[The echocardiographic diagnosis of a rare complication of an aneurysm of the sinus of Valsalva].

We report the case of a patient with complete heart block caused by extension of a congenital aneurysm of the sinus of Valsalva into the upper interventricular septum, which was diagnosed by transthoracic and transesophageal echocardiography. We emphasize the rarity of this pathology and the value of transesophageal echocardiography in its assessment, providing a complete anatomicofunctional characterization and allowing surgical repair without previous cardiac catheterization.