CORONARY FISTUALA 

 

Coronary arterial fistulae are the most common malformations of the coronary arterial circulation (1-9).

The incidence of isolated fistulae is 1 : 50 000 live births.

Congenital heart defects are associated with coronary artery fistulae in 0.25-0.4% of cases (8)

 

 

EMBRYOLOGY

 

 

Coronary vascular development is initiated by proliferating blood islands, which coalesce into a network of myocardial sinusoids, that does not communicate with the ventricle. Ventriculo-coronary fistulae are thought to be initiated at this early stage of development (2).

 

 

ULTRASOUND

 

  • 50% originate from the right coronary artery, 45% from the left coronary artery and 5% originate from both coronary arteries (1).

·         The left, right, or both coronary arteries may be involved. The fistulae predominantly drain into the right side of the heart (92%):

1.      into the right ventricle in 41% of cases

2.      into the right atrium in 26% of cases

3.      into the coronary sinus in 7% of cases

4.      into the pulmonary artery in 17% of cases

5.      into the superior vena cava in 1% of cases

6.      into the left ventricle in only 3% of cases

7.       into the left atrium in 5% of cases

8.       drainage into both ventricles is rare (9).

  • These connections have been diagnosed as early as the first trimester (3).
  • Abnormal connections between the coronary vasculature and ventricular chambers are more in obstructive lesions of the outflow tracts with intact ventricular septum. Ventricular hypertension and hemodynamic disturbances are believed to result in abnormal connections between myocardial sinusoids and cardiac chambers.
  • Cardiac anomalies associated with ventriculo-coronary fistula (3-6):
    1. There have been numerous publications of pulmonary atresia with an intact interventricular septum.
    2. Hypoplastic left heart with transposition of the great vessels and pulmonary atresia with intact interventricular septum.
  • The abnormal connections appear to coalesce into a single vessel connecting the right ventricular apex to the left coronary system (7).
  • A large unobstructed fistula can cause a “steal” phenomenon because aortic blood flows freely into the right ventricle during diastole (2).
  • There may be concurrent abnormalities of coronary venous drainage and intracardiac hemodynamics.
  • The presence of this anomaly may have a significant impact on the approach of corrective postnatal surgery.
  • Color Doppler echocardiography and pulsed Doppler can detect high velocity and turbulent flow, as well as the site of drainage.

 

 

COMPLICATIONS

 

Serious complications due to congenital coronary artery fistulae have been reported:

·         congestive heart failure

·         pulmonary hypertension

·         bacterial endocarditis

·         premature arteriosclerotic changes within the fistulae

·         aneurysm

·         thromboembolic events

·         arrhythmia, symptoms such as angina pectoris and myocardial infarction resulting from coronary steal (9).

 

OUTCOME

 

Spontaneous closure of fistulae may occur (10). However, most authors recommend early intervention at the time of diagnosis to prevent complications.

Mortality resulting from surgical closure ranges from 0% to 4%  (9).

Successful transcatheter occlusion of coronary artery fistulae by coil embolization have been reported (11-13).

 

 

REFERENCES

 

    1. Levin DC, Fellows KE, Abrams HL. Hemodynamically significant primary anomalies of the coronary arteries. Angiographic aspects. Circulation 1978;58:25-34.
    2. Baschat AA, Love JC, Stewart PA et.al. Prenatal diagnosis of ventriculocoronary fostula. Ultrasound Obstet Gynecol 2001;18:39-43.
    3. Chaoui R, Machlitt A, Tennstedt C. Prenatal diagnosis of ventriculo-coronary fistula in a late first-trimester fetus presenting with increased nuchal translucency. Ultrasound Obstet Gynecol 2000;15:160-162.
    4. Chaoui R, Tennstedt C, Goldner B et.al. Prenatal diagnosis of ventriculocoronary communication in a second trimester fetus using transvaginal and transabdominal color doppler sonography. Ultrasound Obstet Gynecol 1997;9:194-197.
    5. Arabin B, Aardenburg R, Schasfoort-Van Leeuven  M et.al. Prenatal diagnosis of  ventriculocoronary arterial communications combined with pulmonary atresia. Ultrasound Obstet Gynecol 1996;7:461-462.
    6. Patel CR, Shah DM, Dahms BB. Prenatal diagnosis of a coronary artery fistula in a fetus with pulmonary atresia with intact ventricular septum and trisomy 18. J Ultrasound Med 1999;18:429-431.
    7. Yokose T, Doi M, Kimura Y, Ogata T. Ventriculo-coronary micro communications in pulmonary atresia and sequential changes of coronary arteries. Acta Pathol Jpn 1987;37:1033-1040.
    8. Apitz J. Angeborene Anomalien der Koronararterien. In Apitz J, ed. Pädiatrische Kardiologie. Darmstadt: Steinkopff-Verlag, 1998: 419-29
    9. Schumacher G, Roithmaier A, Lorenz HP, Meisner H, Sauer U, Müller KD, Sebening F, Bühlmeyer K. Congenital coronary artery fistula in infancy and childhood: diagnostic and therapeutic aspects. Thorac Cardiovasc Surg 1997; 45: 287-94
    10. Wong K, Menahem S. Coronary arterial fistulas in childhood. Cardiol Young 2000; 10: 15-20
    11. Ragnarsson A, Emanuelsson H. Treatment of a large congenital coronary fistula with coil embolization. Scand Cardiovasc J 1999; 33: 57-9
    12. McElhinney DB, Burch GH, Kung GC, Villegas MD, Silverman NH, Moore P. Echocardiographic guidance for transcatheter coil embolization of congenital coronary arterial fistulas in children. Pediatr Cardiol 2000; 21: 253-8
    13. Pedra CA, Pihkala J, Nykanen DG, Benson LN. Antegrade transcatheter closure of coronary artery fistulae using vascular occlusion devices. Heart 2000; 83: 94-6