An unexpected flow abnormality

A 71-YEAR-OLD woman with a recent history of dyspnea and ascites presented for surgical correction of Ebstein’s anomaly of the tricuspid valve. Diagnostic cardiac catheterization before surgery showed severe tricuspid regurgitation with a dilated hypokinetic right ventricle and moderate pulmonary hypertension. There was no evidence of an intracardiac shunt, and the left ventricle was normal in structure and function. Surgical findings were consistent with Ebstein’s anomaly, and tricuspid valve repair was attempted. Transesophageal echocardiography (TEE) examination after trial separation from cardiopulmonary bypass revealed persistent severe tricuspid regurgitation, however, and tricuspid valve replacement with a Carpentier-Edwards bioprosthesis was subsequently performed. Although separation from cardiopulmonary bypass was uneventful, intraoperative TEE revealed a Doppler color-flow abnormality below the prosthetic tricuspid valve (Fig 1). What is the origin of this color-flow jet?