CONGENITAL
CORRECTED
TRANSPOSITION
OF
THE
GREAT
VESSELS:
A STUDY
OF
33 CASES
Gerold L. Schiebler, M.D., Jesse E. Edwards, M.D., Howard B. Burchell, M.D., Ph.D.,
James W. DuShane, M.D., Patrick A. Ongley, M.B., Ch.B., and Earl H. Wood, M.D., Ph.D.
Mayo Clinic and Mayo Foundation, Rochester, Minnesota
Read at tile Asian-Pacific Congress of Cardiology, Melbourne, Australia, May 30 to June 3, 1960.
This study was supported in part by research grants (H-4014 and H-3532) from the National Institutes
of I Icaith, Public Fleaith Service.
ADDRESS: (G.L.S.) Mayo Foundation, Rochester, Minnesota.
PumAmIcs, May, Part II, 1961
851 INTRODUCTION
J(
ARL VON ROKITANSKY’ in 1875de-scribed the hearts of two infants, a
4-month-old girl (Fig. 1) and an 11-month-old boy. In the description of the heart of the boy he noted the following features:
There was cardiornegalv, the heart being 50 mm.
long and 58 nim. wide. The left-sided ventricle was
‘er thick (8 mm.). The left atrioventricular valve
and the left-sided ventricle resembled the usual
right atrioventricular valve and right ventricle.
This ventricle had large trabeculae, and the
atrio-ventricular valve was a three-leaflet valve. The
outer and anterior leaflet of this valve was attached
to an unpaired papillary muscle bundle arising from
the apex of the heart. This muscle bundle enlarges
and extends itself anteriorly to a steep conus, which
lies in the middle of the base of the heart and
pre-sents as a small prottileratce from which the aorta
arises. The aorta is positioned somewhat left and
anterior and has three leaflets-anterior, right and
left. The right-sided ventricle is very thin (3 mm.)
and finely trabeculated, as usually seen in the
left-sided ventricle. The venous atrioventricular ostium
has a hi-valve. From the right-sided ventricle arises
a somewhat right and posteriorly positioned
pul-monary artery, with three leaflets-posterior, right,
and left. The ptiliiiontry artery arises vertically
and then forks into a division. The atria are
nor-mal, a right caval atrium and a left pulmonary
venous atrium. The membranous portion of the
ventricular septum lies on the left side of the
ostium of the pulmonary artery between the
p05-tenor and left leaflet. There the membranous
septum meets the muscular septum originating
from the posterior wall of the ventricle. The
septum is positioned between the aorta and
pul-monarv artery, and finally turns to the right to
insert on the anterior wall of the ventricle. The
pi1momiry artery and aorta are approximately of
equal size (11-12 mm. in diameter). The foramen
ovale and the ductus were clOsC(l.
In discussing these two cases under the
topic of transposition of the great vessels, von Rokitansky’ noted that “the transposi-tion of the great vessels was corrected by the position of the ventricular septum,” thus allowing venous blood to enter the pulmonary artery and arterialized blood to enter the aorta.
Since the original detailed description, similar cases have been described, usually under the term “corrected transposition of
the great vessels”. For many years, this en-tity was considered hardly more than a
mu-seum curio. However, the augmented clini-cal interest in congenital heart disease in the past decade has finally stimulated fur-ther endeavor in the elucidation of the clini-cal, hemodynamic, surgical and pathologic
features of corrected transposition of the great vessels.
Of the 33 cases of congenital corrected
transposition included in this report (Table I) some of which have been men-tioned in previous publications,2-12 three (Cases 2, 27 and 31) represent necropsy specimens from outside sources. These three patients were not evaluated clinically by the authors.
Of the 30 cases evaluated at the Mayo Clinic, in 11 there was necropsy confirma-tion, however, in four of these (Cases 3, 5, 28 and 30), pathologic examination was
\
I-
f-
e-Fic. 1. Reproduction of von Rokitansky’s’ drawing of heart with corrected transposition of great vessels (Fig. 41, page 84). Specimen was from 4-month-old girl whose death was preceded by “bronchial catarrh atelectasis.” This is a transverse section of ventricles just below origin of great vessels and atrioventricular valves. Abbreviations: a = left-sided ventricle; b= left atrioventricular ostium with three-leaflet valve; c = ostium of aorta; ci =
aorta; e = right-sided ventricle;
f
= right atrioventricular ostium with two-leaflet valve; g = ostium of pulmonary artery; It = left branch of pulmonary artery; i = ventricular septum; k = ligamentuni arteriosum; and 1= leftvertebral artery.
852 TRANSPOSITION OF GREAT VESSELS
clinical methods; all of these patients had cardiac catheterization and a few had
an-giocardiography. In all but two cases (14 and 19), cardiac catheterization was
per-formed at the Mayo Clinic.
Those cases in which necropsy showed transposition of the great vessels and inver-sion of the atrioventricular valves and the ventricular musculature, but only a
rudi-mentary or absent septum, were not in-cluded in this study. Though these cases probably fall within the family of
congeni-tal corrected transposition, we have pre-ferred to consider them as representing a type of cor triloculare biatriatum or “single ventricle”.
In some of those cases in which the diag-nosis of congenital corrected transposition was made on clinical grounds only, there
may indeed have been an associated “single
ventricle” rather than a large ventricular septal defect. However, we have not been able to separate these entities conclusively by any clinical means including cardiac
catheterization.
DEFINITION OF TERMS
The terminology in the literature and the exact meaning of terms employed by
vari-ous writers in describing cases of congenital corrected transposition are often confusing.
The term “corrected transposition” itself,
although it has dominated the literature, has not found universal acceptance. In a sense, this term implies to the reader that the transposition of the great vessels has
been functionally, if not anatomically, cor-rected, leaving no functional derangement. That this implication is not always true may
se-CASES OF CORRECTED TRANSPOSITION OF THE GREAT V1.ssE1s*
Caset
g;
‘;ez Confirmationt J’SD Ot’u’r Cardiac Fea1ureC’orreited Transpoaition i,i the Situ. Solilus Heart
I 13 (days M N + ? PL)A. ASD. 1)extroeardia with left :iortic arch. LA enlargement with short (hor(lae of left AV valve. Subvalvular and valvular pulmonic stenosis. 11yp-plaaia of PA
22 4 (Rio.) F N
+ + Ebstein anomaly of left A’ valve. Pl)1
33-i 1 F N + + Ebstein anomaly of left AV valve
ASE). Mild Ebatein anomaly of left AV valve
Eb,tein anomaly of left A%’ valve with aeeesry
orifice. PI)A
46 14 M N + P
56 M N 0 +
6 F N + + Ehatein anomaly of left A’ valve. Al)
7.3.b.7.$ 3
8 4
F N 0 + Ebstein anomaly of left AV valve. PI)A
F N + 0 l.eft AV valve leaflets are all attached to one papil-boy muele. causing “parachute (lefornilty
9 4 M C + ?
10 4 M C + P
I I .5 F (‘ + ? Ineompetenee of pulmonary valve
1 13
6 6
M
M
C (‘A
0
+
+
P ASI)
, 14 M C -f- P ASI). Pulmonary valvular ntenosis 15* 7 M S + 0 Sulivalvular and valvular pulmonic atenosia
- 16 8 F (‘A + ?
