Alternating right bundle branch block or intermittent preexcitation?




Ángel Cueva-Parra, Departamento de Electrofisiología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México
Michael Soto-Gamarra, Department of Cardiology, Hospital Regional Docente de Cajamarca, Cajamarca, Peru
Pedro Iturralde-Torres, Department of Electrofisiology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
Santiago Nava, Departamento de Electrofisiología, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México


Right bundle branch block (RBBB) is a very common electrocardiographic feature in patients with Ebstein anomaly (EA) and it is present in more than 94% of these patients1.