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Complex cardiovascular malformations associated with the corrected type of transposition of the great vessels
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Guillermo Anselmi, M.D.* Simo’n Mun”oz, M.D.* Ivan Ma&do, M.D.* Pablo Blanco, M.D.* Caracas, Venezuela Jorge Espino- Velu, M.D.** Mexico City, Mexico
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orrected transposition of the great vessels (CTGV) is usually associated with other cardiovascular defects, such as interventricular septal defects’ or interauricular septal defectq2s3 or both combined.* Pulmonary stenosis6 patent ductus arteriosus,6 or Ebstein’s malformation of the left atrioventricular valve’** have also been reported in association with CTGV. More complex associated malformations9 render the CTGV very difficult to recognize in vivo. Whatever the associated malformation, regardless of whether the transposition is truly corrected from the functional standpoint, the anatomic diagnosis is possible if one bears in mind the embryologic basis of CTGV.lO Some types of tricuspid atresia and single ventricle which simultaneously exhibit transposition of the great vessels, and some cases of persistent truncus arteriosus have certain angiocardiographic and sometimes electrocardiographic features which permit the recognition of the corrected type of transposition. Obviously, in a persistent Received for publication Jan. 28, 1963. *Department of Cardiology, Hospital Universitario,
**Chief. Department of Congenital Mhico, D.F., Mexico.
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truncus arteriosus there is no true transposition of the great vessels (TGV), but the features which pertain to the corrected position of the ventricles apply to this entity. It seems worth while to report 5 such instances and to emphasize the possibility of recognizing this peculiar combination of malformations. Case reports Case 1. Z.R.P. (H-.51501), a 17-year-old girl, was born of a full-term pregnancy and normal delivery. She had been cyanotic from birth. Dyspnea on effort and squatting were present at an early age. Physical examination revealed a Grade 3+ cyanosis with marked clubbing of the fingers and toes. The apex impulse was felt in the fifth left intercostal space 1 cm. to the left of the mid-clavicular line. The aortic impulse was clearly felt at the suprasternal notch. On auscultation there was a soft continuous murmur in the second right intercostal space and the infraclavicular area. The second pulmanic sound was pure and of normal intensity. X-RAY EXAMINATION. The frontal view disclosed a Grade lf cardiomegaly; the middle left segment was concave, and the apex was turned upward. In the right anterior oblique view a Grade l+ enlargement of the right ventricle was recognized. In the
Caracas,
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left anterior oblique view the left ventricle was thought to be enlarged. Hilar vascularity was increased. ELECTROCARDIOGRAPHY. The electrocardiogram showed a f 150-degree axis deviation and was suggestive of right auricular enlargement. A thoracic circle showed ventricular morphologies suggestive of biventricular enlargement, and it was compatible with transposition of the ventricles, i.e., qR type of complexes were recorded over the right hemithorax, whereas widely diphasic RS complexes were recorded from the left hemithorax. Cardiac catheterization disclosed a high right ventricular pressure: 99 mm. Hg systolic and peripheral arterial unsaturation. ANGIOCARDIOGRAPHY. Opaque substance was injected into the right atrium, from which it entered a right-sided ventricle which showed a smooth inner surface unlike a true right ventricle. Thereafter a single vessel was filled whose left border was coincident with the left border of the cardiac outline. This vessel was directed to the right and descended on the right side of the trachea. The opaque substance also entered the left-sided ventricle through a ventricular septal defect; this ventricle exhibited a trabeculated inner contour, such as is commonly seen in anatomically right ventricles (Fig. 1,B). From the posterior aspect of the single vessel two smaller vessels emerged, both of which entered the right lung. These studies seem to substantiate the diagnosis of persistent truncus arteriosus with probable transposition of the ventricles. Case 2. P.H.R. (INC-63442). a 3-month-old adopted baby girl, was born of a normal full-term pregnancy. The child’s mother was known to have purposely attempted abortion. The patient weighed 2,800 grams at birth and was not cyanotic. When she was 4 days old, she became cyanotic and dyspneic. At the age of 20 days she suffered an infection of the lower respiratory tract and was referred to the Instituto National de Cardiologia in Mexico City. Physical examination disclosed a dyspneic, chronically ill female infant with Grade 3+ cyanosis. Extreme dyspnea interfered with adequate examination, but tachycardia and gallop rhythm were present. The pulmonic second sound was markedly accentuated. No murmurs were discernible. The blood pressure was not taken. X-RAY EXAMINATION. The x-ray films disclosed a small heart with a wide pedicle. On barium swallow the opaque substance followed a normal course at the level of the heart, but occupied a right-sided position in the stomach. The left middle segment (pulmonary segment) appeared to be concave, and the vascularity of the lungs was thought to be normal or even increased. The electrocardiogram showed extreme right axis deviation (- 120 degrees) and negative P waves in Lead I. The rS type of ventricular complexes in all the precordial leads suggested the pattern seen in cases of single ventricle. The complete blood count revealed 7,300,OOO red blood cells and a hemoglobin of 18 Gm. The patient died after several episodes of hypoxia which followed a gastrointestinal infection and dehydration.
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The findings mentioned suggested the diagnosis of levocardia with probable transposition of the great vessels. In other words, the abdominal viscera and the auricles were transposed. Autopsy in this case (No. 2165) disclosed the following features: The liver was placed on the left and the stomach on the right side, i.e., there was
Fig. 1. Comparative angiocardiographic study depicting a classic example of a persistent truncus with the ventricles placed normally to the left (A), and a case of persistent truncus with transposition of the ventricles to the right (B). Notice that in the first case the single vessel occupies the middle portion of the cardiac shadow, whereas in the second case the vessel ascends along the left cardiac contour; the aortic arch and the descending portion of the vessel are placed to the right. In this case the radiopaque substance entered the left-sided ventricle through a ventricular septal defect. Notice the trabeculated aspect of this chamber.
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transposition of the abdominal L ih(era. ‘I‘hc hc4rt was normally placed, i.e., its apes was directed to the left and it was located in the left hemithoras. There was a single vessel arising from the right border of the heart, which described a convex arc to the right. Both pulmonary arteries arose directly from the
hitlglc A esscl. ‘l‘hc atria 1111plac~etl OII the four pulmonary\-eins, and the the left received the two venae Internally, the atrium placed on the features of the anatomically it was smooth, it did not have a
the right received atrium placed on cavae (Fig. 2). the right showed left atrium, i.e., crista terminalis,
Fig. 2. Case 2. A, The anatomically left atrium receiving the pulmonary veins (see arrow) is placed to the right. Notice the muscular band, the only remnant of the atrial septum. B, The anatomically right ventricle, placed to the right, from which arises the single vessel in front of the crista supraventricularis. The ventricular wall is thick. C, The anatomically right auricle receiving both venae cavae (the superior vena cava is pointed out by the indicator) is placed to the left in relation with the anatomically left ventricle. Notice the smooth appearance of the left septal surface, the fine trabeculation of it apical portion, the ventricular septal defect, and the common atrioventricular valve.
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and, again, it received the four pulmonary veins. The interatrial septum was almost completely absent: it was represented by a thin muscular band which was oriented sagittally in the midline about 2 mm. above the annulus of the atrioventricular valves. There was a common atrioventricular orifice formed by three valves: one was anterior, and two were posterior and smaller, one to the right and one to the left. The ventricle on the right side was trabeculated, it exhibited the crista supraventricularis, and it was hypertrophic. In front of the crista supraventricularis, a single vessel emerged, which showed four semilunar sigmoid valve cusps of normal appearance. There was a large ventricular septal defect, the upper limit of which was semilunar, and it was constituted by the upper border of the interventricular septum. This defect was continuous with the suprajacent atria1 septal defect (atrioventricularis communis). The atrium placed to the left showed the features which pertain to the anatomically right atrium, i.e., there was a crista terminalis; the venae cavae entered into it. The ventricle placed on the left showed fine trabeculae, a smooth septal surface, and normal thickness of its wall. All of these features were those normally present in the anatomically left ventricle. In summary, the anatomic diagnosis was: (1) Levocardia with situs inversus viscerum. The cardiac apex was directed to the left, and the heart occupied the left hemithorax. The atria were transposed. (2) Transposition of the ventricles with respect to the position of the atria: the anatomically right ventricle was placed to the right (normally, for this type of levocardia it should be placed to the left), and the anatomically left ventricle was placed on the left (it should be placed on the right side for this type of levocardia). (3) Persistent truncus
Fig. 3. Angiocardiogram in Case 3. The frontal aorta, placed to the left, and the pulmonary artery, of the cardiac contour. The aortic arch is placed front of and parallel to the pulmonary artery.