17 8 M C + +
18
19
9 M C + P
9 F CA + ?
--- M C + ? Pulmonary stenos. Aortieateno,(?)
I3’9 is M N + + Microscopic lt)stein anomaly of left AV valve
14 M S + 0 Complete interruption of aortic arch below left sub-clavian. ‘Reversing” P1)A. Pulmonary
incompe-tenee with huge PA. Aortie insufficiency?
s 17 F C + P Aortie stenosi,?
-
4f O M C.A + P5z
-
F C 0 +I)extnKardia. ASD(Z’) (1
72.3.’.1o
I F (‘ 0 ?
31 1” N 0 + Aneurysm of right PA
Iluge aneurysmal dilatation of PA. Parachute de-formity’ of right A%? valve. Accessory valve tissue between pulmonary valve an(I right AV valve.
L’l-ceration of pulmonary valve leaflet; “healed SHE”
8 33 M N + 0
9l 54 M S + 0 Pulmonary valvular stenosis
306.12 43 M N 0 + Dextrocardia. ASI). Suhpulmonic stenosis and less stenosis of pulmonary valve. Left aortie arch
512 8b710 60 M N 0 0 Normal but for corrected transposition
Corrected Transposition in the Silas Inrersus II earl
s 1 M N + 0 Complete situs inversus. Bilateral SV(’. Pulmonary valvular atresia. Pl)A. ASI). Isolate(l hevocardia
330* 3 M
5’ 0 0 Complete situs inversus. Bilateral SVC. Subvalvular pulmonic stenosis. ASD
SKey to symbols and abbreviations: + =defect present; 0 =defect absent; ?- presence or absence of mitral insufficiency could not be de termined on basis of necropsy or catheterization evidence; N =neeropsv; C =catheterization; A =angiocardiographiy; S =surgery; PDA pat ent ductus arteriosus; ASD =atrial aeptah defect; LA .left atrium; AV=atrioventricular; PA =pulmonary artery; SVC =superior vena cava and SBE =subacute bacterial endocarditis.
tSuperscript numbers indicate references in which cases have been discussed previously.
Necropsy specimens made available through the courtes, of Dr. Walter Rindskopf in Case . Dr. R. ltoveltad in Case 3, l)rs. Gregory and Scharnweber in Case 5, Dra. A. H.Wells and D. W. Vs heeher in Case 7, I)rs. James I)awson and C. alton LiHehei in (‘ase 8, l)r. John R. Camp in Case 30, and Dr. W. B. Chamberlin, Jr., in Case 31.
Still living.
II Died 48 hours after operation (necropsy refuaed).
#{182}Ded suddenly at home several weeks after evaluation. No necropsy.
854 TRANSPOSITION OF GREAT VESSELS
ries, pulmonary valvular atresia existed. Of the many alternates suggested, such as “mirror image transposition of the ventri-cles, aorta and pulmonary artery”,’
“trans-position of the ventricles and the arterial stems”,’ “mixed levocardia with transposed ventricles with complete
pseudotransposi-tion”,’5 and “inverted transposition”,16”7 perhaps the last one best describes this
ana-tomic entity. In our series, all patients had transposition of the great vessels and inver-sion of the ventricles and atrioventricular valves. Thus this phrase “inverted
transposi-tion” describes this entity without use of the term “corrected”. An erroneous implication is then avoided. However, the term “cor-rected transposition” is so firmly established
in the literature that failure to use it would not add clarity.
Since, as a result of recent surgical ac-complishments, “corrected transposition” might imply surgical correction of a com-plete (uncorrected) transposition, use of the
term “congenital corrected transposition of the great vessels” clearly conveys the thought that this malformation is present at birth.
The terms that will be used throughout
this paper will be defined below. Hereafter, congenital corrected transposition of the great vessels will be termed simply “cor-rected transposition”. It will be convenient in understanding the anatomic complexities not only of the usual type of corrected
trans-position but also of corrected transposition with situs inversus, to reflect initially upon
two types of normal hearts. The first occurs in situs solitus (Fig. 2a) (usual disposition of the organs); the second, in situs inversus (Fig. 2c) (mirror-image disposition of the
organs).
If one accepts the statement that there are two types of normal hearts, then it is comparatively simple to envision the addi-tion of corrected transposition in each (Fig.
2b and d).
The 33 cases of corrected transposition in
this study are divided into two groups: 1) 31 cases in which corrected transposition was superimposed on the situs solitus heart, and 2) two cases in which corrected
trans-position was superimposed on the situs in-versus heart. We propose to consider these two types of corrected transposition sepa-rately in different sections of the paper.
In the group of 31 cases in which cor-rected transposition was superimposed on the situs solitus heart, situs inversus was
ruled out by one of several means: 1) ne-cropsy, 2) clinical examination and 3) oper-ation.
The terms “transposition” and “inversion” will be defined because they will be
fre-quently employed in this report.
“Transposition” is defined as any altera-tion of the interrelationships of the arterial trunks and of their sites of origin from the heart. It is thus a comprehensive term and
of itself does not designate any single mal-formation.
“Inversion” means that an organ, or part of an organ, is formed as a mirror image of
the normal. In this there is an alteration in the side-to-side but not in the
ventral-dorsal#{176} relationships. Although
transposi-tion and inversion may coexist, they are separate and distinct from each other, the
one essential feature being that in inversion the ventral-dorsal relationships are pre-served, while in transposition they are dif-ferent from the normal.
The Normal Situs Solitus Heart (Fig. 2a)
In the normal situs solitus heart the
sys-temic venous channels and the coronary si-nus enter the right atrium, which on
ana-tomic examination is seen to contain the fo3sa ovalis, the limbus of the fossa ovalis,
and the pectinate muscles which terminate posteriorly in a crest called the crista ter-minalis. The right atrium empties through the tricuspid valve into the right ventricle,
which anatomically may be divided into
two portions. The caudad portion or body of the right ventricle lies directly below the tricuspid orifice, while the cephalad portion or conus lies just below the pulmonary
oThe terms “anterior” and “ventral”, and “pos-terior” and “dorsal”, are used as synonyms for
purposes of anatomic description herein, as are
“superior” and “cephalad”, and “inferior” and
SUPPLEMENT
Fic. 2. Diagrammatic portrayal of essential anatomic features of congenital corrected transposition of
great vessels in situs solitus and in situs inversus, together with features in corresponding normals. Large
diagram in each panel represents oblique section of heart taken perpendicular to plane of ventricular
septum between origins of great vessels. Thus, ventral great vessel is shaded while dorsal great vessel is
attached to heart in plane of atrioventricular valves. Part of atrioventricular valvular structure that has
continuity with semilunar valvular structure is emphasized (arrow).
In upper right-hand section of each panel is shown relationship of great vessels to each other in same
oblique projection as large diagram, and site of origin of anterior descending (A.D.) coronary artery.
Circular diagram in lower right-hand corner of each panel shows section of heart and great vessels at
plane of atrioventricular valves dorsally and at more cephalad body plane ventrally. Position of this heart
in thorax is indicated by cross section of vertebral body and sternum in stippled area about circular
diagram. Arrow and “eye” at bottom of this circular diagram indicate whether other two diagrams in
each panel are to be viewed as a right or left anterior oblique section of heart perpendicular to the
direc-tion of “eye” and arrow. Note relationship of semilunar valves to each other and to each of atrioventricular
valves in all four panels.
