CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 8, September 2012
e14
AFRICA
coronary artery (LCX), supplying the posterolateral aspect of
the left ventricle. There was 80% stenosis in the mid segment
and two 80% tandem lesions in the distal segment of the RCA.
The patient underwent percutaneous coronary angioplasty
with stenting in the mid and distal RCA, using two drug-eluting
stents in the same operation (Fig. 1D). The procedure was
uneventful. Later the septal course was confirmed by computed
tomographic angiogram (Fig. 2A, B, C). Even though there were
two coronary ostia in our patient, the entire heart was essentially
supplied by the right coronary system.
Discussion
Single coronary artery is a rare coronary anomaly in structurally
normal hearts, with a reported prevalence of 0.024% in the
general population.
2
It accounts for less than 3% of all major
coronary anomalies.
1
Angiographically, Lipton
et al
.
2
classified SCA into various
types depending on its origin, branching pattern and course of
the anomalous vessel. In single coronary arteries arising from the
right coronary sinus, the left system often arises either from the
distal RCA after its usual distribution (R-I) or as a single artery
(
left main coronary artery, R-II), or two separate arteries (LAD
and LCX, R-III) from the proximal part of the common trunk. A
single coronary system with direct origin of the LAD from the
proximal RCA and direct continuation of the circumflex from
the terminal RCA is very rare.
Although an anomalous LAD arising from the right coronary
artery can follow any of the four courses: septal, anterior free
wall, retro-aortic and interarterial, it often follows one of the
former two courses. The septal course is largely benign and no
case of sudden cardiac death has yet been attributed to it.
3,
4
Percutaneous coronary intervention is a viable therapeutic
option for a single anomalous coronary artery. However, the
operator should be aware of the potential risk of complications
and the limitations of the procedure, as vessel compromise
during angioplasty will have an impact on all three territories.
5
The distal location of the stenoses in the RCA placed our patient
at a slightly lower risk for percutaneous coronary intervention.
References
1.
Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients
undergoing coronary arteriography.
Catheter Cardiovasc Diagnosis
1990;
21
: 28–40.
2.
Lipton MJ, Barry WH, Obrez I, Silverman JF, Wexler L. Isolated single
coronary artery: diagnosis, angiographic classification, and clinical
significance.
Radiology
1979;
13
0: 39–47.
3.
Liberthson RR, Dinsmore RE, Fallon JT. Aberrant coronary artery
origin from the aorta. Report of 18 patients, review of literature and
delineation of natural history and management.
Circulation
1979;
59
:
748–754.
4.
Namboodiri N, Harikrishnan S, Tharakan JA. Single coronary artery
from right aortic sinus with septal course of left anterior descending
artery and left circumflex artery as continuation of right coronary
artery: A hitherto unreported coronary anomaly
.
J Invasive Cardiol
2007;
19
:
E102–E103.
5.
Ohta H, Sumiyoshi M, Suwa S, Tamura H, Sasaki A, Kojima T,
et
al
.
Primary coronary angioplasty with stenting for acute coronary
syndrome in patients with isolated single coronary artery: a report of 2
cases.
Jpn Heart J
2003;
44
: 759–765.
Fig. 2. A. Three-dimensional VRT image (left anterior
oblique view) showing the diagonal artery from the left
coronary sinus and a common coronary trunk from the
right coronary sinus dividing into the right coronary
artery (RCA) and left anterior descending coronary
artery. The distal RCA continues as the left circumflex
artery. The stents are
in situ
.
B. Three-dimensional VRT
image (right anterior oblique view) demonstrating similar
features. C. Thick MIP image revealing the septal course
of the left anterior descending artery. LAD, left anterior
descending coronary artery; LCX, left circumflex artery;
ST, stent; D, diagonal artery; S, septal branch.
A
B
C
