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Coronary Artery Anomalies

Coronary Artery Anomalies

1. Normal Coronary Anatomy

A. Anatomic
1) Left and right coronary artery
B. Surgical
1) Left main, left anterior descending
2) Left circumflex and right coronary artery
C. Variability in the origin of the posterior descending artery is expressed by the term dominance
D. Left dominance is less common (10-15%). More frequent in males
E. Left main coronary artery absence (1%)
F. Left anterior descending artery variations (4%)
G. Right coronary artery variations common (dual origin, immediate bifurcation)
H. Left circumflex coronary artery variations common

2. Blood Supply to Specialized Areas of the Heart

A. Ventricular septum
1) Predominantly from the left anterior descending via septals with a small portion (posterior septum) from the posterior descending
B. Sinus Node
1) Right coronary artery 55%
2) Left circumflex main 45%
C. AV Node
1) Right coronary artery 90%
2) Left circumflex artery 10%

3. Proximal HIS Bundle

A. AV node artery (posterior)
B. Kugels artery (anterior)
C. Distal HIS Bundle
1) Septal arteries from left anterior descending
D. Anterolateral papillary muscle
1) Branches of left coronary artery (LAD, diagonal, circumflex)
E. Posteromedial papillary muscle
1) Branches of right and circumflex coronary arteries

4. Minor Coronary Anomalies

A. Definition
1) Clinically and hemodynamically insignificant anomalies due primarily to an abnormal origin from the aorta or unusual distribution Circumflex artery arising from the right coronary artery or sinus. Most common anomaly (0.5%).
2) May be associated with transposition Left anterior descending from right coronary artery or right sinus. Most common coronary artery anomaly associated with Tetralogy of Fallot (2%) Right coronary artery from noncoronary sinus
3) Multiple coronary ostia

5. Major Coronary Anomalies

A. Anomalous origin of a main coronary artery from the aorta
1) Left main coronary artery from right sinus
2) Right coronary artery from left sinus (more common)
3) Single coronary ostia
B. Clinical events related to course between pulmonary artery and aorta resulting in compression, stretching or angulation (especially during exercise)
C. Symptoms
1) Myocardial infarction
2) Angina
3) CHF
4) Sudden death, as high as 15%
D. Natural history is controversial
E. Treatment is revascularization
F. Unroofing of intramural segment of the anomalous coronary artery

6. Hemodynamically Significant Coronary Artery Anomalies

A. Coronary artery aneurysms
1) Congenital (rare)
2) Atherosclerotic more common (3-5%)
3) Complications: Ischemia, thrombosis, distal embolization, infarction
4) Coronary artery atresia/hypoplasia (severe LV dysfunction and sudden death, not surgically correctable)
5) Coronary artery stenosis (occurs with other congenital lesions)
6) Coronary artery fistulas (most common)
7) Anomalous origin of left or right coronary artery from the pulmonary artery

7. Congenital Arteriovenous Fistulas

A. Definition
1) A direct communication between a coronary artery and any one of the four cardiac chambers, coronary sinus, SVC, pulmonary arteries or veins.
B. Right coronary most commonly involved (55%)
C. Left anterior descending (35%), combined (5%)
D. Site of connections
1) 90% drain into the right heart
2) Right ventricle 40%
3) Right atrium 30%
4) Pulmonary artery 20%
E. Fistulous opening most commonly is single

8. Signs and Symptoms

A. Presentation generally late
B. Cardiomegaly, continuous murmur
C. Younger patients asymptomatic
D. Congestive heart failure (older patients)
E. Dyspnea, fatigue (L-R shunt)
F. Angina (uncommon)
G. Myocardial infarction (rare)
H. Bacterial endocarditis (5%), rupture (rare)

9. Surgical technique

A. With or without bypass
B. Hospital mortality approximately zero
C. Late results excellent
D. Diagnosis of coronary AV fistula is an indication for operation unless shunt is small

10. Anomalous Origin of Left Coronary Artery from the Pulmonary Artery

A. Definition
1) Left main/Left anterior descending/or circumflex coronary artery arising from main pulmonary artery or right pulmonary artery
B. Right coronary artery is normal
C. Site of origin in the pulmonary artery is left or posterior cusp
D. 65% of infants die within one year from CHF

