Download Echocardiography in the Normal Neonate

Echocardiography in the Normal Neonate
By ROBERT SOLINGER, M.D., FRANCISCO ELBL, M.D.,
AND
KAREEM MINHAS, M.D.
SUMMARY
Utilizing the atrioventricular and semilunar valves as ultrasonic landmarks, a simple reproducible technic is described for the ultrasonic evaluation of the heart and its great vessels in
the normal neonate. The importance of the clinical application of this method is discussed.
Echocardiographic studies were performed on 240 normal newborns. Qualitative assessment
was made of the interrelationships of the pulmonary, aortic, tricuspid, and mitral valves, and of
interventricular septal motion. Quantitative norms were obtained for the following parameters:
amplitude of motion of anterior leaflets of tricuspid and mitral valves, anteroposterior diameter
of the ventricular and left atrial cavities, thickness of ventricular walls and interventricular septum, outside diameter of aortic and pulmonary roots, and interaortic and interpulmonary cusp
distances.
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
Additional Indexing Words:
Aortic valve
Echocardiographic profile
Left ventricular cavity
Mitral valve
Tricuspid valve
Ultrasoundcardiography
Interventricular septum
Left atrial cavity
Pulmonary valve
Right ventricular cavity
E CHOCARDIOGRAPHY as a painless, atraumatic, and noninvasive technic is ideally
suited to the study of normal and abnormal hearts.
Since its introduction in 1954 by Edler and Hertz,'
pulsed reflected ultrasound has proved to be a
useful tool in adults for the evaluation of a number
of acquired2-7 and congenital8-11 lesions. It has also
standardized technic for the ultrasonic evaluation of
the heart and its great vessels in neonates and
infants and to present data obtained from a study
of normal neonates.
Materials and Methods
Ultrasound examinations were performed on 240
neonates (table 1) who had normal physical examinations, electrocardiograms, and plain chest roentgenograms. The study group consisted of 123 males and 117
females divided into 10 half-pound groups ranging from
5 to 10 lb (2.27-4.54 kg). The majority were studied
during the first 2 days of life, the earliest at 1132 hours of
life, and the latest on the eighth day.
All cardiac echograms were recorded on Polaroid film
using a Smith-Kline Ekoline 20 ultrasonoscope with a
repetition rate of 1000 impulses/sec. A transducer with
a center frequency of 9 MHz and an active area of 10
mm was used as a sound transmitter for 1 p-sec and a
sound receiver for 999 ,usec. The principles of pulsed
reflected ultrasound, including A-mode display and Mmode or "slow sweep" display have been reviewed in
previous papers.'2' 24, 25 Before beginning the study the
controls were set for A-mode display and Polaroid
prints for full scale deflections of 4 cm, 5 cm, and 6 cm
were obtained for future accurate measurements of slow
sweep displays.
The examinations were performed under an Air
Shields Infant Wanner with a Servo Controller set to
maintain the subjects's skin temperature at 97.4°F. The
head was rotated so that the facies were midline in
order to minimize cardiac rotation. All examinations
were performed without sedation with subject in supine
position during normal respirations. The controls on the
ultrasonoscope were set so that the depth compensation
was not in use. The damping control setting was
proved useful for assessment of chamber size,12-14
wall thickness,15, 16 and left ventricular-
function.'7-18
Recent literature has described its use as an
ancillary tool for the study of congenital heart
disease in infants and children.19-23 Applications to
date have incorporated technics acquired in the
study of the adult patient. Examination of the right
ventricle has been incomplete and detection of the
pulmonary artery and valve inconsistent. Thus a
satisfactory cardiac profile has not been offered.
The purpose of this paper is to describe a
From the Cardiology Section, Children's Hospital,
Department of Pediatrics, University of Louisville School of
Medicine, Louisville, Kentucky.
Supported by Grant 233 from the Department of Health,
Education, and Welfare, Division of Maternal and Child
Health Services and research grants from the Louisville and
Jefferson County Heart Association, and Kentucky Heart
Association.
Address for reprints: Robert Solinger, M.D., Children's
Hospital, 226 East Chestnut Street, Louisville, Kentucky
40202.
Received March 2, 1972; revision accepted for publication
August 15, 1972.
108
Circulation, Volume XLVII, January 1973
ECHOCARDIOGRAPHY IN THE NEONATE
109
Table 1
Survey of Material
Race (no.)
Weight
Total
(kg)
no.
M
21
25
28
29
25
25
22
28
23
14
240
7
10
10
14
14
12
15
14
17
10
123
2.27 - 2.47
2.50 - 2.70
2.73-2.93
2.96- 3.15
3.18 - 3.38
3.41 -3.61
3.64-3.84
3.87 - 4.06
4.09 - 4.29
4.32-4.51
Totals
Sex (no.)
