title: About the specialized myocardial conducting tissue.
abstract: The chronological succession of discoveries on the location and structure of the atrio-ventricular conducting system are described. The starting point of this system is located in the sinus atrial node, identified by the English scientists A. Keith and M. W. Flack in 1907. The atrioventricular conducting system was pointed out by the Swiss physician Wilhelm His Jr. in 1893. The atrioventricular node (AV) was first identified by the Japanese pathologist Sumao Tawara and his German professor Ludwig Aschoff in 1906. Likewise the structure and routes of the three internodal bundles are described. These bundles include: Bachmann's bundle (1916) connecting the right with the left atrium and the AV node; the middle Wenckebach's bundle (1910) and the posterior or Thörel's bundle (1910), extending from the region of the sinus atrial node towards the posterior margin of the AV node. Lastly, the ventricular left and right conduction systems are detailed. These include the main trunk and their peripheral subdivisions with respective networks. Regarding the controversial existence of the left middle subdivision, it can exist in animal and human hearts. Nevertheless, an intermediate left septal network of specialized fibers seems to act as a functional equivalent of this subdivision.
authors.affiliation: Research Fallow, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, DF, Mexico. Electronic address: alessandro.micheli@cardiologia.org.mx.
authors.forename: Alfredo
authors.initials: A
authors.lastname: de Micheli Serra
authors.affiliation: Department of Electrocardiology, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, DF, Mexico.
authors.forename: Pedro
authors.initials: P
authors.lastname: Iturralde Torres
authors.affiliation: Department of Patology, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, DF, Mexico.
authors.forename: Alberto
authors.initials: A
authors.lastname: Aranda Fraustro
mesh_terms: D006329:Heart Conduction System / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans
keywords: Left ventricular conducting system; Mexico; Myocardial specialized conducting system; México; Right ventricular conducting system; Sistema cardiaco de excitoconducción; Sistema de conducción ventricular derecho; Sistema de conducción ventricular izquierdo