BrHeartJ1 1983; 50: 182-9

Pulmonary hypertension in scimitar syndrome ininfancy

SHEILA G HAWORTH, URSULA SAUER, KONRAD BtTHLMEYERFrom the Department ofPaediatric Cardiology, Institute of Child Health, London; and Deutsches Herzzentrum,Munich, Germany

suMMARY Four infants with the scimitar syndrome presented with failure to thrive, cardiac failure,and pulmonary hypertension. In all cases systemic arteries arose from the upper abdominal aorta toperfuse the lower part of the right lung, and a large unobstructed anomalous pulmonary veindrained venous blood from almost the entire right lung to the inferior vena cava. An additional smallpulmonary vein joined the inferior vena cava or right atrium and in three of the four cases angiogra-phy showed intrapulmonary connections between the two anomalous veins. At necropsy, in all fourcases the right lung was hypoplastic. The bronchi were abnormal in size or number in three cases,but there was no sequestrated tissue. Microscopical examination showed normal peripheral airwayand alveolar development. The pulmonary arterial branching pattern was deficient in three patients.Postmortem arteriography, dissection, and microscopical studies showed that in areas of lung notperfused by branches of the right pulmonary artery the systemic arteries anastomosed withintrapulmonary arteries to distribute blood to a dilated capillary bed. In all tissue examined arterialmedial thickness was increased in both lungs while vein wall thickness was normal. For comparisona fifth patient, more typical of the syndrome, was included; this patient did not have pulmonaryhypertension and died from septicaemia at 2 years of age.

Symptomatic infants with pulmonary hypertension probably have the most severe form of thescimitar syndrome. It is recommended that sick infants should have a two stage correction, systemicarteries being ligated at the first procedure and the anomalous vein being reimplanted in the leftatrium at a second and later procedure, with closure of an atrial septal defect if present.

The scimitar syndrome consists of anomalous pulmo-nary venous drainage of the right lung into theinferior vena cava, hypoplasia of the right lung withdextroposition of the heart, hypoplasia or other mal-formations of the right pulmonary artery, and ananomalous systemic supply to the lower lobe of theright lung from the abdominal aorta or its mainbranches.' Abnormal lobation and bronchial abnor-malities are also described. The syndrome may besuggested by the scimitar-shaped shadow of theanomalous pulmonary vein along the right border ofthe heart on the chest x-ray film. Many patients haveno symptoms throughout childhood. Only about onethird of cases has been diagnosed in the paediatricage group, usually because of respiratory tract infec-tions.2 Pulmonary hypertension is unusual.

Presentation in infancy is rare. Mortensson andSGH is supported by the Brtish Heart Foundation.Accepted for publication 26 April 1983

Lundstrom3 described a baby who presented in car-diac failure at 9 days of age; the entire right lung wassupplied by arteries which arose from the descendingthoracic aorta. Park4 reported the condition at nec-ropsy in a 2Y2 month old infant. Kuiper-Oosterwaland Moulaert2 described two infants who presentedduring the first two months of life with dyspnoea,neither of whom was said to have had pulmonaryhypertension. By contrast, in 1976 Dupuis and hiscolleagues reported to the Association of EuropeanPaediatric Cardiologists that severe pulmonary hyper-tension was a constant feature in symptomatic infantswith the scimitar syndrome.

This presentation describes the clinical,haemodynamic, and angiographic findings and thestructural changes in the lungs of four infants whodied with the scimitar syndrome, all of whom hadpulmonary hypertension. For comparison, thefindings are also presented in an older child who died

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Table Clnical data

Case Age at Preai Age at cardiac PAP SAPILVP RPa Qp Qp:QsNo. p a cade ( dmnHg) (T,,,)2)

(msh) (mdi)1 1-5 Failure to thrive and 2 60/20 70/12 2.8 8.3 -

cardiac failure2 2.5 Faihire to thrive, 3 85/45 85/45 11i1 5.7 2.4

cardiac failure, cyanosis3 4 Failure to thrive, 4½ 73/26 75/6 12 3.4 1.5

4 3 Failureto thrive 3 80/37 74/37 7 5.2 2-45 10 Murmur 18 25/10 85/65 1-2 5 1-3

Abbreviations; LVP, left ventricular presu; PAP, pulmonary arterial pressure; Qp, pulmonary blood flow; Qp:Qs, pulmonary:systemicblood flow; Rpa, pulmonary arteriolar resistance.

at 2 years 4 months and who did not have pulmonaryhypertension.

