MRCPCH 1: Essential Questions in Paediatrics - PasTest

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8CARDIOLOGY – ANSWERSas coarctation of the aorta and hypoplastic left heart syndrome, tend topresent with acidosis and weak pulses in the first few days of life.1.4 Persistent ductus arteriosus: D EThere is abnormal persistence of the ductus arteriosus beyond 1 monthafter the date the baby should have been born. Those children affected areusually asymptomatic and rarely develop heart failure. On auscultation, acontinuous ‘machinery’ or systolic murmur at the left infraclavicular area isheard. The murmur is initially systolic but, as the pulmonary vascularresistance falls, it becomes continuous in nature because there is acontinual run-off of blood from the aorta to the pulmonary artery (as thepressure in the aorta is greater than in the pulmonary artery throughoutthe cardiac cycle). Other clinical features include bounding pulses and widepulse pressure. If the duct is large, chest radiography can demonstratecardiomegaly and pulmonary plethora. Management is usually by closure inthe cardiac catheter laboratory with a coil or device when the infant is1 year of age. However, if the duct is large, surgical ligation can beundertaken when the infant is aged 1–3 months. The presence of a ductusarteriosus in a pre-term baby is not congenital heart disease, but thesechildren have a higher incidence of persistent ductus arteriosus.1.5 Transposition of the great arteries: A B D EIn this condition, the aorta usually arises anteriorly from the right ventricleand the pulmonary artery arises posteriorly from the left ventricle.Deoxygenated blood is therefore returned to the body, while oxygenatedblood goes back to the lungs. If these two parallel circuits were completelyseparate, the condition would be incompatible with life. These childrenhave high pulmonary blood flow and are very cyanosed, unless there is anatrial septal defect, a ductus arteriosus, or a ventricular septal defect,allowing mixing of the two circulations. Babies become cyanosed when theduct closes, thus reducing the mixing between the systemic and pulmonarycirculations, but there is usually no murmur. Transposition of the greatarteries may be associated with ventricular septal defect, coarctation of theaorta or pulmonary stenosis. Management is to resuscitate the baby,followed by a balloon atrial septostomy (preferably via the umbilical vein)at a cardiac centre in about 20% of cases. In the sick, cyanosed newbornbaby, a continuous intravenous infusion of prostaglandin E 1or E 2should becommenced to keep the duct open. Definitive repair in the form of thearterial switch operation will usually be undertaken before the baby is2 weeks of age.
CARDIOLOGY – ANSWERS 91.6 Eisenmenger syndrome: A B CEisenmenger syndrome was first described in 1897, and occurs secondaryto a large left-to-right shunt (usually a ventricular septal defect oratrioventricular septal defect) in which the pulmonary hypertension leadsto pulmonary vascular disease (increased resistance over many years).Eventually, the flow through the defect is reversed (right-to-left) so thechild becomes blue, typically at 10–15 years of age. There is not usually asignificant heart murmur. Eventually, they develop right heart failure. TheECG shows right ventricular hypertrophy and strain pattern, with peakedP waves indicating right atrial hypertrophy. Management is largelysupportive, as surgical closure is not possible when there is a right-to-leftshunt. They may be commenced on sildenafil or an endothelin-receptorantagonist on the advice of a specialist in pulmonary hypertension.Best of Five Answers1.7 B: Tricuspid atresiaTricuspid atresia is the condition in which there is no tricuspid valve andusually the right ventricle is very small. There is right-to-left shunt at atriallevel, as the blood cannot pass into the right ventricle. Babies become verycyanosed when the ductus arteriosus closes if they are duct-dependent,and they usually have no heart murmur. Management options include aBlalock–Taussig shunt if the child is very blue, a pulmonary artery (PA) bandif they are in heart failure, a hemi-Fontan procedure after they reach 6months of age, and a Fontan procedure at 3–5 years of age. The ECG showsa superior axis, as the atrioventricular junction is located inferiorly, the Pwaves are large as a result of right atrial hypertension, and there is a smallright ventricle, reducing the forces visible on the ECG.1.8 A: Asplenia and a midline liverRight atrial isomerism is a multifactorial genetic defect. Right atrialisomerism is associated with asplenia, small-bowel malrotation, andcomplex heart disease with abnormalities of connection, in which thepulmonary veins always connect abnormally because there is nomorphological left atrium with which to connect. In left atrial isomerism,there is polysplenia, small-bowel malrotation (less common than in rightatrial isomerism), two left lungs and complex heart disease.
Page 2 and 3: ContentsContributorsIntroduction1.
Page 4 and 5: 2CARDIOLOGY - QUESTIONS1.5 The foll
Page 6 and 7: 4CARDIOLOGY - QUESTIONS1.12 A 2-yea
Page 8 and 9: 6CARDIOLOGY - QUESTIONS1.15 Theme:
Page 12 and 13: 10CARDIOLOGY - ANSWERS1.9 C: Alagil
Page 14: 12CARDIOLOGY - ANSWERS3. F: Blalock

MRCPCH 1: Essential Questions in Paediatrics - PasTest

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