F
Black
White
14
15
18
15
11
13
7
14
6
4
11
18
16
16
17
15
16
11
13
4
137
10
7
12
13
8
10
6
17
10
9
102
117
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
minimized and the reject control was set at 0. The near
and far gain controls were set at their maximum
settings. In each case a Polaroid print was obtained
m
T
^_
l
-
PA
.
_
__~~~~~~~
~~I
Day of life
2nd
3rd
lot
8
10
14
16
10
10
6
5
4
1
84
9
12
12
9
11
14
14
16
16
10
124
-
1
1
3
3
2
1
1
1
4
1
2
18
CW=chest wall
EC G=electrocardiogram
PA=pulmonary root
Ao=aortic root
LAW= left atrial wall
T
a Fig. l
1
2
2
3
1
3
2
14
1
.
=~~~-ML
ECG
_
L.
ECG-i
4th-8th
after the direction of the sonic beam was adjusted to
the maximal excursion of the structures under observation.
NORMAL
T=transducer
CW_
American
Indian
Ao
a
7
L AW
~Fig.ld
-T
_-
=
_
cW
AVW~~~~~V
AVWL
,
=
_-~~~~ECG
,
S
TV-
AAoWMV
~~
~
_
ECG-
PAoWPVW
.
<
LAW-
o
.,
r
-
_1
Figure 1
Frontal view of the heart of the newborn showing the precordial locations from which the semilunar and
atrioventricular valves are recorded. (A) Represents an echogram obtained with the transducer directed from
the second interspace through the pulmonary valve. (B) Echogram obtained with the sonic beam directed
from the inferior border of the third rib at its juction with the sternum through the aortic valve. (C) Echogram obtained with the transducer directed from the left border of the sternum at the level of the third
interspace through the tricuspid valve. (D) Echogram obtained with the sonic beam directed from the
third interspace through the mitral valve.
Ciicedation, Volume XLVII, Januafy 1973
SOLINGER ET AL.
110
Recording Technics and Measurements
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
In figure 1, the frontal view of the newborn's heart
has been drawn showing the precordial locations
directly under which the atrioventricular and semilunar
valves lie. Since the neonate's skeletal system is
cartilagenous and there is no intervening lung tissue, all
four valves can be recorded from directly overhead.
Parallel lines can be seen leading to a typical echogram
obtained from each precordial valve location. In these
and all subsequent echograms "T" represents the
transducer on the precordium. Movement toward T is
an anterior movement. White represents appropriate
boundaries from which echoes have returned. Black
represents echo-free spaces such as the fluid-filled
cavities and great vessels. An electrocardiographic lead
(ECG) has been incorporated into each echogram.
The mitral valve (MV) was recorded from directly
overhead by placing the transducer in the third left
interspace just adjacent to the sternum and directing its
beam inferiorly and posteriorly. The most anterior
position of its anterior leaflet echotrace (figs. Id & 2)
was found at a depth of 22-32 mm and its pattern of
movement was similar to that observed in adults.2 3
Various points on the mitral valve echotrace (fig. Id)
have been labeled according to the designation of
Edler.2 In early ventricular systole (isovolumetric
contraction) the trace moves posteriorly from B to C as
the leaflet bows into the left atrium (LA). With the
onset of ventricular ejection it gradually moves
anteriorly from C to D as the ventricle empties. In early
diastole the echotrace shows an abrupt anterior
movement from D to E as the leaflet opens into the left
ventricle (LV). With ventricular filling there is a steep
posterior movement from E to F as the leaflet floats
back toward the LA. In late diastole, following
contraction of the LA, the echotrace again moves
anteriorly as the leaflet is reopened to point A. From
point A it moves posteriorly to point B as the leaflet
closes. If the transducer is angulated medially, the LA
wall (recognized by its posterior movement during
systole14) is found to lie posterior to the mitral valve. If
it is rotated laterally the posterior LV wall (recognized
by its anterior movement during systole'2 15) is found
posterior to the valve. Figure 2 demonstrates the
method used to measure the motion and thickness of
the interventricular septum (septunm), thickness of the
posterior LV wall, anteroposterior (AP) diameter of the
LV cavity, and the mobility of the anterior MV leaflet.
The sonic beam was directed from the MV recording
position through the anterior right ventricular (RV)
wall, RV cavity, septum, LV cavity, anterior MV leaflet,
and posterior LV wall. Assessment of the motion of the
septum was made utilizing the ECG. Measurement of
m)
RIGHT
2
-
Method for RECORDING and MEASURING THICKNESS of INTERVENTRICULAR SEPTUM and POSTERIOR
(LV) WALL; AP DIAMETER of LEFT VENTRICLE CAVITY; and MOBILITY of ANTERIOR LEAFLET of MITRAL
VALVE. The transducer is placed in the third left interspace just adjacent to the sternum and directed inferiorly, laterally and posteriorly through the right ventricle, septum, left ventricle cavity, anterior leaflet
mitral valve and posterior ventricle wall . Measurement of (I) septal thickness, (2) posterior ventricle wall
thickness and (3) AP diameter of left ventricle are made at end diastole. (4) Measurement of mobility of
anterior leaflet of mitral valve is made between the most open (E) and closed (C) points of the leaflet trace.
