RESUMO
Electrical activity of the heart can be presented using different methods, and the standard is ECG, in which the changes in electric amplitude in one axis are written on paper that moves at a known velocity. Vectorcardiography uses Cartesian (rectangular) coordinates and plots points defined by the simultaneous values in the x and y axes. In this paper, a new graphic display of electrical heart activity based on Polar coordinates is presented. In polar coordinates, the point is defined by the magnitude of the vector (electrical amplitude) and the angle in relation to x or y or z axes, and all the leads can be overlapped. The information used by this method is the same that for simultaneous 12 leads standard ECG and it needs no additional cables or technician labor. Polar coordinates are very good for comparison of time/amplitude mismatch in different leads, to detect the cardiac axis and to explore the impulse conduction. Also, it facilitates the learning of ECG physical basis. This method differs from the classic Dower's Polarcardiography because it uses the classic leads instead of the X, Y and Z leads, and it does not apply magnitude tracings.
Assuntos
Humanos , Vetorcardiografia/métodos , Interpretação Estatística de Dados , Gráfico , Eletrocardiografia/métodos , Coração , Tempo , Amplitude de Ondas SísmicasRESUMO
En este artículo se presentan varios métodos nuevos de exploración electrocardiográfica. Todos ellos se basan en la modificación del procesamiento de la información que rutinariamente recoge el ECG standard de 12 canales, sin electrodos o cables adicionales. Se basan en derivaciones bipolares precordiales que miden el desfase en tiempo y amplitud entre los electrodos que van de V1 a V6, y muestran, en forma magnificada y con mucho más detalle, las anormalidades en el eje derecha a izquierda (como lo hace DI). El ECG se realiza rutinariamente y sus resultados son los trazados habituales. No obstante, usando los datos ya recogidos, se obtienen derivaciones precordiales bipolares, coordenadas polares, subderivaciones y derivaciones ponderadas nuevas. Los nuevos trazados permiten apreciar con claridad fenómenos difíciles de apreciar en los trazados de rutina del ECG de 12 canales.
Several new methods of electrocardiographic exploration are presented in this work. All are based on processing the information already obtained when a standard 12-channel ECG is performed. They need no additional electrodes or cables. They are based on precordial bipolar leads measuring time - amplitude mismatch among V1 to V6 unipolar electrodes, and present, with much more detail and magnified, abnormalities on the right to left axis. ECG is performed in the usual way producing the classic 12 tracings. However, using the data already collected, bipolar precordial leads, polar coordinates, sub derivations and new weighted derivations can be obtained. The new methods allow seeing clearly some phenomena difficult to appreciate in the routine tracings of the 12-channel ECG.