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arteriosus. (4) Common atrioventricular canal of the complete variety. Case 3. M.B. (H-100032), a 17-year-old girl, was born of a normal full-term pregnancy and normal delivery. She was asymptomatic until the age of 7 years, at which time dyspnea and short, stabbing precordial pains appeared. A congenital heart condition was diagnosed at that time. Simultaneously, cyanosis appeared. When examined, she complained of minimal dyspnea and frequent rapid palpitations of short duration. She led a normal ife. On physical examination the patient appeared to be in general good health, without dyspnea, but with Grade 2-t cyanosis of the fingers, toes, and lips. The blood uressure was 110/70 mm. Hrr. The aoex beat was feit in the fifth left intercostal ,‘,ace. Tiere was a palpable closure of the pulmonary valves and a soft, protosystolic Grade 2 murmur, which was preceded by a protosystolic snap over the pulmonary area. The pulmonic second sound was “pure” and accentuated. The rest of the examination was not contributory. ELECTROCARDIOGRAPHY. The electrocardiogram was suggestive of left atria1 and ventricular enlargement. X-RAY EXAMINATION. The frontal view disclosed a moderate cardiomegaly. The middle segment was straight and the hilar vascular markings were increased. In the left anterior oblique view, the ventricles contracted synchronously. The left ventricular border was somewhat displaced upwardly and the vascular pedicle appeared to be wider than normal. ANGIOCARDIOGRAPHY. Opaque substance was injected into the left atrium, which was entered through an atria1 septal defect. From this chamber a single ventricle was filled, which showed thick walls.
view (A) depicts a single ventricular chamber from which the placed to the right, are filled. The aorta forms the left border on the right. In the left lateral view (B) the aorta is seen in
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Fig. 4, A-D. X-ray film and angiocardiograms in Case 4. A, Notice the normal size of the heart in the frontal view and the prominence of the middle segment which continues the left inferior cardiac contour. B, and C, Angiocardiograms in frontal view show the filling of the single ventricular chamber from which both vessels arise in a parallel fashion, the aorta to the left and the pulmonary artery to the right. D, The left lateral view depicts an anterior aorta and a very much dilated and posterior pulmonary artery. (For Fig. 4,E and F, see opposite page.)
A ventricular septum was not visualized. Thereafter the two great vessels filled simultaneously: the aorta, placed to the left, formed the left contour of the cardiac shadow and arched to the right (Fig. 3,A); the pulmonary artery was very much dilated and was placed to the right and behind the aorta. Its valves appeared at a lower level than the aortic valves. In the left lateral view both great vessels ran parallel: the aorta was the anterior vessel (Fig. 3,B). The final diagnosis was: (1) single ventricle; (2) transposition of the great vessels, with the arrangement which pertains to the “corrected” variety; and (3) atria1 septal defect. Case 4. P.A.M. (H-080792), an 18-year-old boy, came for consultation because he had suffered from
dyspnea on effort and palpitation in the last few years. Phvsical examination disclosed a slightlv cyanotic patient with minimal clubbing of the fingers and toes. The apex beat was felt in the fifth left intercostal space at the level of the mid-clavicular line. A harsh systolic thrill which was felt in the second left intercostal space extended to the midprecordial and left infraclavicular areas. A harsh Grade 4 systolic murmur was heard over the pulmonary area and was transmitted to the vessels of the neck. The second pulmonic sound was accentuated. X-RAY EXAMINATION. The heart was of normal size in the frontal view. The middle segment was prominent, and was continuous with the remainder of the left lower border of the cardiac contour. The hilar
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vessels and the pulmonary transparency were normal (Fig. 4,A). In the right anterior oblique view the right ventricle appeared to be slightly enlarged, and the cardiac pedicle to be widened. In the left anterior oblique view the right atrium was slightly enlarged. ELECTROCARDIOGRAPHY. The electrocardiogram showed a right axis deviation (+135 degrees). The P waves were peaked and tall in Leads II and aVr. A thoracic circle showed left ventricular morphologies with hypertrophy over the right hemithorax, and right ventricular morphologies over the left hemithorax, also with hypertrophy and systolic overloading (Fig. 4). This was suggestive of transposition of the ventricles and biventricular hypertrophy. CARDIAC CATHETERIZATION. Gasanalysisshoweda step-up at the level of the right-sided ventricle, and peripheral arterial unsaturation. The pressure in this ventricular chamber and that in the aorta were identical. The aorta was entered from the right-sided ventricle; the catheter ascended in close proximity to the left border of the cardiac contour, which suggested that the aorta arose in an abnormal position. ANGIOCARDIOGRAPHY. This study depicted the filling of what appeared to be a single ventricle, from which both great vessels emerged, the aorta anterior and to the left and the pulmonary artery posterior and to the right. The vessels appeared to be uarallel and did not cross each other (Fig. 4.
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left atrium with great ease, from whence it was advanced into the left ventricle. The great vessels were not catheterized. There was arterial unsaturation. ANGIOCARDIOGRAPHY. The opaque substance was seen to pass from the right to the left atrium through a large septal defect. The left ventricular chamber filled immediately afterward. It appeared to be hypertrophic. From this chamber, both great vessels filled, the aorta placed anteriorly and to the left, constituting the left border of the cardiac contour and then crossing over to the right side. The pulmonary artery was placed posteriorly and to the right. The right-sided ventricular chamber never filled. Instead,
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B,k,D). The following conclusions were reached: (1) single ventricle, and (2) transposition of the great vessels arranged in the manner observed in the “corrected” type of transposition. Case 5. C.A.I. (H-086140), a 25-year-old man, had a past history which was noncontributory, except for the fact that cyanosis and clubbing appeared at a very early age. He claimed not to have dyspnea. On physical examination the apex beat was felt in the sixth left intercostal space, 2 cm. outside of the mid-clavicular line. The precordial area was bulging; he had pigeon-breast thorax. There was a soft systolic thrill within the apex. On auscultation there was a Grade 2 systolic murmur at the midprecordial and endoapical areas; it was not transmitted. The second pulmonic sound was loud and pure. X-RAY EXAMINATION. The frontal view disclosed a Grade 2+ to 3+ cardiomegaly. The middle segment was concave; the vascularity of the lungs was greatly increased; the hilar vessels showed vigorous pulsations. The aortic arch descended on the right (Fig. 5,A). In the right anterior oblique view the left atrium was slightly enlarged. In the left anterior oblique view the left ventricle was enlarged to Grade 3+, and the right atrium to Grade 2+. In this position the cradiac pedicle was wider. The contour of a vessel was noticed which seemed to prolong upward the anteroinferior border of the cardiac contour (Fig. 5,B). ELECTROCARDIOGRAPHY. The electrocardiogram showed left axis deviation (-4.5 degrees) and peaked P waves in Leads I and II. It was suggestive of right and left atria1 enlargement and left ventricular hypertrophy. CARDIAC CATHETERIZATION. The right ventricular chamber was not entered. The catheter entered the
Fig. 4, E and F. E, Electrocardiogram in Case 4. The study of the P wave indicates that the atria are normally placed. There is evidence of right atria1 enlargement. The morphology of the ventricular complex is of the qRs type with plus-minus T wave which corresponds to variations in potential of a hypertrophic left ventricle placed on the right. Rs complexes with positive T waves registered in Leads Vb and Vs correspond to variations in potential of a hypertrophic anatomic right ventricle (systofic overloading).
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an empty triangular area was visible, which was limited on the right side by the right atrium, on the left by the left-sided ventricle, and below by the diaphragm (Fig. S,C, D). The final diagnosis was: (1) atresia of the rightsided atrioventricular valve (tt icuspid?), atria1
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septal defect, hypertrophy of the left-sided ventricle; (2) transposition of the great vessels, both vessels arising from the hypertrophic ventricular chamber in the fashion observed in the “corrected” type; and (3) probable transposition of the ventricles.
Fig. $. X-ray films and angiocardiograms in Case 5. A, Notice the cardiomegaly, the increased left inferior cardiac border, the prominent aortic knob to the right, and increased hilar and vascular markings. I?, Left anterior oblique view showing the enlargement of the left ventricle and the right auricle, the wide cardiac pedicle, and the prolongation of the anteroinferior cardiac border upward by the contour of a vessel. C, Angiocardiogram in the frontal view showing the filling of both atria and the hypertrophic left-sided ventricle from which both vessels arise in a parallel fashion, the aorta to the left and the pulmonary artery to the right. D, The lateral view depicts the anterior aorta and posterior pulmonary artery; this latter vessel is very much dilated.