Following abbreviations apply to each diagram in all panels: PT. = main pulmonary artery; P. =
pulmonary valve; AD. = anterior descending coronary artery; R = right side of body; and L = left side
of body.
In right upper segment of each panel, A = aorta. In right lower circular segment, A = aortic valve and
P = pulmonary valve. Anatomic nature of atrioventricular valves (whether tricuspid or bicuspid) is
in-dicated in circular segment by number of leaflets shown.
a. Situs solitus: normal heart. b. Situs solitus: corrected transposition of great vessels. c. Situs inversus:
856 TRANSPOSITION OF GREAT VESSELS
valve. These two portions of the right yen-tricle are separated by a thick ledge of mus-cle, the crista supraventricularis, which thus
also separates the tricuspid valve from the pulmonary valve. The interior of the right ventricle has large thick trabeculae. The ventral aspect of the ventricular septum lies
more to the left than does the dorsal aspect. As a result the right ventricle is, for the most
part, a ventral ventricle and the left
ventri-cle a dorsal one.
The right ventricle empties into the
yen-trally positioned pulmonary artery, which is to the left and in front of the aorta. After passing through the lungs, the blood stream
enters the pulmonary venous bed which connects to the left atrium. The left atrium may he distinguished anatomically by the presence of the valve of the foramen ovale
and the remnant of the interatrial ostium secundum. The left atrium empties into the left ventricle through a bicuspid (mitral) valve. The left ventricle is very finely traheculated in contrast to the heavy tra-beculation of the right ventricle. The chor-dal arrangements of the mitral valve allow
each set of chordae to attach to half of each
leaflet. The large anterior leaflet, forming a portion of the wall of both the inflow and outflow portions of the left ventricle, makes
a firm connection to the aortic root by being continuous with it and portions of the left
and posterior cusps of the aortic valve. Thus the aortic and mitral valves are in part con-tinuous. The aortic valve occupies a more medial, dorsal, and caudad position than
does the pulmonary valve. The aorta at its l)ase gives rise to two coronary arteries.The left coronary artery arises above the left aor-tic sinus and is composed of a circumflex branch, which lies in the left atrioventricu-lar sulcus, and an anterior descending
coro-nary artery, which descends in the anterior interventricular sulcus and supplies the ven-tral portions of both ventricles. The right
main coronary artery arises above the right aortic sinus and lies in the right atrioventric-ular sulcus, gives off a small marginal
branch, and at the base of the posterior in-terventricular sulcus becomes the posterior
descending coronary artery. The aorta
arises dorsal and caudad to the pulmonary artery, and then passes ventral to the right
pulmonary artery, and dorsal to the left pulmonary artery.
Corrected Transposition in the Situs Solitus
Heart (Fig. 2b)
In the corrected transposition in the situs solitus heart the systemic and pulmonary venous connections and the atria are
func-tionally and anatomically identical to those of the normal situs solitus heart. There the similarity ends.
The right atrium empties into the
right-sided ventricle through a bicuspid right atrioventricular valve, whose structure and chordal arrangements resemble in mirror image the mitral valve of the normal situs solitus heart. The anterior leaflet of the right atrioventricular valve forms the wall of both the inflow and outflow tracts of the right-sided ventricle, as does the anterior
leaflet of the mitral valve in the left ventri-cle in the normal situs solitus heart. In addi-tion, the continuity between the anterior
leaflet of the mitral valve and the aortic leaflets seen in the normal situs solitus heart is comparable to the continuity between the anterior leaflet of the right atrioventricular valve and the pulmonary valve cusps in cases of corrected transposition. The inte-rior of the right-sided ventricular wall is finely trabeculated and lacks a crista supra-ventricularis, resembling in these respects
the left ventricle of the normal situs solitus heart. The right-sided ventricle has a more
dorsal and caudad location than does the right ventricle of the normal situs solitus heart.
The ventricular septum, containing a membranous portion, lies in a plane that is inverse to the ventricular septum of the
nor-mal situs solitus heart. The ventral aspect of the ventricular septum is more to the right than is the dorsal aspect. As a result, the left-sided ventricle is a more ventral one, and the right-sided ventricle a more
dorsal one. Also the position of the ventric-ular septum allows the ventrally placed
placed pulmonary valve to communicate
with the right-sided (venous) ventricle. The
l)1lm11try valve lies catidad, medial and dorsal to the aortic valve, occupying the position usually taken by the aortic valve in
the normal situs solitus heart. The pul-monary artery arises dorsal, parallel and medial to the ascending aorta.
The pulmonary veins connect to the left
atrium which in this anomaly occupies a niche-like cavity behind the infundibulurn of the left-sidled ventricle. The left atrium empties through a tricuspid left atrioventri-cular valve. This valve has the structure, in
mirror image, of the tricuspid valve of the normal situs solitus heart, having septal, an-terior and posterior leaflets. The left-sided ventricle anatomically resembles the right ventricle of normal hearts having large thick trabeculae, a crista supraventridularis and an infunclihulum. On the external sur-face of the heart, the infundihulum presents as a small protul)erance from which the
aorta originates. Internally, tile crista supra-ventricularis separates tile left atrioventric-ular and aortic valves, as in the normal situs solitus heart, where the tricuspid and
pulmonary valves are separated.
The aortic valve, situated above the in-funclibulum, is cephalad, ventral and lateral to tile pulmonary valve, taking the position usually occupiedi by tile pulmonary valve in
the normal situs solitus heart. At its base, the ventrally positioned aorta gives rise to
tWo coronary arteries. The right coronary artery arises above the right aortic sinus and
consists of an anterior descending branch which proceeds to tile anterior interventri-cular suicus, and a circumflex branch in the right atrioventricular sulcus. Tile left coro-nary artery arises above the left aortic sinus,
proceeds in the atrioventricular sulcus, and gives off a marginal branch and the poste-nor descending coronary artery. Thus the coronary arteries are tile mirror image of the normal pattern. Tile noncoronary aortic cusp is anterior, while in tile normal situs solitus heart it is posterior. Tile ascending aorta occupies a prominent ventral position (usually occupied by the pulmonary trunk
in the normal situs solitus heart) and rises
l)arahlel to tile pulmonary trunk before crossing over the left pulmonary artery.
Therefore, corrected transposition in the
situs sohitus heart may be considered as an unusual form of transposition that allows a normal route of blood flow (because tile ye-nous veiltricle is connected to tile pulmo-nary artery and the arterial ventricle to tile aorta) even tilough the ventrodorsal
rela-tio)nships of the great vessels are like that in complete (uncorrected) transposition.
Corrected transposition in the situs
soli-tus heart has been called! corrected! transpo-sition type B-3 in other puhlications.hho
Situs Inversus: Normal Heart (Fig. 2c)
Tile normal heart of the situs inversus sit-uation is in all respects a mirror image of the normal situs solitus heart (Fig. 2a).