Case reports

Four children were symptomatic during the first sixmonths of life (Table). All had failed to thrive, andtwo children presented in cardiac failure during thefirst three months. In the fifth child a murmur washeard at a routine emination at 10 months of age,but she remained well until she had meningitis anddeveloped septicaemia from which she died at the ageof 2 years and 4 months. In all five cases the QRS axison the electrocardiogram suggested malposition of theheart in that there were deep Q waves in leads I and IIand R waves of large amplitude in all the standardlimb leads. In cases 1 to 4 there were signs of rightventricular hypertrophy. In all five patients the chestradiograph showed a shift of the heart and medias-tinum to the right and an increase in pulmonary vas-cular markings in the left lung (Fig. 1). In addition, incase 2 there were slight malformations of the ribs onthe left side. In case 3 a scimitar shadow was seen, theright upper lobe appeared hypertranslucent and thelower lobe showed an increase in pulmonary vascularmarkings. In the other four cases the displacement ofthe heart to the right obscured the view of theanomalous pulmonary vein. In all four infants cardiaccatheterisation studies indicated pulmonary hyperten-sion, the systolic pulmonary and systemic arterialpressures being similar (Table). The pulmonaryarteriolar resistance was 2.8 units/M2 in case 1 andgreater than 7 units in the other three infants. In case5 the pulmonary arterial pressure was normal. Thecardiac catheterisation study also showed a small rightto left shunt at atrial level in cases 3 and 4. Case 3 hada small ventricular septal defect and case 4 a smallpersistent ductus arteriosus which could not bedetected by oximetry. Four patients (cases 2 to 5) hadeither bronchographic studies or a bronchoscopy orboth (see below).Three infants had an operation, one infant deterior-

Fig. 1 Chs radiograph ofcase 2, showingdispacementoftheheart and medtians to the right.

ated suddenly and died before operation could be per-formed and the older patient died of an intercurrentinfection. At operation none of the three infants had adefinitive right lower lobe. In cases 1 and 2 ligation ofa large anomalous pulmonary vein connected to theinferior vena cava produced massive intrapulmonaryhaemorrhage which necessitated a pneumonectomy.After operation both patients had episodes of cyanosisand bradycardia. Case 1 died five days and case 2 onemonth after operation. In case 2, two postoperativecardiac catheterisation studies showed a pulmonaryarterial pressure similar to the systemic arterial pres-sure, 75/35 mmHg and 76/55 mmHg, respectively.The infant continued to deteriorate and died with astaphylococcal pneumonia. In case 4, the lower part ofthe right lung was resected, the anomalous systemic

Scimitar syndrome in infancy 183

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Haworth, Sauer, Bilhlmeyer

Fig. 4 Pulmonary angiogram in case 2 showing anomalouspulmonauy vein._wmp9 ........~~~~~~. .-x.NiwR.9.....W.-k-.s

Fig. 2 Aortogram in case 2 showing systeic arterie perfusingthe lower part of the right lung.

arteries were ligated and the large anomalous pulmo-nary vein was reimplanted into the left atrium. At apostoperative cardiac catheterisation study the pul-monary arterial pressure was similar to the systemic

Fig. 3 Pulmonary angiogramn n case 2, shownng dtoruous left intrapulmonary arteries and smaaU rightintrapulmonary arteries.

arterial pressure, and the pulmonary venous returnfrom the right lung could not be visualised, suggest-ing stenosis of the reimplanted right pulmonary vein.The baby died two months after operation with asevere infection.

ANALYSIS OF ANGIOGRAPHIC STUDIES

Right lungIn all five cases, one to three large arteries arose fromthe descending aorta, below the diaphragm, to supply

Fig. 5 Injection into the anomalous punmoaty vein in case 2,showing intrapulmonary connections with a second pulmonaryvein which returns to the right atriun.

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Scimitar syndrome in infancythe lower part of the right lung (Fig. 2). The pulmo-nary arterial branching pattern was abnormal in threecases. The anterobasal segmental artery to the lowerlobe was absent in cases 1 and 2, and in case 4 theupper lobe pulmonary artery was absent. The rightpulmonary artery and its branches were smaller thannormal in cases 1 to 4 (Fig. 3). In these four cases thepulmonary venous return from all parts of the rightlung was totally or predominantly to a large vein, thescimitar vein, and thence to the inferior vena cava(Fig. 4). In cases 1 to 3 at least one small additionalvein returned to the right atrium and connectedwithin the lung with branches of the large anomalouspulmonary vein (Fig. 5).

