The precordial electrocardiogram

摘要: Abstract Using a method which makes it possible to obtain electrocardiograms that represent the potential variations of single electrode, study thirty normal subjects was carried out. The three standard leads and nine special were each taken simultaneously with Lead I. Three recorded right arm, left leg, respectively; others series six precordial points. curves in such way negativity exploring placed upon one extremities or precordium, produced an upward deflection completed record. It is, however, pointed out several advantages might be gained by making connections opposite way. For this reason, avoid introducing new nomenclature, our have been labelled as if direction deflections reversed. In QRS group may normally show distinct apices, for convenience description called "Q," "R," "S." R peak, represents positive variation electrode is therefore inverted records, always present. This peak marks beginning large rapid excursion string corresponds intrinsic direct from ventricular surface. side precordium smaller and, on average, reaches its apex about 0.02 second earlier than side. indicates that, whole, epicardial surface ventral wall ventricle activated corresponding left. records Q S are both summits. former small occurs only precordium. latter larger where absent. When at sternal edge, invariably during inscription T deflection. midline, variable. related useful comparing other. type, leg curve usually resembles those obtained arm small.