Download Echocardiographic Features of Atrial Septal Defect

Echocardiographic Features of
Atrial Septal Defect
By MORTON A. DIAMOND, M.D., JAMES C. DILLON, M.D., CEIARLEs L. HAINE,
SONIA CHANG, B.A.,
AND
HARVEY FEIGENBAUM, M.D.
SUMMARY
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Echocardiographic studies were performed on 39 adult patients with atrial septal
defects. Findings were compared with those from normal subjects, patients with other
congenital left-to-right shunts (ventricular septal defect and patent ductus arteriosus),
patients with uncomplicated right ventricular pressure overload (pulmonic stenosis
and pulmonary hypertension), and patients with pulmonary hypertension complicated
by tricuspid regurgitation. Two echocardiographic features were assessed: 1) a right
ventricilar dimension, or RVD Index, representing the distance between the right
ventricular epicardial echoes and echoes from the right side of the interventricular
septum divided by the patient's body surface area, and 2) motion of the interventricular septum.
The increased RVD Index and abnormal septal motion observed in the patients with
atrial septal defects provided an ultrasound complex that could clearly separate these
patients from normal individuals, those with ventricular septal defect and patent
ductus arteriosus, and those with uncomplicated right ventricular pressure overload.
However, patients with tricuspid regurgitation could not be differentiated from the
group with atrial septal defects, indicating that this echocardiographic complex reflected a volume overload of the right ventricle.
Additional Indexing Words:
Ultrasound cardiography
Tricuspid regurgitation
Pulmonary hypertension
Congenital heart disease
Right ventricular overload
raphy might be of value in the diagnosis of an
atrial septal defect.9 In this study, it was noted
that patients with atrial septal defect not only
had large right ventricles, but they also
exhibited abnormal motion of the interventricular septum.
We designed the present study to determine
the usefulness of echocardiography in evaluation of patients with suspected atrial septal
defects. In so doing, we attempted to answer
the following questions: 1) How specific are
the echocardiographic findings in patients
with an atrial septal defect? Can the echocardiogram distinguish patients with an atrial
septal defect from normal individuals, from
patients with other common congenital cardiac defects causing a left-to-right shunt, from
patients with a pressure overload of the right
ventricle, and from patients with other forms
of right ventricular volume overload? 2) How
E CHOCARDIOGRAPHY is gaining increased recognition as a safe, noninvasive technique for the diagnosis of many
cardiac disorders.'-8 An earlier report, in
which the echoes from the interventricular
septum were studied and a technique for
estimation of the size of the right ventricle
wasdescribed, suggested that echocardiogFrom the Department of Medicine, Indiana
University School of Medicine, and the Krannert
Institute of Cardiology, Marion County General
Hospital, Indianapolis, Indiana.
Supported in part by the Herman C. Krannert
Fund, U. S. Public Health Service Grants HE-0981504, HE-6308, HTS-5363, and HE-5749, and the
Indiana Heart Association.
Address for reprints: Dr. Harvey Feigenbaum,
Indiana University Medical Center, 1100 West
Michigan Street, Indianapolis, Indiana 46202.
Received May 25, 1970; revision accepted for
publication September 24, 1970.
Circulation, Volume XLIII, January 1971
129
130
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sensitive is echocardiography in detecting
patients with atrial septal defects? 3) Can
echocardiography provide any quantitative
assessment of the degree of left-to-right shunt
in patients with atrial septal defects? 4) Can
the echocardiogram distinguish between an
ostium primum and an ostium secundum type
defect? 5) What effect does an elevated
pulmonary vascular resistance have on the
ultrasound findings in patients with atrial
septal defects?
Methods
The patients studied consisted of five groups.