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Case 6. E.C.B. (# 82774), a 13-year-old boy who was known to have been cyanotic since birth, was seen at the Instituto National de Cardiologia iu Mexico City. Although he had a poor tolerance to exercise, he was never critically ill. His body build was reminiscent of that described in Marfan’s syndrome. PHYSICAL EXAMINATION. He appeared to be markedly cyanotic and had marked clubbing of the fingers and toes. A Grade 2 systolic murmur was heard over the left sternal border, and the second sound over the pulmonary area was accentuated. X-RAY EXAMINATION, The heart was slightly increased in size; there was a right-sided aortic arch; the left middle segment was straight. No chamber appeared to be enlarged. The pulmonary fields appeared to be overtransparent (Fig. 7). ELECTROCARDIOGRAPHY. There was a left axis deviation and a right bundle branch block; the tracing was suggestive of left ventricular hypertrophy (Fig. 7). With these findings the possibility of a corrected transposition of the great vessels was considered. Angiocardiography and catheterization were recommended. The angiocardiogram was not conclusive. However, during the test it was seen that the catheter oscillated amply within the ventricular chamber (selective angiocardiography), and the possibility of a single ventricle was raised. Catheterization findings were as follows: (1) the “right ventricular” pressure was 90/10 mm. Hg; the infundibular “right ventricular” pressure was 47/11 mm. Hg; the pressure in the pulmonary trunk was 14 mm. Hg (mean). A pulmonary vein was entered through an atria1 septal defect; the aorta was entered via the “right” ventricle, and the pressure therein was 84/51 mm. Hg. This information was found to be compatible with the diagnosis of an overriding aorta and pulmonary stenosis, that is, with the general picture of a tetralogy of Fallot. Again, the diagnosis of a transposition of the’ great vessels was entertained since it was not in disagreement with the abovementioned findings. An atria1 septal defect was obvious, and a single ventricle was again mentioned as a good possibility. ‘I%e patient was operated upon for improvement of pulmonary circulation and, possibly, for a total correction of malformations. LVhen the heart was viewed, it was seen that the great’ vessels were transpoged and that the aorta was at least four times the size of the posteriorl) placed pulmonary art&y. Thi-ougli an’ atridtomy the folldwing findings were ma’de: (1) a sihgle atrium; (2) a single atrioventricular Valve, i.‘e.; an’ A-V communis; (3) a large ventricular’ septal defect; (4) a markedly trabeculated “left” ventricle from which both the aorta and the pulmonary artery. arose .’ Cvrrectiun of any of these defects was thought to carry an excqssive risk, and the operation ended as an exploratory procedure. The patient recovered and had an uneventful postoperative course. The tinal diagnosis was: corrected transposition of the great vessels, common atrioventricular c-anal, and pulmonary stenosis.
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Discussion The anatomic basis of CTGV for a normally placed heart is as follows: the atria are normally placed, that is, the anatomically right atrium is on the right side, and the anatomically left atrium is on the left side. The right atrium receives the venae cavae and the coronary sinus; the left atrium receives the four pulmonary veins. The ventricles are transposed, that is, the right-sided ventricle is the anatomic left ventricle, and the leftsided ventricle is anatomically the right one. Finally, the great vessels are transposed, i.e., the aorta is anterior and arises from the left-sided ventricle in front of the crista supraventricularis, and the pulmonary artery is posterior and placed to the right of the aorta, emerging from the right-sided ventricle, parallel to the aorta. The embryologic basis of this malformation is the abnormal torsion of the bulboventricular loop, inversely to that which takes place in a normal heartlo (Fig. 6)hence, the left-sided convexity of the loop. The anatomic result is the inversion of the ventricles, since the bulbus cordis will remain on the left side and will give rise to the anatomically right ventricle. Likewise, the primitive ventricle, which gives rise to the anatomically left ventricle, will now be placed on the right side. The anatomically right ventricle will remain the anterior of the two ventricles, whereas the anatomically left ventricle will continue to be, as in the normal heart, the posterior ventricle. Therefore, the truncus-conus which will give rise to the aorta and the pulmonary artery will be placed on the left, and it will be continuous with the bulbus cordis in a reverse position. This abnormal position of the truncus is that which in earlier stages of embryonic development is normal prior to its leftward displacement to the midline due to the normal disappearance of the conoventricular ridge.” TGV is due to the straight development of the truncoconal ridges, the result of which is that the fourth aortic arch will be continuous with the anterior ventricle (the anatomically right ventricle placed to the left). Another consequence of this abnormal development of the truncoconal ridges is that the sixth aortic arch, which
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Fig. 6. Diagram of the torsion of the primitive cardiac tube. A, Normal torsion of the cardiac tube with its convexity directed to the right and its concavity directed to the left. I: At 1 and 2 the right and left interbulbar grooves are seen; 3 and 4 are the bulboventricular grooves; 5 and 6 correspond to the atrioventricular grooves. All of these limit the different portions of the primitive tube: bulbus aorticus (B.Ao.), bulbus cordis (B.C.), ventricle (V.), and primitive atria (R.A. and I.A.). II: The torsion of the cardiac tube is initiated because of the enlargement of grooves 4 and 5. III: The torsion has been completed and the atria occupy their definitive position. The truncus continues the bulbus cordis on the right side of the heart; it was not divided normally because of the absence of the truncoconal ridges. The anatomic result is a persistent truncus in a heart with normally placed chambers. B, This diagram depicts the abnormal torsion of the bulboventricular loop with a left-sided convexity and a right-sided concavity due to an increase in grooves 3 and 6. The truncus continues the bulbus cordis which is placed to the left (III’); the tnmcus is not divided because of failure of development of the truncoconal ridges. The anatomic result is a common trunk with inverse position of the ventricular chambers. C, This diagram depicts the normal torsion of the bulboventricular loop in a heart with mirror-image dextrocardia and some type of levocardia (that with atria1 inversion). I: The primitive left atrium is placed to the right, and the primitive right atrium to the left. II: The normal torsion in this case is due to enlargement of grooves 5 and 6. III: The torsion has been completed and the atria and ventricles occupy their definftive position. The truncus continues the bulbus cordis on the left side; it is not divided, for which reason the anatomic result is a common trunk in a heart with mirror-image dextrocardia or some type of levocardia. D, The abnormal torsion of the bulboventricular loop in a heart with mirror-image dextrocardia or some type of levocardia. The convexity is right-sided because of an increase in grooves 4 and 6 (II). In III ’ the torsion has been completed; the truncus continues the bulbus cordis which is placed to the right. The truncus conus is not divided. The anatomic result is a common trunk with inverse position of the ventricular chambers in a heart with mirror-image dextrocardia or some type of levocardia. (Modified from Davisrs Kramer,19 and de la Cruz.*s)
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is a posterior vessel, will be continuous below with the anatomically left (or posterior) ventricle. Thus, the aorta will arise from the anatomically right ventricle placed on the left side, and the pulmonary artery will arise from the anatomically left ventricle placed to the right; the aorta is anterior and the pulmonary artery is posterior, but, unlike the usual complete transposition of the great vessels, the aorta will be placed on the left and the pulmonary artery on the right. Now then, if the aorta is placed on the left, we may correctly assume that the ventricle from which it emerges, placed also on the left side, is the anatomically right ventricle. If so, the transposition is of the “corrected” type. Such anatomic features have been present in reported cases with autopsy confirmation.6J2 If the embryologic mechanism for transposition is present while the primitive truncus-conus never becomes divided, the result is a transposition of the ventricles with a persistent truncus (Fig. 7,B). Normally, the truncus-conus undergoes a left lateral displacement and eventually where the occupies a medial position, truncoconal septum and the interventricular septum coincide and fuse. The opposite will take place if the bulboventricular loop curves to the left, in which case the truncus-conus will advance from a left lateral position to a medial position. For this reason, in transposition of the ventricles, the undivided truncus-conus occupies either a left position or a medial position but not a right-sided position as in the ordinary type of persistent truncus arteriosus communis (see Fig. 1,A). In our Case 2 the autopsy showed levocardia, and the atria were transposed (in a position pertaining to dextrocardia) ; in other words, the anatomically right atrium was placed to the left and in relationship with an anatomically left ventricle, whereas the anatomically Ieft atrium was placed to the right and was related to an anatomically right ventricle. According to de la Cruz and associates,rO in such a type of levocardia there is an abnormal torsion of the bulboventricular loop in a sense opposite to that normally seen for the atria in this type of levocardia; this gives rise to the inversion of the ventricles. Further-
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more, in our case there was no partition of the truncus-conus, for which reason the result was a persistent truricus arteriosus communis which arose from the anatomically right ventricle in front of the crista supraventricularis, following the right border of the heart. This type of truncus is commonly seen in levocardia with transposition of the atria or in mirror-image dextrocardia with inversion of the ventricles due to abnormal torsion of the bulboventricular loop (Fig. 6,D). Case 1 corresponds to a case of persistent truncus in a normally placed heart. It is also seen in cases of dextrorotation with normally placed atria complicated by abnormal torsion of the bulboventricular loop. The latter complication gives rise to inversion of the ventricles such as that seen in TCGV, save for the fact that there is only one vessel and not two. The same reasoning could be applied in cases of single ventricle, i.e., in a heart in which the bulboventricular loop has bent normally, the inter-ventricular septum may be lacking, with a resulting single ventricle. Likewise, the interventricular septum may be absent in a heart in which the bulboventricular loop was abnormally bent to the left. The disposition of the great vessels, i.e., anterior and left-sided aorta with posterior and right-sided pulmonary artery, will give the clue to the abnormal torsion which the bulboventricular loop underwent, and which resulted, as it were, in a transposition of the *‘ventricles.” This is quite different from the cases of single ventricle with TGV in which the bulboventricular loop was normally bent. Here, the aorta is anterior, but, simultaneously, it is on the right side and the pulmonary artery is posterior, but on the left side.13*, 14a Both the usual type and the “corrected” type of transposition of the great vessels associated with single ventricle have been reported, proved either at autopsy’4 or angiocardiographically,‘” with or without pulmonary stenosis. I6 Edward@ has described this latter type (CTGV) associated with single ventricle and normal pulmonary artery. The electrocardiographic behavior of single ventricle is quite interesting.16” If TGV is present, qRs morphologies of the
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Fig. 7. Case 6. A. Notice the left border of the heart. Its upper segment is formed aortic arch and, finally, the scant pulmonary circulation. B, The electrocardiogram hypertrophy.