The essential point of difference in this mir-ror-image arrangement is tile fact that the venous atrium lies on the left side and is joined to tile left-sided ventricle by a tricus-pid! atrioventricular valve. Since the
left-sided ventricle and its connections are a
mirror image of the right-sided ventricle in the normal situs solitus heart, tile crista su-praventricularis separates the left-sided
tri-cuspid valve and the pulmonary valve. The right-sided atrium is the arterial atrium, which joins tile right-sidled ventricle
through a bicuspid valve. This right-sided bicuspid valve makes continuity with the aortic valve in a mirror-image fashion of
that which occurs in the normal situs solitus heart. The relationships between tile aortic valve and! pulmonary valve are those of the normal situs solitus heart with respect to body levels, tile aortic valve lying more cau-dad than tile pulmonary valve. Tile great vessels are a mirror image of the normal si-tus sohitus arrangement with respect to right and left sides. Thus the aortic arch is on the right. However, the ventrodorsal relation-ships are the same, with the pulmonary
ar-tery ariSillg ventral to tile aorta.
Tile coronary arteries are also a mirror
image of the normal sitiis solitus arrange-ments, the anterior descending coronary ar-tery arising from the right-sided coronary
858 TRANSPOSITION OF GREAT VESSELS
Ill comparing corrected transposition in
the situs solitus heart (Fig. 2b) with the normal situs inversus heart as just de-scribed (Fig. 2c), one should note that the position of the bicuspid and tricuspid atrio-ventricular valves, the anatomic
arrange-ments of their associated ventricle, and the position of the anterior descending coronary
artery are similar.
Situs Inversu 5: Corrected Transposition
(Fig. 2d)
The rare malformation of corrected trans-position occurring in a situs inversus heart
is in all respects a mirror image of corrected transposition as it occurs in a situs solitus
heart (Fig. 2b).
As the atrioventricular valves (and their
connecting downstream intracardiac struc-tures) in corrected transposition in the situs solitus heart represent mirror images of
tilose in tile normal situs solitus heart, so in corrected transposition in the situs inversus heart these same anatomic structures are mirror images o)f those that occur in the nor-trial situs inversus heart.
The venous atrium lies on the left and connects with the left-sided ventricle through a bicuspid atrioventricular valve. The anterior leaflet of this valve makes con-tinuity with the pulmonary valve in a mir-ror-image fashion of both 1) the continuity of the right-sided atrioventricular valve with
tile aortic valve in the normal situs inversus heart and 2) the continuity of the right-sided atrioventricular valve with the
pul-monary valve in the heart with corrected transposition andi situs solitus.
The arterial atrium is on the right side.
The right-sided atrioventricular valve is tri-cuspid and is separated from the aortic
valve by tile crista supraventricularis. As in corrected transposition in situs solitus, the relationships with respect to body plane of
the aortic and pulmonary valves differ from the normal, the pulmonary valve lying cau-dad, dorsal and medial to the aortic valve. The aortic origin is ventral, lateral and
par-allel to the pulmonary artery, and the aortic arch is on the right. Again, this is a mirror-image arrangement of the great vessels in
corrected transposition in situs solitus.
Corrected transposition in situs inversus involves, in a sense, a double mirror image
of the bulboventricular portion of the heart (that is, the atrioventricular valves and their connecting downstream intracardiac structures). Thus the continuity of the bi-cuspid atrioventricular valve and the
semi-lunar valve lies on the left side, as this val-vular continuity does in the normal situs so-litus heart.
However, in corrected transposition in the situs inversus heart, this left-sided
bi-cuspid valve represents a venous atrioven-tricular valve and the semilunar valve is the
pulmonary. In contrast, in the normal situs solitus heart this same bicuspid atrioventric-ular valve lies in the arterial stream and
has continuity with the aortic valve.
In corrected transposition and situs
inver-sus, the anterior descending coronary ar-tery has its origin from the left-sided coro-nary artery and is therefore 1) a mirror
im-age of the origin of this vessel in the normal situs inversus heart and 2) a double mirror image of the origin of this vessel in the nor-mal situs solitus heart-both originating from the left-sided coronary artery.
Corrected transposition in the situs inver-sus heart has been called corrected
trans-position type B-4 in other publications.’ Two other types of corrected transposition, types B-i and B-2, have been postulated,’#{176}2#{176} but have not been encountered in this institution or in the series of Anderson
et al.20
ANALYSIS OF PATHOLOGIC MATERIAL
The material that comprises this portion of the study consists of 14 necropsy speci-mens from persons with corrected transpo-sition of the great vessels. Thirteen of these
are from cases in which corrected transposi-tion was superimposed on the situs soiitus
heart (that is, normal positions of the or-gans), and one is from a case in which cor-rected transposition was superimposed on the situs inversus heart. The patllologic
find-ings in the 13 cases will be considered in this section, while the findings in the
SUPPLEMENT
Subpulmonary stenosis in the right yen-section “Corrected Transposition in Situs
In-versus”.
Corrected Transposition in the Situs
Solitus Heart
The following detailed descriptions of the malformations and associated anomalies are based on 13 necropsy specimens, all of
which had the basic configuration of cor-rected! transposition in the situs solitus heart as previously described!.
When the thorax was opened, tile heart, often described! as globular, round or
pltItlp, usually was found to occupy tile normal position, with the apex pointing to
tile left. However, it should be emphasized that in corrected transposition in the situs solitus heart, the apex may he shifted
vary-ing degrees to tile right. This was true of Cases 1 and 30 (Fig. 3a and b), wherein tile heart occupied the mid-portion of the thoracic cavity and tile apex pointed! to the
right. These two cases should be regarded
as representing minor deviations from the 1)asic pattern. The one common
denomina-t()r of all the cases in this group is that the
collfiguratioll of tile atria was that of the situs solitus heart and showed n#{248}evidence
of inversion. The apex may be ill defined, as in Case 21, wherein the lower border of the heart was rounded, although the heart lay almost totally in tile left hemithorax.
Tile great vessels were transposed and
the corollary arteries were inverted (that is, mirror image of the normal pattern) in all 13 cases. In some cases, contributions to tile anterior interventricular sulcus were from 1)0th coronary arteries. Tile great sys-temic veins connected normally in all cases, being connected to the functional and ana-tomic right atrium. In Case 3, bilateral su-perior vena cavas were present, the right su-perior vena cava draining into the right
atrium directly and the left connecting with an enlarged coronary sinus that in turn
con-nected with the right atrium. The coronary sinus in all cases drained into the right atrium.
The atrial septum was defective at the fossa ovalis in 4 of the 13 cases. In two of
these cases, the defect was small (i by 3
mm in Case i, and 3 by 6 mm in Case 6). In Cases 4 and 30, the defect was large,
measuring 2.5 by 2.0 cm and 1.8 by 1.0 cm respectively. Five patients (Cases 1, 2, 3, 28
and 31) had a valve-competent patent for-allien ovale.
