Angiographic identification of malpositioned balloon catheters during mitral valvuloplasty

The positioning of balloon catheters for the percutaneous mitral valvuloplasty technique is critical to ensure an adequate result and minimize complications. Passage of two balloon catheters in parallel through a thickened atrial septum and maintenance of satisfactory positioning in the left ventricle can be difficult. We describe unsuspected malpositioning of the balloons in two patients documented angiographically in our laboratory. Recognizing and avoiding these positions will reduce the potential for serious complications.