The first group was composed of 30 healthy
subjects, ranging in age from 18-35 years, who
served as controls. The second group consisted of
patients with atrial septal defects. Of these
patients, 33 (21 female, 12 male) ranging in age
from 15-59 years, had ostium secundum atrial
septal defects diagnosed at cardiac catheterization and selective cineangiocardiography. The
remaining six patients (two female, four male)
had ostium primum defects, again diagnosed at
cardiac catheterization. The age range in the
ostium primum group was 20-31 years. In both
groups the presence and size of the shunt was
assessed by the indicator dilution technique and
by selective cineangiography. The actual pulmonary and systemic blood flows were calculated
from oximetric data by standard formulas, and
expressed as a pulmonic:systemic flow ratio. The
tlhird group was composed of 13 patients with
otlher congeniital left-to-right shunts. Seven of
these patients (age range 17-48 years) had a
patent ductus arteriosus. Another six patients,
ranging in age from 15-42 years, with proven
venitricular septal defects were also studied. The
fourth group included 14 patients (age range
24-69 years) with uncomplicated right ventricular pressure overload. Of these, eight had
conigenital pulmonic stenosis and the remaining
six had pulmonary lhypertension calused by
pulmoinary parenchymal or vascular disease. The
last group was composed of six patients (age
range 32-65 years) who had pulmonary hypertenision and functional or organic tricuspid
valvular regurgitation. Of these, three had
rhleumatic heart disease with predominant mitral
stenosis and little or no mitral insufficiency; two
had pulmonary hypertension caused by pulmonary fibrosis; and the remaining patient had
idiopathic pulmoniary hypertension.
A modification of the technique described by
Collinis et al. was used for detection of tricuspid
regurgitatioin.10) Indocyanine green was injected
inito the body of the right ventricle while blood
DIAMOND ET AL.
was sampled via a second catheter in the
superolateral portion of the right atrium. Wide
experience in this laboratory has demonstrated
that this technique gives consistently negative
results in patients without tricuspid regurgitation.
Echocardiographic examinations were carried
out with a commercially available ultrasonoscope
with a 0.5 inch, 2.25 MHz transducer with a
repetition rate of 1000/sec. The technique
employed in this laboratory was described in
detail in an earlier report.9 The patients were
studied in the recumbent position. A water
soluble gel was applied to the chest so that an
airless contact between transducer anid skin might
be produced. The transducer was placed in the
fourth intercostal space anid directed posterolaterally and slightly inferiorly with respect to the
mitral valve echoes so that strong echoes from the
posterior left ventricular wall (LVW) and
interventricular septum might be recorded (fig.
1). The posterior LVW echoes moved anteriorly,
_W
ew
X >.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sREp
.........
r
_t ~F .
_
0
,.
Figure 1
Echocardiogram from a normal sub ject demonstrating type N interventricular septal motion and a normal RVD. The LVW and LS echoes move in opposing
directions during ventricular ejection. LVW = posterior left ventricular wall, CW = chest wall, LS =
left side of the interventricular septum, RS = right
side of septum, RVD = right ventricular dimension,
= epicardial
measured in end-ventricular diastole,
suirface of the right ventricle.
REp
Circulation, Volume XLIII, January 1971
131
ECHOCARDIOGRAPHIC FEATURES OF ASD
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as the left septal (LS) echoes, the RS echoes
were satisfactory for measurement of the RVD.
All measurements were made in end-ventricular
diastole as determined from a simultaneous
electrocardiogram. The right ventricular dimension was divided by the subject's body surface
area, which provided an RVD Index expressed in
Cm/ m2. The RVD measurements were made
independently by two persons, and results were
vithin 0.5 cm of each other.
Secondly, motion of the interventricular septum
was assessed. Description of septal motion in this
study refers to LS motion. Three patterns of
septal motion were noted. Normal motion, type
N, is illustrated in figure 1. The LS echoes move
anteriorly during atrial contraction and isovolumetric ventricular contraction. With the onset of
ventricular ejection, the LS echo moves posteriorly unitil shortly after inscription of the T wave of
the electrocardiogram. Frequently a "notch" was
nioted in the LS echo just before the echo again
moved anteriorly during ventricular diastole. Two
patterns of abnormal septal motion, types A and
B, were observed. Type A motion was manifested
by both the LVW and LS echoes moving in the
same direction, anteriorly, during ventricular
Figure 2
Echocardiogram from a patient with an ostium secundunm atrial septal defect demonstrating type A
septal motion and a large RVD. Both the LVW and
LS echoes move in the same direction, anteriorly,
during ventricular ejection. Symbols same as figure 1.
toward the transducer, during ventricular
systole and posteriorly during diastole."1 Septal
echoes were obtained by increasing the "near
gain" until two nearly parallel lines, originating
from the left and right sides of the interventricular septum were recorded.
