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Left Atrioventricular Valve Atresia:
Clinical Management
JOHN J. MICKELL, M.D., ROBERT A. MATHEWS, M.D., SANG C. PARK, M.D.,
CORA C. LENOX, M.D., F. JAY FRICKER, M.D., WILLIAM H. NECHES, M.D.,
AND JAMES R. ZUBERBUHLER, M.D.
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SUMMARY Forty cases of left atrioventricular valve (LAV) atresia without aortic stenosis or atresia were
reviewed. Thirty-one had mitral atresia and nine had left tricuspid atresia. Eleven had associated pulmonary
outflow tract obstruction. Twenty-two (55%) underwent cardiac catheterization and 12 had more than one
study. Left atrial pressure was normal in seven infants younger than 2 weeks of age. Twelve patients had an
elevated mean left atrial pressure (16-38 mm Hg), including two who had normal left atrial pressures at an
earlier study. This suggests that an initially adequate interatrial opening has the potential to become restrictive. Therefore, balloon atrial septostomy is recommended in all patients with LAV atresia who are less than 1
month of age at initial study. Thereafter, serial cardiac catheterizations should be performed to assess changing hemodynamics.
Twenty-three patients (56%) had palliative operations to decrease left atrial hypertension (atrial septectomy) and/or optimize pulmonary blood flow (pulmonary artery banding, ductus ligation or systemic-topulmonary anastomosis). Nine survivors (23%) have been followed from 13 months to 23 years (median 7
years). Eight of these had at least one surgical procedure. Prognosis was best in patients with mild-tomoderate pulmonic stenosis and worst in cases with pulmonic atresia. Palliative surgery may improve survival
in selected patients with LAV atresia.
LEFT ATRIOVENTRICULAR VALVE (LAV)
atresia with a normal aortic valve is a rare congential
heart defect with clinical and physiologic features that
differ from aortic stenosis or atresia with a hypoplastic
left ventricle.'-8 Moreno in 1976 reviewed 86 cases of
mitral atresia with a normal aortic valve, and reported
his initial cardiac catheterization data in nine
patients.8 Only 9% in his series survived the first year
of life. Few patients have reached adolescence or
young adulthood. Although no corrective operation is
presently available for LAV atresia, survival to early
adulthood may be possible with improved surgical and
nonsurgical palliation. The purpose of this article is to
report a 23% survival rate with LAV atresia and to
review our experience with serial cardiac catheterization before and after palliative surgery in this
anomaly. Cases of left tricuspid atresia with corrected
transposition are considered together with cases of
mitral atresia because both defects exert a similar
hemodynamic effect.
Pittsburgh from 1954-1977. The diagnosis was made
by cardiac catheterization and angiocardiography in
22 patients. Autopsy confirmed the diagnosis in 11
patients. The remaining 18 patients were diagnosed at
autopsy alone. Thus, 29 patients (73%) had postmortem evaluation. Detailed pathologic findings in
those patients will be presented in a subsequent article.
Case material selected fulfilled only two basic
criteria: 1) absence of egress of blood from the left
atrium directly through a left-sided atrioventricular
valve, and 2) presence of a functional aortic valve
capable of supporting forward flow into the aortic
arch. There were 31 cases of mitral atresia and nine
cases of corrected transposition with left tricuspid
atresia. Cases with a common atrioventricular valve of
endocardial cushion defect variety straddling a ventricular septum were excluded. Thirteen cases had aortopulmonary transposition. Moreno recognized the
frequent concurrence of both aortopulmonary
transposition and pulmonic stenosis or atresia.8 He
grouped mitral atresia patients on the anatomic basis
of the presence or absence of aortopulmonary
transposition. We chose to subdivide our case material
on the physiologic basis of the presence or absence of
pulmonary outflow obstruction. Twenty-nine cases
had unobstructed pulmonary outflow (group 1). Only
four of these had aortopulmonary transposition.
Eleven cases had pulmonary outflow obstruction,
either partial (group 2A) or complete (group 2B).
There were six cases in group 2A with pulmonic
stenosis diagnosed by cardiac catheterization (systolic
gradient greater than 35 mm Hg) or autopsy. All of
these had aortopulmonary transposition. The remaining five cases (group 2B) had pulmonary atresia with a
patent ductus arteriosus. Three of these had aortopulmonary transposition. Associated cardiac lesions
Patients
Forty cases of LAV atresia with a normal aortic
valve were identified at Children's Hospital of
From the Division of Pediatric Cardiology, Children's Hospital
of Pittsburgh, and the University of Pittsburgh School of Medicine,
Pittsburgh, Pennsylvania.
