CA anomalies on CT angiography

1. Coronary Artery Anomalies OnCoronary Artery Anomalies On
CT AngiographyCT Angiography
Dr.Sahar Gamal El-Din ,CBCCTDr.Sahar Gamal El-Din ,CBCCT
National Heart InstituteNational Heart Institute

2. Introduction
• The prevalence of coronary artery anomalies is
reported to be approximately 1% to 2% in the
general population .
• The clinical presentation is variable & the
abnormality may remain clinically occult or it can
have life-threatening consequences, such as MI,
arrhythmia, or even sudden death.
• Even if the anomalies are asymptomatic,
knowledge of their presence is important at
cardiac surgery to avoid damage to a vessel with
an anomalous course.

3. • The diagnosis of coronary artery anomalies hasThe diagnosis of coronary artery anomalies has
previously required invasive coronarypreviously required invasive coronary
angiography; however, in up to 50% of patients,angiography; however, in up to 50% of patients,
the coronary artery anomalies may be incorrectlythe coronary artery anomalies may be incorrectly
classified during invasive angiography.classified during invasive angiography.
• This misclassification may result from theThis misclassification may result from the
difficulty in delineating the precise vessel pathdifficulty in delineating the precise vessel path
within a complex 3D geometry using a relativelywithin a complex 3D geometry using a relatively
restricted two-dimensional view.restricted two-dimensional view.
• Coronary CTA has been shown to accurately theCoronary CTA has been shown to accurately the
anomalous vessel origin, its subsequent course,anomalous vessel origin, its subsequent course,
and the relationship to the great vessels.and the relationship to the great vessels.

4. ClassificationClassification
• Anomalies of origin.Anomalies of origin.
• Anomalies of course.Anomalies of course.
• Anomalies of termination.Anomalies of termination.
• IntrinsicIntrinsic

5. Anomalies of OriginAnomalies of Origin
• 1. Number of Coronary Ostia.1. Number of Coronary Ostia. Normally there are Normally there are
2 coronary ostia (one for the right coronary artery2 coronary ostia (one for the right coronary artery
and one for the left).and one for the left).
A.A.Multiple Ostia.Multiple Ostia. Three or more ostia ( considered Three or more ostia ( considered
normal variants). This is most commonly due tonormal variants). This is most commonly due to
the conus branch arising directly from the aorta,the conus branch arising directly from the aorta,
which is seen in 50% of subjects .which is seen in 50% of subjects .
• The other common cause of multiple ostia is anThe other common cause of multiple ostia is an
absent left main artery with separate ostia for theabsent left main artery with separate ostia for the
LAD and LCX (estimated to be seen in 0.5% to 8%LAD and LCX (estimated to be seen in 0.5% to 8%
of populationof population

6. (A and B) Multiple coronary ostia. Note the separate origin of
the conus artery from the aorta (curved black arrow) on 3-D
volume-rendered and multiplanar reformatted CT image.

7. • Absence of the left main coronary artery (so-called split left coronary
artery). The LAD and the LCX arise separately (arrow) from the left
sinus of Valsalva of the aorta (Ao) Panel A shows a cranial view of a
3D volume-rendered image. The separate ostia cannot be recognized
definitely. Better evaluation is possible on a volume-rendered
reconstruction of the coronary tree (Panel B) or a 2-dDmap view
(Panel C)

8. B.B. Single Coronary OstiumSingle Coronary Ostium
• In this rare anomaly only one coronary arteryIn this rare anomaly only one coronary artery
arises from a single ostium (0.0024% to 0.044%arises from a single ostium (0.0024% to 0.044%
of the population).of the population).
• It gives rise to the left main and RCA orIt gives rise to the left main and RCA or
courses directly to the LAD, LCX, & RCA. courses directly to the LAD, LCX, & RCA.
• One or more arteries can have an anomalousOne or more arteries can have an anomalous
course. This abnormality can have an adversecourse. This abnormality can have an adverse
clinical outcome, particularly if one of theclinical outcome, particularly if one of the
arteries takes an interarterial course.arteries takes an interarterial course.