Echoes from the epicardial surface of the right
ventricle (RE,) were recorded just posterior to
the nonmoving anterior chest wall echoes.9 A
distinct RE, echo, moving in a direction opposite
to the left ventricular wall, could occasionally be
recorded (fig. 1), but usually only a group of
"fuzzy" echoes were noted. Notwithstanding the
clarity of the REP echoes, it was noted that they
originated 0.5 em posterior to the nonmoving
chest wall echoes. Therefore, when a distinct REP
echo could not be recorded, the location of the
right ventricular epicardium was estimated to be
0.5 cm posterior to the chest wall echoes.
Two specific features of the echocardiogram
were evaluated in all subjects. First was the right
ventricular dimension (RVD) representing the
distance in centimeters from the right ventricular
epicardial echo to the right septal (RS) echo (fig.
1). Although RS echoes were not as well defined
`In
or
Circulaton,
Volume XLIII. January 1971
Figure 3
Echocardiogram demonstrating type B septal motion
and a large RVD. The LS echoes are flattened during
the ventricular ejection period. Symbols same as figure 1.
DIAMOND ET AL.
132
Table 1
Patients with Atrial Septal Defect
TYPES OF SEPTAL MOTION
ABNORMAL
NORMAL
A
N
Patient
ECG
Echocardiographic data
RVD
Septal
index
motion
Hemodynamic data
PVR
(units)
Pul/Syst flow
Group A: Ostium secundum
LS
LVW
_/\,
>_
Figure 4
A line drawing comparing the normal (N) and the
two abnormal (A and B) types of septal motion demonstrated in figures 1-3.
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ejection (fig. 2). The second pattern of abnormal
septal motion, type B, was present when the
septal echoes were flattened during ventricular
ejection (fig. 3). A diagrammatic representation
of the three types of septal motion is illustrated in
figure 4.
Results
In the normal subjects the RVD Index
ranged from 0.3 to 1.1 cm/M2, with a mean
value of 0.7 cm/rn2. For males the mean value
of 0.8 cm/M2 (range 0.5-1.1) was not
significantly different from the mean value of
0.6 cm/m2 for females (range 0.3-1.1). All
normal subjects demonstrated type N interventricular septal motion.
Of the 33 patients with ostium secundum
atrial septal defects, 28 had normal or low
pulmonary vascular resistance (PVR) (normal range in this laboratory was 0.6-2.3
units). The remaining patients had PVR
values of 2.5, 3.7, 3.9, 12.8, and 18.6 units.
