Ann Thorac Surg 2009;88:1363. doi:10.1016/j.athoracsur.2009.02.012
© 2009 The Society of Thoracic Surgeons
Images in Cardiothoracic Surgery
Retained Intracardiac Air Mimicking Left Atrial Mass by Transesophageal Echocardiography
Kazumasa Orihashi, MD*
Department of Cardiovascular Surgery, Hiroshima University Hospital, Hiroshima, Japan
* Address correspondence to Dr Orihashi, Department of Cardiovascular Surgery, Hiroshima University Hospital, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan (Email: orichan{at}hiroshima-u.ac.jp).
A 74-year-old woman patient with mitral stenosis, tricuspid regurgitation, and chronic atrial fibrillation underwent mitral valve replacement with a bioprosthetic valve, tricuspid annuloplasty, and pulmonary vein box isolation. When she was weaned from cardiopulmonary bypass, transesophageal echocardiography showed an oval-shaped mass in the left atrium (Fig 1A;
LA = left atrium). It was 13 x 21 mm in size, attached to the atrial wall, and presented with a shaking motion similar to jelly.
Because it appeared to be a thrombus, the surgeon decided to perform a second pump-run to prevent systemic arterial embolism. However, no thrombus was found in the left atrium on inspection, and no mass was depicted in the cardiac chamber after cardiopulmonary bypass. The patient's postoperative course was uneventful and without any apparent embolism.
The recorded video was reviewed postoperatively. As the scanning plane was rotated from 100° to 5° (Figs 1A–C), the mass became thinner and finally connected with an echogenic image associated with reverberations caused from retained air near the atrial orifice of right upper pulmonary vein. We concluded that the mass was actually the side lobes generated by intracardiac air.
Although the side lobes are easily identified as an artifact when visualized in the same image plane, they can also extend in the direction that is orthogonal to the scanning plane. They appear thicker and less echogenic the further they are from the artifact source. In addition, the shaking motion of the mass could have been caused by the motion of air associated with cardiac contraction. If the mass disappeared after an aspiration, it would provide evidence that the mass is a false image. Knowledge of this unusual artifact could have avoided an unnecessary second pump-run.
