A 57-year-old male patient was admitted to our
cardiology outpatient with a complaint of chest pain.
He also suffered from type 2 diabetes and non-regular
hypertension. His physical examination revealed a heart
rate of 82 bpm and a blood pressure of 155/88 mmHg
with normal findings. Laboratory test results were
also normal. We performed exercise stress test and
detected 1.5 mm horizontal ST segment depression
in the inferior lead. Using coronary angiogram with
transfemoral route, we detected a long, superdominant
left anterior descending (LAD) coronary artery
continuing on the posterior interventricular groove as
the posterior descending artery (PDA) after apex in
the right cranial oblique view (Figure
1a). Left anterior
descending coronary artery and circumflex (Cx)
coronary artery were normal in the left caudal oblique
view (Figure
1b). In the left cranial oblique view, LAD
continued along the posterior interventricular groove,
reaching to crux, after the crux LAD continued as
the posterior left ventricular branch (Figure
1c). The
right coronary artery (RCA) was nondominant and
diminutive (Figure
1d). There was no lesion in any
coronary arteries, and the patient was discharged from
the hospital.
Figure 1: (a) The LAD (arrow) continues on the posterior
interventricular groove as a PDA (dotted arrow) after apex
(asterisk) in the right cranial oblique view. (b) The LAD (arrow)
continues on the posterior interventricular groove as the PDA
(dotted arrow), and nondominant Cx artery is normal in the left
caudal oblique view. (c) The LAD continues along the anterior and
posterior interventricular groove and reaches to crux (asterisk),
after the crux-LAD continues as the posterior left ventricular
branch (dotted arrow) in the left cranial oblique view. (d) The
RCA was non-dominant and diminutive.
LAD: Left anterior descending; PDA: Posterior descending artery; Cx: Circumflex;
RCA: Right coronary artery.
Coronary artery anomalies have an incidence
varying from 0.3 to 1.3% based on autopsy and
angiographic series.[1] In general, the posteroinferior
part of the interventricular septum is supplied by
the PDA whose variable origin is reflected by the
concept of coronary dominance. The PDA can arise
from the RCA in a pattern of right dominance (85%
of patients) and codominance (7% of patients), or from
the Cx artery in a pattern of left dominance (8% of
patients).[2] An extremely rare form of the left dominant coronary circulation reported in the literature is the
continuation of LAD around the apex into the posterior
interventricular sulcus as the PDA supplying most of
the interventricular septum. Herein, we report a case
of anomalous origin of PDA as the continuation of
superdominant LAD in the presence of a nondominant
RCA.
Declaration of conflicting interests
The authors declared no conflicts of interest with respect to
the authorship and/or publication of this article.
Funding
The authors received no financial support for the research
and/or authorship of this article.