Basics
Description
Anomalous coronary arteries include abnormal anatomy, origin, course, and/or termination of coronary arteries.
Epidemiology
Prevalence
Overall prevalence ranges from 0.17-1% in the general population.
Pathophysiology
- Anomalies of coronary arterial origin:
- Pulmonary arterial origin:
- Anomalous LMCA from pulmonary artery (ALCAPA): 1 in 300,000 live births and 0.5% of all congenital heart disease
- Origin of RCA or left anterior descending or left circumflex arteries from pulmonary artery is less common
- Origin from inappropriate sinus (see Coronary Arteries from Opposite Sinus).
- Anomalies of coronary artery termination:
- 0.2-0.4% of all congenital cardiac anomalies and 50% of congenital coronary anomalies
- These include coronary-cameral fistulas (connection between a coronary artery and a cardiac chamber) and coronary arteriovenous fistulas (between coronary artery and coronary sinus, superior vena cava or pulmonary artery).
- Anomalies intrinsic to the coronary artery:
- Coronary artery aneurysm: Congenital or acquired (atherosclerosis, associated with coronary-cameral fistulas, Kawasaki disease, infectious, or traumatic)
- Congenital left coronary artery (LCA) stenosis or atresia
- Congenital coronary artery hypoplasia
- Myocardial bridges (muscle bridge overlying an epicardial artery) and coronary arterial loops (extreme coiling of the coronary arteries)
Etiology
Predominantly congenital in origin, anomalies can occur in isolation or in association with other intracardiac malformations.
Associated Conditions
Often associated with other congenital heart defects, in particular with tetralogy of Fallot, D- and l-transposition of great arteries, truncus arteriosus, pulmonary atresia, and univentricular hearts
Diagnosis
- Many coronary anomalies are not clinically significant. Serious abnormalities may present with varying profiles and at different ages.
- Anomalous LCA from pulmonary artery: As pulmonary resistance decreases in postnatal life, perfusion pressure decreases, collaterals develop between right coronary artery (RCA) and LCA, and there may be a pulmonary-coronary steal:
- ~90% of patients with this anomaly present in infancy with episodes of myocardial ischemia, mitral insufficiency with symptoms of CHF (irritability, feeding difficulties, poor weight gain, diaphoresis, respiratory distress). Untreated, 65-85% die of intractable CHF in the 1st yr of life (infantile type).
- Some present in later childhood or as young adults with angina of effort or CHF due to mitral incompetence (adult type).
- 15% remain asymptomatic, possibly because of extensive collaterals and a restrictive opening at the origin of the LCA.
- Congenital LCA stenosis, or atresia: Usually present with symptoms of myocardial ischemia with exercise
- Coronary arteriovenous fistulas: Physiology and presentation depend on the size and location of the shunt. Most patients <20 are asymptomatic; the majority >20 become symptomatic with dyspnea on exertion, fatigue, angina, and palpitations. Most have only small left-to-right shunts:
- Fistulas most often occur (in order of frequency) in the RV, right atrium, and pulmonary artery. They also may drain into the LV, left atrium, coronary sinus, or superior vena cava.
- Complications: CHF, fistula rupture, infective endocarditis, myocardial ischemia/infarction, aneurysm formation
History
- In infants: Inquire about symptoms of CHF including irritability, feeding difficulties, failure to thrive, diaphoresis, and respiratory difficulties.
- In children and older children: Inquire about symptoms of chest pain, exercise intolerance, syncope or near-syncope, and palpitations. The occurrence of symptoms with exercise should raise particular concern.
Physical Exam
Physical findings are not pathognomonic but may aid in diagnosis. These include:
- Signs of CHF including hepatomegaly, rales, respiratory distress, LV gallop, and holosystolic murmur of mitral insufficiency
- Continuous murmur in patients with coronary arteriovenous fistula or adult-type ALCAPA with collaterals
- Mitral regurgitation secondary to papillary muscle infarction in ALCAPA. Mitral insufficiency may also occur secondary to LV dilation following acute or chronic myocardial ischemia.
