الفهرس 
Gross anatomy of the heart and coronary arteriesOnly 14 pages are availabe for public view
Abstract
The arterial blood supply to the heart is achieved by two
coronary arteries and their branches. The right & left coronary
arteries arise from aortic sinuses of valsalva at the beginning of
ascending aorta and then descend in right and left
atrioventricular grooves respectively. The left anterior
descending and circumflex arteries are the main branches of the
left coronary artery whereas the acute marginal and posterior
interventricular arteries arise from the right coronary artery.
The term dominance is used to describe the anatomical
pattern of the coronary arteries; the dominant vessel is the one
that supplies the posterior diaphragmatic portion of the
interventricular septum and the diaphragmatic portion of the left
ventricle. So the dominant vessel refers to the coronary artery
which gives the posterior descending artery.
The LAD artery supplies blood to a large part of the
myocardium. However, the amount of myocardium supplied
varies depending on the length of LAD artery and as a result;
occlusion at different portion may influence perfusion of
different part of myocardial.In this study light was focused on the length of LAD artery
and the possible relationship between it and the pattern of
coronary arterial dominancy.
Among patients who underwent CT coronary angiograms in
Ain-Shams hospitals & other private centers a sample of one
hundred CT coronary angiograms with right and left dominance
pattern was chosen by systemic random sampling. The
collected sample was divided into two groups each of fifty:
1- CT coronary angiograms with right dominance pattern.
2- CT coronary angiograms with left dominance pattern.
The entire cases were chosen to be young adult male aged
between 40-60 years and had normal CT coronary angiograms
based on visual assessment of absence of any luminal
irregularities while those patients with history of renal diseases
and cardiomyopathy were excluded.
The entire cases were examined by using Optima GE 64 CT
scanner and Philips Brilliance 64 CT scanner and the obtained
data were interpreted in the following manner:
1- The coronary artery which gave rise to the posterior
interventricular artery was regarded as the dominant one.a- If the posterior interventricular artery arose from the right
coronary artery, then it was said to be right dominant.
b- If the posterior interventricular artery arose from the left
coronary artery, then it was said to be left dominant.
2- Whether LAD artery didn’t reach, reached or reached and
wrap around the cardiac apex.
a- If it didn’t reach the cardiac apex, then it was said to be
LAD type I.
b- If it reached the cardiac apex but didn’t wrap around it,
then it was said to be LAD type II.
c- If it reached and wrap around the cardiac apex, then it was
said to be LAD type III.
The data were analyzed using SPSS software & the
variables expressed as percentages and analyzed by Chi square
test to study the relationship between length of LAD artery and
dominance pattern. The results revealed that there was
significant relationship between the length of LAD artery and
the pattern of dominancy since the P- Value appeared
to be < 0.001.In conclusion the length of LAD artery appeared to be
dependent on the dominance pattern (i.e. length of LAD artery
depends on which of the two main coronary arteries is the
dominant one). Thus length of LAD artery was appeared to be
taller in left coronary dominant pattern.
Key words: LAD, length, dominancy