MRCPCH 1: Essential Questions in Paediatrics - PasTest

CARDIOLOGY – ANSWERS 7MT–F Answers1.1 Muscular ventricular septal defects (VSDs): DVentricular septal defects are the most common form of congenital heartdisease, comprising 30% of the total number of cases. Muscular VSDs occurin the muscular part of the ventricular septum. Subacute bacterialendocarditis (SBE) prophylaxis is no longer indicated, now only beingrequired in rare and specific cases. The pulmonary resistance is high atbirth, and hence there is little shunt between the two ventricles andtherefore no audible murmur in the first 24 hours. Only 25% of VSDsrequire cardiac surgery, and this is usually performed when the child is 3–5months of age. Very few patients have interventional catheter closure,usually for smaller defects and at a later age. The conduction tissue islocated inferiorly in a perimembranous septal defect, which means thatsurgeons need to avoid that area when suturing a patch in place to closethe defect. If the VSD is large, patients present with symptoms of heartfailure after the first week of life and at that age have a right ventricularheave, a soft systolic murmur accompanied by an apical mid-diastolicmurmur, and a loud pulmonary second heart sound on examination.1.2 Scimitar syndrome: B DScimitar syndrome is a form of anomalous pulmonary venous drainage inwhich the veins from the lower right lung drain into the inferior vena cava.The right lung itself is hypoplastic, and there is an associated dextrocardiadue to the heart moving over to the right side of the chest, but withnormal situs. Situs is the orientation of the organs, situs solitus beingnormal, and situs inversus being mirror image. The arterial supply to thelung is from branches of the descending aorta. The right upper lobepulmonary vein draining into the inferior vena cava may be seen as avertical line on a chest X-ray and is known as the ‘scimitar sign’. There maybe an atrial septal defect, and children can suffer with recurrent chestinfections, which may require right lower lobectomy.1.3 Congenital heart disease on the first day of life: D EBabies presenting with left-to-right shunt will have no murmur or symptomson the first day of life, because the pulmonary vascular resistance has yet tofall. Similarly, any common mixing disease, such as atrioventricular septaldefect, can present with severe cyanosis on the first day of life, with highpulmonary vascular resistance, before breathlessness and heart failuredevelop at 1 week of age or more. All the obstructed left heart lesions, such