Book - Congenital Cardiac Disease 10

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Abbott ME. Congenital Cardiac Disease (1915) Osler & Mccrae's Modern Medicine 6, 2nd Edition.

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Pages where the terms "Historic Textbook" and "Historic Embryology" appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms and interpretations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)
1915 Congenital Cardiac: Congenital Cardiac Disease | Heart Development | Literature | Etiology | Cyanosis | Classification | Pericardium | Heart Displacement | Whole Heart | Anomalous Septa | Interauricular Septum | Interventricular Septum | Absence of Cardiac Septa | Aortic Septum | Pulmonary Stenosis and Atresia | Pulmonary Artery Dilatation | Aortic Stenosis or Atresia | Primary Patency and Ductus Arteriosus | Aorta Coarctation | Aorta Hypoplasia | Diagnosis Prognosis and Treatment | Figures | Embryology History | Historic Disclaimer

Pulmonary Stenosis and Atresia

Pulmonary stenosis is the form of cardiac defect most familiar to the practitioner. It is of much clinical importance on account of its comparative frequency, the relatively long duration of life, and the prominence of the cyanosis nearly always associated. To the student also it is a subject of the highest interest, for in its symptomatology and pathogenesis are focused the most difficult problems of congenital cardiac disease.


Owing to the wide variations in the conditions presented and the differing aspects from which the subject must be approached, a classification of the different forms is as difiicult as it is necessary. Rauchfuss points out that the simple anatomical findings furnish the best guide to a useful grouping. Thus, the degree of narroicirig_is important, and a simple stenosis is to be distinguished from a complete atresia; from the stand-point of pathogenesis, the seat and character of the stenosis are criteria of much value; and thirdly, the presence or absence of defects of the mterventricidar seiDtum provides a dividing line of the greatest importance. This last is important etiologically as indicating the stage of embryonic or fetal life at which the stenosis took place, and clinically in that the duration of life and symptomatology differ somewhat in the two groups.


Statistics

Pulmonary stenosis is probably the commonest of all oarc r anomalies. The cases are scalfer'eJ'soTreerv'- through the literature that an exact statistical statement is impossible. Vierordt estimated at least 300 in 1898, and placed coarctation of the aorta next in frequency with 130 cases. Among 181 anomalies of the heart which he analyzed, Peacock found 119 of pulmonary defect. In 1906 Keith^ examined 185 specimens of cardiac malformations in the hospital museums of London, and found that in 135, or 70 per cent., there was an anomalous condition of the pulmonary tract, the deformity being in the conus of the right ventricle in 133 cases and in the pulmonary valve in 22. In his later communication,^ among 272 malformed hearts examined in the various London Museums, Keith found 141 in which the defect was due to an imperfect transformation of the bulbus cordis of the embryo. Of these 141, in 19, there was incomplete fusion of the infundibulum with the body of the right ventricle (conus a separate chamber) ; in 44, partial arrest in development of the infundibulum ; in 37, complete arrest of the infundibulum; in 23 fusion of semilunar valves; in 7, partial or complete absence of the body of the right ^'entricle with development of the infundibulum; in 4 subaortic stenosis; and in 7, congenital aortic stenosis.

Among the cases of anomalies analyzed here, there are 150 of congenital pulmonary disease. The proportion of stenosis to atresia in recorded cases analyzed is as follows:

Number Stenosis. Atresia. analyzed.

Kussmaul 64 26 90

Rauchfuss 81 33 114

Peacock 90 29 119

Vierordt 83 24 107

Theremin 20 10 30

This series .116 34 150

The relatively high percentage of atresia in Theremin's cases is explained b}" the fact that his material was entirely among infants, in whom the mortality from atresia is high.


The condition of the fetal passages was the subject of statistical study by Meyer, Kussmaul, Taruffi, and other authors, of whose work a full review is given by Vierordt. A defect of the interventricular septum exists in the great majority. 'THe number of cases with closed septum is relatively larger in atresia than in stenosis; thus Rauchfuss finds among 192 cases, 171 in which the interventricular septum is defective and 21 in which it is closed. Of these 21, 10 are cases of atresia and 11 of stenosis. Among Vierordt's 83 cases of stenosis are 71 with defective and 12 with closed interventricular septum; among his 24 of atresia, in 14 the septum was defective and in 10 it w^as closed. When the interventricular septum is entire, the foramen ovale is usually widely patent, but it also may in rare cases be closed.