In case 5, the pulmonary arteries were dilated. Thepulmonary venous blood from the middle and lowerlobes and from part of the upper lobe returned to ananomalous vein which joined the inferior vena cava(Fig. 6). In addition, much of the upper lobe venousblood drained to the left atrium and there were largeintrapulmonary connections between the veins drain-ing to the inferior vena cava and the left atrium.

Connections between systemic and pulmonaryarterial systems were not seen on angiography.

Left lungIn all five cases the pulmonary arterial branching pat-tern was normal and the venous blood drainedentirely to the left atrium. The pulmonary arterieswere dilated in all except case 3 and were tortuous incases 1, 2, and 3 (Fig. 3).

Fig. 6 Pulmoiaty angiogram in case S showing the la,ncanomalous puwnoy vein anastonosing within the lung with asecond pulmonary vein which drains to the kft atriun.

185BRONCHIAL ANATOMY IN RIGHT LUNGThe bronchi were normal in cases 3 and 5, as shownby bronchography in both and also by bronchoscopyin case 3 and postmortem dissection in case 5. In case2 the branching pattern was normal, but the rightmiddle and lower "lobe" bronchi were narrow onbronchoscopic examination. The branching patternwas abnormal in cases 1 and 4. In case 1 at necropsythe middle lobe bronchus could not be identified, theorigin of the upper lobe bronchus had a lumen diame-ter of 1 mm and its branches were extremely small andthe five lower lobe bronchi were also small. In case 4,at bronchography the upper lobe bronchus was notvisualised and the middle lobe bronchus was dis-torted. At necropsy, the upper lobe bronchus con-sisted of a blind stump and there was no identifiablemiddle lobe bronchus. In all five cases that part of theright lung supplied by systemic arteries communi-cated with the rest of the tracheobronchial systemsunlike a sequestrated segment.

NECROP1SY FINDINGSAll cases, except case 3, were examined at necropsy; allthe anomalous systemic arteries to the right lung arosefrom the descending aorta above the renal arteries andwere friable and branched as they approached thelung; in case 1 as many as eight branches entered thelower half of the right lung. In cases 1, 2, and 4 thesmall right lung consisted of a single lobe. In thesethree cases a large anomalous pulmonary veinreturned to the inferior vena cava. An additional smallvein returned to the right atrium near the junction ofthe inferior vena cava in cases 1 and 2, confirming theangiographic findings. In case 4, an additional veinjoined the inferior vena cava itself near its entrance tothe right atrium. In cases 1 and 4 there were manyadhesions between the lung and chest wall. In case 5,the right lung was divided normally into three lobes,but the upper lobe was small. An anomalous pulmo-nary vein from the lower lobe returned to the inferiorvena cava and another vein returned normally to theleft atrium. The right ventricle appeared hyper-trophied in all four cases. In case 4 the reimplantedanomalous right pulmonary vein was stenosed, with alumen diameter of 1 mm where it anastomosed withthe left atrium. Cases 1 and 5 had a patent foramenovale and case 4 had a secundum atrial septal defectmeasuring 1 cm in diameter. In cases 1, 4, and 5 theductus arteriosus was closed and in case 2 it waspatent, but the lumen diameter was less than 2 mm.In case 5 necropsy showed endocarditis, meningitis,enterocolitis, and bronchopneumonia.

INJECTION AND MICROSCOPICAL STUDIESThe right lung of case 1 and the left lung of case 2were injected with a barium sulphate gelatin mixture,

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Fig. 7 Postmortem areriogram of the right lung in case 1.Injection cannula is in the pulmonary artety supplying the loverpart of the right lung. pv 1, large anomalous publnary veindraining almost entire lung; pv2, smaler second vein returing toright atrium; ilpa, lower "lobe" pulmonary artery; sa, injectedsystemic arteries; ulpa, upper "lobe" pulmonary artery.

x-rayed, and dissected.56 Tissue from these lungs andfrom the resected and necropsy tissue of the otherthree cases was prepared for histological examination.Sections were stained with Miller's elastic stain coun-

terstained with van Gieson's stain and with haematox-ylin and eosin. Using both injected and uninjectedtissue, quantitative morphometric techniques were

used to analyse mean percentage pulmonary arterialmedial thickness with respect to arterial size and theexternal diameter of arteries accompanying the termi-nal bronchioli, respiratory bronchioli, and alveolarducts.5 6

