Acoustic appearance of atrial septal aneurysm.

Atrial septal aneurysm in the otherwise normal heart is a very rare and usually asymptomatic condition. A midsystolic click was described as the only clinical manifestation so far. A low-pitched early-to-midsystolic acoustic phenomenon in a 39-year-old woman corresponding with maximal leftward motion of the aneurysmatic interatrial septum during early systole is the subject of this case report. Our experience, plus review of the literature, supports the suggestion that atrial septal aneurysm should be considered in the interpretation of added systolic sounds.