<Case
report>
A 16-year-old Chinese girl was admitted due to high fever
and bilateral chest pain for two days. The pain attacked
intermittently and radiated to upper back. On examination, she
had a temperature of 40.2 °C and a tachycardia of 120/min. Her
blood pressure was 150/80 mmHg and her respiratory rate was
38/min. Neither lymph node enlargement nor jugular vein
enlargement was noted on the neck. Her breathing sound was
clear. A grade II/VI systolic murmur was noted over left upper
sternal border.
The total white cell count was 4560
per cubic millimeter and biochemical tests were normal. The
chest roentgenogram showed multiple patches over bilateral
lung fields. Empirical antibiotics with ceftazidime and
amikacin were started under the consideration of septic
pulmonary emboli. Later, blood culture yielded
methicillin-sensitive Staphylococcus aureus and antibiotics
was shifted to oxacillin. Transthoracic echocardiogram showed
normal size of cardiac chambers but a vegetation over
tricuspid valve. Transesophageal echocardiogram revealed the
vegetation and dilatation of right coronary artery with a
fistula draining into right atrium (figure
1 ). In addition, ultrafast
computed tomography (Imatron, South San Francisco, CA) further
demonstrated an aneurysmal dilatation (figure
2). She was treated with a six-week course of antibiotic
and her recovery was uneventful. Cardiac catheterization was
performed six months later and showed a large diameter fistula
from proximal right coronary artery to right atrium (figure3
). The pulmonary to systemic
flow ratio (Qp/Qs) is 1.3:1. Later, operation confirmed the
anatomical diagnosis and the patient underwent surgical
ligation of fistula. She was symptoms free for one year after
operation.
Table 1. Laboratory
data
[CBC+PLT]
WBC |
RBC |
HB |
PLT |
K/μL |
M/μL |
g/dL |
K/μL |
4.56 |
4.43 |
13.5 |
112.0 |
Seg |
Eos |
Baso |
Mono |
Lym |
% |
% |
% |
% |
% |
82.7 |
0.3 |
0.2 |
5.3 |
11.5 | [ Biochemistry ]
ALB |
GLO |
BUN |
CRE |
T-BIL |
AST |
GLU |
mg/dl |
mg/dl |
mg/dl |
mg/dl |
mg/dl |
U/l |
mg/dl |
4.6 |
3.8 |
20.5 |
0.8 |
0.8 |
60.0 |
103.0 |
Na |
K |
Cl |
Ca |
Mg |
Mmmole/l |
mmole/l |
mmole/l |
mmole/l |
mmole/l |
144.0 |
4.3 |
111.0 |
1.98 |
0.8 |
Discussion
Most patients with
congenital coronary artery fistula (CAF) have no symptoms.
Congestive heart failure and angina occurred in approximately
20% of patients, respectively. Bacterial endocarditis is rare,
reported in only 4% of the patients. The endothelial damage
over tricuspid valve by the turbulence flow via fistula might
explain the unusual site of the vegetation in this
case.
In the previously
reported case, the diagnosis depended on coronary angiography.
Angiography is the traditional method used for the definite
diagnosis of CAF. Transesophageal echocardiography and
ultrafast computed tomography could provide more satisfactory
images of the origin, course and drainage site of CAF.
Furthermore, in contrast to conventional angiography,
ultrafast computed tomography provides a more reliable tool to
detect coronary vascular anomaly. The management of
asymptomatic patients with small CAF (Qp/Qs<1.5) remains
controversial, including elective ligation and medication
only. In contrast, surgical ligation of small CAF is favored
for patients with complications, such as bacterial
endocarditis. Several reports have demonstrated that surgical
management is safe and effective. Percutaneous transcatheter
embolic occlusion technique using a variety of material has
been used for the treatment of CAF in recent years. However,
the risk and advantage are still under
investigation.
<Legend
of figure>
Figure 1 :
Transesophageal echocardiography shows dilatation of right
coronary artery with an aneurysmal fistula. A vegetation is
identified over tricuspid valve (left arrow). Color duplex of
the same field reveals a shunt from aneurysm to right atrium
(right arrow). (Ao: arota, RCA: right coronary artery, A:
aneurysm, F: fistula, LA: left atrium, RA: right atrium)Figure
2
: Enhanced ultrafast computer tomography shows dilated
right coronary artery (black arrow) with a fistula (white
arrow). The fistula has an aneurysmal tip (A) bulging into the
right atrium (RA). Figure3
: Cardiac catheterization
identifies a large coronary fistula (white transverse arrow)
ending into an aneurysm (a) which drains into right atrium.
Notice the double contour of aneurysm and right atrium (white
oblique arrow). The distal right coronary artery is faint
(black arrow).
|