ventricular complex are seen in the right precordial leads (V~R, VI. and V,), RS complexes in Leads V3 and Vd, and rS complexes in Leads Vb and Va. This may be interpreted as indicative of transposition of the morphologies of the ventricles, and it is a frequent finding in the “corrected” type of transposition,2J which is to be accounted for by the inversion of the ventricles. Our fourth case is an example of a single ventricle which shows this type of electrocardiographic behavior. However,
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by the aorta; notice the right shows “right” ventricular
ventricular activation in cases of single ventricle is not clearly understood, in view of the absence of an interventricular septum. The ventricular complexes in these cases could be accounted for by the transposition of the morphologies of each ventricle if these cavities are actually transposed, although there is no ventricular septum. In tricuspid atresia with TGV and normal pulmonary artery15 the aorta is anterior and on the right side; it arises from
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the hypoplastic right ventricle, whereas the pulmonary artery is posterior, on the left side, and arises from the left ventricle. In our case with atresia of. the right atrioventricular valve, atria1 septal defect, and hypertrophy of the left-sided ventricle, TGV was clearly discernible. However, the aorta was anterior but on the left side, emerging from the left-sided ventricle, and the dilated pulmonary artery was posterior and on the right side, emerging from the same ventricle. Since the aorta is anterior in this case, the ventricle from which it emerges is also anterior. This automatically leads to the diagnosis of anatomically right ventricle, as can only be the case in instances of corrected transposition of the great vessels. A similar case with pulmonary stenosis reported by Kjellberg and associate+ showed tricuspid atresia and CTGV with an anterior and left-sided aorta arising from the hypertrophic ventricle placed on the left. Summary
Abnormal torsion of the bulboventricular loop, such as is seen in corrected transposition of the great vessels (CTGV) may be present in a number of complex malformations, including single ventricle and persistent truncus arteriosus. Our 6 cases illustrate this point. The diagnosis may be reached by means of angiocardiography, which will show the peculiar disposition of the great vessels, i.e., the aorta anterior and on the left side, and the pulmonary artery posterior and on the right side. On occasion, angiocardiography will permit the recognition of transposition of the ventricles because of the peculiar inner contour of each chamber. In other instances, the electrocardiogram will permit recognition of the inversion of the ventricular chambers through the study of the unipolar ventricular morphologies. The associated malformations may be recognized simultaneously by the very same methods and the clinical and hemodynamic behavior of each case. REFERENCES 1. Mufioz, position
S., Anselmi, corregida
G., and Suarez, de 10s grandes
A.: Transvasos. A
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prop6sitode UII casede comprobacibnnecrbpsica, Gaceta Cardiologica 1:.54, 1961. 2. Esoino Vela. 1.. Saharrhn de la Parra. E.. and Anselmi, 6.:’ Transp%icibn corregida de 10s grandes vases, Arch. Inst. Cardiol. Mexico. 2!&573, 1959. 3. Walker, W. J., Cooley, D. A., McNamara, D. G., and Moser, R. H.: Corrected transposition of the great vessels, atrioventricular heart block and ventricular septal defect. A clinical triad, Circulation 17:249,- 1958. 4. Giraud. G.. Puech. P.. Latour. M.. Thevenet. A., Ohvierj G., and Hertault, J.: La trans: position corrigee des gros vaisseaux avec communications interauriculaire et interventriculaire chez l’adulte. Arch. mal. coeur 53:986, 1960. 5. Anderson, R. C., Lillehei, C. W., and Lester, R. G.: Corrected transposition of the great vessels of the heart, Pediatrics 20:626, 1957. 6. Edwards, J. E., Dry, T. J., Parker, R. L., Burchell. H. B.. Wood. E. H.. and Bulbulian. A. H.: An atlas’ of congenital anomalies of the heart and great vessels, Springfield, Ill., 19.54, Charles C Thomas Publisher. J. W., 7. Becu, L. M., Swan, H. J. C., DuShane, and Edwards, J. E.: Cardiac Clinic CXLIV. Ebstein malformation of the left atrioventricular valve in corrected transposition of the great vessels with ventricular septal defect, Proc. Staff Meet. Mavo Clin. 30:483. 195.5. H. F,, Daugherty, G. W., and Ed8. Helmholz, wards, J. E.: Cardiac Clinic CXLV. Congenital “mitral” insufficiency in association with corrected transposition of the great vessels; report of probable clinical case and review of six cases studied pathologically, Proc. Staff Meet. Mayo Clin. 31:82, 1956. 9. Espino-Vela, J., Portillo, B., Anselmi, G., de la Cruz, M. V., and Reinhold, M.: On a variety of the “corrected” type of transposition of the great vessels associated with dextrocardia. A study of two cases with autopsy report, AM. HEART J. 58:250, 1959. M. V., Anselmi, G., Cisneros, F., 10. De la Cruz, Reinhold. M.. Portillo. B.. and Esoino Vela. J.: An embryological explanation for the corrected transposition of the great vessels; additional description of the main anatomic features of this-malformation and its varieties, AM. HEART 1. 57:104. 1959. J. P.: An 11. De la Cruz,” M. V., and da Rocha, ontogenetic theory for the explanation of congenital malformations involving the truncus and conus, Aha. HEART J. 51:782, 1956. 12. Lev, M.: In Saphir, 0.: A text on systemic pathology, New York 1958, Grunne & Stratton, Inc. J. E.: In Gould, S. E.: Pathology 13. Edwards, of the heart, ed. 2, Springfield, Ill., 1960, Charles C Thomas Publisher, p. 337. 13a Ibid., p. 336. 14. Taussig, H. B.: Congenital malformation of the heart, Vol. II, revised edition, Cambridge, 1960, The Commonwealth Fund, p. 326. 14a. Ibid., p. 327. 15. Keith, J. D., Rowe, R. D., and Vlad, P.: Heart I
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disease in infancy and childhood, New York, 1958, The Macmillan Company, p. 337. 15a. Ibid., p. 516. 15b. Ibid., p. 518. 16. Kjellberg, S. R., Mannheimer, R., Rudhe, U., and Jonsson, B.: Diagnosis of congenital heart disease, ed. 2, Chicago, 1959, The Year Book Publishers, Inc., p. 719. 16a. Ibid., p. 719. 17. Wilkinson, A. H., Potts, W. J., and Lev, M.: The postmortem external appearance of con-
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genitally malformed hearts as an aid to surgical diagnosis. 1. Thoracic Sure. 39:363. 1960. 18. Davis, C: L.: Developmencof the human heart from its first appearance to the stage found in embryos of twenty paired somites, Contrib. Embryol. 19:245, 1927. 19. Kramer, T. C.: The partitioning of the truncus and conus and the formation of the membranous portion of the interventricular septum in the human heart, Am. J. Anat. 71:343, 1942.