- Findings of associated congenital heart defects
Tests
Lab
- There are no pathognomonic blood tests for diagnosis but peripheral markers of myocardial ischemia may aid in diagnosis.
- Cardiac troponin, creatine phosphokinase, creatine kinase MB fraction levels may be elevated during episodes of ischemia
- EKG:
- Resting EKG may be abnormal in symptomatic patients with evidence of myocardial ischemia (ST-T changes), ventricular hypertrophy, and arrhythmias depending on type and location of coronary artery abnormalities.
- Anterolateral infarct in an infant (ie, abnormal Q waves in leads I, aVL, and precordial leads V4-V6 and abnormal R waves or R-wave progression in the left precordial leads) is highly suggestive of ALCAPA in an infant.
- Exercise stress test:
- May uncover ischemia due to underlying coronary anomaly, but is not always conclusive
Imaging
- CXR:
- May show cardiomegaly, pulmonary edema in patients with CHF, and abnormal cardiac silhouette in cases of large aneurysm.
- Transthoracic echo: Is the modality of choice. Intravascular US has not been widely used in children or adults for this indication:
- Echo can diagnose most cases. Coronary anatomy is best visualized in the parasternal long, short, and high short-axis views. ECG features include:
- Abnormal attachment of the origin of the coronary artery (in >1 view to avoid problems due to lateral dropout)
- Doppler color-flow mapping showing flow away from the coronary artery into the pulmonary artery indicates ALCAPA.
- A dilated coronary artery on 2-dimensional echo should prompt a search for anomalous coronaries, eg, ALCAPA (dilated RCA) or coronary arteriovenous fistula (dilated proximal portion of the coronary artery that feeds the fistula).
- Intrinsic coronary artery abnormalities like aneurysm, stenosis, atresia, hypoplasia, fistulas
- Chamber dilation secondary to shunting across large coronary fistula
- Abnormalities of LV size and function (ie, enlarged left atrium and ventricle, diminished LV function, global or regional wall motion abnormalities, endocardial fibroelastosis, and mitral regurgitation), especially in patients with ALCAPA
- Associated congenital intracardiac anomalies and other causes of heart failure (eg, cardiomyopathy)
- Ultrafast CT with 3D reconstruction may be useful in defining coronary anatomy and has been used in adults. Advantages include high spatial resolution, fast acquisition, and patient comfort.
- Cardiac MRI:
- May be useful in defining coronary anatomy
- Importantly, cardiac MRI can provide additional information including myocardial scarring and regional perfusion defects.
- Myocardial perfusion imaging:
- These include resting and stress thallium imaging and dobutamine stress ECG. These studies have not been widely used in children. They may uncover ischemia due to underlying coronary anomaly but are not always conclusive due to false-negative results. PET can be used to assess myocardial perfusion and viability but the experience is limited in the pediatric population.
Surgery
- Cardiac catheterization and angiocardiography remain a gold standard for diagnosis of most coronary anomalies. Injection of contrast into the aortic root and, in cases of anomalous origin, into the pulmonary artery can identify coronary abnormalities. Selective coronary angiography should be attempted where possible.
- Screening procedures:
- In general, standard testing with EKG is unlikely to provide clinical evidence of myocardial ischemia and is not reliable as a screening test in large athletic populations. A history of exertional syncope or chest pain requires exclusion of a coronary anomaly in athletes. ECG and stress imaging are indicated in suspected cases.
Differential Diagnosis
ALCAPA is most often misdiagnosed as cardiomyopathy or myocarditis because of failure to identify the anomalous coronary artery. Every attempt must be made to define coronary artery anatomy in any young patient presenting with apparent cardiomyopathy or unexplained heart failure.
Treatment
Additional Treatment
General Measures
- Medical treatment is usually supportive.
- Treatment of CHF and arrhythmias to stabilize the patient with LV dysfunction prior to surgery
- Avoidance of athletics and military participation in at-risk individuals may lower the risk of sudden death.
- Patients with persistent LV dysfunction post surgical repair may benefit from chronic heart failure medications including ACE inhibitors and β-blocker therapy. These can be discontinued with return of normal function.
