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Transcript
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531
Vol. 2. No 3
September J983 .531-7
PEDIATRIC CARDIOLOGY
Atrioventricular Valve Abnormalities in Infancy: Two-Dimensional
Echocardiographic and Angiocardiographic Comparison
HOWARD P. GUTGESELL, MD, FACC , JOHN CHEATHAM, MD, LARRY A. LATSON, MD,
MICHAEL R. NIHILL , MD, FACC, CHARLES E. MULLINS, MD, FACC
Houston . Texas
The results of two-dimensional echocardiography and
biplane angiocardiography from 47 infants with congenital atrioventricular (AV) valve abnormalities were
compared. Eleven patients had atresia of the right AV
valve, 10 had atresia of the left AV valve, 4 had hypoplasia of the right AV valve and 5 had hypoplasia of the
left AV valve. Twelve patients had endocardial cushion
defect, three had single ventricle and two had straddling
of the left AV valve.
There was agreement between the two techniques as
to the number of AV valves present in each patient. The
echocardiographic estimate of valveanular diameter was
below normal in seven of the eight patients thought to
have a hypoplastic anulus by angiocardiography. In 10
of the 12 patients with endocardial cushion defect, there
was agreement between the two techniques as to the
presence or absence of atrial and ventricular septal defect. The chordal attachments of straddling valves were
better visualized by echocardiography; flow patterns and
effective orifice size were better demonstrated by angiocardiography.
The subcostal four chamber echocardiographic views
and cranially angulated oblique angiocardiographic views
were comparable and provided the best images for determination of the size and number of AV valves and
their relation to the atrial and ventricular septa.
The development of intracardiac operations for lesions formerly thought to be uncorrectable has heightened the need
for accurate preoperative diagnoses in infants with congenital heart disease. In addition, nonoperative techniques such
as balloon and blade atrial septostomy provide palliation in
infants with appropriate intracardiac anatomy. Therefore,
precise determination of the number, size and chordal attachments of the atrioventricular (AV) valves has become
increasingly important in the management of infants with
congenital heart disease.
Axial angiocardiography (1-3) and two-dimensional
echocardiography are diagnostic techniques that provide detailed anatomic information in children with congenital heart
disease. Axial angiocardiography, utilizing cranially angulated views in either the straight anteroposterior or oblique
projections, has been used primarily in assessment of the
atrial and ventricular septa , the left ventricular outflow tract
and the pulmonary arteries. Our initial experience suggested
that these views were also useful in assessment of AV valve
anatomy . Two-dimensional echocardiography gives improved spatial orientation compared with that available by
M-mode echocardiography. The four chamber echocardiographic views obtained from either the cardiac apex (4) or
the subcostal area (5,6) provide a frontal section of the heart
that is similar to that of the cranially angulated left anterior
oblique (hepatoclavicular) angiocardiogram .
The present study was undertaken to compare and contrast selective angiocardiography and two-dimensional
echocardiograph y in the assessment of AV valve abnormalities in infants .
From the Lillie Frank Abercrombie Section of Cardiology . Department
of Pediatrics, Baylor College of Medicine and Texas Children 's Hospital ,
Houston, Texas . This study was supported in part by Grant HL-07190
from the National Institutes of Health , U. S. Public Health Service. Bethesda . Maryland , and by Grant RR-OOI88 from the General Clinical
Research Branch of the National Institutes of Health . Manuscnpt received
January 12, 1983; revised manuscript received April 5, 1983, accepted
April 6. 1983.
Address for repnnts: Howard P. Gutgesell, MD, Pediatric Cardiology.
6621 Fannin . Houston, Texas 77030
Methods
© 1983 by the American College of Cardiol ogy
Subjects. The study group consisted of 47 infants under
2 years of age , 33 of whom were less than 6 months of age
at the time of initial evaluation . Their weights ranged from
2.5 to 10.0 kg. Eleven patient s had atresia of the right
atrioventricular (AV) valve, 10 had atresia of the left AV
valve , 4 had a patent but hypoplastic right AV valve (each
0735-1097/83/$3 00
532
GUTGESELL ET AL.
ATRIOVENTRICULAR VALVE ABNORMALITIES
associated with pulmonary valve atresia), 5 had a hypoplastic left AV valve, 12 had endocardial cushion defect
(partial AV canal in 3, complete AV canal in 9), 3 had
single ventricle with a common AV valve and 2 had AV
discordance, large ventricular septal defect and a straddling
left AV valve. In addition to their AV valve abnormalities,
17 of the patients had transposition of the great arteries, 3
had tetralogy of Fallot and 1 had total anomalous pulmonary
venous connection.