The right atrioventricular valve had two leaflets, and its configuration and chordal arrangements were a mirror image of those of tile normal mitral valve in 12 of tile 13
cases. In tile single exception, Case 28, the right atrioventricular valve had a
“para-chute deformity”, in which all the chordae were attached to a single papillary muscle
lying below the center of the valve orifice, and the valve was almost a continuous sheet of tissue in which the individual leaflets were poorly demarcated. Thus, in looking
through the atrioventricular ostium from
al)Ove, the appearance was like that of a parachute whose top had been removed. In adidition, in Case 7 there was a cleft in tile posterior leaflet of the right atrioventricular valve, and in Case 30 there were muitiple
calcified vegetations on the anterior leaflet. The ventricular septum was intact in 5 of
tile 13 specimens (Cases 5, 7, 27, 30 andl 31). In the other eight, a ventricular septal defect was present. In general, the
relation-ship o)f tile ventricular septal defect to the pulmonary valve is similar to the
relation-ship of the usual type of ventricular septal defect to the aortic valve in hearts without
corrected transposition. One exception in corrected transposition is that often a sheet of meml)ranous septum lies interposed be-tween tile pulmonary valve above and the ventricular septal defect below. From the left-sided ventricle, the ventricular septal defect is seen to lie under the septal leaflet of the left atrioventricular valve. Since, as will be seen, the chordae of this leaflet are often unusually adherent to the septal wall, the defect is obscured by the valvular tissue when viewed from the left. These septal
860 TRANSPOSITION OF GREAT VESSELS
Fi;. 3 (Case :30). Necropsv confirmation of corrected transposition in sitiis solitiis with dextrocaidia,
sub-valvtilar and valvular ptilmonic stenosis, atrial septal defect, and left atrioveutricular valvular ius,ifEiciei,c.
i. Posteroanterior roentgenograni of thorax and, b, unopened gross specimen viewed in same
prspec’-tive as is heart in roentgenogram. Prominence (A.) in roentgenogram is slla(low of transposed ascending
aorta. While in roentgenogram cardiac apex (L.A.) appears to be oil tht’ left, shadow is that of enlarged
left auricular appen(lage, and cardic apex is actually on p;ltient’s right. The anterior surface of ventricular
portion of heart is formed almost entirely b left-sided ventricle (LV.) which In-s to left of anterior
(IC-scendmg coronary artery (A. D.C.).
c. Semilunar valves as viewed from above. Aortic valve (A) is ventral, and steiiotic pti1moi;try valve
(P) is dorsal and directly behind aortic valve. This accounts for inability to visualize ptil:ioiiary ;trterv in
thoracic roentgcnogram (a) or in 1)hotograph (b) of heart. Brokeii line across plilIllolliry valve indicates
level of frontal section of heart in d.
(1.Frontal section of heart has been made in plane indicated in C, and posterior half of heart is \iewed
from in front. In outflow tract of small smooth-walled right-sided ventricle (I1.V. is a lone of
sub-pulmonary stenosis (S.P.S.). This stenosis is of more severe degree than that of pti1noiiary valve (P.V.).
II ighlv trabeculated left-sided ventricle (LV. is characteristic of learts with corrected transposition in
SUPPLEMENT
tricular Otitflo\V tract was Present in two
cases. Anatomically, this formed the coun-ter1)art of subaortic stenosis seen in normally oriented! ilearts. In Case 1, the stenosis
ap-peared to result mainly from a prominence of the ventricular septum protruding into
the subpulmonary region. In Case 30 (Fig. 3d), the subpulmonary stenosis was caused principally by a fibrous ring that encircled tile outflow tract. Attachments of this ring
iflcludle(l the ventricular septum and the
Veiltricular aspect of the anterior leaflet of
tile right atrioventricular valve.
Tile leaflets of the pulmonary valve were normal in 10 specimens. The three excep-tions mcludled Case 28, in which there were a healed ulceration on one leaflet (probably a manifestation of healed subacute bacte-rial endocarditis) and a fold! of accessory valve tissue between the pulmonary valve and the. rigilt atrioventricular valve; Case 30, in which, in addition to the subvalvular
stenosis, there was fusion of the leaflets (Fig. 3c) which represented additional, but
less, obstruction to pulmonary flow; and Case 1, in which there was a peculiar pul-mo)liary valve composed of nonspecific connective tissue with several tiny perfo-rations in it. Tilis obviously was a severe barrier to pulmonary flow.
Tile’ pulmonary artery was coilsidlered to .be normal ill caliber in only one patient
(Case 31). In two Otilers, each with sub-pulmonary and! pulmonary valvular steno-sis (Cases 1 and! 30), the artery was smaller than normai. In all otilers the artery was
collsid!eredl to l)e enlarged. In each case of
enlargement there was ready explanatioll in tile form of pulmonary hypertension from an associated! ventricular septal dlefect, pat-ent ductus arteriosus, or left atrioventricular valvular incompetence. In Case 27, tilere was an aneurysm of the right Pulmonary artery, and in Case 28 the pulmonary trunk
was of such aneurysmal proportions that it formed! the upper left border of the cardiac silhouette roentgenographically.
The pulmonary veins were all normally connected to tile left atrium. Tile left-sidled! atrioventricular valve was deformed in 11 of the 13 cases. The tendency was for the
deformity to assume the left-sided Eb-stein4 pattern. This occurred in seven cases. In this deformity, tile septal and dorsal
leaf-lets were attached to the wall of tile
left-Sidled! ventricle, and tile basal attachments
of the leaflets were to the left ventrkular vall at varying levels below tile annulus fi-brosus. In three cases (2, 3 and 5), the
Eb-stein-type deformity might he described as cOfllplete, while in the other four cases (4, 6, 7 and 21) the Ebstein-type dieformity was present to only a slight or moderate degree.
In these instances, the basal attachments of either the posterior or tile septal cusp were to the left ventricular wall. In these cases there was a strong tendlency for tile chordae
tendineae of the septal and posterior cusps to he fused and short. In this way, the de-formed chord!ae seemed to exert’ an uncom-mon degree of restraint upon the involved
leaflets.
In Case 5 (Fig. 4), in which a complete variety of tile left-sided Ebstein-type mal-formation had! occurred, there was an
acces-sory orifice in the anterior cusp (Fig. 4c). In each of tile cases in which some dlegree of left-sided Ebstein deformity existed
(ex-cept Case 4) there was ample evidence of valvular incompetence. In all cases in
\Vilicil tile left-sided Ebstein-type deformity
was present, whatever its degree, the
an-tenor leaflet was the most normal, while the
posterior andi septal leaflets were mal-formed!, fused, poorly demarcated,
per-forated! with multiple small openings, and attached by multiple small chordae to the
ventricular wall. The leaflet derangement
is similar to that seen in the usual Ebstein
anomaly.
Of the remaining four patients with de-formed left atrioventricular valves, tilree (Cases 1, 27 and 30) also had evidence of left atrioventricular valvular incompetence, caused by abnormal structure of leaflets or
cilordal shortening and malinsertion. Again,
tile posterior and septal leaflets were the
most malformed!. Tile fourth patient (Case 8) had a parachute deformity of the left atnioventricular valve (similar to that. de-scribed in Case 28 in the right
de-862 TRANSPOSITION OF GREAT VESSELS
Fic. 4 (Case 5). Corrected transposition in sittis solitus, left-sided Ebstein malformation, and narrowly
patent ductus arteriosus in a 2-year-old boy.
a. Right atrium (HA.), right-sided ventricle (R.V.) and atrioventricular valve. Structure of right
atrio-ventricular valve is a mirror image of that of normal mitral valve. Fossa ovalis is noniial.
b. Right-sided ventricle (R.V.), pulmonary valve (P.V.) and main pulmonary artery (PT.). Smooth
contour of right-sided ventricular wall and shape of cavity are similar to those of left ventricle in normal
situs solitus heart. Continuity of right atrioventricular and pulmonary valvular tissues is like that vhich
occurs between mitral and aortic valves in normal hearts. Pulmonary artery is wide, and ventricular
septum intact.
c. View of large, thickened left atrium (L.A.) and “atrialized ventricle.” True annulus may ie seen as
a distinct crescent across middle of illustration. Left-sided “Ebstein” malformation is present with part of
left atrioventricular valvular tissue malformed and attached to wall of left-sided ventricle (L.\T.).