9. • Prepulmonary benign course of the left coronary artery
arising from the RCA after a short common trunk,
which originates from the right sinus of Valsalva. The
anomalously coursing left coronary artery passes
anterior to the pulmonary artery to the anterior
interventricular sulcus, where it splits into LAD and

10. • Prepulmonary benign course of the left coronary artery
arising from the RCA after a short common trunk,
which originates from the right sinus of Valsalva.

11. • Anomalous coronary artery anatomy with a single
coronary ostium arising from the right coronary cusp
giving off a left main taking a retroaortic course and a
right coronary artery. (a) 3D reconstruction of the
coronary arteries. (b) Double-oblique maximal
intensity projection (MIP).

12. • 2. Anomalous Location of Ostium in Relation to2. Anomalous Location of Ostium in Relation to
the Appropriate Coronary Sinus.the Appropriate Coronary Sinus.
• A. High ostium.A. High ostium. This refers to a coronary ostiumThis refers to a coronary ostium
(either Lt or Rt) that is at least(either Lt or Rt) that is at least 1 cm1 cm above theabove the
sinotubular junction (instead of being at thesinotubular junction (instead of being at the
aortic sinus).aortic sinus).
• Rarely, the coronary artery can arise from theRarely, the coronary artery can arise from the
aortic arch, the brachiocephalic artery, theaortic arch, the brachiocephalic artery, the
internal mammary, bronchial, or subclavianinternal mammary, bronchial, or subclavian
arteries, or even the descending aorta.arteries, or even the descending aorta.

13. • These situations are usually well tolerated &These situations are usually well tolerated &
asymptomatic, but they may cause difficultiesasymptomatic, but they may cause difficulties
in cannulation during coronary angio. & CABG.in cannulation during coronary angio. & CABG.
• B. Commissural Ostium.B. Commissural Ostium. When the ostium isWhen the ostium is
located within 5 mm of the commissurelocated within 5 mm of the commissure
between 2 sinuses, it is termed a commissuralbetween 2 sinuses, it is termed a commissural
ostium.ostium.

14. 3-D volume-rendered image of coronary tree shows a high
origin of the RCA (black curved arrow) above the
sinotubular junction.

15. • 3. Anomalous Origin of the Coronary Artery3. Anomalous Origin of the Coronary Artery
from Opposite Sinus.from Opposite Sinus.
• In this anomaly, the coronary artery arises fromIn this anomaly, the coronary artery arises from
the opposite sinus & then takes one of the 4the opposite sinus & then takes one of the 4
paths .paths .
• The precise path taken by the artery is importantThe precise path taken by the artery is important
clinically.clinically.
• An interarterial course (called malignant course)An interarterial course (called malignant course)
carries a high risk of sudden cardiac death,carries a high risk of sudden cardiac death,
while the other 3 courses are consideredwhile the other 3 courses are considered
nonmalignant or relatively benign.nonmalignant or relatively benign.

16. • A. Interarterial. A. Interarterial.
• In this case, a coronary artery (such as theIn this case, a coronary artery (such as the
RCA, LM, LAD or LCX) arises from theRCA, LM, LAD or LCX) arises from the
opposite sinus & courses between theopposite sinus & courses between the
aortic root and pulmonary artery/rightaortic root and pulmonary artery/right
ventricular outflow tract .ventricular outflow tract .
• This anomaly has been linked withThis anomaly has been linked with
sudden cardiac death.sudden cardiac death.