Regardless of the PVR, all patients with
ostium secundum atrial septal defects had an
increased RVD Index (table 1). The mean
RVD Index for all patients with secundum
defects was 2.2 cm/M2, with a range of 1.2 to
3.3. When the RVD Index was plotted against
the pulmonic:systemic blood flow ratio in
patients with a normal PVR, a linear expression was noted with a correlation coefficient of
0.64 (P < 0.001; fig. 4). Only in the three
patients with PVR values of 3.9 units or
greater was there a disproportionately high
RVD Index with respect to the pulmonic:sys-
FH
DO
IL
LR
ER
RE
RM
RC
RA
AB
MC
CL
OC
ME
JS
HL
DL
JD
GG
LK
KT
MS
LW
JF
KA
JS
PS
AH
IB
RS
AP
DC
BG
(1)
RH (1)
EK (3)
JL (2)
TO (1)
DD (2)
WM
A
0.70
0.4
A
A
0.5
1.3
A
1.9
A
0.4
A
A
0.3
B
0.8
A
2.0
A
1.0
A
A
0.8
0.4
A
A
1.5
A
0.7
A
0.6
A
0.6
A
1.0
A
0.9
A
0.3
A
0.3
1.1
A
A
0.9
A
0.1
A
0.3
A
0.2
A
A
1.8
A
2.5
A
2.7
B
3.9
N
12.8
N
18.6
B:
Group Ostium primum
1.3
A
0.6
1.5
A
0.1
A
1.7
3.1
A
0.4
2.1
A
0.4
2.1
A
0.7
3.1
2.5
1.2
1.4
2.0
3.3
1.8
2.0
1.2
2.4
1.5
2.1
2.3
1.9
2.0
3.3
2.6
2.9
1.8
1.6
2.2
2.5
2.2
2.1
1.9
3.2
2.4
1.6
2.5
1.8
2.9
3.1
3.2
2.9
2.9
1.1
2.7
2.5
4.5
3.6
2.2
2.3
2.5
2.9
1.9
2.7
1.8
2.3
3.0
3.4
5.1
2.9
2.4
2.0
2.8
2.3
2.2
3.4
4.2
2.5
1.8
2.3
2.7
1.4
Balanced
Balanced
2.5
2.5
1.7
3.6
2.7
3.2
(1) no mitral insufficiency; (2) mild mitral insufficiency; (3) moderate mitral insufficiency.
PVR = pulmonary vascular resistance; Pul/Syst
flow = pulmonic/systemic blood flow ratio.
temic flow ratio. When the RVD Index was
plotted against the pulmonary blood flow, a
correlation coefficient of 0.52 (P<0.01) was
found. As a measure of sensitivity, it should be
noted that five patients with normal PVR had
Circulation, Volume XLIII, January 1971
133
ECHOCARDIOGRAPHIC FEATURES OF ASD
ATRIAL SEPTAL DEFECT
Norma.
1
RVD
0
IASD 20I
1
0
IX ASD
2
0
Index
0
~"4.0X
3.0
2.0dvau
N~~~~~~~
T
021.0
RVD
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
(cmn/M2)
INDEX
Figure 5
Graph illustrating relationship between
RIVD
Index
flow ratio in patients
with atrtl septal defects. The three patients with
secundum defects and highest pulmonary vascular
and
pulmonic:systemic
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resistance have
blood
disproportionately increased
RVD In-
dex values.
pulmonic: systemic
blood flow
These patients,
2:1.
puhmonic: systemic
ratios
including
flow
ratio
less than
with
one
1.t1:e1
of
a
had
increased RVD Index values.
of the
Thirty-one
33
patients with
se-
cundum defects demonstrated abnormal septal
motion
(table 1). Type
A
motion
was
patients with normal
the remaining patient,
57-year-old
with a 2.2:1 shunt, had type B motion.
present
PVR;
in 27 of the 28
a
Table 2
a
woman
Of the five
patients with an elevated PVR, two
patients with PVR values of 2.5 and 2.7 units
demonstrated type A motion, and
with
which varied from none to moderate in
degree.
As noted in table 2, patients with patent
ductus arteriosus and ventricular septal defect
had an echocardiographic pattern different
from that of the patients with atrial septal
defects. All seven patients with patent ductus
arteriosus had a normal RVD Index (range
0.6-0.8 cm/M2) and demonstrated type N
septal motion.
All six patients with ventricular septal
defects had. a normal pulmonary vascular
resistance. The five patients with a left-toright shunt ratio less than 2.1:1 had a normal
RVD Index (range 0.5-1.0 cm/M2) . The
remaining patient who had a 4.2:1 left-to-right
shunt had an increased RVD Index value of
1.2 cm/M2. Motion of the interventricular
septum was type N in all the patients with
ventricular septal defect.
Patients with uncomplicated right ventricular pressure overload demonstrated distinctly
different echocardiographic findings from
those of the group with atrial septal defects.