Photo-micrograph of this area is shown in Figure 5a. Accessory left atrioventricular orifice is present directly
below main orifice, which is indicated by probe.
d. Left-sided ventricle and aorta (A.). Note heavy trabeculation of left-sided ventricular wall. Crista
supraventricularis (CS.) separates left atrioventricular valve (“M.” V.) and aortic valve (A.V.). Anatomic
relationships are in mirror image of those that occur be’ween heart and pulmonary artery in normal
formity was unaccompanied by any evi-dlence of valvular incompetence. In Case 30 there were, in addition, multiple
calcifi-cations imbedded in all leaflets.
Tile left atrium was often abnormal, re-flecting the effects of the high incidence of associated ventricular septal defect and
the even higher incidence of deformity of tile left atrioventricular valve with incom-petence. Of the 13 cases in this group, the left atrium showed slight enlargement in 3 and gross enlargement in 10. In the three patients with slight enlargement, two had
velltricular septal defects (Cases 8 and 28) and no evidence for incompetency of the left atrioventricular valve; in the third
(Case 31) no explanation for the slight en-largement could be uncovered.
In the other 10 cases, wherein tile left
atrium was grossly enlarged, the endocar-dium was white. Histologic examination showed deposition of thin strands of elastic
tissue in the endocardium. Five of these 10 cases (6, 7, 21, 27 and 30) demonstrated
“jet lesions”,8,9 which are thought to result
from action of the regurgitant stream in
val-vular incompetence upon the atriai
endocar-dium. In Cases 27 and 30 there were
nu-meroits corrugations on the endocardial
sur-face, and, in addition, in Case 27 there was
an adherent thrombus in the left atrial
ap-pendage. A supravalvular fibrous ring,
com-plete in Cases 7 and 21 and partial in Case 6, was also thought to be part of the patho-logic picture seen with valvular incompe-tence.8 The supravalvular fibrous ring in Cases 7 and 21 appeared to have a stenotic effect upon the egress of left atrial blood.
The left ventricle in cases in which there
was a complete degree of left-sided Eb-stein-type deformity showed the “atrialized” portion to have a thinner wall than that
portion of the ventricle which lay distal to tile valve (Fig. 5). Because of the nature of the associated defects, the left-sided ven-tricle was usually enlarged and hyper-trophied, although in the “complete” left-sided Ebstein-type deformity the volume was distinctly diminished (Fig. 4d).
In no case was there any evidence of sub-aortic stenosis, which in this pathologic
entity would be anatomic infiindibular ste-nosis. The aortic valve in all specimens was
normal. The aorta itself was normal in all cases, without evidence of coarctation, and
a left aortic arch was present in all cases. The ductus arteriosus was patent in four patients (Cases 1, 2, 5 and 7), wherein the youngest patient was 13 days Old!, while tile others ranged in age from 21/2 months to 3 years. The internal lumen in three of tile
cases varied from 2 to 4 mm, while in the fourth (Case 7) the ductus was described
as “large”.
On review of the literature of cases
re-ported, or interpreted by others, to be
in-stances of corrected transposition,” 3-15, I 58I1 it is easy to understand Spitzer’s com-ment11’17 that “cases reported in the
litera-ture frequently are unable to offer a clear
picture of the finer details of this anomaly”.
This confusion is not greatly clarified by limiting oneself to necropsy reports.
If one arbitrarily accepts tilose necropsy
cases reported, or reviewed by others, as
rep-resenting types of corrected transposition,
a classification is difficult to evolve. Several broad observations may, however, be made. Although many different defects or
combi-nations of defects may be present in hearts with corrected transposition, our analysis of the reported cases shows that a ventricular septal defect is by far the most common re-ported associated malformation. This defect
may be so large that only a rudimentary septum may exist, so that in essence a
“sin-gle ventricle” is present.30’ 38, 39, 55, 60, 64
De-fects in the atrial septum are much less fre-quent. In this survey of the literature we
found that the next most common associ-ated anomalies were pulmonic stenosis or atresia, patent ductus arteriosus, and
dex-trocardia. In at least three cases20’5#{176} the
patent ductus was “reversing”. Coarctation
of the aorta was present in some
cases.15’ l5.3, 27, 50, 56, 73,55
Some authors include in the category, “corected transposition,” cases in which
the great vessels arise from the same
re-864 TRANSPOSITION OF GREAT VESSELS
Fin. 5. Low-power photomicrographs of sections through left atrioventricular valve and adjacent
struc-tures in three cases of corrected transposition in situs sohtus, demonstratitig different degrees of left-Si(led
“Ebsteiii” malformation.
a (Case 5). Section through posterior leaflet. Leaflet takes origin from left ventricular ‘all at
con-siderable distance from annulus fibrosus. Because of abnormal attaclinu-i it of valvular tissue, a portion
of left-sided ventricle joins left atrium in forming receiving chamber. L.A. = left atrial wall; LV. =
functional left-sided ventricular cavity. Gross illustrations of this heart appear in figure 4a to il
electro-cardiogram in figure 7a, aiid roentgenograns in figures fib and Sc and il.
b (Case 7). Section through septal leaflet of left atrioventricular valve and adjacent atrial septum and
ventricular septum (VS.). Septal leaflet originates from septal wall of left-sided ventricle below annulus
fhrosus (A.F.), but closer to latter than is true in case illustrated in a. Left atrium shows focus of fibrous
tissue (J.L.) considered to be a jet lesion resulting from effects of insufficiency of left atrioventricular
valve. L.A. = left atrial cavity; LV. = left-sided ventricular cavity; HA. = right atrial cavity; H.V. =
right-sided ventricular cavity; and AL. = aiterior leaflet of right atrioventricular valve.
c (Case 21). Slight (legree of Ebstein deformity. Section through posterior leaflet (P.L.) Leaflet takes
origin from left-sided ventricular wall (LV.) just below annulus fibrosus (A.F.). Tissue (j.L.) is
con-sidered to be a jet lesion as are elevations in mural endocardium of left atrium (L.A.).
ported cases’ the posterior pulmonary
artery “overrode” the septum hut in all
other features fitted the description of
cor-rected ‘transposition given in tile present paper.