17. • Several pathologic processes have beenSeveral pathologic processes have been
implicated; they include a narrow slit-likeimplicated; they include a narrow slit-like
orifice, an acute angle of the ostium with aorifice, an acute angle of the ostium with a
tangential proximal course of the ectopictangential proximal course of the ectopic
coronary artery, and an intramural coursecoronary artery, and an intramural course
where the coronary artery exits the aorticwhere the coronary artery exits the aortic
lumen and courses into the aortic wall beforelumen and courses into the aortic wall before
emerging on the surface.emerging on the surface.
• A consequence of this anomaly is lateralA consequence of this anomaly is lateral
arterial compression, which worsens in systole,arterial compression, which worsens in systole,
and the artery appears ovoid in cross-and the artery appears ovoid in cross-
section. The flow can be further compromisedsection. The flow can be further compromised
during exercise due to aortic dilatation.during exercise due to aortic dilatation.

18. • RCA arising from the left coronary sinus and taking an interarterial
course (a) VRT image of the top of the heart shows both the RCA
(straight arrow) and the LCA (curved arrow) originating from the left
coronary sinus. The RCA courses between the pulmonary artery (PA) and
the aorta (A).Note the slit-like ostium (arrowhead) of the RCA.

19. VRT of single coronary ostium in the left sinus of Valsalva (LSV). The dilatedVRT of single coronary ostium in the left sinus of Valsalva (LSV). The dilated
LMT divided into the LAD and the LCX .The LCX then coursed in the leftLMT divided into the LAD and the LCX .The LCX then coursed in the left
atrioventricular groove and continued to the posterior atrioventricular grooveatrioventricular groove and continued to the posterior atrioventricular groove
where it occupied the anatomic position normally occupied by RCA.where it occupied the anatomic position normally occupied by RCA.

20. (a) RCA and LCA origin from the ascending aorta above the left sinus of Valsalva(a) RCA and LCA origin from the ascending aorta above the left sinus of Valsalva
together, (b) RCA passed between the aorta and pulmonary artery before reachingtogether, (b) RCA passed between the aorta and pulmonary artery before reaching
the right atrioventricular groove.the right atrioventricular groove.

21. • B. Transseptal (subpulmonic).B. Transseptal (subpulmonic).
• The artery traverses anteriorly & inferiorlyThe artery traverses anteriorly & inferiorly
through the interventricular septum & takes anthrough the interventricular septum & takes an
intramyocardial course, giving off septalintramyocardial course, giving off septal
branches and finally emerging at its normalbranches and finally emerging at its normal
epicardial position. It is considered a relativelyepicardial position. It is considered a relatively
benign anomaly, though in some cases of suddenbenign anomaly, though in some cases of sudden
& unexpected cardiac death it has been found to& unexpected cardiac death it has been found to
be the only reported abnormalitybe the only reported abnormality

22. trans-septal LAD artery that arises from the RCAtrans-septal LAD artery that arises from the RCA

23. • C. Retroaortic.C. Retroaortic. This is the most commonThis is the most common
coronary artery anomaly, seen in 0.9% of thecoronary artery anomaly, seen in 0.9% of the
population. The ectopic coronary artery (morepopulation. The ectopic coronary artery (more
commonly the LCX) runs posteriorly betweencommonly the LCX) runs posteriorly between
the aortic root and the left atrium.the aortic root and the left atrium.
• D. Prepulmonic.D. Prepulmonic. The ectopic coronary artery The ectopic coronary artery
runs anterior to the pulmonary artery or rightruns anterior to the pulmonary artery or right
ventricular outflow tractventricular outflow tract

24. • LCx artery arising from the right coronary sinus
and taking a retroaortic course

25. Anomalous retroaortic course of the left circumflex artery (LCX)
(black arrow) arising from right coronary artery in two separate subjects
as seen on volume-rendered (A) and axial contrast-enhanced CT image (B).

26. Axial contrast-enhanced CT image showing anomalous LAD and LCX
arising from the right sinus of Valsalva. The LAD courses anterior to
the RVOT (i.e. prepulmonic) while the LCX courses posterior
to the aortic root (retroaortic).