T=transducer; CW=chest wall; AVW=anterior (RV) ventricle wall; ECG=electrocardiogran; S=interventricular septum; MV=anterior leaflet mitral valve; and PVW=posterior (LV) ventricle wall.
Figure 2
Method for recording and measuring the thickness of the interventricular septum and posterior left
ventricular wall, AP diameter of the left ventricular cavity, and mobility of the anterior leaflet of the mitral
valve.
Circulation, Volume XLVII, January 1973
ill
ECHOCARDIOGRAPHY IN THE NEONATE
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
the thickness of the septum (fig. 2 at 1) was made
between the endocardial echoes of the left and right
sides of the septum at end-diastole. Measurement of the
thickness of the posterior LV wall (at 2) was made
between the endocardial and epicardial echoes of the
posterior LV wall at end-diastole. Measurement of the
AP diameter of the LV cavity (at 3) was made
between the left septal echo and the endocardial echo
of the posterior LV wall at end-diastole. Measurement
of the mobility of the anterior MV leaflet was made
between the most anterior or open (E) point and the
most posterior or closed (C) point of the leaflet trace.
End-diastole was determined from the echocardiographic pattern in conjunction with the ECG and
electrocardiographically it occurred approximately at
the peak of the R wave. In the presence of normal sinus
rhythm the maximum mobility of the anterior MV
leaflet measured on the echogram was used for mobility,
while the average of two measurements was used for
wall thickness and cavity size.
The tricuspid valve (TV) was recorded from directly
overhead by placing the transducer over the left half of
the sternum at the level of the third interspace and
directing its beam posteriorly. The most anterior
position of its anterior leaflet echotrace (figs. lc and 3)
was found at a depth of 13-19 mm and its pattern of
movement was similar to that of the mitral valve.
Figure 3 demonstrates the method used to measure the
thickness of the anterior RV wall, AP diameter of the
RV cavity, and the mobility of the anterior TV leaflet.
From the TV recording position the sonic beam was
directed through the sternum, anterior RV wall, RV
cavity, anterior TV leaflet, aortic root, LA cavity, and
LA wall. Measurement of the thickness of the anterior
RV wall (fig. 3 at 1) was made between the
endocardial and epicardial echoes of the anterior RV
wall at end-diastole. Measurement of the AP diameter
of the RV cavity (at 2) was made at end-diastole
between the endocardial echo of the anterior RV wall
and the most posterior boundary of the RV cavity
which was taken to be the most posterior point on the
anterior leaflet trace. Measurement of the mobility of
the anterior TV leaflet (at 3) was made between the
most anterior or open (E) point and the most posterior
or closed (C) point of the leaflet trace.
The aortic valve (AV) was recorded from directly
overhead by placing the transducer over the inferior
border of the third rib at its junction with the sternum
and directing its beam posteriorly and, because of the
thoracic curvature, slightly medially and superiorly.
The echo pattern of movement of the aortic root and
AV cusps was similar to that observed in adults. The
aortic root consists of paired, undulating signals moving
anteriorly during systole and posteriorly during diastole.
Between the margins of the aortic root the echotraces of
the aortic valve cusps can be seen as they open toward
the margins of the root and close toward its center.
Figure 4 demonstrates the method used to measure the
,o
_*
*70,4?
Method for RECORDING and MEASURING THICKNESS of ANTERIOR (RV) WALL, AP DIAMETER of RIGHT
VENTRICLE CAVITY, and MOBILITY of ANTERIOR LEAFLET of TRICUSPID VALVE. The transducer is placed
at the level ofthe third interspace over the left border of the sternum and directed inferiorly and posteriorly
through the right ventricle, aortic root and left atrium. Mecsurement of the (I) anterior ventricle wall thickness and (2) AP diameter of the right ventricle are made at end diastole. Measurement of mobility of
anterior leaflet of tricuspid valve is made between the most open (E) and closed (C) points of the leaflet
trace. Scale in centimeters. MPA=main pulmonary artery; Ao=aorta; TV=anterior leaflet tricuspid valve;
MV=mitral valve; AVW=anterior ventricle wall; and ECG=electrocardiogram.
Figure 3
Method for recording and measuring the thickness of the anterior right ventricular wall, AP diameter of
the right ventricular cavity, and mobility of the anterior leaflet of the tricuspid valve.
Circulation, Volume XLVII, January 1973
(cM)
112
SOLINGER ET AL.
5to
( (cm)
10MHz
3
2
1
f7t7@7 0
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
Method for RECORDING and MEASURING ROOT OF AORTA and AP DIAMETER LEFT ATRIUM.