On rare occasions, tile bicuspid! right atri-oventricular valve may be ‘anomalous, with atresia5’ or abnormal chordlal insertions23’ being present. However, malformations of the three-leaflet left atrioventricular valve are far more frequent in our material and have only recently been emphasized. One of the central themes of this
communica-tion is that lesions of the left atrioventricu-lar valve are so common that they should be considered almost a basic part of this pathologic entity, corrected transposition.
it is particularly important in c!ealing with
cases of corrected! transposition to examine
tile left atrioveiltricular valve and
surround!-ing structures carefully for evidence of
val-vular insufficiency when no septal defect or otiler obvious lesiolls are associated, before concludling that tile inversion of the
atrio-veiltridular i’alves and! the veiltricular
mus-culature was the sole genesis of tile
pa-tiellts difficulties.
Tile two original patients studie(l by von Rokitanskv’ Iladi no septal defects; yet botil
died in infancy. In one of these cases, tile
description and photograph (Fig. 1) reveal a large, thickened, left-sided ventricle and a wide left atrioventricu!ar valve ring. One
may surmise that perhaps another lesioll existed which was not described.
SUPPLEMENT
tile case of dextrocardia reported by Graan-boom42, in which he stated that no septal defects were present and all tile valves were well formed and completely normal. How-ever, in tile original necropsy description by
Reddingius9 in this same case in the Dutch
literature, a translation#{176} of the notations on the left atrioventricular valve indicates that it was not normal. Some of the leaflets were attached to tile ventricular wall below tile annulus fibrosus, and thus this is a case of left-sided Ebstein-type malformation. A
similar case was described by Kernen5#{176}
(Case 1) in which the lateral and posterior
medial leaflets of the left atrioventricular
valve attached! directly or by very tilick
short chordae to the valI of the left-sided ventricle. Thus the leaflets were depressed about half way into the ventricle.
It is important to note that on very rare occasions a left-sided Ebstein-type malfor-mation may occur in patients without cor-rected transposition of tile great vessels.
Other cases have been reported in which
the left atrioventricular valve leaflets or the chordal insertions were abnormal. Wurm55
reported a patient who had chordae
tendineae of the medial anterior and pos-terior leaflets that were described as being only 2.5 mm long. These chordae arose from the parietal endocardium and were attached to the leaflets in an abnormal way that appeared to decrease mobility of the leaflets. Walmsley’4 and SatoT3 reported cases in which tile anterior leaflet of the left
atrioventricular valve was cleft, while
Sha-ner and Adams76 and Shaner77 described a
cleft in the septal leaflet of the left
atrio-ventricular valve.
Other forms of anomaly of the left
atrio-ventricular valve have been noted. Thus, both stenosis (“mitral” stenosis)#{176}’52, 79 and
atresia (“mitral” atresia)’8’ 20, 25, 26. 31 have
been reported in cases of corrected trans-position. Hence, although anomalies of the
three-leaflet left atrioventricular valve usu-ally produce incompetence, the spectrum includes instances in which stenosis or
atre-sia is present. Instances from the Mayo
#{176}Translation by Drs. Walter Beck and Cornelis Wagenvoort.
Clinic files of “mitral” atresia in which tle
configuration of the heart resembled
cor-recte! transposition are not includled in this study.
Examinations of the conduction system in specimens with corrected transposition have been reported.i4457157 Sato4 and!
Hell-mer45 botil noted that there was inversion
of the conduction system, so that the
ana-tomic “left” bund!le was placed! Oil tile right-sided ventricular wall. As Sato73 concluded, the mirror-image arrangement of the con-ductiori system was in concert witil tile other mirror-image arrangements in corrected!
transposition.
Walmsley’ in his case report noted that,
in corrected transposition in order to reach
tile ventricular septum, tile course of tile stem of the atrioventricular bundle through the fibrous tissue at the base of the ventricles must be much longer when there in inver-sion of the ventricles and tile ventricular septum. This extra traversal distance is re-quired because in corrected transposition
the dorsal and cephalad portion of tile ‘en-tricular septum is attached! to tile base of tile
left atrium just to the left of the atrial
sep-tum. Since, as Yater et al.57 noted, the atrio-ventricular node in corrected transposition and situs solitus is in tile normal position on
the floor of tile rigilt atrium, this anatomic arrangement requires that the atrioventricu-lar bundle take a longer pathway from the atrioventricular node to the ventricular sep-tum. In contrast, in the normal situs solitus heart, the dorsal and cephalad portion of
tile ventricular septum attaches just to the
right of the atrial septum and thus the
ven-tricular septum lies in closer proximity to the atrioventricular node.
On microscopic examination, Walmsley”t noted fibrosis in the main stem of the atri-oventricular bundle, which he felt was the cause of complete heart block in his patient.
Yater and associates,’57 in two patients
with congential heart block, both of whom in later years were noted by others to repre-sent examples of corrected transposition,2’ “
866 TRANSPOSITION OF GREAT VESSELS
His, which could have accounted for the congenital heart block.
INCIDENCE
The incidence of corrected transposition
in the Mayo Clinic pathologic collection may be gauged from the report of Fontana,5 who studied 357 specimens of congenital
cardiac malformations, among which were 5 specimens of corrected transposition. Four of these (Cases 3, 7, 27 and 31) are in-cluded in the group of 14 specimens that comprise the total pathologic part of this study.
The incidence of corrected transposition, as judged by a survey of the world litera-ture, obviously depends upon its recognition and reporting.
As noted previously, von Rokitansky’ originally reported two cases. Sir Arthur
Keith,7 in his Hunterian lectures, discussed two other cases that could well be exam-pies of corrected transposition.
Abbott21’22 in her analysis of 1,000 ne-cropsy cases of congenital heart disease in-cluded six cases in four24’59’62 of which the anomaly of the great vessels was called the
primary disease. In addition, Abbott’s atlas2l
contains the case of Roos.23
Cardell,19 in 1956, reported one additional
case and reviewed the literature. From this, he accepted 24 other cases as meeting his criteria for corrected transposition.
Ander-son et al.20 reported 17 cases in detail and
mentioned 7 others; this same series now
totals more than 40 cases.9’
Cases reported, reviewed or interpreted by others as representing various types of
corrected transposition now number ap-proximately 100. Most of these have been reported within the past several years.
EMBRYOLOGY
The embryologic explanation of corrected transposition has been a matter of debate
since it was originally considered.
The recent theories of de la Cruz et al.92
are entirely compatible with the necropsy material in our collection. These authors ex-pressed the belief that the anatomic picture
of corrected transposition (in the situs
soil-tus heart) is caused by the bulboventricular loop going to the left plus the lack of spiral
rotation of the truncoconal septum. This gives rise to a straight truncoconal septum,
an abnormality that is functionally “cor-rected” when attached to the anatomically anchored (and thus normally positioned)
atria.
The anomaly of corrected transposition
is not limited to man, as Shaner77 has ob-served it in a 50-mm pig embryo.
PRENATAL HISTORY
Analysis of the prenatal history of the
pa-tients in our series gave no obvious clue to the genesis of this malformation. One of the
patients was born prematurely by weight standards (information available in 21 of the
33 patients).
Similar findings were present in the
re-view of the cases from the world literature. Only rarely did a patient87 not have a nor-mal birth weight, and (where mentioned) the prenatal history was similarly unre-warding in pointing to any specific etiologic factor.