As noted in table 3, part A, eight patients with
right ventricular pressure overload had con-
a
PVR
value
one
Patients with Patent Ductus Arteriosus and Ventricular Septal Defect
patient
of 3.9 units had type B
Patient
motion. Only the two patients with balanced
shunts (PVR of 12.8 and 18.6 units) demonstrated type N or normal septal motion.
The echocardiogram could not differentiate
between patients with ostium primum and
ostium secundum atrial septal defects. All six
patients with primum defects had a normal
PVR. The RVD Index, as noted in table 1, was
abnormally increased in all. The mean RVD
Index in this group was 2.0 cm/M2, with a
range of 1.3 to 3.1. Again, as noted in the
ostium secundum group, the RVD Index
appeared to correlate with the pulmonic:
systemic flow ratio (fig. 5). Septal motion in
all ostium primum patients was type A,
regardless of the degree of mitral insufficiency,
Cuculation, Volume XLIII,
January
1971
WM
SJ
MG
AH
CB
CR
ES
LB
CS
NH
RB
RC
SS
Echocardiographic data
RVD
Septal
motion
index
Hemodynamic data
PVR*
(units)
Pul/Syst* flow
Group A: Patent ductus arteriosus
N
2.1
0.7
N
0.6
0.7
N
0.4
0.7
0.7
0.8
0.6
0.8
N
N
N
N
0.7
6.5
0.3
0.8
Group B: Ventricular septal defect
N
0.5
0.7
0.8
0.5
1.0
1.2
0.8
N
N
N
N
N
1.0
0.1
1.0
0.3
2.1
1.5
1.4
1.9
1.9
1.9
1.8
1.2
2.0
2.1
1.4
1.7
4.2
1.1
*Estimated values.
PVR = pulmonary vascular resistance; Pul/Syst
flow = pulmonic/systemic blood flow ratio.
DIAMOND ET AL.
134
Table 3
Other Patients with Right Ventricular Overload
Echocardiographic data
Patient
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GH
GP
RV
MV
HW
JF
JM
AS
GS
ES
BM
BS
TG
CY
NF
EK
MM
RE
HG
JH
Diagnosis
RVD index
Septal motion
Hemodynamic data
Peak resting
gradient
(mm Hg)
RV
pressure
Group A: Uncomplicated pressure overload
N
36
PS
0.9
56/6
N
65
1.1
PS
90/5
11
N
PS
0.8
30/5
125
PS
1.7
N
140/12
N
66
PS
1.0
104/15
23
N
PS
0.5
52/12
N
2.2
182
PS
194/6
N
PS
0.7
60/5
23o
0
PH-emboli
1.5
Unsat.
38/2
0
3.4
Emphysema
Unsat.
88/25
0
IPH
2.7
N
104/7
0
N
IPH
2.7
96/15
0
N
2.2
PH-emboli
106/18
0
N
IPH
1.4
80/5
Group B: Pressure overload complicated by tricuspid regurgitation
A
0
Pul. Fib.
3.0
70/16
IPH
1.9
N
84/15
0
RHD w/MS
2.1
0
A
65/31
RHD w/MS
2.3
A
0
97/20
RHD w/MS
A
0
Unsat.
84/11
Pul. Fib.
A
3.9
no cath
Degree of TR
0
0
0
0
0
0
0
0
0
0
0
0
0
0
*
Mod.
Mod.
Severe
Severe
*
*Classic physical findings of tricuspid regurgitation.
