A method of producing focal ventricular block is described. The sequence of the electrocardiographic variations is ascribed to changes in the velocity and direction of the excitatory process in the ventricular wall. The epicardial electrocardiograms resemble those considered indicative of ventricular hypertrophy or of "incomplete" or of "complete" bundle branch block. When the focal block is pronounced a positive deflection appears in the cavitary tracing. The ventricular blocks can be subdivided into "conduction blocks" and "fiber blocks," the former produced by the delay of the stimulus in the specialized conduction system and the latter produced by the delay of the excitatory process in the ordinary heart muscle. polarizable electrode, and the left arm terminal was connected to the exploring electrode through a similar nonpolarizable boot.2 A rather large, olive shaped, electrode of German silver was introduced in the ventricular cavities, the indifferent electrode was attached to the left hind leg. Direct leads were taken upon the epicardial surface of the ventricular muscle supplied by the artery in which the injection was given. Control electrocardiograms were always taken; during the experiments tracings were obtained from distant ventricular zones, and occasionally curves were recorded while the exploring electrode was moved slowly over the epicardial surface. Cavitary leads were obtained where the more illustrative electrocardiographic changes were observed; curves were also taken while the electrode was moved in the ventricular cavity. Direct-writing electrocardiographs were found to be useful in locating the most convenient points for obtaining permanent records. IN RESULTSThe saline solution of cocaine when injected in a coronary artery caused a "parietal focal block" (p.f.b.) in the ventricular territory irrigated by the vessel. The focal block developed rapidly while the injection was being given, and disappeared gradually in 15 to 30 minutes. The electrocardiograms taken while the exploring electrode was moved slowly over the epicardial surface demonstrated that the ventricular region where the parietal focal block was maximal was encircled by zones in which the degree of the block gradually decreased ( fig. 1). The blocked ventricular zone was found

Patrolling and surveillance in cities around the world is a principal activity to guarantee the security of its citizens that is why nowadays the use of technology is of vital importance in order to identify offenses and criminal groups. The present article proposes the development of a model which generates dynamic routes applying artificial intelligence with the algorithm K-means, to identify critical points when patrolling a circuit within Ecuadorian territory. Also, the API tool from Google Maps is used to design the routes and the ways of transportation that are going to be utilized by the police agent. It showed good results in the testing phase and there has been developed a mobile application based on Android technology.

Las modificaciones de las ondas r precoces en las derivaciones precordiales derechas cuando sobreviene un bloqueo izquierdo se deben al curso anormal de la excitación en el tabique. La manera como progresa la onda de activación en las regiones comprometidas por el bloqueo y la anormal orientación de los vectores que representan las fuerzas eléctricas de esas regiones, pueden explicar las modificaciones de QRS-T que se observan en los electrocardiogramas al sobrevenir el bloqueo izquierdo. El análisis de los cambios correlativos de las "ondas B" u ondas de bloqueo y de las ondas que representan la activación ventricular normal aclara- la patogenia de los bloqueos izquierdos. Los bloqueos izquierdos electrocardiográficamente se manifiestan como "intraparietales". Los diferentes tipos de bloqueo izquierdo se deben al grado y magnitud del deterioro funcional de las fibras musculares especializadas en las cuales la activación progresa muy velozmente. Por su extensión los bloqueos izquierdos son "parciales" o "totales". La duración del complejo ventricular no define si un bloqueo izquierdo es "completo" o "incompleto". En una determinada derivación la forma del electrocardiograma puede indicar si un bloqueo izquierdo es "completo" o "incompleto". Un bloqueo izquierdo es "incompleto" en la zona explorada cuando "ondas B" coexisten con deflexiones que pueden representar la activación normal de músculo ventricular izquierdo. Un bloqueo izquierdo es "completo" en la zona explorada cuando solo existen "ondas B" y no hay ninguna evidencia de inflexiones que representan la activación normal. En el texto se discuten las dificultades y las limitaciones que existen para el diagnóstico electrocardiográfico de la hipertrofia ventricular izquierda.

Over a period of 8 years, 176 cases of cardiac anomalies have been found in over 10,000 consecutive admissions. The place of birth and its altitude have been recorded for each one of these causes. Patent ductus arteriosus and persistent interatrial communications are more likely to be found in patients born at high altitudes. It is suggested, but remains to be shown, that this is true for defects of the pulmonary artery. No apparent relation could be found in this series for other malformations. It is presumed that mechanical factors tied to the pulmonary circulation and the lower oxygen tension both have a decisive influence.