1 Festschrift, Quater centenary Aberdeen University, July, 1906.

2 Hunterian Lectures, Lancet, 1909, ii, 359, 433, 519.


Among the 116 cases of stenosis analyzed here the interventricular septum was defective in 95, and entire in 21 cases. In 12 of these 21 the foramen ovale was patent, but in 9 the auricular septum was also closed, and no communication existed between the two sides of the heart. Among the 34 cases of atresia the interventricular septum was defective in 26 and entire in 8 cases. Of these 8, in one the foramen ovale was also closed but there was a large patent ductus. The ductus arteriosus is nearly always patent in atresia but is usually closed in jtenosis. Among the 82 cases of pulmonary stenosis classed as the primary lesion in the chart, the ductus was patent in only 11; of the 24 cases of atresia, it was patent in 15 cases. The condition of the cardiac septa and ductus in these cases was as follows:

Stenosis. Atresia.

Number Number with Number Number with analyzed. patent D. A. analyzed, patent D. A.

F. 0. and V. S. closed ... 7 1 1

F. O. patent, V. S. closed . . 11 1 5 4

F. O. closed, defect V. S. ... 40 5 7 3

F. O. patent, defect V. S. ... 24 5 11 7

Total 82 11 24 15

Rechtslage of the aorta is present in the majority of cases with septal defect, and is especially frequent in atresia. Among the 64 cases of pulmonary stenosis with septal defect, classified in the chart as the primary lesion, it was present in 39 cases, in 29 of which the aorta arose from both ventricles above the defect, and in 10 chiefly or entirely from the right ventricle. Among the 18 cases of atresia with septal defect the aorta arose from both ventricles above the defect in 5, entirely from the right ventricle in 10.

Pathology

Pulmonary Stenosis. - The narrowing may involve the whole pulmonary tract, or be localized to the valve, artery, or conus.

Two distinct types may be recognized:

1. In a few cases the stenosis is valvular in character and is produced by a thickening, shortening, or fusion of the pulmonary cusps. A thick diaphragm with three raphe of fusion on its arterial surface is usually formed, which protrudes into the pulmonary artery in a funnel-shaped way and is perforated by a circular or triangular opening of varying size. The pulmonary artery is frequently dilated above, may be normal, or somewhat thin-walled. The conus below the valve shares in the hypertrophy of the right ventricle, but is otherwise normal; the interventricular septum is usually closed. There is every evidence to show that the stenosis has originated in an inflammatory process, in later fetal life after the heart has been fully formed. ^'


2. In the second and larger group, the cusps may or may not be thickened or fused, but the stenosis is due to a rudimentary condition, hypoplasia, or deformity of some part of the pulmonary tract. In these cases a defect of the interventricular septum is usually associated

"^and a deviation to the right of the aorta, so that this arises from both ventricles above the defect, or chiefly from the right ventricle, communicating with the left through the defect. Such forms, which suggest a 'developmental origin, make up the great majority of cases of pulmonary stenosis, and the combination of these three conditions, pulmonary stenosis, defect of the septum at the base, and rechtslage of the aorta, is probably the commonest of all cardiac anomalies.


In the majority of cases - in Keith's estimate 90 per cent. - the conns of the right ventricle is involved in the deformity. Two distinct types of conus stenosis may be distinguished. The whole infundibulum may be more or less constricted, its musculature thickened, and th^ endocardium opaque. In a case of this kind, reported by Cautley,^ the pulmonary cusps were delicate and healthy above the stenosis, but both they and the artery were very small. Usually the valves are thickened, fused, or rudimentary, and they are often bicuspid. Sometimes a thin diaphragm with delicate raphe showing no sign of inflammatory change, is stretched across the pulmonary orifice, suggesting an incomplete division of the endocardial cushions. In these cases a defect of the septiun is almost invariably present.


A second group of conus deformities is that in which a cavity, described by some of the older pathologists as a third ventricle, is cut off from the sinus of the right ventricle by a definite septum perforated by a small opening. There are 19 in this series, including one case of atresia. Keith describes and figures an illustration of this anomaly. The infundibulum is enormously dilated and communicates with the sinus by a small opening with thickened fibrous borders. The pulmonary cusps are large and competent, the artery dilated above, and there is a small defect of the interventricular septum. Another variation of this form of conus deformity is figured by Andrewes.^ The conus is atrophied and is represented by a small cavity with thick muscular walls. It communicates with the sinus of the ventricle by an opening admitting a crow-quill one-quarter inch below the pulmonary cusps, which are small, bicuspid, and not thickened.