of
Guillermo Anselmi, M.D.* Simo’n Mun”oz, M.D.* Ivan Ma&do, M.D.* Pablo Blanco, M.D.* Caracas, Venezuela Jorge Espino- Velu, M.D.** Mexico City, Mexico
C
orrected transposition of the great vessels (CTGV) is usually associated with other cardiovascular defects, such as interventricular septal defects’ or interauricular septal defectq2s3 or both combined.* Pulmonary stenosis6 patent ductus arteriosus,6 or Ebstein’s malformation of the left atrioventricular valve’** have also been reported in association with CTGV. More complex associated malformations9 render the CTGV very difficult to recognize in vivo. Whatever the associated malformation, regardless of whether the transposition is truly corrected from the functional standpoint, the anatomic diagnosis is possible if one bears in mind the embryologic basis of CTGV.lO Some types of tricuspid atresia and single ventricle which simultaneously exhibit transposition of the great vessels, and some cases of persistent truncus arteriosus have certain angiocardiographic and sometimes electrocardiographic features which permit the recognition of the corrected type of transposition. Obviously, in a persistent Received for publication Jan. 28, 1963. *Department of Cardiology, Hospital Universitario,
**Chief. Department of Congenital Mhico, D.F., Mexico.
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truncus arteriosus there is no true transposition of the great vessels (TGV), but the features which pertain to the corrected position of the ventricles apply to this entity. It seems worth while to report 5 such instances and to emphasize the possibility of recognizing this peculiar combination of malformations. Case reports Case 1. Z.R.P. (H-.51501), a 17-year-old girl, was born of a full-term pregnancy and normal delivery. She had been cyanotic from birth. Dyspnea on effort and squatting were present at an early age. Physical examination revealed a Grade 3+ cyanosis with marked clubbing of the fingers and toes. The apex impulse was felt in the fifth left intercostal space 1 cm. to the left of the mid-clavicular line. The aortic impulse was clearly felt at the suprasternal notch. On auscultation there was a soft continuous murmur in the second right intercostal space and the infraclavicular area. The second pulmanic sound was pure and of normal intensity. X-RAY EXAMINATION. The frontal view disclosed a Grade lf cardiomegaly; the middle left segment was concave, and the apex was turned upward. In the right anterior oblique view a Grade l+ enlargement of the right ventricle was recognized. In the
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left anterior oblique view the left ventricle was thought to be enlarged. Hilar vascularity was increased. ELECTROCARDIOGRAPHY. The electrocardiogram showed a f 150-degree axis deviation and was suggestive of right auricular enlargement. A thoracic circle showed ventricular morphologies suggestive of biventricular enlargement, and it was compatible with transposition of the ventricles, i.e., qR type of complexes were recorded over the right hemithorax, whereas widely diphasic RS complexes were recorded from the left hemithorax. Cardiac catheterization disclosed a high right ventricular pressure: 99 mm. Hg systolic and peripheral arterial unsaturation. ANGIOCARDIOGRAPHY. Opaque substance was injected into the right atrium, from which it entered a right-sided ventricle which showed a smooth inner surface unlike a true right ventricle. Thereafter a single vessel was filled whose left border was coincident with the left border of the cardiac outline. This vessel was directed to the right and descended on the right side of the trachea. The opaque substance also entered the left-sided ventricle through a ventricular septal defect; this ventricle exhibited a trabeculated inner contour, such as is commonly seen in anatomically right ventricles (Fig. 1,B). From the posterior aspect of the single vessel two smaller vessels emerged, both of which entered the right lung. These studies seem to substantiate the diagnosis of persistent truncus arteriosus with probable transposition of the ventricles. Case 2. P.H.R. (INC-63442). a 3-month-old adopted baby girl, was born of a normal full-term pregnancy. The child’s mother was known to have purposely attempted abortion. The patient weighed 2,800 grams at birth and was not cyanotic. When she was 4 days old, she became cyanotic and dyspneic. At the age of 20 days she suffered an infection of the lower respiratory tract and was referred to the Instituto National de Cardiologia in Mexico City. Physical examination disclosed a dyspneic, chronically ill female infant with Grade 3+ cyanosis. Extreme dyspnea interfered with adequate examination, but tachycardia and gallop rhythm were present. The pulmonic second sound was markedly accentuated. No murmurs were discernible. The blood pressure was not taken. X-RAY EXAMINATION. The x-ray films disclosed a small heart with a wide pedicle. On barium swallow the opaque substance followed a normal course at the level of the heart, but occupied a right-sided position in the stomach. The left middle segment (pulmonary segment) appeared to be concave, and the vascularity of the lungs was thought to be normal or even increased. The electrocardiogram showed extreme right axis deviation (- 120 degrees) and negative P waves in Lead I. The rS type of ventricular complexes in all the precordial leads suggested the pattern seen in cases of single ventricle. The complete blood count revealed 7,300,OOO red blood cells and a hemoglobin of 18 Gm. The patient died after several episodes of hypoxia which followed a gastrointestinal infection and dehydration.
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The findings mentioned suggested the diagnosis of levocardia with probable transposition of the great vessels. In other words, the abdominal viscera and the auricles were transposed. Autopsy in this case (No. 2165) disclosed the following features: The liver was placed on the left and the stomach on the right side, i.e., there was
Fig. 1. Comparative angiocardiographic study depicting a classic example of a persistent truncus with the ventricles placed normally to the left (A), and a case of persistent truncus with transposition of the ventricles to the right (B). Notice that in the first case the single vessel occupies the middle portion of the cardiac shadow, whereas in the second case the vessel ascends along the left cardiac contour; the aortic arch and the descending portion of the vessel are placed to the right. In this case the radiopaque substance entered the left-sided ventricle through a ventricular septal defect. Notice the trabeculated aspect of this chamber.
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transposition of the abdominal L ih(era. ‘I‘hc hc4rt was normally placed, i.e., its apes was directed to the left and it was located in the left hemithoras. There was a single vessel arising from the right border of the heart, which described a convex arc to the right. Both pulmonary arteries arose directly from the
hitlglc A esscl. ‘l‘hc atria 1111plac~etl OII the four pulmonary\-eins, and the the left received the two venae Internally, the atrium placed on the features of the anatomically it was smooth, it did not have a
the right received atrium placed on cavae (Fig. 2). the right showed left atrium, i.e., crista terminalis,
Fig. 2. Case 2. A, The anatomically left atrium receiving the pulmonary veins (see arrow) is placed to the right. Notice the muscular band, the only remnant of the atrial septum. B, The anatomically right ventricle, placed to the right, from which arises the single vessel in front of the crista supraventricularis. The ventricular wall is thick. C, The anatomically right auricle receiving both venae cavae (the superior vena cava is pointed out by the indicator) is placed to the left in relation with the anatomically left ventricle. Notice the smooth appearance of the left septal surface, the fine trabeculation of it apical portion, the ventricular septal defect, and the common atrioventricular valve.
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and, again, it received the four pulmonary veins. The interatrial septum was almost completely absent: it was represented by a thin muscular band which was oriented sagittally in the midline about 2 mm. above the annulus of the atrioventricular valves. There was a common atrioventricular orifice formed by three valves: one was anterior, and two were posterior and smaller, one to the right and one to the left. The ventricle on the right side was trabeculated, it exhibited the crista supraventricularis, and it was hypertrophic. In front of the crista supraventricularis, a single vessel emerged, which showed four semilunar sigmoid valve cusps of normal appearance. There was a large ventricular septal defect, the upper limit of which was semilunar, and it was constituted by the upper border of the interventricular septum. This defect was continuous with the suprajacent atria1 septal defect (atrioventricularis communis). The atrium placed to the left showed the features which pertain to the anatomically right atrium, i.e., there was a crista terminalis; the venae cavae entered into it. The ventricle placed on the left showed fine trabeculae, a smooth septal surface, and normal thickness of its wall. All of these features were those normally present in the anatomically left ventricle. In summary, the anatomic diagnosis was: (1) Levocardia with situs inversus viscerum. The cardiac apex was directed to the left, and the heart occupied the left hemithorax. The atria were transposed. (2) Transposition of the ventricles with respect to the position of the atria: the anatomically right ventricle was placed to the right (normally, for this type of levocardia it should be placed to the left), and the anatomically left ventricle was placed on the left (it should be placed on the right side for this type of levocardia). (3) Persistent truncus
Fig. 3. Angiocardiogram in Case 3. The frontal aorta, placed to the left, and the pulmonary artery, of the cardiac contour. The aortic arch is placed front of and parallel to the pulmonary artery.