27. 4.4. Inverted Coronary Arteries.Inverted Coronary Arteries.
• In this rare anomaly, the LCA arises from theIn this rare anomaly, the LCA arises from the
right aortic sinus, and the RCA arises from theright aortic sinus, and the RCA arises from the
left aortic sinus. The anomaly can becomeleft aortic sinus. The anomaly can become
hemodynamically significant if the anomaloushemodynamically significant if the anomalous
artery courses interarterially.artery courses interarterially.
5.5. Anomalous origin of the coronary artery fromAnomalous origin of the coronary artery from
non-coronary sinus.non-coronary sinus. Either the RCA or the LMEither the RCA or the LM
can arise from the non-coronary sinus.can arise from the non-coronary sinus.
• This is a rare anomaly and may have no clinicalThis is a rare anomaly and may have no clinical
relevance . However, there are reports of casesrelevance . However, there are reports of cases
that can be symptomatic, particularly if thethat can be symptomatic, particularly if the
proximal part of the artery has an intramuralproximal part of the artery has an intramural
course inside the aortic wall and is hypoplastic.course inside the aortic wall and is hypoplastic.

28. • Anomalous origin of the left main artery from
non-coronary sinus

29. 6.6. Anomalous Origin of the Coronary Artery fromAnomalous Origin of the Coronary Artery from
Pulmonary Artery (ALCAPA – ARCAPA)).Pulmonary Artery (ALCAPA – ARCAPA)).
• This is one of the most serious anomalies, with aThis is one of the most serious anomalies, with a
90% mortality rate in the first year of life. Most90% mortality rate in the first year of life. Most
patients are symptomatic in infancy and earlypatients are symptomatic in infancy and early
childhood.childhood.
• Either the LCA (ALCAPA)Either the LCA (ALCAPA) also referred to asalso referred to as Bland–Bland–
White–Garland syndromeWhite–Garland syndrome or the RCA (ALCAPA)or the RCA (ALCAPA)
can arise from the pulmonary artery.can arise from the pulmonary artery.
• ALCAPA appears more common (0.008% vs 0.002%ALCAPA appears more common (0.008% vs 0.002%
for RCA). It is conceivable that this apparentfor RCA). It is conceivable that this apparent
difference may be due to the fact that ALCAPAdifference may be due to the fact that ALCAPA
carries a worse prognosis and is more likely to comecarries a worse prognosis and is more likely to come
to clinical attention.to clinical attention.
• In rare instances the LCX or both the RCA and theIn rare instances the LCX or both the RCA and the

30. • Coronary artery origin from the pulmonary arteryCoronary artery origin from the pulmonary artery
can occur as an isolated finding, though ancan occur as an isolated finding, though an
associated cardiac abnormality, such as ASD,associated cardiac abnormality, such as ASD,
VSD, tetralogy of Fallot, aortic coarctation, DORV,VSD, tetralogy of Fallot, aortic coarctation, DORV,
and PDA, can be seen in 5% of cases.and PDA, can be seen in 5% of cases.
• Extensive intercoronary collaterals develop thatExtensive intercoronary collaterals develop that
are often dilated and tortuous. Symptoms usuallyare often dilated and tortuous. Symptoms usually
occur due to coronary steal phenomenon causedoccur due to coronary steal phenomenon caused
by the flow of blood from the higher pressureby the flow of blood from the higher pressure
coronary arterial system to the lower pressurecoronary arterial system to the lower pressure
pulmonary arteries.Surgical treatment is usuallypulmonary arteries.Surgical treatment is usually
recommended for these anomalies.recommended for these anomalies.

32. • Volume-rendered image of a Bland-White-Garland
syndrome in a right anterior oblique view. The RCA is
dilated. The LAD originates from the pulmonary artery
(arrow) and is also markedly dilated and tortuous.

33. VRT CT angiogram shows dilated intercoronary collateral arteriesVRT CT angiogram shows dilated intercoronary collateral arteries
(arrowheads), which connect the tortuous RCA (long arrow) to the(arrowheads), which connect the tortuous RCA (long arrow) to the
LCA (short arrow).LCA (short arrow).