The transducer is placed in the third left interspace just inferior to the third rib, adjacent to the
sternum and directed superiorly, medially and posteriorly through the root of aorta and left atrium.
(I) Measurement of the root of aorta is made at end systole of its outside diameter. (2) Measurement
of the left atrium is made at end diastole of its inside diameter. Scale in centimeters. MPA=main
pulmonary artery; Ao=aorta; TV=tricuspid valve; MV=mitral valve; and ECG=electrocardiogram.
Figure 4
Method for recording and measuring the outside diameter of the aortic root and AP diameter of the left
atrial cavity.
outside diameter of the aortic root and the AP diameter
of the LA cavity. From the AV recording position the
sonic beam was directed through the RV outflow tract,
aortic root and valve cusps, LA cavity and LA wall.
Measurement of the outside diameter of the aortic root
(at 1) was made at end-systole between the outside
signals of the aortic walls. Measurement of the AP
diameter of the LA cavity (at 2) was made between
the endocardial echo of the LA wall and the outside
echo of the posterior wall of the aortic root at endsystole. End-systole was determined from the echocardiographic pattern in conjunction with the ECG and
electrocardiographically occurred approximately at the
end of the T wave. An average of two measurements
was used for both parameters. Figure 5 focuses on the
aortic valve and demonstrates the method described by
Gramiak and Shahll 24 for recording, assessing, and
measuring aortic valve cusp motion. In the diagram the
anterior position of the right coronary cusp, posterior
position of the posterior noncoronary cusp, and lateral
position of the left coronary cusp are clearly exhibited.
With systolic movement the left cusp does not alter
the distance between it and the transducer, while the
right and posterior cusps execute significant movements
toward or away from the transducer and produce boxlike configurations as seen on the echogram. The
distance between the inside edges of the open valve
cusps (interaortic cusp distance) was measured in order
to estimate the valve orifice.
The pulmonary valve (PV) was recorded from
directly overhead by placing the transducer in the
second left interspace just adjacen,t to the sternum and
directing its beam posteriorly and inferiorly. The echo
pattern of movement of the pulmonary root and PV
cusps was similar to that of the aortic. Figure 6
demonstrates the method used to measure the outside
diameter of the pulmonary root and the pulmonary
valve cusp motion. The sonic beam was directed from
the PV recording position through the pulmonary root.
Measurement of the outside diameter of the pulmonary
root (at 1) was made at end-systole between the
outside echoes of the anterior and posterior pulmonary
walls. In the diagram the anterior position of the
anterior cusp, posterior position of the left cusp, and
lateral position of the right cusp are clearly exhibited.
With systolic movement the right cusp does not alter
the distance between it and the transducer, while the
anterior and left cusps execute significant movements
toward or away from the transducer and produce
boxlike configurations as seen in the echogram.
Estimation of the valve orifice was made by measuring
the interpulmonary cusp distance (at 2).
Assessment of mitral-aortic valve continuity was
made utilizing the same technic described in
adults.11 24, 25 Figure 7 demonstrates this procedure
which is essentially a rapid, medial, and superior
rotation of the sonic beam from the anterior MV leaflet
onto the aortic root.
Handling of Data
All measurements were made to the nearest 0.5 mm.
The measurements were separated into 10 half-pound
Circulation, Volume XLVII, January 1973
113
ECHOCARDIOGRAPHY IN THE NEONATE
-
--
-
..
1-
-
-
m
,od %Posterior
(Non coronary)
Cusp
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
Figure 5
Method for recording, assessing, and measuring aortic valve cusp motion. The transducer is placed along the
inferior margin of the third rib just adjacent to the sternum and directed posteriorly and slightly medially
and superiorly through the aortic root. The anterior position of the right coronary cusp, posterior position of
the posterior noncoronary cusp, and lateral position of the left coronary cusp are clearly exhibited. With
systolic movement the left cusp does not alter the distance between it and the transducer while the right
and posterior cusps execute significant movements toward or away from the transducer and produce boxlike configurations. Estimation of valve orifice can be made by measuring the distance between the opened
valve cusps.
ranging from 5 to 10 lb (2.27-4.54 kg).
Following a statistical analysis of the data, a graph was
constructed for each parameter measured, relating the
size of the parameter to the weight of the subject. From
these graphs table 2 was constructed.
groups
Results
Qualitative Findings of Septal Motion and AtrioventricularSemilunar Valve and Great Vessel Relationships
The interventricular septal echoes moved anteriorly during ventricular diastole as the left ventricle
filled and posteriorly during ventricular systole as
the left ventricle emptied. Comparison of the septal
and posterior LV wall echoes revealed them to
move in opposition to each other (figs. Id and 2).
The anterior wall of the aortic root at its most
anterior position (end-systole) was found at a
depth of 18-27 mm below the inferior border of the
third rib at its junction with the sternum. The
pulmonary root was located superiorly, anteriorly,
and slightly to the left of this position under the
second interspace (fig. 1). Its anterior wall at endsystole was found at a depth of 11-16 mm.