Echocardiography. Two-dimensional echocardiograms were performed with mechanical sector scanners utilizing 5 MHz transducers. Images were obtained in the
parasternal long-axis, parasternal short-axis, apical and subcostal projections. All studies were recorded on '12 inch
(1.27 em) videotape for subsequent analysis.
Echocardiograms were analyzed with particular attention to the following: 1) number of AV valves, 2) relative
and absolute size of each AV valve anulus, 3) chordal attachments, and 4) the relation of the AV valves to the atrial
septum.
Anular size was estimated by measurement of the largest
diameter of each valve ring at the proximal attachment of
the leaflets from the apical or subcostal four chamber image
(Fig. 1). For comparison, similar measurements were made
from the echocardiograms of 30 normal infants between 1
day and 12 months of age.
Figure 1. Subcostal four chamber two-dimensional echocardiogram (A) and selective right atrial angiocardiogram (B) in a 2 week
old infant with right atrioventricular AV valve atresia. In the echocardiogram, the atretic right AV valve produces a dense curvilinear
band of echoes at the inferior border of the right atrium (RA). The
dashed line illustrates the points used for estimation of the lateral
diameter of the left AV valve anulus. On the angiocardiogram,
obtained in a cranially angulated left anterior oblique projection,
all contrast material leaves the right atrium (RA) by way of the
foramen ovale into the left atrium (LA). LV = left ventricle.
lACC Vol. 2, No 3
September 1983531-7
Angiocardiography. Angiocardiograms were performed as part of cardiac catheterization in each patient. Selective
left or right atrial injections (0.8 to 1.2 cc/kg of contrast
medium) were made in 30 of the patients. These angiograms
were imaged in the cranially angulated, left anterior oblique
projection (hepatoclavicular projection) to achieve maximal
separation of the cardiac chambers.
Angiocardiograms were analyzed with respect to: 1) the
number of valves, 2) the size of the anulus of each valve,
and 3) the "commitment" of the valve with respect to the
ventricles, based on the flow pattern through the valve. The
angiocardiographic assessment of whether the anulus was
hypoplastic was subjective, based on visual comparison of
the anulus with the other AV valve, the ventricular chamber
or chambers and the overall cardiac size.
Results
Number of Atrioventricular Valves
There was complete agreement as to the number of atrioventricular (AV) valves in each patient as determined by
the two techniques. In the patients with atresia of the right
AV valve, a dense, curvilinear and relatively immobile band
of echoes was present at the inferior aspect of the right
atrium (Fig. l A). The left AV valve anulus appeared large
with mobile leaflets. Selective right atrial angiocardiograms
were performed in eight of these patients (Fig. lB). In each
patient, all contrast material left the atrium by way of the
foramen ovale. The inferior border of the atrium was smooth
except for the density produced by contrast material refluxing into the coronary sinus.
In the patients with atresia of the left AV valve, a dense
mass of echoes separated the left atrium from the ventricular
chambers (Fig. 2A). The echocardiographic features of this
tissue did not appreciably differ from those present in the
lACC Vol 2. No 3
September 1983:531-7
patients with atresia of the right AV valve. Left atrial angiocardiograms were performed in each of these patients,
and all contrast material passed through an atrial septal
defect or foramen ovale into the right atrium (Fig. 2B).
One patient with atresia of the left AV valve was initially
thought to have common atrium and a common AV valve
by echocardiography . Catheterization and angiocardiography demonstrated a small left atrium with a restrictive atrial
septal defect and atresia of the left AV valve. Review of
the echocardiograms confirmed these findings and empha
sized the need for a careful search for atrial septal tissue in
all patients with evidence of only one AV valve.
Anular Diameter
By angiocardiography, five patients were diagnosed as
having a hypoplastic left AV valve anulus (Fig. 3) and three
as having a hypoplastic right AV valve anulus. The echo-
GUTGESELL ET AL
ATRIOVENTRICULAR VALVE ABNORMALITIES
533
Figure 2. Subcostal four chamber two-dimensional echocardiogram (A) and selective left atrial angiocardiogram (B) in a 3 week
old infant with atresia of the left atrioventricular (AV) valve. There
was AV discordance, the right atrium (RA) connecting to the
anatomic left ventricle (LV). The atretic left AV valve produces
a relatively thick, immobile band of echoes at the inferior surface
of the left atrium (LA). On the left atrial angiocardiogram, the
sole egress of contrast material is through the atrial septal defect
into the right atrium.
