Silent Giant: Right Coronary Artery Ectasia with a Hidden Fistula to the Coronary Sinus in an Asymptomatic Patient

Keywords
Congenital Heart Defects; Arteriovenous Fistula; Coronary Sinus; Coronary Vessels

Palavras-chave
Cardiopatias Congênitas; Fístula Arteriovenosa; Seio Coronário; Vasos Coronários

Keywords
Congenital Heart Defects; Arteriovenous Fistula; Coronary Sinus; Coronary Vessels

Palavras-chave
Cardiopatias Congênitas; Fístula Arteriovenosa; Seio Coronário; Vasos Coronários

A 62-year-old woman, asymptomatic and without significant medical history, was referred to a routine transthoracic echocardiogram (TTE). The TTE had no abnormal findings but showed, in subcostal view, three round images adjacent to the lateral wall of the right atrium. Color Doppler showed that these were apparently vascularized (Figure 1, panels A and B, supplemental videos 1 and 2). A transesophageal echocardiogram showed a giant right coronary artery (RCA), apparently originating from the RCA ostium, with turbulent flow inside (Figure 1, panel C, supplemental video 3). It was not possible to observe shunts or fistulae in this imaging modality. Given the suspicion of a fistula to the RCA, computed tomography coronary angiography was performed, showing an ectatic RCA with a normal origin, a diameter of 10,5 mm, and a tortuous trajectory, with fistulation to the coronary sinus in its final segment (Figure 1 panels D to F). Right heart catheterization demonstrated a non-significant left-to-right shunt (Qp: Qs ratio of 1.60). Cardiac magnetic resonance imaging (MRI) had no evidence of perfusion defects during hyperemia, thus excluding the coronary "steal phenomenon". After a multidisciplinary team discussion, since the patient was asymptomatic and the fistula had no hemodynamic significance, no invasive treatment was performed at this time.

Figure 1

Right Coronary Artery Ectasia and Fistula to the Coronary Sinus. Panel A: Transthoracic echocardiogram (TTE) in subcostal view, showing round pericardial structures (yellow arrows). Panel B: TTE with Doppler, showing vascularization of the structures (white arrows). Panel C: Transesophageal echocardiogram showing a giant right coronary artery (RCA) (green arrow) with turbulent flow inside. Panel D: Computed tomography coronary angiography (CTCA) showing an ectatic RCA with fistulation to the coronary sinus (CS) (red arrow). Panel E: CTCA Posterior view showing the CS (blue arrow), the ectatic RCA (purple arrow), and the location of the fistula (green square). Panel F: CTCA Anterior view showing the RCA (purple arrow), the anterior descending artery (Blue arrowhead), a marginal artery (white arrowhead), and the circumflex artery (red arrowhead).

Coronary arteriovenous fistulas are rare, with an incidence of 0.002%.¹,² The majority of these are congenital² and asymptomatic at presentation.³ Coronary steal can lead to several complications, including ischemia.¹,³ The treatment approach remains controversial. The presence of symptoms, significant left-right shunt, and large fistula are the most frequent indications for percutaneous or surgical approach.⁴,⁵

Data Availability

The underlying content of the research text is contained within the manuscript.

• Sources of funding
  There were no external funding sources for this study.
• Study association
  This study is not associated with any thesis or dissertation work.
• Ethics approval and consent to participate
  This study was approved by the Ethics Committee of the Saúde da USLL José under the protocol number 1655/2025. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. Informed consent was obtained from all participants included in the study.
• Use of Artificial Intelligence
  The authors did not use any artificial intelligence tools in the development of this work.

References

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  » https://doi.org/10.14744/AnatolJCardiol.2017.7868
• ² Challoumas D, Pericleous A, Dimitrakaki IA, Danelatos C, Dimitrakakis G. Coronary Arteriovenous Fistulae: A Review. Int J Angiol. 2014;23(1):1-10. doi:10.1055/s-0033-1349162.
  » https://doi.org/10.1055/s-0033-1349162
• ³ Sharma U, Aslam A, Tak T. Diagnosis of Coronary Artery Fistulas: Clinical Aspects and Brief Review of the Literature. Int J Angiol. 2013;22(3):189-92. doi:10.1055/s-0033-1349166.
  » https://doi.org/10.1055/s-0033-1349166
• ⁴ Poretti G, Lo Rito M, Varrica A, Frigiola A. A Case Report of a Coronary Artery Fistula to Coronary Sinus with Giant Aneurysm: Risk Does Not End with Repair. Eur Heart J Case Rep. 2020;4(6):1-6. doi:10.1093/ehjcr/ytaa297.
  » https://doi.org/10.1093/ehjcr/ytaa297
• ⁵ Gala AB, Pope MTB, Leo M, Kelion AD, Bashir Y. Giant Right Coronary Artery Aneurysm and Fistula into the Coronary Sinus. 2021;40(6):463-4. doi:10.1016/j.repc.2020.10.013.
  » https://doi.org/10.1016/j.repc.2020.10.013

Edited by

• Editor responsible for the review:
  Nuno Bettencourt

Publication Dates

• Publication in this collection
  28 July 2025
• Date of issue
  2025

History

• Received
  03 Sept 2024
• Reviewed
  13 Nov 2024
• Accepted
  13 Nov 2024