1 Hypertrophy and dilatation of the right ventricle and auricle are constant in pulmonary 'stenosis, and in the cases associated with defect of the septum at the base and rechtslage of the aorta. In these the hypertrophy is sometimes most marked in the wall of the sinus of the ventricle, indicating that it had been produced by the force needed to send the blood into the aorta through the defect, rather than by the obstruction in the pulmonary artery. The aorta is usually thick walled and of large caliber. In the developmental cases the pulmonary artery is usually narrow and thin-walled, resembling a vein in structure. When the stenosis is confined to the valve, the artery may be dilated.

Pulmonary Atresia

All that has been said of the seat and character of the deformity in pulmonary stenosis applies equally to a complete atresia. In a small series of cases the point of obliteration is at the valve, the artery dilated above, the foramen ovale widely open, and the septum entire. In Weiss'^ case the seat of atresia was in the conus, which admitted only a pinhead or a fine straw, and was lined by thickened endocardium; just above this were two fairly large pulmonary cusps, and the artery itself was comparatively large. There was a small patent foramen ovale, a large defect of the septum at the base, and a large thick-walled aorta arose frora the right ventricle above the defect.


1 Edin. Med. Jour., 1902, xii, 257. 2 Trans. Path. Soc, 1865, xvii, 45.

s Brit. Med. Jour., 1877, ii, 378.


The pulmonary artery may be obliterated for some distance above the valve, forming a fibrous cord, which may emerge suddenly from the fleshy outer wall of the ventricle and give no sign of its origin from within, or it may be patent throughout, diminishing toward the orifice in a funnelshaped way. In such cases the cusps may be seen thickened and fused with each other at the bottom of the cul-de-sac formed by the artery, or they may form a triradiate elevation of three fleshy cushions; or no trace of them may remain. The aorta is usually very large. When a defect in the septum is present it rides over it, or in many cases arises entirely from the right ventricle.


Fig. 36 Heart and lungs of an infant, cyanotic from birth, showing (A) atresia of the pulmonary artery; B, patent ductus arteriosus suppljdng lungs; C, defect of interventricular septum at pars membranacea, guarded by (D) an anomalous valve with false chordse tendinese; E, tricuspid orifice; F, left pulmonary artery; G, right pulmonary artery; H, cord passing through the septal defect; LA, left auricle. (From a specimen in the McGill Pathological Museum, presented by Sir Wilham Osier.)


The foramen ovale is frequently widely patent. It may be the only means of communication between the two sides of the heart, the interventricular septum remaining entire. Such cases are less frequent, and the condition is more serious than that associated with septal defect.


The alterations in the cavities of the heart vary with the condition of the interventricular septum. When this is entire the left ventricle is greatly hypertrophied and dilated, and both auricles share in the enlargement, while the right ventricle undergoes a true concentric hypertrophy, its wall becoming greatly thickened and its cavity aplastic and lined with opaque thickened endocardium, or in some instances completely obliterated. When a defect of the septum exists, the right ventricle is greatly hypertrophied and is dilated as well, and the right auricle is correspondingly enlarged, the left chambers remaining relatively small. When the aorta rides over the defect in the septum, the left ventricle may share in the hypertrophy.

The Pulmonary Circulation

When the pulmonary artery is obliterated the blood supply usually reaches the lungs through the widely patent ductus, but this is sometimes closed or absent. Meckel first suggested that in these cases the dilated bronchial arteries might perform this function, and this is usually the case. The lungs were supplied from the left subclavian in Chambers' case, from a dilated ductus arising from the left subclavian in Ramsbotham's. In a case reported by Voss two large bronchial arteries passed into each lung, and were accompanied by an anomalous branch from each coronary. In Koller-Aeby's case the ductus was absent, and three large vessels, equalling the carotid in size, arose from the upper thoracic aorta at the site of origin of the bronchial arteries. The first turned to the right lung, following the bronchi ; the others were given off as a common trunk, which divided into a larger branch going to the right and a smaller to the left lung.

Pathogenesis

Two problems are presented. (1) Is the stenosis of inflammatory or of developmental origin? (2) What is the relation of the septal defect so often associated?


It must be recognized that a small group of cases occurs in which the stenosis is strictly limited to the valves and no septal defect is associated and which present appearances identical with those produced by the chronic valvular disease of postnatal life. Such cases must be supposed to be the result of an endocarditis in later fetal life.