The echotrace of the anterior leaflet of the
tricuspid valve in its most posterior (closed)
position was found to lie at the same level as the
anterior wall of the aortic root (fig. lc).
It was demonstrated that the echo of the anterior
leaflet of the mitral valve in its most posterior
Circulation. Volume XLVII, January 1973
(closed) position was continuous with the posterior
wall of the aortic wall (fig. 7). In the-vast majority
of subjects studied it was at the same depth as the
posterior wall of the aortic root. However, in some
instances, it was found to lie as much as 3 mm
below the wall.
Quantitative Results of Measurements of Cardiac
Dimensions Related to Weight
Table 2 summarizes the relationships of the
various cardiac dimensions measured to the weight
of the subject. In this table it can be seen that the
thickness of the interventricular septum is approximately equal to that of the posterior LV wall, and
that the thickness of each of these structures is
greater than the thickness of the anterior RV wall
by about 0.7 mm for each weight group. A
comparison of TV and MV mobilities reveals the
TV to be about 0.5 mm greater than the MV
mobility at 5 lb (2.27 kg) and 0.8 mm at 10 lb
(4.54 kg). The outside diameter of the pulmonary
artery is greater than that of the aorta by about 1.8
mm at 5 lb and 2 mm at 10 lb. The interpulmonary
cusp distance is greater than the interaortic by
about 2 mm at 5 lb and 3 mm at 10 lb.
Discussion
In the adult and older child a calcified sternum
makes it necessary to angulate the untrasonic beam
SOLINGER ET AL.
114
5 to
10 MHz
-X_____
;-O
_(cm)
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
Figure 6
Method for recording, assessing, and measuring pulmonary root and valve cusp motion. The transducer is
placed in the second left interspace just adjacent to the sternum and directed inferiorly and posteriorly
through the pulmonary root. The anterior position of the anterior cusp, posterior position of the left cusp,
and lateral position of the right cusp are clearly exhibited. With systolic movement the right cusp does not
alter the distance between it and the transducer while the anterior and left cusps execute signifiant movements toward or away from the transducer and produce boxlike configurations. (1) Measurement is made
at end-systole of the outside diameter of the MPA. (2) Estimation of valve orifice can be made by measuring
the distance between the opened valve cusps. MPA = main pulmonary artery; ECG electrocardiogram.
from the left parasternal area to record tricuspid
valve motion. This technic is not always successful.
Likewise, the presence of lung tissue over the
pulmonary valve makes it difficult to record.
(1) (2)
M
10MHZ
_
T-
EFT ATRIAL WA_
Method for RECORDING and ASSESSING MITRAL-AORTIC VALVE CONTINUITY. The transducer is
placed in the third left interspace just adjacent to the sternum and directed inferiorly, laterally cad
posteriorly through the right ventricle, interventricular septum, anterior leaflet of mitral valve, and left
ventricle (position 1). The transducer is then rotated superiorly and medially through the aortic root
(position 2). The posterior aortic wall lies at the same depth as the anterior leaflet of the mitral valve
in systole. LA=left atrium; LV=left ventricle.
Figure 7
Method for recording and assessing mitral-aortic continuity.
Circulation, Volume XLVII,
January
1973
ECHOCARDIOGRAPHY IN THE NEONATE
115
Table 2
Relationship betweetn Weight of the Subject and Magnitude of Various Echocardiographic Parameters
Dimensions
TV mobility (mm)
AP diameter RV cavity
at end-diastole (mm)
Thickness ant (RV) wall
at end-diastole (mm)
Outside diameter MPA
at end-diastole (mm)
Interpulm cusp distance
(mm)
AP diameter LA cavity
at end-systole (mm)
MV nmobility
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
AP diameter LV cavity
at end-diastole (mm)
Thickness septum
at end-diastole (mm)
Thickness post (LV) wall
at end-diastole (mm)
Outside diameter aorta
at
end-systole (mm)
Interaortic cusp distance
(mm)
Predicted normal
Mean
-2 SD = Mean
-2 SD =
Mean
-2 SD = Mean
-2 SD = Mean
=1=2 SD = Mean
-2 SD = Mean
-2 SD =
Mean
2 SD = Mean
=i=2 SD =
Mean
-2 SD =
Mean
2 SD =
Mean
-2 SD =
2.27
2.73
10.4
1.8
6.8-10.5
9.8
10.8
9.2-12.4
13.1
11.0-15.2
2.2
1.3- 3.1
12.5
11.2-13.8
7.1
6.3- 7.9
9.3
7.4-11.1
10.2
1.3
8.5-11.1
8.9-11.5
18.9
16.1-21.7
2.7
2.1- 3.3
2.7
2.0- 3.4
10.3
9.3-11.3
4.7
4.0- 5.4
19.3
16.5-22.1
3.0
2.4- 3.6
3.0
2.3- 3.7
10.7
1.6
2.1
0.9
1.3
0.8
2.8
0.6
0.7
1.0
0.7
8.8-12.0
12.5
10.4-14.6
2.0
1.1- 2.9
12.0
10.7-13.3
6.6
5.8- 7.4
8.7
Gramiak et al.26 have developed a technic utilizing
a focused transducer in which they angulate the
beam in a lateral and cephalic direction from a high
left parasternal location. Using this technic they
were able to detect the pulmonary valve in 25% of
the adults and 60% of the older children studied. In
contrast, the neonate and infant possess a cartilagenous skeletal system and a minimum of intervening lung tissue allowing direct overhead or
antero-posterior recordings. Using a high-frequency
transducer a satisfactory cardiac profile, including an
adequate assessment of the right ventricle and
pulmonary artery, can uniformily be obtained.