34. Anomalous origin of the right coronary arteryAnomalous origin of the right coronary artery
from pulmonary artery (ARCAPA).from pulmonary artery (ARCAPA).

35. • Anomalous origin of the right coronary artery
(black arrow) from pulmonary artery. Note the

36. Anomalies of CourseAnomalies of Course
• 1. Myocardial Bridge.. Myocardial Bridge. In this anomaly, aIn this anomaly, a
portion of the coronary artery that is normallyportion of the coronary artery that is normally
epicardial traverses through the myocardium.epicardial traverses through the myocardium.
The myocardial tissue covering the artery isThe myocardial tissue covering the artery is
called a myocardial bridge, and the artery itselfcalled a myocardial bridge, and the artery itself
is called a tunneled segment.is called a tunneled segment.
• The bridging can be superficial or deep andThe bridging can be superficial or deep and
has been most commonly described in the midhas been most commonly described in the mid
LAD—80% .LAD—80% .

37. • The myocardial bridge is diagnosed on catheterThe myocardial bridge is diagnosed on catheter
angiography by observing systolic compression ofangiography by observing systolic compression of
the artery, or the so-calledthe artery, or the so-called "milking effect.""milking effect."
Angiography may be somewhat insensitive toAngiography may be somewhat insensitive to
superficial bridging that does not causesuperficial bridging that does not cause
significant systolic compression.significant systolic compression.
• However, coronary CTA can demonstrate theHowever, coronary CTA can demonstrate the
coronary artery directly(not just the lumen) andcoronary artery directly(not just the lumen) and
its relationship to the adjacent myocardium.its relationship to the adjacent myocardium.
• The length and depth of tunneled segment can beThe length and depth of tunneled segment can be
accurately determined by CT.accurately determined by CT.
• Additional indirect signs (such as systolicAdditional indirect signs (such as systolic
compression) can also be seen usingcompression) can also be seen using
retrospectively-gated coronary CT throughretrospectively-gated coronary CT through

39. • This capability of CT may explain the higherThis capability of CT may explain the higher
prevalence of myocardial bridging reported onprevalence of myocardial bridging reported on
CT (26%) compared to conventionalCT (26%) compared to conventional
angiography (0.5% to 4.5%).angiography (0.5% to 4.5%).
• Though myocardial bridging can be seen as aThough myocardial bridging can be seen as a
normal variant, without being clinically overtnormal variant, without being clinically overt
in a large proportion of cases, it has beenin a large proportion of cases, it has been
infrequently linked with ischemia,infrequently linked with ischemia,
tachycardia-induced ischemia, conductiontachycardia-induced ischemia, conduction
disturbances, myocardial infarctions, and evendisturbances, myocardial infarctions, and even
sudden cardiac death.sudden cardiac death.

40. • Additionally, the coronary segment proximal to theAdditionally, the coronary segment proximal to the
tunneled artery is vulnerable to atherosclerotictunneled artery is vulnerable to atherosclerotic
disease presumably due to low-wall shear stress,disease presumably due to low-wall shear stress,
while the tunneled segment itself may be protectedwhile the tunneled segment itself may be protected
because of high-wall shear stress.because of high-wall shear stress.
• Myocardial bridging (black arrow) as seen on a curved planar reformattedMyocardial bridging (black arrow) as seen on a curved planar reformatted
image of the LAD (A). Note the decrease in caliber of the artery in systole (C)image of the LAD (A). Note the decrease in caliber of the artery in systole (C)
compared to diastole (B) on a cross-sectional orthogonal view of the LAD.compared to diastole (B) on a cross-sectional orthogonal view of the LAD.