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arteriosus. (4) Common atrioventricular canal of the complete variety. Case 3. M.B. (H-100032), a 17-year-old girl, was born of a normal full-term pregnancy and normal delivery. She was asymptomatic until the age of 7 years, at which time dyspnea and short, stabbing precordial pains appeared. A congenital heart condition was diagnosed at that time. Simultaneously, cyanosis appeared. When examined, she complained of minimal dyspnea and frequent rapid palpitations of short duration. She led a normal ife. On physical examination the patient appeared to be in general good health, without dyspnea, but with Grade 2-t cyanosis of the fingers, toes, and lips. The blood uressure was 110/70 mm. Hrr. The aoex beat was feit in the fifth left intercostal ,‘,ace. Tiere was a palpable closure of the pulmonary valves and a soft, protosystolic Grade 2 murmur, which was preceded by a protosystolic snap over the pulmonary area. The pulmonic second sound was “pure” and accentuated. The rest of the examination was not contributory. ELECTROCARDIOGRAPHY. The electrocardiogram was suggestive of left atria1 and ventricular enlargement. X-RAY EXAMINATION. The frontal view disclosed a moderate cardiomegaly. The middle segment was straight and the hilar vascular markings were increased. In the left anterior oblique view, the ventricles contracted synchronously. The left ventricular border was somewhat displaced upwardly and the vascular pedicle appeared to be wider than normal. ANGIOCARDIOGRAPHY. Opaque substance was injected into the left atrium, which was entered through an atria1 septal defect. From this chamber a single ventricle was filled, which showed thick walls.
view (A) depicts a single ventricular chamber from which the placed to the right, are filled. The aorta forms the left border on the right. In the left lateral view (B) the aorta is seen in
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Fig. 4, A-D. X-ray film and angiocardiograms in Case 4. A, Notice the normal size of the heart in the frontal view and the prominence of the middle segment which continues the left inferior cardiac contour. B, and C, Angiocardiograms in frontal view show the filling of the single ventricular chamber from which both vessels arise in a parallel fashion, the aorta to the left and the pulmonary artery to the right. D, The left lateral view depicts an anterior aorta and a very much dilated and posterior pulmonary artery. (For Fig. 4,E and F, see opposite page.)
A ventricular septum was not visualized. Thereafter the two great vessels filled simultaneously: the aorta, placed to the left, formed the left contour of the cardiac shadow and arched to the right (Fig. 3,A); the pulmonary artery was very much dilated and was placed to the right and behind the aorta. Its valves appeared at a lower level than the aortic valves. In the left lateral view both great vessels ran parallel: the aorta was the anterior vessel (Fig. 3,B). The final diagnosis was: (1) single ventricle; (2) transposition of the great vessels, with the arrangement which pertains to the “corrected” variety; and (3) atria1 septal defect. Case 4. P.A.M. (H-080792), an 18-year-old boy, came for consultation because he had suffered from
dyspnea on effort and palpitation in the last few years. Phvsical examination disclosed a slightlv cyanotic patient with minimal clubbing of the fingers and toes. The apex beat was felt in the fifth left intercostal space at the level of the mid-clavicular line. A harsh systolic thrill which was felt in the second left intercostal space extended to the midprecordial and left infraclavicular areas. A harsh Grade 4 systolic murmur was heard over the pulmonary area and was transmitted to the vessels of the neck. The second pulmonic sound was accentuated. X-RAY EXAMINATION. The heart was of normal size in the frontal view. The middle segment was prominent, and was continuous with the remainder of the left lower border of the cardiac contour. The hilar
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vessels and the pulmonary transparency were normal (Fig. 4,A). In the right anterior oblique view the right ventricle appeared to be slightly enlarged, and the cardiac pedicle to be widened. In the left anterior oblique view the right atrium was slightly enlarged. ELECTROCARDIOGRAPHY. The electrocardiogram showed a right axis deviation (+135 degrees). The P waves were peaked and tall in Leads II and aVr. A thoracic circle showed left ventricular morphologies with hypertrophy over the right hemithorax, and right ventricular morphologies over the left hemithorax, also with hypertrophy and systolic overloading (Fig. 4). This was suggestive of transposition of the ventricles and biventricular hypertrophy. CARDIAC CATHETERIZATION. Gasanalysisshoweda step-up at the level of the right-sided ventricle, and peripheral arterial unsaturation. The pressure in this ventricular chamber and that in the aorta were identical. The aorta was entered from the right-sided ventricle; the catheter ascended in close proximity to the left border of the cardiac contour, which suggested that the aorta arose in an abnormal position. ANGIOCARDIOGRAPHY. This study depicted the filling of what appeared to be a single ventricle, from which both great vessels emerged, the aorta anterior and to the left and the pulmonary artery posterior and to the right. The vessels appeared to be uarallel and did not cross each other (Fig. 4.
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left atrium with great ease, from whence it was advanced into the left ventricle. The great vessels were not catheterized. There was arterial unsaturation. ANGIOCARDIOGRAPHY. The opaque substance was seen to pass from the right to the left atrium through a large septal defect. The left ventricular chamber filled immediately afterward. It appeared to be hypertrophic. From this chamber, both great vessels filled, the aorta placed anteriorly and to the left, constituting the left border of the cardiac contour and then crossing over to the right side. The pulmonary artery was placed posteriorly and to the right. The right-sided ventricular chamber never filled. Instead,
.1.
B,k,D). The following conclusions were reached: (1) single ventricle, and (2) transposition of the great vessels arranged in the manner observed in the “corrected” type of transposition. Case 5. C.A.I. (H-086140), a 25-year-old man, had a past history which was noncontributory, except for the fact that cyanosis and clubbing appeared at a very early age. He claimed not to have dyspnea. On physical examination the apex beat was felt in the sixth left intercostal space, 2 cm. outside of the mid-clavicular line. The precordial area was bulging; he had pigeon-breast thorax. There was a soft systolic thrill within the apex. On auscultation there was a Grade 2 systolic murmur at the midprecordial and endoapical areas; it was not transmitted. The second pulmonic sound was loud and pure. X-RAY EXAMINATION. The frontal view disclosed a Grade 2+ to 3+ cardiomegaly. The middle segment was concave; the vascularity of the lungs was greatly increased; the hilar vessels showed vigorous pulsations. The aortic arch descended on the right (Fig. 5,A). In the right anterior oblique view the left atrium was slightly enlarged. In the left anterior oblique view the left ventricle was enlarged to Grade 3+, and the right atrium to Grade 2+. In this position the cradiac pedicle was wider. The contour of a vessel was noticed which seemed to prolong upward the anteroinferior border of the cardiac contour (Fig. 5,B). ELECTROCARDIOGRAPHY. The electrocardiogram showed left axis deviation (-4.5 degrees) and peaked P waves in Leads I and II. It was suggestive of right and left atria1 enlargement and left ventricular hypertrophy. CARDIAC CATHETERIZATION. The right ventricular chamber was not entered. The catheter entered the
Fig. 4, E and F. E, Electrocardiogram in Case 4. The study of the P wave indicates that the atria are normally placed. There is evidence of right atria1 enlargement. The morphology of the ventricular complex is of the qRs type with plus-minus T wave which corresponds to variations in potential of a hypertrophic left ventricle placed on the right. Rs complexes with positive T waves registered in Leads Vb and Vs correspond to variations in potential of a hypertrophic anatomic right ventricle (systofic overloading).
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an empty triangular area was visible, which was limited on the right side by the right atrium, on the left by the left-sided ventricle, and below by the diaphragm (Fig. S,C, D). The final diagnosis was: (1) atresia of the rightsided atrioventricular valve (tt icuspid?), atria1
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septal defect, hypertrophy of the left-sided ventricle; (2) transposition of the great vessels, both vessels arising from the hypertrophic ventricular chamber in the fashion observed in the “corrected” type; and (3) probable transposition of the ventricles.
Fig. $. X-ray films and angiocardiograms in Case 5. A, Notice the cardiomegaly, the increased left inferior cardiac border, the prominent aortic knob to the right, and increased hilar and vascular markings. I?, Left anterior oblique view showing the enlargement of the left ventricle and the right auricle, the wide cardiac pedicle, and the prolongation of the anteroinferior cardiac border upward by the contour of a vessel. C, Angiocardiogram in the frontal view showing the filling of both atria and the hypertrophic left-sided ventricle from which both vessels arise in a parallel fashion, the aorta to the left and the pulmonary artery to the right. D, The lateral view depicts the anterior aorta and posterior pulmonary artery; this latter vessel is very much dilated.
