ATRIAL SEPTAL ANEURYSM - MORPHOLOGICAL-CHARACTERISTICS IN A LARGE POPULATION - PATHOLOGICAL ASSOCIATIONS - A FRENCH MULTICENTER STUDY ON 259 PATIENTS INVESTIGATED BY TRANSESOPHAGEAL ECHOCARDIOGRAPHY

A strong association between interatrial septal aneurysm (IASA) and st roke has recently led many authors to consider IASA as a potential car diac source of embolism. We studied the morphological characteristics and main associations of MSA in a large cooperative study based on tra nsoesophageal echocardiographic examinations; 259 IASA were studied in 134 men and 125 women with a mean age of 59 +/- 15 years. Fifty-five percent of IASA were found to overlap the commonly described fossa ova lis region, IASA protruded into the right atrium in 90% of the cases. They appeared thin in 81% of the patients and highly mobile in 79%. Fi fty-eight percent of patients had a history of systemic embolic events , while an atrial septal shunt was detected in 61% of the patients. In patients with an embolic event, only the mobility of IASA was signifi cantly higher than in those with no embolic event. In nine cases a pul monary embolism was associated with arterial embolism. Furthermore, we reported three cases of paradoxical embolism. However, the true demon stration of a thrombus within the IASA was quite rare. Conclusion: IAS A is probably an important risk factor for stroke. In patients with IA SA and a history of embolic events, IASA may enhance migration of a th rombus constituted in situ or transiting through it. Marked mobility o f IASA may also increase the risk of peripheral embolus.