Methods of registration of ECG

Chest leads. Clinical observations have shown, that along with the standard leads are very important chest leads in which one or two electrodes placed on the surface of the chest.
Sky (W. Nehb) proposed chest leads by type of small heart of the triangle. The vertices of the triangle represent the three points: first - at the junction of the second one from the right edge of a breast bone, the second - level projection apex beat on the posterior axillary line, the third - on terminal point (Fig. 6).

Fig. 6. Chest leads across the Sky: D - spinal abstraction; And - forward abstraction; I - lower abstraction.
Fig. 7. Localization breast electrode in a variety of positions chest leads.

Spinal abstraction D (dorsalis) receive for discharge from the first (wire right hand) and the second (wire left hand); switch lead ECG recorder installed on the I abstraction.
Front abstraction of A (anterior) receive for discharge from the first point (the wire right hand) and the third point (the wire left foot); switch lead ECG recorder installed on II abstraction. The lower abstraction I (inferior) receive for discharge from the second point (the wire left hand) and the third point (the wire left foot); switch lead ECG recorder installed on III abstraction. Normal ECG leads across the Sky little different from the standard ECG leads.
When localizing one electrode on different points of the chest in the heart, and the other away from the heart to the size and shape of teeth, ECG are determined mainly by the localization of electrodes placed on the front surface of the chest. This is because: the farther the electrode is from the source of EMF - heart, the smaller part of the EMF heart he catches. Therefore, it was proposed one electrode to place turn on the right arm, left arm and left leg, and the other electrode - breast - place at various points in the positions of the front surface of the chest - bipolar chest leads. Breast electrode localize in the following positions (Fig. 7): 1-I - right edge of a breast bone in the IV intercostal space; 2-I - left edge of a breast bone in the IV intercostal space; 3-I am on the left okolovrusno line at the point of intersection her with the line connecting the left edge of the sternum in the IV intercostal space V mirabilem on srednesrochnoi line; 4-I - srednesrochnoi line in the fifth intercostal space; 5-I - in the left anterior axillary line at the level of the fifth intercostal space on srednesrochnoi line; 6-I - on the left mid-axillary line at the level of the fifth intercostal space on srednesrochnoi line; 7-I am on the left posterior axillary line at the level of the fifth intercostal space on srednesrochnoi line; 8-I am on the left scapular line-level V intercostal space on srednesrochnoi line; 9-I - on the left paravertebral line at the level of the fifth intercostal space on srednesrochnoi line.
Breast electrode regardless of its location attached to the wire ECG unit for the left hand, and the second to the wire for the right hand. Switch electrocardiograph set I lead. The 1st and 2nd positions, catching mainly electromotive force of the right ventricle, defined as the right position; 3-th and 4-th - as an intermediate; 5-th and 6-th, catching mainly EMF of the left ventricle, the left position.
These chest leads indicate the following way: first Latin letter With chest - chest) or Russian G; the second letter indicates the position of the electrode on the limbs. Latin letter R (or Russian P) denote the position of the electrode on the right hand, the Latin letter L (or Russian L) - on the left hand, the Latin letter F (or Russian M) is on the left leg. The figure below indicate the position breast electrode; the figure above, the position of the breast electrode is horizontally relevant intercostal space, when it is placed above the generally accepted provisions; the number at the top is lowered when breast electrode is localized according to the conventional method.
Between the value of the EMF heart registered in standard leads and these bipolar chest leads, there is some correlation, like the balance between individual standard leads. EMF, registered in lead CR - SE equal to EMF, registered in the second abstraction, plus electromotive force, registered in lead CF - GN (CR = II+CF). EMF, registered in lead CL - CH equal to EMF, registered in lead CF - GN, plus EMF registered in the third lead (CL = CF+III).
Location breast electrode on the right side of foreign authors indicate the addition of the Latin letter R to the bottom of the figure that indicates the position of the chest leads. In the USSR the location breast electrode on the right side indicate the sign-set before the figure below indicates the position of the electrode; for example, on the right okolovrusno line -3; on the right srednesrochnoi -4, on the right anterior axillary - 6.
In two-pole chest leads the electrode potential, located on the limbs, has some impact on the nature of EMF registered breast electrode.
Wilson (F. N. Wilson) offered at check-breast leads to switch off the influence of the building, away from the heart (on the right hand, left hand and left foot), and create indifferent electrode, which potential is equal to zero. Indifferent, in his opinion, is the electrode, which unites the electrodes placed on the right hand, left hand and right leg through the same resistance 5000 Ohms (Fig. 8, 1). Such a combined electrode does not register or, more precisely, almost does not register potentials caused by the activity of the heart. The second electrode, differently, impose on the front surface of the chest in the above positions. Registered by this method chest leads designated as single pole. For the indifferent electrode Goldberger (that is, Goldberger) proposed to connect the electrodes placed on a limb, without the use of resistance (Fig. 8, 2). ECG chest leads in applying the simplified United electrode little different from that obtained with the use of resistances.
Indicate pole chest leads Latin letter V (or Russian). Position breast electrode indicate, as with bipolar chest leads.
When registering chest leads the majority of the authors is a single-pole chest leads.

Fig. 8. Indifferent electrode: 1 - Wilson; 2 - at Goldberger.