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Case 6. E.C.B. (# 82774), a 13-year-old boy who was known to have been cyanotic since birth, was seen at the Instituto National de Cardiologia iu Mexico City. Although he had a poor tolerance to exercise, he was never critically ill. His body build was reminiscent of that described in Marfan’s syndrome. PHYSICAL EXAMINATION. He appeared to be markedly cyanotic and had marked clubbing of the fingers and toes. A Grade 2 systolic murmur was heard over the left sternal border, and the second sound over the pulmonary area was accentuated. X-RAY EXAMINATION, The heart was slightly increased in size; there was a right-sided aortic arch; the left middle segment was straight. No chamber appeared to be enlarged. The pulmonary fields appeared to be overtransparent (Fig. 7). ELECTROCARDIOGRAPHY. There was a left axis deviation and a right bundle branch block; the tracing was suggestive of left ventricular hypertrophy (Fig. 7). With these findings the possibility of a corrected transposition of the great vessels was considered. Angiocardiography and catheterization were recommended. The angiocardiogram was not conclusive. However, during the test it was seen that the catheter oscillated amply within the ventricular chamber (selective angiocardiography), and the possibility of a single ventricle was raised. Catheterization findings were as follows: (1) the “right ventricular” pressure was 90/10 mm. Hg; the infundibular “right ventricular” pressure was 47/11 mm. Hg; the pressure in the pulmonary trunk was 14 mm. Hg (mean). A pulmonary vein was entered through an atria1 septal defect; the aorta was entered via the “right” ventricle, and the pressure therein was 84/51 mm. Hg. This information was found to be compatible with the diagnosis of an overriding aorta and pulmonary stenosis, that is, with the general picture of a tetralogy of Fallot. Again, the diagnosis of a transposition of the’ great vessels was entertained since it was not in disagreement with the abovementioned findings. An atria1 septal defect was obvious, and a single ventricle was again mentioned as a good possibility. ‘I%e patient was operated upon for improvement of pulmonary circulation and, possibly, for a total correction of malformations. LVhen the heart was viewed, it was seen that the great’ vessels were transpoged and that the aorta was at least four times the size of the posteriorl) placed pulmonary art&y. Thi-ougli an’ atridtomy the folldwing findings were ma’de: (1) a sihgle atrium; (2) a single atrioventricular Valve, i.‘e.; an’ A-V communis; (3) a large ventricular’ septal defect; (4) a markedly trabeculated “left” ventricle from which both the aorta and the pulmonary artery. arose .’ Cvrrectiun of any of these defects was thought to carry an excqssive risk, and the operation ended as an exploratory procedure. The patient recovered and had an uneventful postoperative course. The tinal diagnosis was: corrected transposition of the great vessels, common atrioventricular c-anal, and pulmonary stenosis.
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Discussion The anatomic basis of CTGV for a normally placed heart is as follows: the atria are normally placed, that is, the anatomically right atrium is on the right side, and the anatomically left atrium is on the left side. The right atrium receives the venae cavae and the coronary sinus; the left atrium receives the four pulmonary veins. The ventricles are transposed, that is, the right-sided ventricle is the anatomic left ventricle, and the leftsided ventricle is anatomically the right one. Finally, the great vessels are transposed, i.e., the aorta is anterior and arises from the left-sided ventricle in front of the crista supraventricularis, and the pulmonary artery is posterior and placed to the right of the aorta, emerging from the right-sided ventricle, parallel to the aorta. The embryologic basis of this malformation is the abnormal torsion of the bulboventricular loop, inversely to that which takes place in a normal heartlo (Fig. 6)hence, the left-sided convexity of the loop. The anatomic result is the inversion of the ventricles, since the bulbus cordis will remain on the left side and will give rise to the anatomically right ventricle. Likewise, the primitive ventricle, which gives rise to the anatomically left ventricle, will now be placed on the right side. The anatomically right ventricle will remain the anterior of the two ventricles, whereas the anatomically left ventricle will continue to be, as in the normal heart, the posterior ventricle. Therefore, the truncus-conus which will give rise to the aorta and the pulmonary artery will be placed on the left, and it will be continuous with the bulbus cordis in a reverse position. This abnormal position of the truncus is that which in earlier stages of embryonic development is normal prior to its leftward displacement to the midline due to the normal disappearance of the conoventricular ridge.” TGV is due to the straight development of the truncoconal ridges, the result of which is that the fourth aortic arch will be continuous with the anterior ventricle (the anatomically right ventricle placed to the left). Another consequence of this abnormal development of the truncoconal ridges is that the sixth aortic arch, which
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LA---~-R,A -
Fig. 6. Diagram of the torsion of the primitive cardiac tube. A, Normal torsion of the cardiac tube with its convexity directed to the right and its concavity directed to the left. I: At 1 and 2 the right and left interbulbar grooves are seen; 3 and 4 are the bulboventricular grooves; 5 and 6 correspond to the atrioventricular grooves. All of these limit the different portions of the primitive tube: bulbus aorticus (B.Ao.), bulbus cordis (B.C.), ventricle (V.), and primitive atria (R.A. and I.A.). II: The torsion of the cardiac tube is initiated because of the enlargement of grooves 4 and 5. III: The torsion has been completed and the atria occupy their definitive position. The truncus continues the bulbus cordis on the right side of the heart; it was not divided normally because of the absence of the truncoconal ridges. The anatomic result is a persistent truncus in a heart with normally placed chambers. B, This diagram depicts the abnormal torsion of the bulboventricular loop with a left-sided convexity and a right-sided concavity due to an increase in grooves 3 and 6. The truncus continues the bulbus cordis which is placed to the left (III’); the tnmcus is not divided because of failure of development of the truncoconal ridges. The anatomic result is a common trunk with inverse position of the ventricular chambers. C, This diagram depicts the normal torsion of the bulboventricular loop in a heart with mirror-image dextrocardia and some type of levocardia (that with atria1 inversion). I: The primitive left atrium is placed to the right, and the primitive right atrium to the left. II: The normal torsion in this case is due to enlargement of grooves 5 and 6. III: The torsion has been completed and the atria and ventricles occupy their definftive position. The truncus continues the bulbus cordis on the left side; it is not divided, for which reason the anatomic result is a common trunk in a heart with mirror-image dextrocardia or some type of levocardia. D, The abnormal torsion of the bulboventricular loop in a heart with mirror-image dextrocardia or some type of levocardia. The convexity is right-sided because of an increase in grooves 4 and 6 (II). In III ’ the torsion has been completed; the truncus continues the bulbus cordis which is placed to the right. The truncus conus is not divided. The anatomic result is a common trunk with inverse position of the ventricular chambers in a heart with mirror-image dextrocardia or some type of levocardia. (Modified from Davisrs Kramer,19 and de la Cruz.*s)
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is a posterior vessel, will be continuous below with the anatomically left (or posterior) ventricle. Thus, the aorta will arise from the anatomically right ventricle placed on the left side, and the pulmonary artery will arise from the anatomically left ventricle placed to the right; the aorta is anterior and the pulmonary artery is posterior, but, unlike the usual complete transposition of the great vessels, the aorta will be placed on the left and the pulmonary artery on the right. Now then, if the aorta is placed on the left, we may correctly assume that the ventricle from which it emerges, placed also on the left side, is the anatomically right ventricle. If so, the transposition is of the “corrected” type. Such anatomic features have been present in reported cases with autopsy confirmation.6J2 If the embryologic mechanism for transposition is present while the primitive truncus-conus never becomes divided, the result is a transposition of the ventricles with a persistent truncus (Fig. 7,B). Normally, the truncus-conus undergoes a left lateral displacement and eventually where the occupies a medial position, truncoconal septum and the interventricular septum coincide and fuse. The opposite will take place if the bulboventricular loop curves to the left, in which case the truncus-conus will advance from a left lateral position to a medial position. For this reason, in transposition of the ventricles, the undivided truncus-conus occupies either a left position or a medial position but not a right-sided position as in the ordinary type of persistent truncus arteriosus communis (see Fig. 1,A). In our Case 2 the autopsy showed levocardia, and the atria were transposed (in a position pertaining to dextrocardia) ; in other words, the anatomically right atrium was placed to the left and in relationship with an anatomically left ventricle, whereas the anatomically Ieft atrium was placed to the right and was related to an anatomically right ventricle. According to de la Cruz and associates,rO in such a type of levocardia there is an abnormal torsion of the bulboventricular loop in a sense opposite to that normally seen for the atria in this type of levocardia; this gives rise to the inversion of the ventricles. Further-
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more, in our case there was no partition of the truncus-conus, for which reason the result was a persistent truricus arteriosus communis which arose from the anatomically right ventricle in front of the crista supraventricularis, following the right border of the heart. This type of truncus is commonly seen in levocardia with transposition of the atria or in mirror-image dextrocardia with inversion of the ventricles due to abnormal torsion of the bulboventricular loop (Fig. 6,D). Case 1 corresponds to a case of persistent truncus in a normally placed heart. It is also seen in cases of dextrorotation with normally placed atria complicated by abnormal torsion of the bulboventricular loop. The latter complication gives rise to inversion of the ventricles such as that seen in TCGV, save for the fact that there is only one vessel and not two. The same reasoning could be applied in cases of single ventricle, i.e., in a heart in which the bulboventricular loop has bent normally, the inter-ventricular septum may be lacking, with a resulting single ventricle. Likewise, the interventricular septum may be absent in a heart in which the bulboventricular loop was abnormally bent to the left. The disposition of the great vessels, i.e., anterior and left-sided aorta with posterior and right-sided pulmonary artery, will give the clue to the abnormal torsion which the bulboventricular loop underwent, and which resulted, as it were, in a transposition of the *‘ventricles.” This is quite different from the cases of single ventricle with TGV in which the bulboventricular loop was normally bent. Here, the aorta is anterior, but, simultaneously, it is on the right side and the pulmonary artery is posterior, but on the left side.13*, 14a Both the usual type and the “corrected” type of transposition of the great vessels associated with single ventricle have been reported, proved either at autopsy’4 or angiocardiographically,‘” with or without pulmonary stenosis. I6 Edward@ has described this latter type (CTGV) associated with single ventricle and normal pulmonary artery. The electrocardiographic behavior of single ventricle is quite interesting.16” If TGV is present, qRs morphologies of the
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Fig. 7. Case 6. A. Notice the left border of the heart. Its upper segment is formed aortic arch and, finally, the scant pulmonary circulation. B, The electrocardiogram hypertrophy.
