Mural Thrombus in the Left Atrium Secondary to Transseptal Catheterization of the Left Side of the Heart

Abstract

TRANSSEPTAL catheterization of the left side of the heart, as introduced by Ross et al.,¹ has many advantages over previous methods of entering the left chambers of the heart. Studies in animals did not produce permanent injury to the interatrial septum or create shunting mechanisms.² In a modification of the original procedure, after the needle is passed through the interatrial septum, the sheath catheter is advanced over the needle through the septum and into the left atrium.^{3 4 5} The large-bore catheter can then be advanced to the left ventricle for pressure recording and angiographic studies, or the needle can be removed . . .