Surgery
- Corrective surgery is the treatment of choice for most coronary anomalies and can be undertaken with excellent results. However, not all coronary artery anomalies require surgery.
- Indications for surgery:
- ALCAPA should be repaired urgently once diagnosis is made.
- As part of surgical repair of associated congenital heart defects; failure to recognize an anomalous coronary artery may result in the artery being injured at surgery or inadequate myocardial protection when cardioplegia is given directly into the major coronary arteries.
- Surgical options:
- Direct aortic reimplantation of the anomalous coronary artery (with a button of pulmonary artery around origin) provides the most physiologic repair in the absence of ostial abnormalities. The surgical mortality is <15%. Short-term use of LV assistive device in the immediate postoperative period may assist recovery. Most often there is excellent recovery of normal or near-normal LV function and regression of mitral insufficiency, usually within 6-24 mo of corrective surgery.
- Historical alternatives include creation of an intrapulmonary baffle or tunnel (Takeuchi procedure), primary angioplasty, and coronary artery bypass grafting.
- Aneurysm: Ligation of aneurysm, aneurysmorrhaphy, aneurysmectomy with interposition of graft
- Fistulas: Surgical ligation or transcatheter closure of coronary AV fistulas.
- Myocardial bridging: Unroofing of myocardial bridge in symptomatic patients.
- Catheter interventions: The role of catheter interventions is limited in the primary management of anomalous coronary arteries. However, balloon angioplasty or coronary stenting may be considered postoperatively in cases with residual or recurrent coronary stenosis or obstruction at surgical repair site.
Ongoing Care
Follow-Up Recommendations
Patient Monitoring
Asymptomatic patients with mild abnormalities should be followed for development of symptoms or EKG or ECG evidence of progression of lesion (eg, enlarging aneurysm, chamber enlargement secondary to fistula, thromboembolism). According to AHA guidelines, patients with large coronary aneurysms secondary to Kawasaki disease should be followed with serial ECGs and exercise stress testing every 6 mo to 1 yr. Angiography may be required.
Patient Education
- Infective endocarditis prophylaxis is generally not required for dental and invasive procedures based on recent guidelines.
- Activity
Prognosis
- The majority of infants improve markedly after timely repair of ALCAPA, ventricular function normalizes, and over time mitral insufficiency lessens. LV dilation and dysfunction may persist in 20-25% of patients post repair.
- In infants who have had severe MI prior to surgery resulting in inadequate functioning myocardium may have persistent chronic heart failure. Cardiac replacement may be the only ultimate management alternative.
- Late mitral valve surgery may be required in some cases.
- Repair of coronary fistulas rarely are associated with late complications. In some cases, alternate fistulas may persist after closure of the main channel. If small, they do not require further intervention. But reintervention may rarely be necessary.
Additional Reading
1Allen HD, Gutgesell HP, Clark EB Moss and Adams' Heart Disease in Infants, Children and Adolescent, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2000.2Friedman AH, Fogel MA, Stephens PJr.. Identification, imaging, functional assessment and management of congenital coronary arterial abnormalities in children. Cardiol Young. 2007;17(2):56-67. [View Abstract]3Garson A, Bricker JT, Fisher DJ The Science and Practice of Pediatric Cardiology, 2nd ed. Baltimore: Williams & Wilkins, 1998.4Pelliccia A. Congenital coronary artery anomalies in young patients. J Am Coll Cardiol. 2001;37:598-600. [View Abstract]5Shirani J, Roberts WC. Solitary coronary ostium in the aorta in the absence of other major congenital cardiovascular anomalies. J Am Coll Cardiol. 1993;21:137-143. [View Abstract]6Snider RA, Serwer GA, Ritter SB. Echocardiography in Pediatric Heart Disease, 2nd ed. St. Louis: CV Mosby, 1997.
Codes
ICD9
746.85 Coronary artery anomaly, congenital
SNOMED
- 28574005 congenital anomaly of coronary artery (disorder)
- 75398000 anomalous origin of coronary artery (disorder)