ventricular complex are seen in the right precordial leads (V~R, VI. and V,), RS complexes in Leads V3 and Vd, and rS complexes in Leads Vb and Va. This may be interpreted as indicative of transposition of the morphologies of the ventricles, and it is a frequent finding in the “corrected” type of transposition,2J which is to be accounted for by the inversion of the ventricles. Our fourth case is an example of a single ventricle which shows this type of electrocardiographic behavior. However,
Am. Iicart J. Kmmbrr, 1963
by the aorta; notice the right shows “right” ventricular
ventricular activation in cases of single ventricle is not clearly understood, in view of the absence of an interventricular septum. The ventricular complexes in these cases could be accounted for by the transposition of the morphologies of each ventricle if these cavities are actually transposed, although there is no ventricular septum. In tricuspid atresia with TGV and normal pulmonary artery15 the aorta is anterior and on the right side; it arises from
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the hypoplastic right ventricle, whereas the pulmonary artery is posterior, on the left side, and arises from the left ventricle. In our case with atresia of. the right atrioventricular valve, atria1 septal defect, and hypertrophy of the left-sided ventricle, TGV was clearly discernible. However, the aorta was anterior but on the left side, emerging from the left-sided ventricle, and the dilated pulmonary artery was posterior and on the right side, emerging from the same ventricle. Since the aorta is anterior in this case, the ventricle from which it emerges is also anterior. This automatically leads to the diagnosis of anatomically right ventricle, as can only be the case in instances of corrected transposition of the great vessels. A similar case with pulmonary stenosis reported by Kjellberg and associate+ showed tricuspid atresia and CTGV with an anterior and left-sided aorta arising from the hypertrophic ventricle placed on the left. Summary
Abnormal torsion of the bulboventricular loop, such as is seen in corrected transposition of the great vessels (CTGV) may be present in a number of complex malformations, including single ventricle and persistent truncus arteriosus. Our 6 cases illustrate this point. The diagnosis may be reached by means of angiocardiography, which will show the peculiar disposition of the great vessels, i.e., the aorta anterior and on the left side, and the pulmonary artery posterior and on the right side. On occasion, angiocardiography will permit the recognition of transposition of the ventricles because of the peculiar inner contour of each chamber. In other instances, the electrocardiogram will permit recognition of the inversion of the ventricular chambers through the study of the unipolar ventricular morphologies. The associated malformations may be recognized simultaneously by the very same methods and the clinical and hemodynamic behavior of each case. REFERENCES 1. Mufioz, position
S., Anselmi, corregida
G., and Suarez, de 10s grandes
A.: Transvasos. A
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prop6sitode UII casede comprobacibnnecrbpsica, Gaceta Cardiologica 1:.54, 1961. 2. Esoino Vela. 1.. Saharrhn de la Parra. E.. and Anselmi, 6.:’ Transp%icibn corregida de 10s grandes vases, Arch. Inst. Cardiol. Mexico. 2!&573, 1959. 3. Walker, W. J., Cooley, D. A., McNamara, D. G., and Moser, R. H.: Corrected transposition of the great vessels, atrioventricular heart block and ventricular septal defect. A clinical triad, Circulation 17:249,- 1958. 4. Giraud. G.. Puech. P.. Latour. M.. Thevenet. A., Ohvierj G., and Hertault, J.: La trans: position corrigee des gros vaisseaux avec communications interauriculaire et interventriculaire chez l’adulte. Arch. mal. coeur 53:986, 1960. 5. Anderson, R. C., Lillehei, C. W., and Lester, R. G.: Corrected transposition of the great vessels of the heart, Pediatrics 20:626, 1957. 6. Edwards, J. E., Dry, T. J., Parker, R. L., Burchell. H. B.. Wood. E. H.. and Bulbulian. A. H.: An atlas’ of congenital anomalies of the heart and great vessels, Springfield, Ill., 19.54, Charles C Thomas Publisher. J. W., 7. Becu, L. M., Swan, H. J. C., DuShane, and Edwards, J. E.: Cardiac Clinic CXLIV. Ebstein malformation of the left atrioventricular valve in corrected transposition of the great vessels with ventricular septal defect, Proc. Staff Meet. Mavo Clin. 30:483. 195.5. H. F,, Daugherty, G. W., and Ed8. Helmholz, wards, J. E.: Cardiac Clinic CXLV. Congenital “mitral” insufficiency in association with corrected transposition of the great vessels; report of probable clinical case and review of six cases studied pathologically, Proc. Staff Meet. Mayo Clin. 31:82, 1956. 9. Espino-Vela, J., Portillo, B., Anselmi, G., de la Cruz, M. V., and Reinhold, M.: On a variety of the “corrected” type of transposition of the great vessels associated with dextrocardia. A study of two cases with autopsy report, AM. HEART J. 58:250, 1959. M. V., Anselmi, G., Cisneros, F., 10. De la Cruz, Reinhold. M.. Portillo. B.. and Esoino Vela. J.: An embryological explanation for the corrected transposition of the great vessels; additional description of the main anatomic features of this-malformation and its varieties, AM. HEART 1. 57:104. 1959. J. P.: An 11. De la Cruz,” M. V., and da Rocha, ontogenetic theory for the explanation of congenital malformations involving the truncus and conus, Aha. HEART J. 51:782, 1956. 12. Lev, M.: In Saphir, 0.: A text on systemic pathology, New York 1958, Grunne & Stratton, Inc. J. E.: In Gould, S. E.: Pathology 13. Edwards, of the heart, ed. 2, Springfield, Ill., 1960, Charles C Thomas Publisher, p. 337. 13a Ibid., p. 336. 14. Taussig, H. B.: Congenital malformation of the heart, Vol. II, revised edition, Cambridge, 1960, The Commonwealth Fund, p. 326. 14a. Ibid., p. 327. 15. Keith, J. D., Rowe, R. D., and Vlad, P.: Heart I
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disease in infancy and childhood, New York, 1958, The Macmillan Company, p. 337. 15a. Ibid., p. 516. 15b. Ibid., p. 518. 16. Kjellberg, S. R., Mannheimer, R., Rudhe, U., and Jonsson, B.: Diagnosis of congenital heart disease, ed. 2, Chicago, 1959, The Year Book Publishers, Inc., p. 719. 16a. Ibid., p. 719. 17. Wilkinson, A. H., Potts, W. J., and Lev, M.: The postmortem external appearance of con-
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genitally malformed hearts as an aid to surgical diagnosis. 1. Thoracic Sure. 39:363. 1960. 18. Davis, C: L.: Developmencof the human heart from its first appearance to the stage found in embryos of twenty paired somites, Contrib. Embryol. 19:245, 1927. 19. Kramer, T. C.: The partitioning of the truncus and conus and the formation of the membranous portion of the interventricular septum in the human heart, Am. J. Anat. 71:343, 1942.