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Echocardiography
in Practice
A Case Oriented Approach
by Susan Wiegers, Ted Plappert, and Martin St. John Sutton
Congenital Heart Disease: Tricuspid Atresia
Martin St. John Sutton, MB, BS, FRCP
Susan E. Wiegers, MD
A 17-year-old woman was admitted via the emergency
room with sudden onset of altered mental status, an
expressive dysphasia and right faciobrachial weakness
consistent with an acute dominant hemispherical stroke.
In the emergency room she was deeply cyanosed with a
hemoglobin level of 23.8 g/dl and an oxygen saturation of
73% on room air. She had a history of complex cyanotic
congenital heart disease diagnosed at birth for which she
had undergone cardiac catheterization at 3 months of age
having faded to thrive. The diagnosis was tricuspid atresia,
ventricular septal defect, rudimentary right ventricle, and
an unobstructed right ventricular outflow tract with
normally related great arteries. She had a pulmonary
artery band performed to prevent development of
pulmonary vascular disease soon after the cardiac
catheterization. Her mother declined a Fontan procedure
because of the high operative mortality quoted to her by
the cardiac surgeon. From her early teens there was a
progressive decline in her exercise capacity and deepening
central cyanosis. During the 3 years prior to her stroke she
had undergone intermittent venesections but had become
hypotensive; she had a syncopal episode after venesection
of one unit several months previously and the practice was
discontinued.
On examination she was not able to communicate,
because she was dysphasic and had an ipsilateral facial and
right upper extremity weakness. She was centrally
cyanosed with digital clubbing and an elevated jugular
venous pressure with a normal blood pressure and in
sinus rhythm. Peripheral arterial pulses were present and
equal bilaterally. The apical impulse was hyperdynamic
and there was a harsh ejection systolic murmur at the
upper left sternal border. Her respiratory and alimentary
systems were within normal limits. Electrocardiography
showed sinus rhythm, left axis deviation and left ventricular
hypertrophy. A chest X-ray showed mild
cardiomegaly, right atrial enlargement, and a dilated
proxirnal pulmonary artery with normal pulmonary
vasculature.
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Figure 147.1
(a) Apical four-chamber view. The tricuspid valve (arrow) is
atretic, being an imperforate band of fibrous tissue. The
right atrium (RA) is enlarged, but the right ventricle (RV)
is rudimentary. There is a non-restrictive ventricular septal
defect (VSD) but the obligatory atrial septal defect is
not visible in this frame. The size of the left ventricle
is at the top
limit of normal size. The mitral valve and left atrium are
normal. |
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Figure 147.2
(a) Anterior angulation of the transducer permits visualization
of the aorta arising from the left ventricle. The aortic
valve was normal.
(b) Lesser anterior angulation shows the pulmonary artery taking
origin from the left ventricle, as does the aorta. The ventricular
I septa1 defect and a small portion of the dysplastic right
ventricle are visible on the left of the image (the patient's
right). The
surgically placed pulmonary artery band is immediately distal
to the pulmonary valve. The main pulmonary artery distal to
the
band is severely dilated. |
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Figure 147.3
(a) Apical long-axis view of the left ventricle demonstrating
double-outlet left ventricle. The aorta (AO) and the pulmonary
artery (PA)
arise in parallel from the left ventricle (LV). The pulmonary
artery band is visible again in the proximal pulmonary artery.
(b) Close-up image of the pulmonary artery from the same view
demonstrates both semilunar valves and the continuity between
the anterior mitral valve leaflet and the pulmonary artery.
The pulmonary artery band is not as clearly seen, but the post-stenotic
dilatation is again appreciated. |
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Figure 147.4
Spectral display of continuous-wave Doppler across the
pulmonary valve and the pulmonary artery. The increased
velocity is due to obstruction at the level of the band rather
than the pulmonary valve. The peak velocity of 3 m/s (each
calibration mark represents 1.0 m/s) indicates that the
gradient between the left ventricular peak systolic pressure
and the pulmonary artery pressure is only 36 mmHg.
Therefore, the patient has significant pulmonary hypertension. |
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Figure 147.5
Apical four-chamber view with anterior angulation and slight
clockwise angulation. A second muscular ventricular septal
defect (arrow) is visible in the septum near the apex. |
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Discussion
This patient had tricuspid atresia presenting soon after
birth with failure to thrive due to heart failure. The diagnosis
of tricuspid atresia with ventricular septal defect and double-outlet
left ventricle with an unprotected pulmonary circulation was made
correctly at cardiac catheterization. Pulmonary artery banding
was performed to protect against progressive pulmonary vascular
disease. The apical two-dimensional echocardiographic images
clearly show the anatomical defects in this patient. There
is absence of the right atrioventricular connection as
demonstrated by the echodense band in that region with
no inflow from the right atrium to the right ventricle.1 Systemic
return reaches the only viable ventricle via a large secundum
atrial septal defect that is not well seen in these images. The
patient also has a rudimentary right ventricle, two ventricular
septal defects, the residual stenotic pulmonary artery band,
and the post-stenotic aneurysmal dilatation of the distal main
pulmonary artery. The obligate shunting has resulted in cyanosis
from birth.
Over the course of growing up, the pulmonary artery
band had become insufficiently stenotic, so that her
systolic pulmonary arterial pressure was only 36 mmHg
less than left ventricular pressure (115 mmHg). Thus, the
pulmonary artery pressure was 115 - 36 = 79 mmHg. The
prolonged exposure to high flows at near systemic
pressures had resulted in the development of fixed
pulmonary hypertension. Two-dimensional and Doppler echocardiography
can be used to assess the adequacy of
banding as the patient ages.2,3
The patient's stroke syndrome was caused by interarterial
thrombosis due to hyperviscosity syndrome and
polycythemia. Endocarditis is also a consideration, based
on her presentation, but there was no evidence of vegetations
on echocardiography and blood cultures were
negative. She made an almost complete recovery from her
stroke with resolution of her dysphasia and only mild
residual monoparesis of her right arm. She stabilized for
a time, but died while listed for heart and lung transplantation.
References
I. Orie JD, Anderson C, Ettedgui JA, et al. Echocardiographic-morphologic
correlations in tricuspid atresia. J Am Coll Cardiol 1995;26:750-8.
2. Jureidini SB, Alpert BS, Durant RH, et
al. Two-dimensional echocardiographic
assessment of adequacy of pulmonary artery banding. Pediatr Cardiol
1986;6:239-44.
3. Fyfe DA, Currie PJ, Seward JB. et al. Continuous-wave
Doppler determination of the pressure gradient across pulmonary
artery bands: hemodynamic correlation in 20 patients. Mayo Clin
Proc 1984;59:744-50.
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