Case 1: Right lungInjection of each of the systemic arteries opacified a

small volume of lung tissue and showed a backgroundhaze caused by filling of many small arteries. Thepulmonary arterial branching pattern was abnormal(Fig. 7). Dissection and arteriography showed thatthe anterior, basal, cardiac, and apical regions of thelower "lobe" were not supplied by pulmonary arteriesconnected to the right pulmonary artery, but by sys-

Haworth, Sauer, Buhlmeyer

temic arteries which entered the lung to connect withintrapulmonary arteries. Three microscopical serialreconstructions showed that the peripheral pulmo-nary arteries were normally related to the airways andbranched with them to supply the capillary bed in anormal manner. The right pulmonary arterybranched at the hilum. One branch supplied theupper part of the lung. The other branch was equival-ent to the posterobasal artery of the lower lobe in thenormal lung, and it also gave rise to a lateral branch.The large anomalous vein drained the whole of thelower part and much of the upper part of the lung. Asecond, smaller vein drained the upper part of thelung (Fig. 7). Injection of the pulmonary arteriesrapidly filled the two pulmonary veins with injectionmaterial and this is unusual ufing this technique.Examination of serial and random sections failed toshow any precapillary arteriovenous connections.Throughout the lung, however, the alveolar capil-laries were distended.

Case 2: Left lungPostmortem arteriography confirmed the presence ofa normal pulmonary arterial branching pattern seen atangiography. Measurement of the lumen diameter ofthe pre-acinar arteries showed that they were largerthan normal for age.

GENERAL MICROSCOPICAL FEATURES (CASES 1-5)

In all the lung tissue examined from both lungs thesmall pre- and intra-acinar arteries, airways, andalveoli had a normal appearance, except in the firstcase, where the upper part of the right lung showedthickened alveolar septa, peribronchiolar fibrosis, andorganised masses of cells within the alveoli, changesprobably secondary to the hypoplasia of the bronchussupplying this area. The small pre- and intra-acinararteries and veins were normally related to the air-ways. There were no findings to suggest dysplastic orsequestrated lung tissue. The arteries appearedabnormally thick walled.

Intimal proliferation was seen only in case 4 in thepart of the right lung perfused by systemic arteries,and occurred in only a few vessels and was mild. Veinwall thickness appeared normal in all cases.

QUANTITATIVE MORPHOLOGICAL STUDIES

Right lungUsing uninjected tissue, percentage arterial muscular-ity was significantly increased in the three infantsstudied, but not in case 5 (Fig. 8a). In all the fourcases examined tissue was analysed from the lowerpart of the lung supplied by anomalous systemicarteries. In cases 1 and 5 tissue from parts of the lung

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Scimitar syndrome in infancy40

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36

34

32

30

28

8) 26a)cZ4 240

22

V 208)E 18

< 1 4

200 300 400 500e O(

External diameter (pm) External diameter (pm)

Fig. 8 (a) Right lung: percentage arterial medial thickness related to exteral diameter (pm) showing a significant increase inmuscularity in cases 1, 3, and 4 as compared with the normal, and normal muscularity in case 5. (b) Left lung: percentage arterialmedial thickness related to external diameter (pm), showing a pronounced increase in muscularity in cases I and 3, while muscularity isnormal in case 5.

connected to pulmonary arteries was also analysedand the muscularity did not differ in parts of the lunghaving a different source of blood supply. The mean

external diameter of arteries accompanying the intra-acinar airways was normal in cases 1 and 4. Thearteries were small in case 3, being similar to the nor-

mal during the first day of life, and this case alsoshowed the greatest increase in pulmonary arterialmuscularity and the highest resistance in the group.

In case 5, the intra-acinar arteries were dilated in lungtissue connected to the pulmonary arteries and were

small in tissue connected to systemic arteries, beingsimilar to the normal during the first few months oflife.

Left lungUsing uninjected tissue, in the two infant cases

studied (cases 1 and 3) muscularity was significantlygreater than normal in arteries of all sizes (Fig. 8b). Incase 2 studies on injected tissue showed an increase inmuscularity only in arteries larger than 300 um indiameter, where percentage arterial medial thicknesswas 6% as compared with a normal value of 2%. In theolder case (case 5) muscularity was normal. In cases 1and 5, the mean external diameter of intra-acinararteries was normal for age. In case 3 the arteries inthe left lung, like those in the right, were small for

age. In case 2, the arteries were dilated with respect toage, by a factor of 3.