Figure 3. Subcostal four chamber echocardiogram (A) and selective left atrial angiocardiograrn (B) in a 6 week old infant with
a hypoplastic but patent left atrioventricular(AV) valve. The anulus is 8 mm in diameter by echocardiography and the leaflets
appear thick. The angiocardiogram, obtained in a cranially angulated left anterior oblique projection, demonstrates relative hypoplasia of the left atrium (LA), left AV valve and left ventricle
(LV). RA = right atrium; RV = right ventricle.
A
l ACC Vol 2. No 3
September 1983:531-7
GUTGESELL ET AL.
ATRIOVENTRICULAR VALVE ABNORMALITIES
534
20
B
111
2
23
22
18
21
17
... ••
HI
15
20
111
18
•
....
ANULUS 17
DIAMETER18
(mm) 15
ANULUS14
DIAMETER
(mm) 13
12
14
o
13
11
10
..
0-
Il
8
3
. .. .
••
..
...
•
•
•
0
1
•
o
0
2
12
11
o
••
5
8
7
8
BODY WEIGHT (Kg)
8
II
10
Figure 4. Graph s correlating the diameter of the left (A) and right
(B) atriove ntricular (AV) valve anulus, as determined by echocardiography, with body weig ht. The solid dots are from normal
infants, the open circles from eight infant s believed to have a
hypoplastic anulus by angioc ardiography . The echographically detennined anular diameter is distinctl y less than normal in each of
the three patients with a hypopl astic right AV valve (B) and in
four of the five patients with hypopla stic left AV valve (A).
Figure 5. Subcostal four chamber two-dim ensional echocardiogram (A) and selective left atrial angiocardiogram (B) in a 7 month
old infant with atrio ventr icular (AV) discordance (ventricular inversion ) and a straddling left AV valve . In the echocardiogram ,
the medial leaflet of the left AV valve (a r r ows) passes through
the ventricular septal defect and inserts on the contralateral side
of the interventricular septum (l VS). The angiocardiograrn, performed in a cranially angulated right anterior oblique projection ,
shows the stream of contrast material passing through the left AV
anulus , then splitting into separate streams into the left (LV) and
right ventricles (RV). LA = left atrium ; RA = right atrium.
0
2
3
4
5
7
8
BODY WEIGHT (Kg)
8
II
10
cardiographic estimates of anular diameter in these patients
and the values from the 30 normal ch ildre n are shown in
Figure 4 . In th e five patients judged to have a small left A V
valve anulus by an g iocardiography , the ec hocard iograph ic
estimate of anular diamet er was clearly below th e normal
range in four a nd at th e lower limit of normal in one (F ig.
4 A) . The echographic estimate of anular diameter was below
the normal rang e in e ac h of the three patients with an an g ioc ard iogra phic appearance of right A V valve hypoplasia
(Fig.4B) .
In general, the most useful angiocardiographic techniqu e
for demonstration of anular diameter was se lective atrial
inj ec tion with the heart imaged in th e hepatoclavicular projection. The exceptio ns to this were the patients with pulmonary atre si a a nd intact ventricular se ptum , in who m right
atria l injections produced poor opacifi c ation of the right
ve ntricle and the anulus was more clearly visualized during
the late stages o f the right ventricular angiocardiogram .
lACC Vol 2, No.3
September 1983:531-7
535
GUTGESELL ET AL.
ATRIOVENTRICULAR VALVE ABNORMALITIES
Table 1. Two-Dimensional Echocardiographic and Angiocardiographic Findings in 12 Infants With Endocardial Cushion Defect
Two-Dimensional Echocardiography
Pattent
Ostium Primum
ASD
I
2
3
4
5
6
7
8
9
10
II
12
+
+
+
+
+
+
+
+
+
+
+
+
Angiocardiography
VSD
Chordal
Attachments
Ostium Pnmum
ASD
VSD
+
+
+
+
+
+
+
+
LV,RV
LV,RV
LV,RV
Crest of septum
Right side of septum
Right side of septum
Right side of septum
Right side of septum
Right side of septum
Right side of septum
LV,RV
LV,RV
+
+
+
+
+
+
+
+
+
+
+
+
+ (small)
+ (small)
+
+
+
+
+
+
+
+
ASD = atrial septal defect; LV = left ventricle; RV = right ventricle; VSD = ventncular septal defect;
defect not present.
