Among 4000 transesophageal echocardiograms in adult patients, we have found cor triatriatum in 7.
Obstructive cor triatriatum
A 41-year-old man presented with dyspnea on exertion. A transthoracic echocardiogram demonstrated a linear echodensity in the left atrium (LA) of questionable significance. Transesophageal echocardiography (TEE, Fig 1A⇓) showed a discrete membrane (thick white arrows) attached medially to the atrial septum at the inferior margin of the fossa ovalis membrane (thin white arrows) and laterally to the junction of the left upper pulmonary vein and LA appendage. This membrane divided the left atrium into posterosuperior (PS-LA) and anteroinferior (AI-LA) chambers. The pulmonary veins are posterior and the left atrial appendage anterior to the membrane. Color Doppler (Fig 1B⇓) showed an aliased high-velocity flow jet (white arrowheads) across the membrane. The peak gradient was 8 mm Hg and the mean gradient, 4 mm Hg. The findings were those of obstructive cor triatriatum. Surgical correction was recommended.
Nonobstructive cor triatriatum
A 70-year-old man with coronary artery disease was evaluated for worsening angina without dyspnea. Transthoracic echocardiography, performed to assess left ventricular function, revealed a poorly delineated linear echodensity in the LA. TEE showed a membrane (Fig 1C⇑, thick white arrows) that had attachments similar to those seen in Fig 1A⇑ (thin white arrows, fossa ovalis membrane). Doppler examination showed low velocity flow across the membrane orifice (Fig 1D⇑, white arrowheads). This represents a nonobstructive form of cor triatriatum. No specific treatment was recommended for this abnormality. RA indicates right atrium; AV, aortic valve; LV, left ventricle; AML, anterior mitral leaflet; and PML, posterior mitral leaflet.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Lukes Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to Dr Hugh A. McAllister, Jr, St Luke’s Episcopal Hospital and Texas Heart Institute, 6720 Bertner, MC 4-265, Houston, TX 77030.
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