Discussion

The scimitar syndrome comprises a wide range ofabnormalities of the right lung in addition to theanomalous pulmonary venous connection to theinferior vena cava. In the present series the four chil-dren presenting in infancy showed most of the addi-tional features, namely hypoplasia of the right lungwith defective lobation and bronchial abnormalities, a

systemic arterial supply to the lower part of the rightlung and abnormalities of branching and size of theright pulmonary artery. The vascular rather than theairway manifestations of the syndrome dominated theclinical picture.The abnormal lobation of the lung, the partial

retention of a systemic arterial supply, and the persis-tent connection of a.pulmonary vein to the splanchnicvenous system suggests that lung development was

impaired at an early stage during fetal life. In thenormal fetus division of the lung buds into lobes isapparent at 20 to 30 days of gestation.7 At 50 days thelung ceases to be connected to segmental systemicarteries and is entirely and exclusively connected tothe central pulmonary arteries.8 The intrapulmonary

81).0C8)

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188

veins drain into the left atrium by the eleventh weekof gestation.9'0 In the present series, the normalappearance of the peripheral arteries, veins, and air-ways suggests that subsequently fetal developmentproceeded normally, particularly after the 16th weekof gestation, when pre-acinar arterial, venous, andairway branching is complete.The scimitar syndrome is so called because on the

chest radiograph the anomalous right pulmonary veinproduces a shadow likened to a Turkish sword alongthe right border of the heart.' Hypoplasia of the rightlung, however, causes a shift of the heart and medias-tinum to the right and may obscure the scimitarshadow, as occurred in four of the five cases in thepresent study. The diagnosis is most likely to be mis-sed before cardiac catheterisation in young children inwhom the scimitar shadow is obscured and the signsof a large left to right shunt suggest an intracardiacabnormality. At cardiac catheterisation the systemicarterial supply to the lower part of the right lungmight suggest a sequestrated segment unless the pul-monary venous drainage is demonstrated.One child in the series (case 5) had the typical clini-

cal picture of the scimitar syndrome in that she had nosymptoms in early childhood, the diagnosis was madeincidentally, there was no clinical or pathological evi-dence of significant pulmonary hypertension, and theleft to right shunt was small, 1 2: 1. By contrast, thefour children presenting in infancy had severe pulmo-nary hypertension, an unusual finding in patients withthe scimitar syndrome. In 1977, Honey"I collectedfrom the published material eight cases in which thepulmonary arterial pressure exceeded 50 mmHg andadded one of his own. In four patients the presence ofpulmonary hypertension was explained by associatedanomalies such as a large ductus arteriosus or anatrioventricular canal or by obstruction of theanomalous vein. In four cases, however, there was noapparent explanation. Three of the patients wereadult, but one patient presented at 7 months of ageand died at 2½ years with severe pulmonary vascularobstructive disease including plexiform lesions in theleft lung. In the present study also, associatedintracardiac abnormalities, a secundum atrial septaldefect in one case, and a small ventricular septaldefect in another, are unlikely to have influenced thedevelopment of pulmonary hypertension. In addition,obstruction of the anomalous veins was not seen

angiographically or at necropsy, and on microscopypulmonary vein wall structure was normal.

In our study the young age of the patients withsymptoms suggests that pulmonary hypertensionmight have been caused by failure of the pulmonarycirculation to adapt normally to extrauterine life in thepresence of a large pulmonary blood flow. In all fourinfant cases pulmonary arterial tni6Qliilty was

Haworth, Sauer, Buhlmeyer

increased in all parts of both lungs examined histolog-ically, and in three, muscularity was significantlyincreased in arteries less than 300 ,um in diameter. Itis these intra-acinar arteries which in the normal lungshow the most rapid reduction in relative wall thick-ness after birth and which remain thick walled inexperimental animals in which the pulmonary bloodflow is doubled from birth.12 It is unclear, however,why the lung should fail to adapt normally in somebut not in other cases of the scimitar syndrome. Thepresence of an interatrial shunt alone does not usuallyprevent adaptation from occurring normally, as intotal anomalous pulmonary venous return withoutobstruction. It can be argued that interatrial shuntingafter birth is influenced by ventricular compliance anddoes not reach a maximum until the lungs have atleast started to adapt normally to extrauterine life.'3The explanation of the presence of pulmonary hyper-tension in a minority of symptomatic infants with thescimitar syndrome could be that they have a largersystemic arterial flow to the lung, and a larger left toright shunt through a smaller total lung volume thando asymptomatic infants.