In the large majority of cases a defect of the interventricular septum is associated, indicating that if the stenosis be due to an endocarditis, this must have occurred before the development of the heart was complete at the end of the second month of gestation. It is upon these cases that the discussion really turns. It is evident that if endocarditis can take place during the later stages of gestation, it may occur earlier as well. On the other hand, there are many cases in which the presence of associated defects and the absence of inflammatory action show positively that arrest of development has been the cause. The view is now generally held that in the past far too great weight has been laid upon the part which inflammatory processes take in the etiology of the many forms of pulmonary stenosis which date back to early embryonic life, before the development of the heart was completed. The theory of fetal endocarditis as a cause must now be considered to be of but limited application. The fault lies undoubtedly in most cases in a primary arrest of development.


Reference has been made to the explanation communicated by Keith,, which is now generally accepted, that in the majority of cases the stenosis j is primary in the conus, and is the result of an arrest of development' at a stage when there existed in the heart a fourth primitive chamber, the bulbus cordis. In accordance with the researches of Greil, he describes three changes as taking place in the evolution of the mammalian from the primitive heart of the fish and reptilia: (1) The division of the primitive auricle and ventricle; (2) the submerging of the sinus venosus in the musculature of the right auricle; and (3) the separation of the bulbus cordis from the left ventricle and aorta, and its complete incorporation in the right ventricle as the infundibulum of that chamber. This last change takes place by an upgrowth of the ventricular musculature around the cavity of the bulbus, the musculature of the latter being replaced by that of the ventricle, in the same way as the musculature of the auricle replaces a great part of that of the sinus venosus. The author considers that "the submergence of the bulbus constitutes a critical phase in the developmental metamorphosis of the heart, and it is during this time that malformations are apt to occur."


Four different types of conus stenosis are distinguished by him, of which the first is that well-differentiated form in which the conus forms a separate chamber, being separated from the sinus by a muscular partition. Peacock, in describing a similar case, compared it to the threeventricled heart of the curtle, and considered that it represented an arrest of development. Keith explains the condition as being simply an arrest of development in which the infundibulum and body of the right ventricle have developed to a normal extent, while a constriction has remained between them, representing the Dentricular origin of the bulbus or a persistence of the lower bulbar orifice. The other forms of conus stenosis, in which there is a constriction more or less complete of the whole infundibulum, he explains as an arrest of development of the bulbus as a whole, its musculature failing to become submerged in that of the right ventricle proper.

Associated Anomalies

Grave cardiac defects are frequently associated, especially in pulmonary atresia, and constitute another argument in favor of a developmental origin. In Ettlinger's case there was a large defect in the interauricular septum above, with multiple defects of the interventricular septum, and the pulmonary veins opened into the right auricle. In Habershon's there was false dextrocardia, tricuspid stenosis^ defect of the interventricular septum, and horseshoe kidney.


A fact of much importance is the presence of associated anomalies in cases of atresia with closed ventricular septum, which might reasonably be considered to be of inflammatory origin. It seems probable that the primary condition here was a narrowing of the conus or orifice in an arrest of development, and that the obliteration was produced by an endocarditis supervening in later fetal life.

Symptoms

The majority of cases of pulmonary stenosis and atresia present the classical picture of congenital cyanosis in all its details. So frequent is the association between the two conditions, that morbus cceruleus and pulmonary stenosis have been considered almost synonymous terms. The clinical aspects vary to a certain extent with the presence or absence of defects of the interventricular septum, and with the degree of deformity. In stenosis with closed septum cyanosis is usually slighter and of later incidence, and the duration of life much longer. The most typical instances of congenital cyanosis with bluish discoloration of the skin, becoming pronounced on exertion, clubbing of the fingers, dysnpoea, and cyanotic attacks are seen in the many cases in which pulmonary stenosis is combined with defect of the septum and rechtslage of the aorta. Pulmonary atresia differs from a simple stenosis in the more extreme degree of the cyanosis. These are the cases of true morbus ceruleiis, in which a constant deep blue, or even purple, discoloration exists, increasing to black on violent exertion. Here the opposite condition in relation to septal defects is seen. When the septum is closed the cyanosis is more extreme and the duration of life correspondingly shorter. Pulmonary stenosis with defect of the septum in which no cyanosis is present is exceedingly rare, but a few cases are on record.