The transducer is the most important component
of the instrument. In general, higher frequencies
result in less beam spread and greater resolution,
however, tissue penetration is diminished. In
addition, the divergence of the beam is inversely
proportional to the diameter of the crystal, thus, the
larger the diameter the less beam spread. Following
the early investigations of Edler and Hertz' in
which they showed that echo signals were best
obtained from the deeper parts of the thorax in the
average adult using a transducer with a center
frequency of around 2.5 MHz, transducers with a
center frequency of 2.25 MHz became commercially available. They also showed that a transducer
Circulation, Volume XLVII, January 1973
Weight (kg)
3.18
9.7-11.7
11.3
9.7-12.9
13.7
11.6-15.8
2.5
1.6- 3.4
13.0
11.7-14.3
7.6
6.8- 8.4
9.9
8.0-11.7
10.6
9.3-11.9
19.8
17.0-22.6
3.2
2.6- 3.8
3.2
2.5- 3.9
11.2
10.2-12.2
5.0
4.3- 5.7
5.2
4.5- 5.9
3.64
4.09
4.54
11.7
10.1-13.3
12.2
10.6-13.8
15.0
12.9-17.1
2.9
2.0- 3.8
14.0
12.7-15.3
8.6
7.8- 9.4
11.1
9.2-12.9
11.4
10.1-12.7
20.8
18.0-23.6
3.7
3.1- 4.3
3.7
3.0- 4.4
12.6
11.0-14.2
15.6
13.5-17.7
3.2
2.3- 4.1
14.5
13.2-15.8
12.1
11.1-13.1
5.8
5.1- 6.5
12.6
11.6-13.6
6.1
5.4- 6.8
14.4
12.3-16.5
2.7
1.8- 3.6
13.5
12.2-14.8
8.1
7.3- 8.9
10.5
8.6-12.3
11.0
9.7-12.3
20.3
17.5-23.1
3.5
2.9- 4.1
3.5
2.8- 4.2
11.7
10.7-12.7
5.5
4.8- 6.2
9.1
8.3- 9.9
11.7
9.8-13.5
11.8
10.5-13.1
21.3
18.5-24.1
3.9
3.3- 4.5
3.9
3.2- 4.6
with a center frequency of 5 MHz had good results
in thin adults, and particularly in children. Despite
this finding, to our knowledge, all the published
studies to date in infants and children have been
made using a commercially available 2.25 MHz
transducer of 0.75 in (19 mm) diameter. While this
transducer has given fairly satisfactory results as far
as the more distant left ventricular and aortic
echoes have been concerned, the echoes returning
from the more anterior structures such as the
anterior right ventricular wall have been "fuzzy"
and unacceptable for quantitative measurement.
Spectrum and real-time analysis was performed on
the transducer used in this study by Aerotec
Laboratories and it was found to have a center
frequency of about 9 MHz and to be capable of
resolving two structures 0.5 mm apart.
The movement of the interventricular septal
echoes was the same as that originally described in
the adult by Popp et al.'2 and later confirmed in the
child by Chesler et al.22 The relationships of the
anterior leaflet of the tricuspid valve to the anterior
wall of the aortic root and the anterior leaflet of the
mitral valve to the posterior wall of the aortic root
were the same as these originally described in the
adult by Gramiak and Shah"l 24,25 and later
confirmed in the child by Chesler et al.2" 22
SOLINGER ET AL.
116
ITRANSDUCER
_-
_
_ ^ ^f _
-;WALL
A WALL
. -~~~~~
~ANTERIOR WALL
~
~
_
~
~
~
~
PULMONARY,
ROOT
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
i~~~~
r'
tii
'1
~~~
t
;4
m u_
_
41
~
_
Figure 8
Indocyanine green dye injection into main pulmonary artery. The resulting cloud of echoes is confined by
the margins of the pulmonary root.