41. • 2. Duplication.2. Duplication. This anomaly refers mainly to 2 LADThis anomaly refers mainly to 2 LAD
arteries (9 types): Type 1 is the most common, one shortarteries (9 types): Type 1 is the most common, one short
LAD, which terminates in the anterior interventricularLAD, which terminates in the anterior interventricular
groove without reaching the apex, and one long LAD,groove without reaching the apex, and one long LAD,
which originates from the LAD proper or anomalouslywhich originates from the LAD proper or anomalously
from the RCA/opposite sinus, enters the distal anteriorfrom the RCA/opposite sinus, enters the distal anterior
interventricular groove, and terminates at the apex.interventricular groove, and terminates at the apex.
• Care should be taken to avoid mistaking a long LADCare should be taken to avoid mistaking a long LAD
for a parallel diagonal branch.for a parallel diagonal branch.
The differentiation is relatively straightforward,The differentiation is relatively straightforward,
since a diagonal artery does not enter the anteriorsince a diagonal artery does not enter the anterior
interventricular groove . Knowledge of this anomaly isinterventricular groove . Knowledge of this anomaly is
important for planning surgical vascularization & toimportant for planning surgical vascularization & to
avoid mistaking a short LAD artery for a mid-LADavoid mistaking a short LAD artery for a mid-LAD
occlusion.occlusion.

42. • Duplication of LAD seen on volume-rendered image of the heart
(A) and coronary tree image (B). Note a short LAD (black arrow),
which terminates high in the anterior interventricular groove
without reaching the apex and a long LAD (white arrow) which
courses parallel to the short LAD, enters the distal anterior
interventricular groove and supplies the apex.

45. Duplication of RCADuplication of RCA

46. Anomalies of Termination
• 1. Coronary Arteriovenous Fistula.Coronary Arteriovenous Fistula.
• Coronary artery fistula is a condition in which aCoronary artery fistula is a condition in which a
communication exists between one or twocommunication exists between one or two
coronary arteries and either:coronary arteries and either:
a.a. A cardiac chamberA cardiac chamber
b.b. The coronary sinusThe coronary sinus
c.c. The superior vena cavaThe superior vena cava
d.d. The pulmonary arteryThe pulmonary artery
• The involved fistulous artery is often dilated andThe involved fistulous artery is often dilated and
tortuous.tortuous.

47. • The most common site of drainage is the rightThe most common site of drainage is the right
ventricle (45% of cases), followed by the rightventricle (45% of cases), followed by the right
atrium (25%) and the pulmonary artery (15%).atrium (25%) and the pulmonary artery (15%).
The fistula drains into the left atrium or leftThe fistula drains into the left atrium or left
ventricle in less than 10% of cases.ventricle in less than 10% of cases.
• There may be steal phenomenon with consequentThere may be steal phenomenon with consequent
myocardial ischemia. Drainage to a left-sidedmyocardial ischemia. Drainage to a left-sided
heart chamber causes a hemodynamic stateheart chamber causes a hemodynamic state
similar to aortic regurgitation.similar to aortic regurgitation.
• Clinical symptoms are based on the inducedClinical symptoms are based on the induced
hemodynamic abnormality. If the patient ishemodynamic abnormality. If the patient is
symptomatic, treatment options include closingsymptomatic, treatment options include closing
the fistula, either by coil embolization or bythe fistula, either by coil embolization or by
ligation of the fistula with or without CABG.ligation of the fistula with or without CABG.

48. • Fistula between the RCA and the coronary sinus (CS)
depicted by three-dimensional reconstruction (Panel
A) and multiplanar reformation (Panel B).

49. • Fistula between the LAD and the right ventricle displayed
on three-dimensional reconstructions (Panel C) and the
corresponding conventional angiogram (Panel D).

