総動脈幹遺残症

An 18-year-old woman with truncus arteriosus presented with septic shock due to methicillin-sensitive Staphylococcus aureus infective endocarditis of her right-ventricle-to-pulmonary-artery (RV-PA) conduit requiring urgent conduit replacement and a prolonged admission complicated by acute respiratory distress syndrome and significant deconditioning. She had three separate presentations to external medical practitioners in the week preceding admission. This case underscores the complexity of managing infective endocarditis in patients with congenital heart disease and the importance of early referral to a specialist congenital centre.

Tetralogy of Fallot (TOF) is the commonest cyanotic congenital heart disease, arising from antero-cephalad deviation of the outlet septum during outflow tract (OFT) morphogenesis, producing a ventricular septal defect, overriding aorta, pulmonary stenosis, and right ventricular hypertrophy. Despite advances in surgical correction, the developmental origins of TOF remain incompletely understood, and the genetic architecture of the majority of non-syndromic cases is yet to be resolved. Experimental models have been central to progress in this field, yet each model may capture only part of the disease. This review evaluates animal and genetic models of TOF across species, discussed in order of increasing cardiovascular similarity to humans. Zebrafish and Xenopus enable rapid in vivo interrogation of candidate genes and conserved developmental pathways, despite fundamental differences in cardiac anatomy. Avian models have been instrumental in defining the contributions of the second heart field and cardiac neural crest cells to OFT elongation and septation. Mouse models, with their four-chambered heart and amenability to precise genetic modification, have provided the most detailed mechanistic insights, and we examine key models across the multiple signalling pathways in depth. A recurring finding is that individual models reproduce discrete components of the TOF tetrad rather than its complete set of defects, frequently producing double outlet right ventricle or persistent truncus arteriosus rather than classical TOF. No single model fully recapitulates all four features with complete penetrance. Continued integration of human genomic data with targeted experimental perturbations will be essential for closing this gap.

A neonate with common arterial trunk presented with severe cyanosis rather than pulmonary overcirculation. Echocardiography, cardiac CT, catheterisation, and surgery showed a pulmonary trunk arising from a truncal valvar sinus, with systolic obstruction by a dysplastic truncal cusp. Staged palliation restored antegrade pulmonary flow, allowed pulmonary arterial growth, and enabled successful complete repair.

BACKGROUND: Aortic atresia is typically associated with a hypoplastic left ventricle and mitral valve. Rarely, the left ventricle is normal-sized with a concomitant unrestrictive ventricular septal defect (VSD), which can resemble truncus arteriosus when the ascending aorta is rudimentary. CASE: A term infant with an antenatal diagnosis of truncus arteriosus was delivered uneventfully. Initial echocardiography revealed balanced ventricles, an unrestrictive VSD, and a single outlet with a dominant arterial trunk giving rise to both pulmonary arteries and continuing to the descending aorta but with an unusual craniobrachial branching pattern. Computed tomography (CT) additionally showed narrowing of this arterial trunk proximal to the descending aorta. The infant deteriorated rapidly despite intravenous prostaglandin and dopamine infusion. Emergency surgery was performed to establish an unobstructed aortic arch. Postoperatively, the infant required extracorporeal membrane oxygenation and developed multiorgan failure. Given the poor prognosis, comfort care was adopted and the infant died. Retrospective review of the echocardiography and CT angiogram suggested aortic atresia with a rudimentary ascending aorta and severe coarctation. The presumed arterial trunk was in fact the dilated pulmonary artery connected to the descending aorta through the ductus arteriosus. CONCLUSIONS: Aortic atresia with an unrestrictive VSD and a normal-sized left ventricle can mimic truncus arteriosus. Timely differentiation is pivotal to improving outcomes.