Review ArticleCoronary artery fistula: a review
Section snippets
History and prevalence
As the aorta exits the left ventricle, two coronary arteries originate from its root to supply the muscle and tissues of the heart. The left coronary artery originates from the left aortic sinus, whereas the right coronary artery originates from the right aortic sinus. As the right coronary artery descends it branches to give a sinuatrial nodal branch, right marginal branch, and a posterior interventricular branch. On the other hand, the left coronary artery descends and gives an anterior
Morphology
While the exact percentage of morphological origins and terminations of coronary artery fistulas differ, the consensus is that fistulas are typically found on the right side of the heart. Studies show that the point of origin in 52–60% of coronary artery fistulas is the right coronary artery, 30% at the left anterior interventricular (left anterior descending) artery, and 18% at the left circumflex artery [2], [13], [14]. Regardless of point of origin, nearly 90% of fistulas drain to the right
Histology
In order to study the histology of coronary artery fistulas, Neufeld et al. removed a segment of the parent coronary artery involved in a fistula that terminated in the right ventricle. Microscopic analysis showed that most of the vessels studied had prominent muscle bundles and contained a duplicated internal elastic lamina dispersed between them. Additionally, the tunica intima layer had nonspecific fibrous thickening [17], [20]. A similar study also reported the same histological changes in
Presentation and symptoms
Typically coronary artery fistulas are often asymptomatic during childhood. Based on several studies, symptoms are present in 19–63% of patients, with the majority occurring after 18 years of age [4], [21], [22]. The most common symptom reported is dyspnea, with exertion [4], [21]. Murmurs are also commonly reported with coronary artery fistulas; in fact, many otherwise asymptomatic fistulas are often found after angiographic investigation of continuous murmurs heard at the lower left sternal
Pathophysiological consequences
According to Ata et al. [33], coronary artery fistulas are a very rare cardiac anomaly; however, they are the most hemodynamically significant lesions affecting the cardiovascular system. Ata et al. [33] states that approximately half of all CAF patients are asymptomatic and some congenital fistulas may spontaneously regress during childhood [33]. In patients with symptoms, most report atypical chest pain and exertional dyspnea that is often due to the progressive enlargement of the fistula and
Complications
Though the majority of coronary artery fistulas are etiologically congenital, complications typically do not present until after age 20 years [37]. These complications display a wide range in severity, from being asymptomatic in 75% of cases to presenting with myocardial ischemia and aortic insufficiency [23], [38], [39]. Symptoms, when present, are usually secondary to congestive heart failure, which, in turn, is as a result of a left-to-right shunt. Arrhythmias can also occur due to excessive
Diagnostics
Due to the asymptomatic nature of coronary artery fistulas, many are incidental findings during routine examinations. The gold standard for identifying them remains coronary angiography; however, less invasive two- and three-dimensional imaging techniques are becoming more common [41], [42], [43], [44]. The benefit of coronary angiography is that it helps to determine which coronary artery is involved in the fistula. Based on this, it can help to identify the communicating chamber or vessel and
Pediatric
In a retrospective study, Mavroudis et al. reviewed the diagnosis and treatment of pediatric coronary artery fistula patients. As in the general population, most of the pediatric patients were asymptomatic and the majority of fistulas were congenital. Only one of the patients studied had an acquired fistula as a consequence of tetralogy of Fallot repair. In addition to tetralogy of Fallot, other cardiac anomalies that present in the pediatric patient cohort were patent arterial duct and atrial
Prenatal
Coronary artery fistulas account for 50% of pediatric coronary vascular aberrations and are believed to originate from the thebesian vessels [4], [7]. During prenatal life, the coronary arteries communicate with the ventricles via intratrabecular spaces. As the fetus develops, these intratrabecular spaces become sinusoids that communicate between the coronary arteries and veins and the chambers of the heart. Fistulas are thought to develop if these intratrabecular spaces do not close to
Treatment
Due to the fact that CAF mostly remain asymptomatic, the treatment of CAF is essentially medical; conservative management with continued follow up [71]. While rare, there have been cases of spontaneous closure of coronary artery fistulas without surgical or catheter repair [4], [72], [73], [74]. Among these, most spontaneous closures occur in children diagnosed with a coronary artery fistula prior to 2 years of age, and these fistulas almost always drain into the right ventricle [75]. Surgical
Surgical correction
In coronary artery fistula patients where operative correction proves necessary, surgical ligation or percutaneous transcatheter occlusion are possible treatment options [43], [66], [79], [80]. The type of operative correction for coronary artery fistulas depends on the location of the fistula, the coronary artery involved, and the termination of the connection. Typically, direct ligation of the fistula at the drainage site is preferred because it should eliminate the possibility of myocardial
Transcatheter techniques
Studies suggest that transcatheter approaches are more beneficial than surgical approaches for eligible coronary artery fistula cases. Transcatheter techniques do not require median sternotomy or cardiopulmonary bypass, thus limiting potential iatrogenic complications. Transcatheter closure is also a less expensive procedure with decreased morbidity, decreased recovery time, and better cosmetic results [43], [83], [84]. On the other hand, the use of transcatheter approaches and coil occlusion
Management
Luo et al. suggest that there is potential for thrombotic events that may lead to myocardial infarctions after coronary artery fistula closure. Prophylactic low-dose aspirin is suggested in such cases. In large postoperative coronary artery dilations, anticoagulant therapy such as warfarin is recommended [4]. Angina secondary to coronary artery fistula is managed according to the standard-of-care guidelines for angina medical management. As such, beta-blockers, calcium channel blockers, and
Conclusion
Coronary artery fistulas, while rare, are pathophysiologically important and should be included in the differential diagnosis of cardiac-associated pathologies. Proper recognition, imaging, diagnosis, treatment, and symptom management can prevent potentially deadly cardiac complications associated with these anomalous communications. This review highlights the best imaging and treatment techniques for coronary artery fistulas, along with information describing the prevalence for both adult and
Acknowledgments
The authors wish to thank Jessica Holland, MS, Medical Illustrator at St. George's University, Grenada, West Indies, for the creation of her illustrations used in this publication.