Dr. Neches is a Teaching Scholar of the American Heart
Association.
Presented in part at the Eighth World Congress of Cardiology,
September 17-23, 1978, Tokyo, Japan.
Address for correspondence: Robert A. Mathews, M.D., Division
of Pediatric Cardiology, Children's Hospital of Pittsburgh, 125
DeSoto Street, Pittsburgh, Pennsylvania 15123.
Received January 16, 1979; revision accepted July 13, 1979.
Circulation 61, No. 1, 1980.
123
VOL 61, No 1, JANUARY 1980
CI RCULATION
124
TABLE 1. Associated Cardiac Lesions
Total
Group 1 Group 2A Group 2B
n = 29
n - 6
n = 5
n = 40
1
17
5
23
PDA
10
0
0
10
COA
2
0
7
5
L-SVC
4
1
0
5
APVR
1
0
0
1
TI
1
1
0
0
IAA
Abbreviations: APVR = anomalous pulmonary venous
return; COA = coarctation of the aorta; IAA = interrupted
aortic arch; L-SVC = persistent left superior vena cava;
PDA = patent ductus arteriosus; TI = tricuspid insufficiency.
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found in these patients are presented in table 1. A high
incidence of patent ductus arteriosus was found in
both groups. Coarctation of the aorta was found only
in patients with increased pulmonary blood flow.
Observations
TABLE 2. Group 1. Summary of Procedures
Catheterization
LA
Operation
Survival
(mm Hg)
Case Age
BAS/KAS Age
Type Alive Died
3m 1
5y PB, AS
12y
4y 26
lly 14
5m PB, AS
2
loy
5m 31--31 +/
8y 31
9y 38-42 + /+
5m PB, PDX 9y
3d 10
3
6y
4
5
7
Cardiac Catheterization
Twenty-two patients (55%) underwent cardiac
catheterization and angiocardiography and 12 (30%)
had more than one study. A total of 42
catheterizations were performed (tables 2 and 3). Ten
patients were younger than 2 weeks of age when
studied, including five in group 2.
Left atrial hypertension (mean pressure greater
than 15 mm Hg) was noted in 63% of patients in whom
left atrial pressures were obtained. Two of those
patients had a normal left atrial pressure at an earlier
catheterization.
Left atrial pressures were normal in seven newborns
younger than 2 weeks of age at study. Left atrial
pressures were elevated (mean 18-35 mm Hg) in eight
infants 1-5 months old at initial catheterization.
8
20
8d
8
lm 16
2m 26->7 +/+
2m 25 -45 +/
5y 30
2d 12
6y
2m PB, AS,
COX
4y
3y
6
Clinical Presentation
The median age of clinical presentation for all
patients was 10 days. Most patients in group 1
presented early in life (range 1 day to 5 months; median 12 days) with congestive heart failure with or
without a murmur and cyanosis. ECGs showed right
ventricular hypertrophy, and chest roentgenograms
showed cardiomegaly with increased pulmonary
vascular markings. Fourteen patients in group 1 underwent cardiac catheterization and 12 had operative
palliation.
Cyanosis was the usual presenting manifestation of
patients in group 2 with pulmonic stenosis (2A). The
median age of presentation was 18 days (range 1 day
to 6 weeks). Patients in group 2 with pulmonic atresia
(2B) presented with extreme cyanosis early in life
(range 1-9 days; median 1 day). ECGs showed right
ventricular predominance, and chest roentgenograms
showed decreased pulmonary vascular markings.
Eight patients in group 2 underwent cardiac
catheterization and 10 had operative palliation.
ld 12d
2y
2m 26->20 +/
lm
PB, PDX
5y
PB, AS
5y
9m
PB, PDX,
9m
ly
COX
9
7m
9m
2m
3m
20-÷7 +/+
22
18-341 +/
15-45 +/
5m
AS
5m
AS, PDX
3m
2m
2m
lm AS
2m
2m AS
2m 32
-lm
5d 15
lm
lm AS
lm 20
lm
lm PB, AS
lm 35
All
None
None
Abbreviations: AS = atrial septectomy (surgical); BAS
= balloon atrial septostomy; COX = coaretectomy; d =
days; KAS = knife atrial septostomy; LA = mean left
atrial pressure; m = months; PB = pulmonary artery
banding; PDX = patent ductus ligation; y = years.
