1Department of Ultrasound and Medical Electronics Sapporo Medical University, 2Department of Cardiology Sapporo Chuou Hospital, 3First Department of Internal Medicine Megumino Hospital, 4Department of Cardiology Sapporo Higashi Tokusyukai Hospital
We evaluated echocardiographic findings and their clinical significance in six atrial septal aneurysms detected on transesophageal echocardiographic examination between February 1992 and April 1994. An atrial septal aneurysm was defined as a localized bulging of the interatrial septum, protruding more than 6 mm into the right atrium, the left atrium, or both (the diagnostic criteria of Gallet et al.). Four of the six aneurysms were in men, and two were in women; mean age was 65.5 years; range, 33 to 78 years. Transthoracic echocardiography failed to demonstrate the lesion in one patient. All of the aneurysms protruded into the left atrium during systole and into the right atrium during diastole when the patient breathed normally, and protrusion into the left atrium was greater than that into the right atrium. These aneurysms also protruded farther into the left atrium immediately after release of the Valsalva maneuver. No fenestrations or thrombi were detected within the aneurysms. Atrial septal aneurysms were associated with mitrial valve prolapse in all six (100%) patients; tricuspid valve prolapse was detected in three (50%). Patent foramen ovale, with left-to-right and right-to-left shunt flow, was detected in four (67%) of the patients by contrast-Valsalva maneuver transesophageal echocardiography and angiography. Cerebral ischemic attack, pulmonary embolism, or both, occurred in three (50%) of six patients, and two of these three had supraventricular premature contraction. We conclude that formation of atrial septal aneurysm results from deficiency of connective tissue, that atrial septal aneurysm and patent foramen ovale closely related, and that atrial septal aneurysm should be considered to be a potential embolic risk factor.