Operation for correction of anomalous pulmonaryvenous connection is usually recommended only whenthe left to right shunt exceeds 5OO/o.II The four infantsin the present series were ill because of the magnitudeof the shunt. Two children had a right pneumonec-tomy and a third had a resection of part of the lowerlobe supplied by systemic arteries and reimplantationof the anomalous vein into the left atrium. Though allthese children withstood the operation, none ulti-mately survived. In the scimitar syndrome resectionof lung tissue is usually carried out only in olderpatients in whom the affected part of the lung ischronically infected. In the small number of adultswith a large left to right shunt blood is redirec ed fromthe right to the left atrium by detaching the inomal-ous vein from the inferior vena cava and reimplantingit into the left atrium."I

In young symptomatic children with the scimitarsyndrome and a significant systemic arterial supply to ahypoplastic lung the abnormality is probably best cor-rected in two stages. At a first procedure the anomal-ous systemic arteries are ligated and at a second opera-tion the large anomalous vein can be reimplanted intothe left atrium with closure of an atrial septal defect ifpresent. In adults with the scimitar syndrome anassociated atrial septal defect is thought to be impor-tant in the pathogenesis ofpulmonary hypertension."ISince the part of the lung supplied by systemicarteries is also supplied by normal bronchial arteriesthe-jnpg should not infarct provided that the bron-chial arteries are not damaged during the dissection.An enlarged bronchial arterial supply will replace thesystemic arterial supply in the lower part of the right

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Scimitar syndrome in infany

lung. Though this lung tissue will be functionlessunder normal conditions, it is advisable not to resecttissue in a hypoplastic lung with abnormal lobationand poorly defined planes of cleavage.

References

1 Neil CA, Ferencz C, Sabiston DC, Sheldon H. Thefamilial occurrence of hypoplastic right lung with sys-temic arterial supply and venous drainage "scimitar syn-drome". Bulletin oftheJohns Hopkins Hospital 1960; 107:1-20.

2 Kuiper-Oosterwal, Moulaert A. The scimitar syndromein infancy and childhood. EurJ Cardiol 1973; 1: 55-61.

3 Mortensson W, Ltndstrom NR. Broncho-pulmonaryvascular malformation syndrome causing left heart fail-ure during infancy. Acta Radiol [Diagn] (Stockh) 1971;11: 449-58.

4 Park EA. Defective development of the right lung, dueto anomalous development of the right pulmonary arteryand vein, accompanied by dislocation of the heartsimulating dextrocardia. Proceedings of the New YorkPathological Society 1912; 12: 88-93.

5 Davies G, Reid L. Growth of the alveoli and pulmonaryarteries in childhood. Thorax 1970; 25: 669-81.

6 Hislop A, Reid L. New pathological findings inemphysema of childhood. I Polyalveolar lobe withemphysema. Thorax 1970; 25: 682-90.

7 O'Rahilly R, Boyden EA. The timing and sequence of

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events in the development of the human respiratory sys-tem during the embryonic period proper. Zeitschtift frAnatomie und Enwicklungsgeschichte 1973; 141: 237-50.

8 Congdon ED. Transformation of the aortic arch systemduring the development of the human embryo. Contribu-tions to Embryology (Publications of the Camnegie Instite)1922; 14: 47-110.

9 Van Praagh R, Corsini I. Cor triatriatum: pathologicanatomy and a consideration of morphogenesis based on13 postmortem cases and a study of normal developmentof the pulmonary vein and atrial septum in 83 humanembryos. Am HeartJ 1979; 78: 379405.

10 Anderson RH, Ashley GT. Growth and development ofthe cardiovascular system-anatomical development. In:Davis JA, Dobbing J, eds. Scientific foundations ofpaediatrics. London: Heinemann, 1974: 165-98.

11 Honey M. Anomalous pulmonary venous drainage ofright lung to inferior vena cava (scimitar syndrome): clin-ical spectrum in older patients and role of surgery. Q JMed 1977; 46: 463-83.

12 Haworth SG, de Leval M, Macartney FJ. Hypoperfusionand hyperperfusion in the immature lung.J Thorac Car-diovasc Surg 1981; 82: 281-92.

13 Rudolph AM. Congenital diseases of the heart. Chicago:Year Book Medical Publishers, 1974.

Requests for reprints to Dr S G Haworth, The Hospi-tal for Sick Children, Great Ormond Street, LondonWC1N 3JH.

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syndrome in infancy.Pulmonary hypertension in scimitar

S G Haworth, U Sauer and K Bühlmeyer

doi: 10.1136/hrt.50.2.1821983 50: 182-189 Br Heart J 

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