Congenital Heart Disease - Cases

1348478 - Coronary cameral fistula

Thursday, January 26, 2023

7:00 AM – 7:50 AM

Location: Pacific Jewel

Presenting Author(s)

AS

Arghavan Sharifi, MD

Resident
New York University Langone Medical Center, United States

Primary Author(s)

AS

Arghavan Sharifi, MD

Resident
New York University Langone Medical Center, United States

Co-Author(s)

Jadranka Stojanovska, MD, MS

Associate professor
New York University Langone Medical Center
New York, New York, United States
PB

Puneet Bhatla, MD

Director Congenital Cardiac Imaging
NYU Langone Health
Edison, New Jersey, United States
RD

Robert Donnino, MD

Assistant Professor
New York University Langone Medical Center, United States
JJ

Jill Jacobs, MD

Professor
New York University Langone Medical Center, United States
Leon Axel, MD, PhD

Professor
New York University Grossman School of Medicine
NEW YORK, New York, United States

Disclosure(s):

Jadranka Stojanovska, MD: No financial relationships to disclose

Description of Clinical Presentation: A 32 year-old female with no prior cardiac history presented to the emergency department with daily fevers for 10 days. Blood cultures were positive for Streptococcus sanguinis and patient was admitted for further evaluation of bacteremia. Patient reported no dental procedures. She was started on ceftriaxone and further work up included transthoracic and transesophageal echocardiograms, which were negative for vegetations, but which noted a dilated left circumflex coronary artery with posterior course, aneurysm formation and termination of this fistula in the right atrium. The patient then underwent coronary CTA and cardiac MRI.

Diagnostic Techniques and Their Most Important Findings: Coronary CTA demonstrated a coronary-cameral fistula of the left circumflex coronary artery which was dilated, had a saccular aneurysm, and took a retroaortic course to terminate in the right atrium. For further evaluation of cardiac function, cardiac MRI was performed. The MRI exam included sequences for evaluating ventricular function (ejection fraction (EF)) and size (volumes), flows (aortic, main pulmonary artery, branch pulmonary arteries and fistula), and tissue characterization (late gadolinium enhancement (LGE)). MR imaging not only demonstrated anatomical details of the coronary cameral fistula, but also provided important physiologic information by estimating the left-to-right shunt from pulmonary (Qp) and systemic (Qs) flows; Qp/Qs >~1.5/1 is generally considered significant.

Learning Points from this Case:

Coronary artery fistulas are congenital or acquired abnormal communications of coronary arteries with any cardiac chamber or any segment of the systemic or pulmonary circulation. These fistulas are uncommon (0.3% of congenital heart diseases), and typically occur in asymptomatic young patients; however, clinical manifestations can also vary by the size, origin, and drainage site of the fistulas (1-3).
Follow up MRI imaging of these cases can be performed to evaluate ventricular size, serial assessment of proximal coronary artery size, development/progression of aneurysms, and signs of coronary steal. Additionally, physiologic implications of coronary fistulas can vary with their drainage site. Pre-tricuspid drainage, for example, results in potential dilatation of all four cardiac chambers. In such cases, ventricular stroke volume differences cannot be used for accurate Qp/Qs estimation. An additional method of calculating Qp is by including flows in the fistula, with Qp= fistula + aorta. Another method of estimation is by including SVC and IVC flows, with Qp = fistula + SVC +IVC.
Although CT is considered the gold standard for anatomical coronary evaluation, MRI provides critical information that cannot be obtained by other testing, including accurate ventricular size/volume assessment, flow analysis and estimation of volume burden (Qp/Qs), and LGE to assess for myocardial viability. Additionally, the lack of ionizing radiation with MRI is especially important in young patients who may need to undergo prolonged follow-up imaging.