Gramiak et al.,24-26 using selective injections of
indocyanine green dye to produce intracardiac
echoes, have clearly shown that the various cardiac
chambers, the interventricular septum, the atrioventricular valves, the aortic root and valve, and the
pulmonary root and valve can be identified
ultrasonically. Using this technic we have confirmed
their work in the neonate and we have also proved
that ultrasonic tracings obtained from the second
left interspace just adjacent to the sternum
represent the pulmonary root and valve (Fig. 8).
Studies performed in adults have demonstrated
an excellent correlation between cardiac measurements by ultrasound and by other established
methods.14-16, 18 The thickness of the LV wall has
been compared to surgical and autopsy estimations
and to angiocardiographic measurements.16 The AP
diameters of the LA and LV cavities have been
compared with those calculated by angiocardiography. 14. 18
Measurements have been made on normal
newborn hearts at autopsy of the thickness of the
walls of the right and left ventricles and the
circumferences of the atrioventricular and semilunar valve orifices. Variations in fixation procedures
and technics of measurements have resulted in
conflicting data. Studies performed in the
1950'S27, 28 showed the thickness of the right
ventricle to be greater than that of the left ventricle.
Studies performed in the 1960S29-32 showed the
thickness of the right ventricular wall to be less
than that of the left ventricular wall. The mean
thickness reported in the latter studies for the right
ventricular wall ranged from a low of 2.4 mm to a
high of 3.2 mm. The mean thicknesses reported for
the left ventricle ranged from a low of 4 mm to a
high of approximately 5 mm. All the studies were in
Circulation, Volume XLVII, January 1973
ECHOCARDIOGRAPHY IN THE NEONATE
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
agreement on the size of the valve orifices. The
tricuspid valve circumference and diameter were
greater than the mitral, and the pulmonary valve
circumference and diameter were greater than the
aortic.
Utilizing the unique physical characteristics of
the neonate and infant a simple reproducible
technic has been developed which can be used in
the nursery with a minimum of equipment. A
minimum of five echograms are required for an
"echocardiographic profile" of the heart and its
great vessels. The profile consists of the quantitative
parameters summarized in table 2, plus the
assessment of the qualitative features of pulmonary
artery-aorta, tricuspid valve-great vessel, and mitral
valve-semilunar valve relationships as well as septal
motion. The clinical application of this "echocardiographic profile" in our institution has been very
helpful in the differential diagnosis of newborns
presenting in cardiorespiratory distress and/or
cyanosis, rapidly separating those neonates with
normal hearts from those with cardiac malformations. Its use in the abnormal hearts promises to
make echocardiography a valuable tool for a fast
and accurate clinical diagnosis of congenital heart
disease in the critical neonatal period.33 3
Acknowledgment
We wish to thank Dr. Chalmer S. Wheeler for his
technical assistance. We are further indebted to Dr. Billy F.
Andrews and Dr. Jerry Seligman whose cooperation made it
possible for us to study the normal neonate.
References
1. EDLER I, HERTZ CH: Use of ultrasonic reflectoscope for
the continuous recording of movements of heart
walls. Kungl Fysiogr Sallsk Lund Forhandl 24: 5,
1954
2. EDLER I: Atrioventricular valve mobility in the living
human heart recorded by ultrasound. Acta Med
Scand 170 (suppl 370): 85, 1961
3. EDLER I: Ultrasound cardiography in mitral valve
stenosis. Amer J Cardiol 19: 18, 1967
4. JOYNER CR, HEY B, JOHNSON J, REID JM: Reflected
ultrasound in the diagnosis of tricuspid stenosis. Amer
J Cardiol 19: 66, 1967
5. FEIGENBAUM H, WALDHAUSEN JA, HYDE LP: Ultrasound diagnosis of pericardial effusion. JAMA 191:
711, 1965
6. WOLFE SB, PoPP RL, FEIGENBAUM H: Diagnosis of
atrial tumors by ultrasound. Circulation 39: 615,
1969
7. PopP RL, HARRISON DC: Ultrasound in the diagnosis
and evaluation of therapy of idiopathic hypertrophic
subaortic stenosis. Circulation 40: 905, 1969
8. DIAMOND MA, DILLON JC, HAINE CL, CHANG S,
FEIGENBAUM H: Echocardiographic features of atrial
septal defect. Circulation 43: 129, 1971
Circulation, Volume XLVII, January 1973
117
9. DILLON JC, HAINE CL, CHANG S, FEIGENBAUM H:
Use of echocardiography in patients with prolapsed
mitral valve. Circulation 43: 503, 1971
10. KERBER RE, ISAEFF DM, HANCOCK EW: Echocardiographic patterns in patients with the syndrome of
systolic click and late systolic murmur. New Eng J
Med 284: 691, 1971
11. GRAMIAK R, SHAH PM: Echocardiography of the
normal and diseased aortic valve. Radiology 96: 1,
1970
12. PoPP RL, WOLFE SB, HIRATA T, FEIGENBAUM H:
Estimation of right and left ventricular size by
ultrasound: A study of the echoes from the
interventricular septum. Amer J Cardiol 24: 523,
1969
13. FEIGENBAUM H, WOLFE SB, PoPP RL, HAINE CL,
DODGE HT: Correlation of ultrasound with angiocardiography in measuring left ventricular diastolic
volume. Amer J Cardiol 23: 111, 1969
14. HIRATA T, WOLFE SB, PoPP RL, HELMEN CH,
FEIGENBAUM H: Estimation of left atrial size uising
ultrasound. Amer Heart J 78: 43, 1969
15. FEIGENBAUM H, Popp RL, CHiP JN, HAINE CL: Left
ventricular wall thickness measured by ultrasound.