Physical Signs in Pulmonary Stenosis

These are generally distinctive, but may be obscured by those of the septal defect so often associated. In typical cases, enlargement of cardiac dulness to the right and above, precordial bulging, epigastric and precordial pulsation indicate an enlargement of the right heart. Sometimes the cardiac impulse may be so violent that the head and neck share in the vibration of the chest. A thrill, localized to the second and third left spaces, or diffuse over the precordium, is fairly frequent. Its presence seems to depend somewhat upon the condition of the septa. Rolleston,^ in reporting a case of stenosis with rechtslage, in which there was no precordial thrill, explains this by the presence of a large defect of the septum, through which the blood current passed with ease into the aorta. He says that the evidence in recorded cases is contradictory upon this point, and suggests a statistical study of it. A thrill was present in 17 of the 82 "primary" cases analyzed. In these the condition of the fetal passages was as follows:

Cardiac septa. Number analyzed. Number with thrill.

F. O. and V. S. closed 7 " 3

F. O. patent and V. S. closed .... 11 4

F. O. patent, defect V. S 24 7

F. 0. closed, defect V. S 40 3

That is to say, in more than a third of the cases with closed ventricular septum a thrill was present, as also in 7 of the 24 in which both foramen ovale and ventricular septum were opon. But in the 40 cases with closed foramen ovale and with defect of the septum a thrill was absent in all but 3; in one of which there was a large patent duct, which was apparently the cause.


These figures are puzzling at first, but interesting on reflection, and are large enough to be of value as facts. The inference is that a thrill is frequently present when the interventricular septum is entire, and also when a defect of that septum coexists with a widely patent foramen ovale; when the interauricular septum is closed and the interventricular open a thrill is rare, and when it does occur may perhaps be ascribed to the associated septal defect. Further statistics are needed.


The pulmonary second sound is weak or absent in a certain proportion of cases. Much stress has been laid upon the absence of pulmonary accentuation as a diagnostic sign of pulmonary stenosis, but in a number it has been distinctly louder than normal.


^Trans. Path. Soc, London, 1892, xliii, 32.


A prolonged, harsh, rasping, or blowing systolic murmur heard over the whole cardia, but chiefly at the base, with its point of maximum intensity over the upper part of the sternum and the second left space, is present in the great majority of cases. It is transmitted upward toward the clavicle, along the course of the pulmonary artery, and over the sternum, but is faint or inaudible at the apex and to the right of the sternum. It may be so loud as to be heard over the whole chest. From this type important variations occur. (1) The murmur may be heard over the whole cardia, but with maximum intensity at the apex, as in Cassel's case, a boy aged thirteen years, w^ith pulmonary stenosis and a patent foramen ovale, but the ventricular septum entire. In a case of Peacock's there was a loud systolic murmur over the whole heart and along the sternum, the maximum intensity of which was at the inner side of, and immediately above, the left nipple. In this instance a septal defect was associated. (2) In cases in which the septal defect is present the murmur may be heard over the aortic area and along the carotids. Eisenmenger mentions this as a diagnostic point for the association of pulmonary stenosis with a septal defect. In Scheele's[1] case, a girl aged fifteen years, with marked cyanosis, the pulmonary orifice admitted a thin pencil, the valves were small and shrunken, the conus was reduced to the size of a pea, and the septum was defective at the base. There was a systolic murmur along the course of the pulmonary artery and at the left sternoclavicular articulation, which was transmitted far up the carotids and along both subclavians, and was most marked over the left carotid. It was heard also at the aortic cartilage. (3) The murmur may be heard in the back, in the left infrascapular region. This occurred in a number of the cases in this series, but in all a septal defect was associated, to which the transmitted murmur was probably due. (4) In a few cases physical signs are absent. Variot reports a child aged five years, with a large defect of the septum, and the pulmonary a small thin cord with rudimentary valves, who presented marked cyanosis with clubbing, but whose heart sounds were clear.

Diagnosis

In the majority of cases the decided localization of murmur and thrill, the increased cardiac dulness to the right, the absence of pulmonary accentuation, and the presence of the distinctive symptoms of pronounced congenital cyanosis make a positive diagnosis possible. On the other hand, the variation in the character of the murmur and of the pulmonary second sound, and the occasional absence of cyanosis, render the diagnosis indefinite in a certain proportion of cases. That such atypical cases occur also makes it very difficult to exclude the possibility of pulmonary stenosis in the differential diagnosis of other cardiac defects. The presence of constant and marked cyanosis, the distinctive character of the murmur, and the fact that it is not usually heard in the back, are points in favor of stenosis. In patency of the duct, pulmonary accentuation is the rule, in pulmonary stenosis it is the exception.


