Congenital arteriovenous fistulas of the internal thoracic artery are rare. We observed a 12-year-old girl, who presented with a thrill and a loud continuous murmur over the right precordium, heard maximally over the 2nd and 3rd right and left intercostal spaces. The murmur had been detected as a chance finding during a routine check by her school physician a few months earlier.

At cardiac catheterization, contrast medium was injected into the dilated proximal part of the right internal thoracic artery (A) (Fig. 1). The fistula (*) was visualised filling a large vein (V), which drained into the superior caval vein (SCV) (Fig. 2). A coil (C) was implanted through the internal thoracic artery into the fistula. After the procedure, the injected contrast passed freely along the artery, with only a residual amount of contrast being captured in the vein (Fig. 3). On auscultation, the murmur was no longer audible.

Figure 1.

Figure 2.

Figure 3.