Arch Intern Med (Chicago) 121: 391, 1968
16. TROY BL, POMBO JF, RACKLEY CE: Ultrasonic
measurements of left ventricular wall thickness and
mass. Circulation 42 (suppl III): III-38, 1970
17. FEIGENBAUM H, ZAKEY A, NASSER WK: Use of
ultrasound to measure left ventricular stroke volume.
Circulation 35: 1092, 1967
18. POMBO JF, TROY BL, RUSSELL RO JR: Left ventricular
volumes and ejection fraction by echocardiography.
Circulation 43: 480, 1971
19. ULTAN LB, SEGAL BL, LIKOFF W: Echocardiography
in congenital heart disease. Amer J Cardiol 19: 74,
1967
20. CHESLER E, JOFFE HS, VECHT R, BECK W, SCHRIRE V:
Ultrasound cardiography in single ventricle and the
hypoplastic left and right heart syndromes. Circulation 13: 123, 1970
21. CHESLER E, JOFFE HS, BECK W, SCHRIRE V:
Echocardiographic recognition of mitral-semilunar
valve discontinuity: An aid to the diagnosis of origin
of both great vessels from the right ventricle.
Circulation 43: 725, 1971
22. CHESLER E, JOFFE HS, BECK W, SCHRIRE V:
Echocardiography in the diagnosis of congenital
heart disease. Pediat Clin N Amer 4: 1163, 1971
23. LUNDSTR6M N-1R, EDLER I: Ultrasoundeardiography in
infants and children. Acta Paediat Scand 60: 117,
1971
24. GRAMIAK R, SHAH PM: Echocardiography of the aortic
root. Invest Radiol 3: 356, 1968
25. GRAMIAK R, SHAH PM, KRAMER DH: Ultrasound
cardiography: Contrast studies in anatomy and
function. Radiology 92: 939, 1969
26. GRAMIAK R, NANDA NC, SHAH PM: Echocardiographic
detection of the pulmonary valve. Radiology 102:
153, 1972
118
27. KEEN JA: The postnatal development of the human
cardiac ventricles. J Anat 89: 484, 1955
28. HORT W: Morphologische untersuchungen an Herzen
vor, wahrend und nach der postnatalen Kreislaufumschaltung. Arch Path Anat 326: 458, 1955
29. DE LA CRUZ MV, ANSELMI G, ROMERO A, MoNRoY G:
A qualitative and quantitative study of the ventricles
and great vessels of normal children. Amer Heart J
60: 675, 1960
30. SCHULZ DM: Hearts of infants and children. Arch Path
(Chicago) 74: 78, 1962
SOLINGER ET AL.
31. ROWLATT UF, RIMOLDI HJA, LEV M: The quantitative
anatomy of the normal child's heart. Pediat Clin N
Amer 10: 499, 1963
32. ECKNER FAO, BROWN BW, DAVIDSON DL, GLAGOV S:
Dimensions of normal human hearts. Arch Path
(Chicago) 88: 497, 1969
33. SOLINGER R, ELBL F, MINHAS K: Echocardiography in
congenital heart disease. Lancet 13: 1093, 1971
34. SOLINGER R, ELBL F, MINHAS K: Echocardiography in
congenital heart disease in neonates and infants.
Circulation 44 (suppl II): 11-229, 1971
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
Circulation, Volume XLVII, Jan~y 1973
Echocardiography in the Normal Neonate
ROBERT SOLINGER, FRANCISCO ELBL and KAREEM MINHAS
Circulation. 1973;47:108-118
doi: 10.1161/01.CIR.47.1.108
Downloaded from http://circ.ahajournals.org/ by guest on August 12, 2017
Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231
Copyright © 1973 American Heart Association, Inc. All rights reserved.
Print ISSN: 0009-7322. Online ISSN: 1524-4539
The online version of this article, along with updated information and services, is located on the World
Wide Web at:
http://circ.ahajournals.org/content/47/1/108
Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in
Circulation can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office.
Once the online version of the published article for which permission is being requested is located, click Request
Permissions in the middle column of the Web page under Services. Further information about this process is available
in the Permissions and Rights Question and Answer document.
Reprints: Information about reprints can be found online at:
http://www.lww.com/reprints
Subscriptions: Information about subscribing to Circulation is online at:
http://circ.ahajournals.org//subscriptions/