11. Anomalous Origin of Left Coronary Artery from the Pulmonary Artery

A. Signs and symptoms in infants
1) Cardiomegaly
2) CHF
3) Mitral regurgitations
4) Anterolateral infarctions
5) Dilated cardiomyopathy
6) Cardiac catheterization definitive
B. Signs and symptoms in adults
1) Angina (50%)
2) Mitral regurgitation (may be severe),
3) EKG abnormal
4) Stress EKG usually abnormal

12. Medical management - 100% mortality

A. Surgical technique: Establish a two coronary system. Do not replace mitral valve
1) Left coronary artery transfer
2) Subclavian to left coronary anastomosis
3) Tunnel operation (Takeuchi repair)
4) Coronary bypass grafting
5) Ligation of left coronary artery

EXTENDED OUTLINE

1. Anomalies of Origin

A. Origin from the PA
1) Left coronary
a) general
(1) most common coronary anomaly of origin
(2) incidence is 1 in 300,000 live births
(3) usually arises from the L posterior sinus
b) presentation
(1) symptoms depend on the amount of collaterals and subsequently the degree of L to R shunting
(2) critical time is between 1-3 months when PVR begins to fall, flow reverses in the coronary, and collaterals develop or an infarct occurs
(3) 75% are in CHF by 4 months secondary to papillary muscle dysfunction from subendocardial ischemia
(4) untreated leads to a one year mortality of 80-90%
(5) "Bland-White-Garland Syndrome"
(6) feeding leads to sweating, pallor, fatigue, FTT
(7) exam is often normal
c) diagnosis
(1) ECHO/Doppler is often all that is needed
(2) Cath is diagnostic, but often not needed
d) Treatment
(1) operate when diagnosis is made
(2) simple ligation carries a50% mortality
(3) bypass
(4) LIMA
(5) SVG difficult in neonate (mortality 0-38% with SVG)
(6) SCA can be used
(7) Aortic reimplantation
(8) mobilize
(9) PA tunnel (Takeuchi)
(10) 0-30% mortality
B. Right coronary
1) very rare
2) treat the same as the left, but easier to move
C. both coronaries
1) exceedingly rare
2) usually incompatible with life

2. Origin from the Aorta

A. Single Coronary
1) Type 1: one coronary supplies the entire heart
2) Type 2: single coronary divides into two coronaries with normal distribution
3) Type 3: does not fit either type 1 or 2
B. Anomalous Circumflex (Cx)
1) Cx off R sinus - most common anomaly of origin
2) ? of increased risk of ostial atherosclerosis
C. Anomalous LAD off the R sinus
1) Very rare and usually not of significance unless L coronary off the R courses between the aorta and the PA then it can present with sudden death
2) 5-7% incidence in TOF which can be a problem in RVOT reconstruction

3. Anomalous Termination of the Coronaries

A. Coronary artery to cardiac chamber fistula
1) course
a) RCA most common to the RV, but can go to the SVC, RA, CS, PA
b) L heart fistulas are very rare, but can go to the LA or LV
2) symptoms
a) 30-70% symptomatic
b) angina, palpitations, CHF
c) may have a continuous murmur
3) Treatment
a) operate if symptomatic
b) if asymptomatic in an infant, follow to childhood
c) Glenn's: ligate at endocardial surface to avoid ischemia
d) Mavroudis: extracardiac ligation is OK

4. Aneurysms of the Coronaries

A. Congenital
1) may lead to dilatation and rupture
2) prong to thrombosis
B. Acquired
1) Etiology
a) atherosclerosis, polyarteritis, Kawasaki, syphilis, trauma, mucocutaneous lymph node syndrome
b) thrombosis and rupture rate unknown

5.' Anomalous Coronary Sinus (CS)

A. persistent L SVC
B. Anomalous PV to CS
C. Coronary artery to CS fistula
D. Absence of CS
E. atresia of CS ostia - ass. with L SVC
F. CS diverticula - ass. with WPW
G. CS septal defect