A giant right coronary artero-venous fistula revealed by an integrated multimodality imaging approach

Excerpt

Coronary artery venous fistulae (CAVF) are rare and, although sometimes asymptomatic, most patients may present chest pain, palpitations or syncope [1]. A continuous systo-diastolic murmur is the most common clinical finding [2]. Right coronary artery (RCA)-coronary sinus (CS) fistulae account for 7% of all CAVF [3]. Diagnosis of CAVF relies on clinical manifestations, echocardiography, computed tomography (CT) and coronary angiography (CA). Two-dimensional ultrasound clearly with color-Doppler examination shows the origin, the course and the blood flow into the corresponding chambers of the heart. CA, moreover, by directly revealing the blood vessel distribution, can provide physicians definitely diagnosis and treatment suggestion options for CAVF [4]. Congenital CAVF undergo, indeed, natural closure very rarely. The treatment, therefore, should be percutaneous or surgical based on a heart team decision [5]. This report describes a case of CAVF to the CS, with atypical clinical presentation and association with other artero-venous malformations (AVM). A 59-year-old woman had been diagnosed with a large patent foramen ovale (PFO). Ten years later, she reported mild dyspnoea and was referred to our hospital for a systo-diastolic murmur. The trans-thoracic echocardiography revealed both enlargement of RCA and CS. The color-Doppler examination showed a continuous systo-diastolic turbulent flow to the dilated CS, highly suggestive of a CAVF (Fig. 1, Panel A). Right and left upper limb saline contrast echocardiography excluded various right-to-left shunts (Fig. 1, Panel B). The trans-esophageal echocardiogram excluded intracardiac shunt. The CT scan showed a large CAVF between the RCA and the CS (Fig. 1, Panel C). Both RCA and CS were extremely dilated (Ø 2.1 cm and Ø 4.5 cm, respectively, on the axial plane, Fig. 1, Panel D), opacification of the vena cordis magna could not be documented, segmental pulmonary embolism was revealed in the right superior lobe and a large cavernous haemangioma was documented in the right liver (Fig. 1, Panel E). The pulmonary/systemic flow ratio was 1.2 and no ischemia was documented in the RCA territory by cardiac magnetic resonance (Fig. 1, Panel F). A cerebral angio-MR excluded intraparenchymal arterio-venous malformations. Because surgery was considered at high risk, a yearly clinical follow-up was proposed and an anticoagulation therapy with a direct anticoagulant drug was started in view of the coexistence of thrombosis and pulmonary embolism. This is a rare case of CAVF between RCA and CS, initially misinterpreted as PFO, associated with further hepatic AVM. Echocardiography may not detect every CAVF; thus, a multimodal integrated approach should be preferred to avoid erroneous diagnoses. Color-Doppler examination shows origin and course of blood flow, while saline contrast echocardiography rules out other congenital anomalies. CT scan with 3D reconstruction may define carefully the anatomy of CAVF, that may be directly revealed by coronary artery angiography. This may guide physicians to a definitive diagnose and treatment of CAVF.

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