10
11
12
13
14
15
16
17-29
-
2m
3m
-
Seven of these infants were from group 1 and the last
was a patient with pulmonic stenosis (group 2A) and a
pulmonary-to-systemic flow ratio of 1.5:1 at initial
catheterization.
Eleven patients died before the introduction of
balloon atrial septostomy in 1966.9 Subsequently,
seven patients have had an attempt at nonsurgical
enlargement of the interatrial opening at cardiac
catheterization: four patients have undergone balloon
atrial septostomy, and three patients have undergone
knife atrial septostomy.''11
Serial catheterizations were performed in eight
patients before palliative operations (table 3). Eight of
the nine survivors have had surgery and seven have
had postoperative catheterization.
LEFT AV VALVE ATRESIA/Mickell et al.
TABLE 3. Group 2. Summary of Procedures
Catheterization
T-A
Case
Group 2A
30
31
Age
6y
8y
15y
3m
3y
6y
32
ld
7m
3y
33
34
35
2m
5d
8d
(mm Hg)
BAS
Operation
Age
Type
Survival
Alive Died
15y
AS
23y
4y
AS
6y
-
ly
BT
5y
2
7
15
6
3
2m AS, WA
22
21
21
24
7
-+
18d
WA
2m
lm
18d
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Group 2B
ld WA
2y
5m
2m AS, BT
5m BT
4m
38
4m PT
2m
6d PT
39
lld
40
lld WA
lld Abbreviations: AS = atrial septectomy (surgical); BAS
= balloon atrial septostomy; BT = Blalock-Taussig anastomosis; d = days; LA = mean left atrial pressure; m
= months; PT = Potts anastomosis; WA = Waterston
*anastomosis; y = year.
36
37
ld
-
2
-
Surgery
Twenty-three patients (56%) had palliative
operations, 13 in group 1 and 10 in group 2 (tables 2
and 3). Ten patients in group 1 underwent surgical
atrial septectomy (Blalock-Hanlon), half with
simultaneous banding of the pulmonary artery. The
other three group 1 patients underwent pulmonary
artery banding without atrial septectomy.
In group 2, four patients had surgical atrial septectomy, half with simultaneous creation of a systemicto-pulmonary artery anastomosis. The remaining
seven group 2 patients had a systemic-to-pulmonary
artery anastomosis without atrial septectomy. There
were four patients with a Waterston anastomosis, two
with a Potts anastomosis and two with BlalockTaussig shunts (one bilateral).
Additional operative procedures in group 1 (table 2)
included patent ductus ligation in four patients and
coarctectomy in three. The median year of surgery for
the entire study was 1970, and only three operations
were performed before 1968.
Morbidity and Mortality
Thirty-one cases died between 2 days and 5 years of
age (median 1 month), for an overall mortality of
77%. The mortality in group 1 patients (79%) did not
differ significantly from this. However, there was a
125
disparity in overall mortality in group 2, with only a
50% mortality in group 2A and no survivors in group
2B. Nine patients died of serious medical complications not directly related to their congenital heart
defects, including septicemia in three,3 bronchopneumonia in three, intestinal malrotation with
peritonitis in one, subarachnoid hemorrhage in one
and trisomy 18 in one case diagnosed at autopsy. The
remaining 22 patients died of cardiac causes. Four
died intraoperatively and eight in the early postoperative period. There was no difference in the
perioperative mortality before and after 1971, with six
of 12 cases dying before and six of 11 dying after that
year. One patient died late postoperatively with scar
closure of an inadequate atrial septectomy noted at
autopsy. Seven patients died of congestive heart
failure. Two of the unoperated cases died at home of
probable cardiac causes by history.
The influence of operative palliation on mortality is
shown in table 4. The overall mortality for operated
patients was 65%. The mortality for patients undergoing atrial septectomy, alone and in combination with
other procedures, did not differ significantly from this.
However, only one of the eight patients who underwent atrial septectomy before 3 months of age survived. In contrast, four of the six patients who had this
procedure after 5 months of age survived. Atrial
septectomy without simultaneous pulmonary artery
banding was unsuccessful in five patients in group 1.
Only one of eight patients who received a systemic-topulmonary artery anastomosis survived.
TABLE 4. Operative Palliation and Mortality
n
Procedures
Atrial septectomy
6
Alone
4
With PA banding
2
With shunt
With PA banding and
1
coaretectomy
1
With PDA ligation
14
Total
Shunt alone
Waterston
Potts
Blalock-Taussig
Total
Mortality
4
2
2
0
1
9 (64%)
3
3
2
2
1
6
5
1
2
3
1
0
1 (33%)
0
(83%)
PA banding
With PDA ligation and
coarctectomy
With PDA ligation
Total
23
15 (65%)
Total operative palliation
Abbreviations: PA = pulmonary artery; PDA = patent
ductus arteriosus.
