Abstract
WEB SITE FEATURE
A 2-year-old girl in whom a cardiac murmur had been detected at the age of 4 months underwent physical examination. She had no cyanosis, but a continuous murmur was detected. The murmur was centered in the 4th right intercostal space and radiated vertically. The echocardiogram showed right coronary artery (RCA) dilation.
We sedated the patient and obtained computed tomographic (CT) images by use of contrast-enhanced electrocardiographic-gated multidetector computed tomographic (MDCT) angiography. A 64-slice CT scanner (Siemens Sensation 64; Erlangen, Germany) (120 kV, 35 mA) was used, with a detector configuration of 64 × 0.6 mm and a reconstruction interval of 0.6 × 0.4 mm. We administered 2 mL/kg of nonionic iodinated contrast medium at 2 mL/sec through the antecubital vein; a threshold of 100 Hounsfield units was used to trigger the diagnostic image acquisition. The scan time was 3.4 seconds, with an effective radiation dose of 1.3 mSv. The MDCT coronary angiograms showed RCA dilation with a fistula to the posterobasal region of the right ventricle (RV) (Figs. 1, 2 and 3). The fistula was closed successfully with an intraluminal occlusion device (AMPLATZER® Duct Occluder, AGA Medical Corporation; Plymouth, Minn), as shown on invasive coronary angiograms (Figs. 4 and 5).
Fig. 1 Volumetric multidetector computed tomographic image shows aneurysmal dilation of the right coronary artery and its drainage into the right ventricle.
Fig. 2 Maximum-intensity projection image from multidetector computed tomographic angiography shows the fistulous trajectory of the right coronary artery and its drainage into the basal portion of the right ventricle.
Fig. 3 Multiplanar reconstruction from multidetector computed tomographic angiography shows the trajectory of the right coronary artery. The distal segment of the artery has a normal diameter (arrowhead), and the proximal segment is dilated (arrow) and drains into the right ventricle.
Fig. 4 Invasive coronary angiography shows aneurysmal dilation of the right coronary artery and drainage into the right ventricle. The distal segment of the artery has a normal diameter.
Real-time motion image is available at www.texasheart.org/journal.
Fig. 5 Invasive coronary angiography after transcatheter closure of the fistula with an intraluminal occlusion device. The fistulous trajectory that was seen before treatment (arrowhead) is totally occluded.
Real-time motion image is available at www.texasheart.org/journal.
Comment
Primary coronary artery-to-camera fistula is a rare congenital anomaly in which a communication is present between a coronary artery and a cardiac chamber.1,2 Usually, symptoms appear when patients reach adulthood. More than 50% of patients have no symptoms other than a continuous murmur. Heart failure is the most common complication.1 Elective closure has been recommended.3,4
The quality of coronary artery images obtained by use of MDCT enables the assessment of congenital coronary anomalies, such as fistulae, even in children. Some questions regarding the usefulness of MDCT in children remain, however, because children have higher heart rates than adults do. Higher heart rates have been shown to have a negative effect on the quality of MDCT images, introducing motion artifacts and reducing the number of evaluable images.5 In the case of our pediatric patient who had an RCA-to-RV fistula, MDCT proved effective in evaluating the RCA, measuring its diameter, determining the path of tortuosity, and, most important, locating the site of drainage into the ventricle. The fistula was totally occluded by an intraluminal occlusion device.
Magnetic resonance imaging (MRI) has also been used to diagnose coronary artery fistulae, but it has some limitations. For example, MRI requires that patients be sedated for longer periods than CT does, which increases the risk of complications. In addition, the spatial resolution is often limited, and the distal course of arteries and the fistulous connection are not always clear. In contrast, MDCT enables excellent imaging of the distal coronary arteries and side branches; moreover, the spatial resolution is superior to that of MRI.6 The exposure to radiation on MDCT is not entirely risk free; however, in our patient, the ability to obtain a clear and accurate diagnosis and the potential for therapeutic benefit outweighed the risks.7
Supplementary Material
Footnotes
Address for reprints: Erick Alexanderson, MD, Department of Nuclear Cardiology and Cardiac CT. Instituto Nacional de Cardiología Ignacio Chávez, Juan Badiano No.1, Col. Sección XVI. Del. Tlalpan, Mexico City, 14080, Mexico E-mail: alexanderick@yahoo.com
References
- 1.Reagan K, Boxt LM, Katz J. Introduction to coronary arteriography. Radiol Clin North Am 1994;32(3):419–33. [PubMed]
- 2.Wilde P, Watt I. Congenital coronary artery fistulae: six new cases with a collective review. Clin Radiol 1980;31(3):301–11. [DOI] [PubMed]
- 3.Armsby LR, Keane JF, Sherwood MC, Forbess JM, Perry SB, Lock JE. Management of coronary artery fistulae. Patient selection and results of transcatheter closure. J Am Coll Cardiol 2002;39(6):1026–32. [DOI] [PubMed]
- 4.Auf der Maur C, Chatterjee T, Erne P. Percutaneous transcatheter closure of coronary-pulmonary artery fistula using polytetrafluoroethylene-covered graft stents. J Invasive Cardiol 2004;16(7):386–8. [PubMed]
- 5.Shapiro MD, Pena AJ, Nichols JH, Worrell S, Bamberg F, Dannemann N, et al. Efficacy of pre-scan beta-blockade and impact of heart rate on image quality in patients undergoing coronary multidetector computed tomography angiography. Eur J Radiol 2008;66(1):37–41. [DOI] [PubMed]
- 6.Manning WJ, Nezafat R, Appelbaum E, Danias PG, Hauser TH, Yeon SB. Coronary magnetic resonance imaging. Magn Reson Imaging Clin N Am 2007;15(4):609–37, vii. [DOI] [PubMed]
- 7.Einstein AJ, Henzlova MJ, Rajagopalan S. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA 2007;298 (3):317–23. [DOI] [PubMed]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.