50. Fistula between proximal LAD and MPAFistula between proximal LAD and MPA

51. • 2. Coronary Arcade.2. Coronary Arcade.
• This is defined as angiographically evidentThis is defined as angiographically evident
connections between the RCA and LCA in theconnections between the RCA and LCA in the
absence of coronary stenosis. Though smallabsence of coronary stenosis. Though small
connections between the RCA and LCA areconnections between the RCA and LCA are
normal, these are not normally large enough tonormal, these are not normally large enough to
be visible on angiography.be visible on angiography.
• These connections differ from collaterals byThese connections differ from collaterals by
virtue of straight connections between thevirtue of straight connections between the
coronaries in the absence of significant coronarycoronaries in the absence of significant coronary
artery diseaseartery disease
• Coronary arcades are mainly seen near the cruxCoronary arcades are mainly seen near the crux

52. • 3. Extracardiac connections.3. Extracardiac connections.
• Coronary arteries may have connections toCoronary arteries may have connections to
extracardiac arteries, such as the bronchial,extracardiac arteries, such as the bronchial,
internal mammary, pericardial, superior andinternal mammary, pericardial, superior and
inferior pherenic, intercostals, and esophagealinferior pherenic, intercostals, and esophageal
branches of the aorta.branches of the aorta.
• These connections become significant with theThese connections become significant with the
development of coronary artery disease.development of coronary artery disease.

53. Intrinsic Coronary Arterial AbnormalitiesIntrinsic Coronary Arterial Abnormalities
• 1. Coronary stenosis.1. Coronary stenosis. Though coronary stenosis Though coronary stenosis
is mostly acquired, congenital coronary stenosisis mostly acquired, congenital coronary stenosis
has been described and can be ostial (due to ahas been described and can be ostial (due to a
valve-like ridge of the aortic wall or fusion ofvalve-like ridge of the aortic wall or fusion of
the aortic leaflets and aortic wall) or peripheral.the aortic leaflets and aortic wall) or peripheral.
• 2. Congenital Atresia of the CA (mostly LMCA).2. Congenital Atresia of the CA (mostly LMCA).
• In this condition there is complete atresia of theIn this condition there is complete atresia of the
left coronary ostium , so the entire coronaryleft coronary ostium , so the entire coronary
arterial supply to the heart is derived from thearterial supply to the heart is derived from the
RCA and its branches. The LAD and LCX areRCA and its branches. The LAD and LCX are
seen in their respective locations , but theyseen in their respective locations , but they
receive blood from the RCA.receive blood from the RCA.

54. • This is an extremely rare condition and differsThis is an extremely rare condition and differs
from a single RCA because some of thefrom a single RCA because some of the
branches fill retrograde through the RCA. Thebranches fill retrograde through the RCA. The
collateral circulation from the right to the leftcollateral circulation from the right to the left
coronary system is usually not sufficient socoronary system is usually not sufficient so
almost all patients eventually developalmost all patients eventually develop
myocardial ischemia.myocardial ischemia.
• Surgical reconstruction of a 2-coronary systemSurgical reconstruction of a 2-coronary system
by coronary artery bypass graft is performed inby coronary artery bypass graft is performed in
these patients.these patients.

55. Congenital Atresia of the LMCACongenital Atresia of the LMCA

56. • 3. Coronary Artery Ectasia or Aneurysm.3. Coronary Artery Ectasia or Aneurysm.
• This lesion is defined as a coronary artery with aThis lesion is defined as a coronary artery with a
diameter of more than 1.5 times the adjacentdiameter of more than 1.5 times the adjacent
normal segment and can be either focal or diffuse.normal segment and can be either focal or diffuse.
• Coronary aneurysms may be congenital orCoronary aneurysms may be congenital or
acquired; in the acquired group, Kawasaki diseaseacquired; in the acquired group, Kawasaki disease
is the most common cause of aneurysmsis the most common cause of aneurysms
worldwide.worldwide.
• Congenital aneurysms are more commonlyCongenital aneurysms are more commonly
described in the RCA.described in the RCA.
• Possible complications include myocardialPossible complications include myocardial

57. Right sinus of Valsalva aneurysmRight sinus of Valsalva aneurysm