Valve Commitment
Two patients had a "straddling" left AV valve with chordal attachments on each side of the ventricular septum. The
abnormal chordal attachments were best demonstrated by
echocardiography in the subcostal and apical four chamber
views (Fig. 5A). The abnormal flow pattern through the
valve was well demonstrated by angiocardiography. Both
of these patients had AV discordance (ventricular inversion)
with an abnormally oriented ventricular septum. As a result,
the lesion was best demonstrated by selective left atrial
injection in a cranially angulated, right anterior oblique
projection (Fig. 5B).
Two additional patients had a straddling right AV valve
in association with atresia ofthe left AV valve. The abnormal
flow patterns through these valves were best demonstrated
by cranially angulated, left anterior oblique projections.
Endocardial Cushion Defect
Echocardiography. The echocardiographic appearance
of the AV valves in patients with the various forms of
endocardial cushion defect was distinctive, and these lesions
were easily distinguished from the other conditions described in this study. Table I summarizes the echocardiographic and angiocardiographic findings in the patients with
endocardial cushion defect. In each of the 12 patients, a
large ostium primum atrial septal defect was present. The
medial portion of the AV valve apparatus was displaced
inferiorly toward the apex. In eight patients, a discrete gap
was present between the anterior bridging leaflet of the AV
valve and the crest of the ventricular septum (Fig. 6A). In
six of these patients, chordae from the anterior leaflet appeared to insert on the right side of the ventricular septum,
+
denotes defect present; - denotes
suggestive of Rastelli type B lesions (7). In two, the anterior
leaflet had no apparent attachments to the septum, the chordae connecting to papillary muscles in the respective ventricular chambers (Rastelli type C).
Each of these eight patients was thus believed to have
complete AV canal with a definitive ventricular septal defect
by echocardiography (Table 1). In two patients, the anterior
leaflet appeared to be firmly adherent to the ventricular
septum, and in another two patients, there appeared to be
a dense network of chordae between the anterior leaflet and
the ventricular septum (Fig. 6A). These four patients were
diagnosed as having partial or intermediate forms of AV
canal without distinct ventricular septal defect.
Angiocardiography. By angiocardiography, the ostium
primum atrial septal defect was clearly demonstrated by left
atrial or right upper pulmonary vein injection in the hepatoclavicular projection. The degree of attachment of the
valve leaflets to the ventricular septum was best demonstrated by left ventricular injection in this projection. In
each of the eight patients whose echocardiogram had demonstrated a distinct gap between the anterior leaflet and the
septum, the left ventricular angiocardiogram demonstrated
prompt opacification of the right ventricle, with contrast
medium passing over the crest of the ventricular septum in
systole (Fig. 6B). No early opacification of the right ventricle occurred in the two patients whose echocardiogram
showed attachment of the leaflets directly to the septum. In
the two patients with multiple chordae between the anterior
leaflet and the septum, the left ventricular angiocardiogram
demonstrated a trace of shunt from left ventricle to right
ventricle. One of these patients died and at autopsy was
found to have a dense but probe-patent network of chordae
3 to 4 mm long between the anterior bridging leaflet and
the crest of the septum.
536
GUTGESELL ET AL.
ATRIOVENTRICULAR VALVE ABNORMALITIES
Figure 6. Subcostal four chamber two-dimensional echocardiogram (A) and left ventricular angiocardiogram (B) in a 4 month
old infant with complete form of atrioventricular(AV) canal. Note
the large gap (arrow) between the anterior bridging and leaflet of
the common AV valve and the crest of the interventricular septum
(lVS). There was almost complete absence of atrial septal tissue.
The angiocardiogram performed in a cranially angulated left anterior oblique projection demonstrates the ventricularseptal defect
with shunting of dye from left (LV) to right (RV) ventricle. CA
= common atrium.
Discussion
The two imaging techniques employed in these infants
gave complementary information about the anatomy of the
atrioventricular (AV) valves and the surrounding structures.