126
CIRCULATION
TABLE 5. Survival
Operated pts.
(n = 23)
n
%
38
Group 1
5/13
60
Group 2A
3/5
0
Group 2B
0/5
Total
8/23
35
Unoperated
pts. (n = 17)
Total
(n = 40)
n
%
n
%
1/16
0/1
6
0
-
6/29
3/6
0/5
21
50
0
6
9/40
23
1/17
There are currently nine survivors in the overall
group (23%) ranging in age from 13 months to 23
years (median 7 years). Eight of these had palliative
operations (table 5). There was a 38% survival in
group 1 and a 60% survival in group 2A with palliative
surgery. No patient in group 2B survived, despite
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palliative surgery. Medical problems in the survivors
include exercise limitation in nine, growth and
developmental delay in seven, polycythemia
(Hgb > 18 g%) in six, atrial arrhythmias in two and
scoliosis in two.
Pathology
Thirty-one cases in this series had mitral atresia and
nine had corrected transposition with left tricuspid
atresia. There were five cases with anomalies of
pulmonary venous return, including two survivors
with total anomalous pulmonary venous return
without obstruction and three cases with partial
anomalous pulmonary venous return noted at autopsy. The remainder relied entirely on an adequate interatrial opening for pulmonary venous blood to enter
the systemic circulation. The size of the interatrial
communication was measured at autopsy in 29
patients (table 6). Twenty-two had an inadequate
opening, including 16 with a patent foramen ovale
measuring 5 mm or less, and six with an unsuccessful
atrial septectomy. The interatrial opening was adequate in seven heart specimens: two with a patent
foramen ovale, three with a secundum atrial septal
TABLE 6. Interatrial Opening Measured at Autopsy
n
Type
Range (mm) Mean (mm)
PFO
16*
1-5
3
9-10
2t
9.5
ASD
3t
8-14
12
AS
6*
2t
2-6
12-20
3
16
*Inadequate.
tAdequate.
Abbreviations: AS = surgical atrial septectomy (BlalockHanlon); ASD = atrial septal defect; PFO patent foramen
ovale.
=
VOL 61, No 1, JANUARY 1980
defect and two with a successful atrial septectomy.
Pulmonary venous blood coursed through a rightsided atrioventricular valve and had direct access to
the aorta in 22 cases of double outlet ventricle. There
are six survivors (27%) with this flow pattern, including four with no identifiable ventricular septal defect
(VSD) or left ventricular chamber on catheterization
(cases 1, 30, 31 and 32).
Systemic blood flow was dependent upon an
associated VSD in the remaining 18 cases. There are
three survivors (17%) with this flow pattern (cases 2, 3
and 5), including one with a functionally restrictive
VSD (case 5) and a right ventricular systolic pressure
of 230 mm Hg on catheterization. There was no
relationship in the other 15 hearts between the size of
the VSD supporting systemic blood flow and the
length of survival.
VSDs could not be identified in seven cases, including four survivors as noted above. The remaining 33
cases, including five survivors, had VSDs ranging in
size from 1-10 mm in diameter (mean 4.6 mm). Half
were located in the membranous ventricular septum
and the rest were equally divided between posterior
and apical defects. Five hearts had multiple VSDs at
autopsy.
The VSD communicated with a posterior ventricle
in 27 cases and with an anterior outlet chamber to the
aorta in six cases. The posterior ventricles ranged
from a rudimentary slit to a ventricular chamber of
normal size. Most were small to moderate in size.
Thirteen cases had aortopulmonary transposition,
including nine of the 11 cases with pulmonary outflow
obstruction. Blood coursing through the right-sided
atrioventricular valve had direct access to the
pulmonary artery in 35 cases, including six with
pulmonic stenosis. Five cases of pulmonic atresia were
dependent on a patent ductus arteriosus for
pulmonary blood flow. There was no instance where
pulmonary blood flow was dependent on an associated
VSD.
Discussion
Survival in patients with LAV atresia and a normal
aortic valve usually depends upon factors that affect
pulmonary blood flow. A review of the literature'-8 indicates that the longest survival without palliation is in
patients with mild-to-moderate pulmonic stenosis and
either a large interatrial opening or anomalous
pulmonary venous return without obstruction.