In our total series of 33 patients. 31 had known birth data. Of these 31 patients, 24 (77%) were born in the 6-month period of August to January inclusive. Furthermore, 13 of the 31 (42%) were born in the last
quarter of the year. This percentage is strik-ingly similar to that reported by Anderson
et al.,20 in whose series 7 of 17 (41%) were born in the last quarter of the year.
Whether this incidence late in the year is caused by maternal infections of the late winter or early spring is a matter of conjec-ture.
FAMILY HISTORY
Detailed family information was avail-able in 30 of the 33 cases. There was no known evidence of congenital heart disease
in any of the parents of these patients or in any of 71 known siblings. Patient 26 alleg-edly had a nephew with congenital heart disease and a sister with rheumatic heart
disease.
In the world literature, there is as yet no
transposition. Instances in which a patient with corrected transposition had a sibling
with congenital heart disease have been re-ported.45’70’75 In one of these7#{176} there was consanguinity between the parents.
SEX INCIDENCE
Twenty-one of the 33 patients were males
(64%). The sex incidence in corrected transposition was thought to be equal on the
basis of the reviews of the literature con-ductec! by CardelP9 and Fontana.5
How-ever, in the recent series reported by An-derson Ct al.20 13 of the 17 patients (76%)
were males. This indicates that in large
per-sonal series the number of males will ex-ceed tile number of females. This male pre-ponderance is not unexpected!, as in com-plete (that is, uncorrected) transposition there is also a male dominance.49
SYMPTOMS
In patients whose sole abnormality is
cor-rected transposition of the great vessels, there is no basic functional derangement, and consequently no symptoms. In our
ser-ies, one case (Case 31) was an example of that unusual condition of corrected transpo-sition without associated cardiac defects.
Until death at age 60, this patient had no cardiovascular signs or symptoms. Platzer’s61 recent case appears to fall in this category.
How many asymptomatic persons with corrected transposition who never come to
necropsy or whose condition masquerades
as rheumatic mitral incompetence is a mat-ter of conjecture. However, in the patient with corrected transposition, there exists an anatomic basis for possible functional
de-rangement. As noted previously, the con-duction pathway from the atrioventricular
node to tile ventricular septum is thought to be longer in corrected transposition than in the normal heart. This added length may be the reason why the conduction pathway is unusually prone to be affected by lesions.
The manifestations of these lesions are conduction disturbances that may be
pres-ent at birth or appear later in life. When the conduction abnormality is severe enough to cause second or third degree
heart block, then the patient with corrected
transposition may have symptoms based solely on his heart block. Such a case was not present in our series.
In all the other 32 cases in this series, the symptoms were dependent upon the pres-ence and nature of the associated defect, most often a ventricular septal defect, left atrioventricular valvular insufficiency or pulmonic stenosis. Superimposed heart block may be associated with each of these defects. In accordance with the type and
severity of these associated defects, all of the 32 patients had symptoms by the age of
3 years, and 24 of the 32 had symptoms during the first month of life.
In this neonatal period, cyanosis,
tachyp-nea and poor gain in weight were most com-monly noted. Later in infancy and during childhood, repeated pulmonary infections, congestive heart failure (manifested most often by bouts of pulmonary edema),
cya-nosis, tachypnea, dyspnea on exertion, poor gain in weight, and attacks of tachycardia were frequently observed. Many of these
symptoms and signs would be expected in any child of similar age with a large
ventric-ular septal defect.
Those individuals surviving to adulthood
suffered mainly from decreased exercise tolerance and terminally from cardiac
fail-ure.
PHYSICAL EXAMINATION
The physical examination is of limited value in diagnosing corrected transposition.
The following descriptions of physical signs that may alert the clinician to include corrected transposition in his differential diagnosis apply to those patients who have corrected transposition with situs solitus, though they are applicable in mirror image to corrected transposition with situs
inver-sus. These physical signs include a second
heart sound in the second left intercostal space which may be palpable and much louder than normal. This loud sound is
868 TRANSPOSITION OF GREAT VESSELS
of the aortic valve. Thus the diagnosis of pulmonary hypertension may be erroneously
made, since the sound may be thought to be caused by a normally positioned pul-monic valve; this occurred in Case 26.
Also, since corrected transposition is fre-quently complicated by 2:1 or complete
heart block, the resultant bradycardia should alert the clinician to the possibility
that corrected transposition may be present. Additional cardiac anomalies in association with 2:1 or complete heart block are
fre-quent enough, so that any patient with the
cO1Tli)inatiOn of 2:1 or complete heart block and congenital cardiac disease should be
suspected of having corrected transposi-tion.
Since corrected transposition is commonly
associated with left atrioventricular val-vular incompetence, ventricular septal
de-fects or pulmonic stenosis, then tile physical findings are similar to those produced by
these same defects when present without corrected! transposition.
However, when the history indicates con-genital cardiac disease and the ausculta-tory findings of left atrioventricular valvular
diseasc are present, then corrected trans-position has to be suspected because anomalies of the left atrioventricular valve
are so frequent in this malformation.
Furthermore, pulmonic stenosis, when present in corrected transposition, results in a systolic murmur that is in a different
po-sition from the murmur of pulmonic
steno-sis in tile normal heart, since the pulmonic valve is diorSal, caudlad and medial to its lo-cation in the normal lleart. This systolic murmur in corrected transposition, while it
still may be maximal to the left of the
ster-num, is more caud!ad than usual, in about the third intercostal space; or the maximal intensity of the murmur may be just to the right of the sternum lose to the usual “aor-tic area” in the normally oriented heart.
Thus, the position of tile murmur and its transmission to the vessels of the right side of tile neck are suggestive of the diagnosis of aortic stenosis in a normal situs solitus heart, \viler in actuality pulmonic stenosis in a ilealt with corrected trausposition and
situs solitus is present. This occurred in
Cases 14 and 29.
Conversely, the diagnosis of pulmonic stenosis in a normal heart could! be made, when actually aortic stenosis in a heart with
corrected transposition was present. This we have not observed in our series.
Similar physical findings have been
de-scribed2o52 in other series of cases of
cor-rected transposition.
NONCARDIAC ANOMALIES
Associated noncardiac anomalies in this
series were uncommon. These consisted of metatarsus varus of the left foot in Case 8, congenital ptosis of both upper hd!s in Case
25, and a congenital coloboma of the right optic disk, an ectopic kidney at the right
pelvic brim and a benign hepatoma of the liver in Case 5.
Corrected transposition in the cases re-ported in the literature also were only rarely associated with noncardiac
anoma-lies. The exception was partial or total situs
inversus. The concept may then be
broached that, since corrected transposition may be viewed as situs inversus of tile bul-boventricular portion of the heart, partial or total situs inversus of the other visceral organs is in concert with this theme.
This paucity of associated noncardiac anomalies in corrected transposition is
simi-lar to the paucity of these same anomalies in complete (that is, “uncorrected”)
trans-position.’#{176}
ROENTGENOLOGIC FEATURES
The anteroposterior thoracic
roentgeno-grams in 32 cases were reviewed; roentgen-ograms were not available in one case
(Case 32).
The following observations were made from a study of the 31 cases of corrected
transposition in the situs sohtus ileart. In these, the thoracic roentgenogram showed wide variation in tile cardiac contour and in the nature of the pulmonary vasculature,