There was complete agreement as to the number of AV
valves present. In our initial experience with echocardiography, we occasionally demonstrated two AV valves in patients previously thought to have tricuspid or mitral atresia
on the basis of cardiac catheterization and angiocardiography. In retrospect, this diagnosis had generally been based
on inability to pass a catheter through the valve orifice and
visualization of only one valve orifice by negative "washout" during ventricular injections. Conversely, we were
occasionally able to demonstrate only one AV valve by Mmode echocardiography in patients subsequently found to
have two valves . However, as demonstrated in this study,
improved angiographic and echocardiographic techniques
allow an accurate assessment of the number of AV valves
in virtually all patients. The hepatoclavicular angiocardiographic view and the subcostal echocardiographic projections display cardiac anatomy in a similar orientation, allowing easy comparison of images obtained by the two
methods .
lACC Vol 2. No 3
September 1983.531-7
AV anulus diameter: hypoplastic or atretic valves.
Knowledge of AV anulus diameter is important in planning
surgical therapy for many congenital cardiac anomalies,
especially if valve replacement is a consideration. Autopsy
data are available relating AV anulus circumference to body
size in normal children (8) . We are unaware of similar data
obtained by angiocardiography . Thus. the angiocardiographic diagnosis of a "hypoplastic" anulus is generally
subjective, based on a comparison of the anulus to the overall heart size, the other AV valves and the catheter size . In
the present study, valves diagnosed as hypoplastic by angiocardiography consistently had a diameter smaller than
normal (based on body size) when measured by echocardiography. We did not consider it justified to define the precise
limits of normal anular diameter on the basis of the relatively
small number of normal subjects, and chose to simply present the data in graphic form (Fig . 4). We are currently
measuring anular diameter in a large number of normal
children, ranging from newborn through adolescence, to
prepare growth charts relating anular diameter to body size .
We have found a good correlation between anular size estimated by echocardiography and that measured at autopsy
(9).
The atretic right and left ventricular AV valves in this
study had a similar appearance by echocardiography. They
produced a relatively thick (3 to 5 mm) immobile band of
echoes separating the atrium from the appropriate ventricle.
Thus, we assume that these patients have so-called absent
AV connection rather than an imperforate valve (10) ; however, only two patients have had autopsy confirmation .
Endocardial cushion defect: partial versus complete
AV canal. There was good agreement between echocardiography and angiocardiography in the assessment of patients
with various forms of endocardial cushion defect. The single
lACC Vol. 2, No.3
September 1983 531-7
most reliable echocardiographic feature allowing differentiation of complete AV canal from the partial or immediate
forms was the presence of a gap between the anterior bridging leaflet and the crest of the ventricular septum in the four
chamber projection, In each patient with this finding , angiocardiography demonstrated direct shunting from the left
ventricle to the right ventricle, consistent with the observations of others (11,12) . The most difficult distinction to
make by either technique was between large ostium primum
defect with intact ventricular septum and the Rastelli type
A form of AV canal with multiple chordae between the
anterior leaflet and the ventricular septum . Although no
distinct ventricular septal defect was apparent by echocardiography in these patients, a small amount of left to right
shunting was present by angiocardiography , Previous studies have also reported occasional error s in distingu ishing
partial from complete forms of AV canal (13-15) .
Straddling AV valves. The recognition of straddling
AV valves is of importance because their presence com plicates or precludes intracardiac repair of the associated
ventricular septal defect. The M-mode echocardiographic
features have been described (16,17), but recognition of
straddling valves has been greatl y facilitated by two-di mensional echocardiography (18,19). Of the available angiocardiographic techniques , we prefer ventricular injections to determine the plane of the ventricular septum, followed
by selective atrial injections with cranial angulation to separate the atria from the ventricles and then oblique angulation as required to place the ventricular septum parallel to
the X-ray beam. Contrast echocardiography with selective
atrial injections is an alternative method for studying flow
patterns through straddling AV valves .
Implications. The techniques used in this study are complementary. Echocardiography can be performed quickly
and safely , and is the first procedure performed. It provides
an outline of the intracardiac anatomy and allows cardiac
catheterization to be performed more expediently. In particular , the echocardiogram can be used to determine which
angiocardiographic projections will best delineate the intracardiac anatomy. In some instances, echocardiography may
provide sufficient information for appropriate medical or
surgical therapy . In many infants , however, cardiac catheterization is indicated as a therapeutic as well as diagnostic
procedure , Of the 47 infants in our study , 22 had balloon
or blade atrial septostomy performed at the time of initial
cardiac catheterization. If AV valve abnormalities are suspected , they are best demon strated by angiocardiography in
cranially angulated oblique projections with selective atrial
injections.
GUTGESELL ET AL
ATRIOVENTRICULAR VALVE ABNORMALITIES
537
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