Leads limb, placement

Einthoven s electrode placement has been adopted and standardized into the ECG Lead system known as the Einthoven triangle and is shown in Fig. 17.38. Electric potential differences are measured between the three limb electrodes along the line between the electrode placements, and their potentials are called lead I, n, and III such that... 

Occasionally ICD systems require the placement of additional leads and/or patches to achieve adequate DFTs. An additional patch electrode may be added through a small, left anterior chest incision (Fig. 4.57). This incision is generally placed along the left inframammary skin fold. A subcutaneous pocket is developed and a supplemental patch placed. The patch is sutured to the chest wall. The proximal lead is then tunneled to the ICD. A variation on this system is the subcutaneous array developed by CPI (Fig. 4.58). The array consists of three flexible defibrillator leads that are joined at a common connector. The leads are designed to be placed subcutaneously along the contour of the chest wall. The leads fuse as a common electrode that connects to the ICD. Creating a small incision in the left lateral inframammary skin fold places the array. Three separate subcutaneous tracts are created using a blunt-tipped malleable stylet. The stylet is loaded with a sheath that is advanced down each traa. The stylet is removed and the limbs of the array are passed down each sheath. 

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