PS = pulmonic valvular stenosis; PH-emboli = chronic pulmonary hypertension due to pulmonary emboli; IPH =
idiopathic pulmonary hypertension; RHD w/MS = rheumatic heart disease with mitral stenosis; Pul. Fib. = pulmonary fibrosis; RV = right ventricle; Peak resting gradient = across pulmonic valve; TR = tricuspid regurgitation; Unsat. = unsatisfactory.
genital pulmonic valvular stenosis. Six of these
patients had normal echocardiograms manifest by RVD Index values ranging from 0.5 to
1.1 cm/M2 and type N septal motion. The
remaining two patients with pulmonic stenosis, who had resting pressure gradients across
the pulmonic valve of 125 and 182 mm Hg,
respectively, had increased RVD Index values,
but the septal motion was also type N. There
were, in addition, six patients with pulmonary
hypertension with uncomplicated right ventricular pressure overload. All six patients had
increased RVD Index values. Three patients
were in congestive heart failure, manifest by
increased right ventricular end-diastolic and
right atrial mean pressures. With the exception of patient B.M., the RVD Index was
highest in those with heart failure. Septal
motion was type N or normal in these patients
with pulmonary hypertension.
The patients with right ventricular pressure
overload complicated by tricuspid regurgitation had the same echocardiographic findings
as did patients with atrial septal defects (table
3, part B). All six patients with tricuspid
regurgitation had increased RVD Index values. The mean RVD Index was 2.6 cm/Mi2,
with a range of 1.9 to 3.9. Five patients had
type A septal motion. The remaining patient
with a very high PVR value of 20.5 units
demonstrated type N septal motion.
Discussion
It is well recognized that patients with atrial
septal defects may have a murmur that sounds
identical to the innocent pulmonic systolic
murmur.12 The clinical differentiation of the
normal heart from one with an atrial septal
defect is made more difficult by the presence
of an incomplete right bundle branch electroCirculation, Volume XLIII, January 1971
ECHOCARDIOGRAPHIC FEATURES OF ASD
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cardiograph pattern in normal persons. A
simple noninvasive technique that would
enable the clinician to solve this difficult and
relatively common problem would obviously
be of value. The present study suggests that
by measuring the size of the right ventricle
(RVD Index) and assessing the motion of the
interventricular septum, echocardiography is
able to distinguish patients with atrial septal
defects from normal individuals, those with
patent ductus arteriosus and ventricular septal
defects, and those with uncomplicated right
ventricular pressure overload.
The present investigation indicates that
these echocardiographic findings, however,
cannot differentiate between secundum and
primum atrial septal defects. Furthermore,
patients with atrial septal defects demonstrated the same echocardiographic features as
did patients with tricuspid regurgitation. This
finding suggests that the echocardiographic
complex of an increased RVD Index and
anterior motion of the septum during ventricular ejection is a manifestation of right
ventricular volume overload as opposed to a
specific finding in atrial septal defect. Fortunately, the clinical differential diagnosis between tricuspid insufficiency and atrial septal
defect is not difficult.
The echocardiographic pattern seen in
patients with atrial septal defects undoubtedly
is caused in part by right ventricular dilatation. However, both the RVD Index and the
abnormal septal motion cannot be explained
by increased right ventricular blood flow
alone, since patients with ventricular septal
defects and left-to-right shunts up to 2.1:1 did
not exhibit these echocardiographic abnormalities. Even the patient who had a ventricular septal defect with a 4.2:1 shunt had only a
slightly increased RVD Index and normal
septal motion. One reasonable possibility is
that these changes are a result of the right
ventricular stroke volume being greater than
the left ventricular stroke volume. Such a
theory would be especially attractive for
explaining the septal motion since, in those
patients with atrial septal defect and balanced
shunts, the septal motion was normal. In
Circulation, Volume XLIII, January 1971
135
addition, patients with a right ventricular
pressure overload and right heart failure still
had normal septal motion unless tricuspid
regurgitation was present.
Undoubtedly, further studies are necessary
for an explanation of the mechanism for these
echocardiographic changes. Nonetheless, these
findings seem to be quite specific for right
ventricular volume overload, and they should
be very useful in the evaluation of patients
with a suspected atrial septal defect. Thus,
echocardiography should be of distinct value
in enabling the clinician to differentiate
between the normal patient and the patient
with an atrial septal defect, an often difficult
differential diagnosis.
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Circulation. 1971;43:129-135
doi: 10.1161/01.CIR.43.1.129
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