References (91)
- et al.
Coronary artery fistulae
Am J Med Sci
(2006) - et al.
Coil embolization of an aorticopulmonary fistula in a dog
J Vet Cardiol
(2010) - et al.
The anatomic variability of coronary arterial fistulae termination in the right and left atria
Chest
(1974) - et al.
Congenital communication between the right coronary artery and right atrium
J Thorac Surg
(1958) - et al.
Congenital coronary artery-cardiac chamber fistula: review of operative management
Ann Thorac Surg
(1975) - et al.
A case of anomalous right coronary artery to right atrial fistula presenting as atypical aortic insufficiency
Am J Cardiol
(1969) - et al.
Prognostic significance of clinically silent coronary artery fistulas
Am J Cardiol
(1999) - et al.
Coronary artery fistulas: long-term results of surgical correction
Ann Thorac Surg
(2001) Coronary artery fistula
Ann Thorac Surg
(2012)- et al.
Multiple bilateral coronary arterial to pulmonary artery fistulae in an asymptomatic patient
Int J Cardiol
(1987)
A review of aorto-pulmonary fistulas in aortic dissection
Ann Thorac Surg
Coronary artery fistulas in infants and children: a surgical review and discussion of coil embolization
Ann Thorac Surg
Myocardial ischemia in generalized coronary artery–left ventricular microfistulae
Int J Cardiol
Acquired coronary artery fistulae after right ventricular myotomy and/or myomectomy for congenital heart disease
Am J Cardiol
Two-dimensional and Doppler transesophageal echocardiographic delineation and flow characterization of anomalous coronary arteries in adults
J Am Soc Echocardiogr
Diagnosis of a right coronary artery–right atrial fistula using two-dimensional and Doppler echocardiograph
Am J Cardiol
Aberrant fistula arteries from the left main branch and right coronary artery to the left pulmonary arterial sinus demonstrated by multislice computed tomography
Int J Cardiol
Diagnosis of coronary artery fistula by two-dimensional echocardiography pulsed Doppler ultrasound and color flow imaging
J Am Coll Cardiol
Congenital malformations of the coronary arteries: the Texas Heart Institute experience
Ann Thorac Surg
Cine magnetic resonance imaging for diagnosis of right coronary arterial-ventricular fistula
Chest
Management of coronary artery fistulae: patient selection and results of transcatheter closure
J Am Coll Cardiol
Right coronary artery-to-right ventricle fistula complicating percutaneous transluminal angioplasty: case report and review of the literature
J Am Soc Echocardiogr
Percutaneous closure of congenital coronary artery fistulae results and angiographic follow-up
Jacc Cardiovasc Interv
Coil embolization of coronary artery fistulas. A single-centre experience
Cardiovasc Revasc Med
Bicoronary-pulmonary fistulae with coexistent mitral valve prolapse: a case report and literature review of coronary-pulmonary fistula
Eur Heart J
Multiple coronary-cameral fistulae
Tex Heart Inst J
Coronary arterial variations in the normal heart and in congenital heat disease
Coronary artery anomalies in 126,595 patients undergoing coronary arteriography
Cathet Cardiovasc Diagn
Iatrogenic coronary fistula in post transplant patients: pathogenesis, clinical features and therapy
J Clin BAs Cardiol
Congenital coronary artery anomalies: the pediatric perspective
Coron Artery Dis
Coronary artery fistula in the heart transplant patient: a potential complication of endomyocardial biopsy
Circulation
Traumatic right coronary artery-right ventricular fistula with retained intramyocardial bullet
Am J Cardiol
Coronary artery fistulae: a 10-year review
Cleve Clin J
Congenital heart malformations in mammals
Congenital coronary artery fistula
Surgery
Coronary arterial fistulas
Orphanet J Rare Dis
Hemodynamically significant primary anomalies of the coronary arteries
Circulation
Congenital communication of a coronary artery with a cardiac chamber or the pulmonary trunk
Circulation
Large congenital aneurysm of the right coronary artery
Arch Pathol
Multiple coronary arterioventricular fistulae
Circulation
Congenital coronary arteriovenous fistula. Report of 13 patients, review of the literature and delineation of management
Circulation
Bilateral coronary artery to pulmonary artery fistulas: report of 5 cases and review of literature
Circulation
Myocardial infarction due to multiple coronary-ventricular fistulas
Cathet Cardiovasc Diagn
Diagnosis of right coronary artery to right atrial fistula in a dog using two-dimensional echocardiography
J Small Anim Pract
Pneumococcal aortic valve endocarditis causing aortopulmonary artery fistula
Ann Thorac Surg
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