An unusual cause of enhancement of the swirling motion of left atrial spontaneous echo contrast

Abstract

Left atrial spontaneous echo contrast consists of the visualization of smoke-like echoes within the left atrial cavity or appendage [1]. This phenomenon implies an increased risk of thromboembolic complications and is associated with left atrial blood stasis, red blood cell aggregation, atrial fibrillation, and hematocrit level [2]. We describe the case of a 66-year-old woman with rheumatic mitral valve disease in which the swirling motion of the smoke-like echoes was enhanced due to the existence of a small coronary fistula draining into the left atrial appendage. The patient had been subjected to a mitral commissurotomy 12 years before due to rheumatic valve disease, and was referred to our hospital for re-evaluation in view of a worsening of her functional class status. The patient presented atrial fibrillation, and transthoracic echocardiography revealed dilatation of the left atrium and right cavities, with a thickened mitral valve showing signs of calcification and fibrosis, and a valve area estimated by planimetry of 1.2 cm2. The maximum transmitral pressure gradient was 27 mmHg, with a mean gradient of 9 mmHg, and moderate valve regurgitation was diagnosed, together with severe tricuspid valve regurgitation—the estimated pulmonary artery systolic pressure being 74 mmHg. Transesophageal echocardiography in turn discarded the presence of thrombi in the left atrial cavity and appendage, and left atrial spontaneous echo contrast with enhancement of the swirling motion of the smoke-like echoes was observed in the left atrial appendage (Fig. 1). Upon performing coronariography, a small fistula was identified arising from a branch of the circumflex artery and draining into the left atrial appendage (Fig. 2). The presence of this coronary fistula was probably related to the previous surgical intervention. The presence of spontaneous echo contrast in this patient was related to the left atrial blood stasis caused by the mitral restenosis, and the swirling motion was enhanced by drainage of the fistula into the left atrial appendage—thus locally modifying the hemorrheologic conditions and giving rise to a local smoke-like echo clearance effect which favored visualization of the spontaneous echo contrast phenomenon.