied immunohistochemically.

Epicardium-derived cells in development of annulus fibrosis and persistence of accessory pathways.

Background: The developmental mechanisms underlying the persistence of myocardial accessory atrioventricular pathways (APs) that bypass the annulus fibrosis are mainly unknown. In the present study, we investigated the role of epicardium-derived cells (EPDCs) in annulus fibrosis formation and the occurrence of APs.

Methods And Results: EPDC migration was mechanically inhibited by in ovo microsurgery in quail embryos.

Cardiac malformations and myocardial abnormalities in podoplanin knockout mouse embryos: Correlation with abnormal epicardial development.

Epicardium and epicardium-derived cells have been shown to be necessary for myocardial differentiation. To elucidate the function of podoplanin in epicardial development and myocardial differentiation, we analyzed podoplanin knockout mouse embryos between embryonic day (E) 9.5 and E15.

Nkx2.5-negative myocardium of the posterior heart field and its correlation with podoplanin expression in cells from the developing cardiac pacemaking and conduction system.

Recent advances in the study of cardiac development have shown the relevance of addition of myocardium to the primary myocardial heart tube. In wild-type mouse embryos (E9.5-15.

Targeted mutation reveals essential functions of the homeodomain transcription factor Shox2 in sinoatrial and pacemaking development.

Background: Identifying molecular pathways regulating the development of pacemaking and coordinated heartbeat is crucial for a comprehensive mechanistic understanding of arrhythmia-related diseases. Elucidation of these pathways has been complicated mainly by an insufficient definition of the developmental structures involved in these processes and the unavailability of animal models specifically targeting the relevant tissues. Here, we report on a highly restricted expression pattern of the homeodomain transcription factor Shox2 in the sinus venosus myocardium, including the sinoatrial nodal region and the venous valves.