Patients with less favorable anatomy may benefit from
palliative procedures designed to normalize
pulmonary blood flow and alleviate pulmonary venous
hypertension. In our series only one patient had survived to 5 years of age without operation. Mortality
was least with naturally occurring pulmonary outflow
tract obstruction. Patients with pulmonic atresia had
the worst prognosis.
Pulmonary artery banding or systemic-topulmonary artery anastomosis alone does not always
result in hemodynamic improvement because of coexistent lesions. Four patients in this study died at opera-
LEFT AV VALVE ATRESIA/Mickell et al.
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tion and eight did not survive the early postoperative
period. In 1953, Lam reported a case of LAV atresia
with pulmonic atresia who died of pulmonary congestion after a Pott's anastomosis.12 He suggested that
creation of an adequate interatrial communication at
the time of operation might have been desirable. The
present study includes three cases with a similar
clinical course after systemic-to-pulmonary artery
anastomosis. In 1967, Hait noted the small size of the
interatrial opening in a large series of patients with
hypoplastic left heart, and stressed the hemodynamic
significance of an adequate interatrial communication
in left atrial obstructive defects.13 His measurements
are in close agreement with those found in the present
study.
A firm diagnosis can be made only with cardiac
catheterization and selective angiography. The information obtained at cardiac catheterization is
necessary in planning the appropriate therapy. The
importance of serial cardiac catheterization is illustrated by patient 6 (table 2) who required
pulmonary banding for refractory heart failure in the
first week of life. He subsequently developed a significant left-to-right shunt through a previously unrecognized patent ductus arteriosus. After ligation of
the ductus he developed radiographic evidence of
pulmonary venous congestion. A third catheterization
at 2 months of age revealed left atrial hypertension
that had not been present on previous studies. Knife
atrial septostomy provided an adequate interatrial
opening, thus obviating the need for an additional
operative procedure in this patient and two others.
This study indicates that left atrial pressures may be
normal in newborn infants, but left atrial hypertension
can subsequently develop (table 2), especially in group
1 patients, as pulmonary blood flow increases. This
progressive functional impairment of the interatrial
opening may occur without apparent change in the
clinical status of the patient. Therefore, balloon atrial
septostomy is indicated in all newborns with LAV
atresia, whether or not there is a significant interatrial
pressure gradient. Balloon atrial septostomy alone
may be unsuccessful in infants presenting beyond 1
month of age. In these patients, a thickened interatrial
septum may necessitate surgical septectomy or knife
atrial septostomy. Pulmonary artery banding or a
systemic-to-pulmonary artery anastomosis may be indicated to provide optimal pulmonary blood flow.
Serial cardiac catheterizations are necessary during
the first few years of life to assess the adequacy of the
interatrial opening and to evaluate the effect on left
atrial presure of any palliative operation. If the interatrial opening is inadequate, knife atrial septostomy or open surgical atrial septectomy should be
performed to reduce pulmonary venous hypertension.
If surgical septectomy is necessary, an open procedure
is preferable because the left atrium is small in most
patients. An adequate interatrial opening often cannot
be obtained with closed atrial septectomy. If the
127
proper hemodynamic balance can be achieved during
infancy, the patient may survive to young adulthood.
Conclusion
LAV atresia without associated aortic stenosis or
atresia is a rare anomaly with a high mortality in early
life. There are nine survivors in our series of 40
patients. Patients with mild-to-moderate pulmonic
stenosis have the best prognosis and those with
associated pulmonic atresia the worst. Left atrial
hypertension due to an inadequate interatrial opening
was identified on serial cardiac catheterizations in
several patients. Hypertension was progressive and
not always with obvious clinical deterioration.
Although no definitive operation is presently available
for LAV atresia, survival to early adulthood is possible with palliative procedures. Repeat cardiac
catheterization should be routinely performed, especially within the first year of life and periodically
thereafter, to evaluate the size of the interatrial communication and the effectiveness of any palliative
procedure. If an inadequate interatrial opening is
found in an older infant or child, knife atrial septostomy or open surgical atrial septectomy is
necessary to relieve pulmonary venous hypertension.
It is especially important to provide an adequate interatrial opening in patients who require a systemicto-pulmonary artery anastomosis.
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Left atrioventricular valve atresia: clinical management.
J J Mickell, R A Mathews, S C Park, C C Lenox, F J Fricker, W H Neches and J R
Zuberbuhler
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Circulation. 1980;61:123-127
doi: 10.1161/01.CIR.61.1.123
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