Both the associated defect in the interventricular septum and the pulmonary stenosis have frequently been diagnosed. The presence of a thrill speaks rather for a closed septum, or for cases in which the foramen ovale also is patent. In a large number of cases the presence of the two distinctive murmurs can be easily traced, that due to the pulmonary obstruction heard best at the base and transmitted beneath the clavicle, that due to the defect localized at the fourth space, heard also in the back, both harsh, but of the two, the pulmonary usually of a more blowing character.


Course

The duration of life in pulmonary stenosis with closed interventricular septum is relatively high. Peacock reports a patient dying at forty-five years, and the lowest age in this series was four years. The possibility exists in such cases that the stenosis had advanced, or even originated since birth. In stenosis with septal defect death occurs earlier, but adult life is also sometimes attained. The maximum age in this series was twenty years. In pulmonary atresia life is very short. The patients with closed septum all die within the first few months. When a defect of the interventricular septum exists these subjects may live some years. The highest age recorded was thirteen years, in one of Peacock's cases. The table gives the duration of life in the cases in the series in which this point is mentioned:


Many patients who survive until early adult life die, not of the lesion, but of pulmonary tuberculosis. The frequency of this disease in pulmonary stenosis and its grave prognosis can be no longer disputed. The cause of the predisposition seems to be: (1) The reduced blood supply to the lungs produces an anemic condition which favors infection; (2) the marked cyanosis usually present depresses the general powers of resistance and tends to destructive tissue metabolism; (3) the subjects of pulmonary stenosis frequently live to an age when tuberculosis is likely to invade the organism when the nutrition is low. This last point is illustrated in an interesting way in this series. Among the 18 patients with closed septum, in whom the duration of life was longer, pulmonary tuberculosis occurred 7 times. Among the remaining 64 patients with defect of the interventricular septum (in whom life was shorter) it occurred in only 9 cases, making an incidence of 16 cases in the 82.


Another not infrequent termination is by infection from an acute endocarditis developing at the seat of the defect. Robinson reports two instances in patients who both died at the age of twenty years, in both of whom the conus formed a separate chamber with narrow bulbar orifice. In the one case there were large vegetations on the conus wall, in the other these formed a fine fringe around its ventricular orifice, and coarse outgrowths about the associated defect in the interventricular septum. Acute endocarditis appears to be especially common in this form of conus deformity, and among the 19 cases in which the conus formed a separate chamber, recent vegetations fringing the conus orifice, on the wall, or on the tricuspid valve were present in 6. In Saundby's case there was a vegetative arteritis of the pulmonary artery, but none of the valves.

Dilatation of the Pulmonary Artery

Dilatation of the pulmonary artery is very common in combination with certain cardiac anomalies but is rare as an isolated condition. A few cases are recorded in which it appears to be primary and to originate in an irregular division of the common arterial trunk. The main vessel is diffusely enlarged and its branches are tortuous and dilated, but the heart and lungs are otherwise normal. The artery is usually dilated in persistence of the fetal passages connecting the two sides of the heart, especially in patent ductus and defects of the lower part of the interauricular septum, or in widely patent foramen ovale. In the two latter conditions hypoplasia of the aorta is frequently associated and it is difficult to say which is the primary condition. The dilated artery may be atheromatous even in young subjects.


In defects of the interventricular septum at the base, the hypoplasia of the pulmonary artery so often present may give place to a marked dilatation. This was the case in 9 among the 34 primary defects of the septum in this series. The clinical manifestations of pulmonary dilatation are discussed by Abrahams[2] with the report of a case in which this was diagnosed as the primary condition.




  1. Deut. med. Woch., 1888, xl, 294.
  2. Jour. Anat. and Physiol., 1877, xi, 302.


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Abbott ME. Congenital Cardiac Disease (1915) Osler & Mccrae's Modern Medicine 6, 2nd Edition.

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1915 Congenital Cardiac: Congenital Cardiac Disease | Heart Development | Literature | Etiology | Cyanosis | Classification | Pericardium | Heart Displacement | Whole Heart | Anomalous Septa | Interauricular Septum | Interventricular Septum | Absence of Cardiac Septa | Aortic Septum | Pulmonary Stenosis and Atresia | Pulmonary Artery Dilatation | Aortic Stenosis or Atresia | Primary Patency and Ductus Arteriosus | Aorta Coarctation | Aorta Hypoplasia | Diagnosis Prognosis and Treatment | Figures | Embryology History | Historic Disclaimer


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