Is it far or is it close? – clinically important examples of far and near fields

Acknowledgement

Piotr Lodzinski

Electrophysiologist

What will you learn?

Proper classification of potentials as a near-field and far-field potentials is one of the basic skills in EP
Near-field potentials represent locally recorded electrical activity: most frequently near-field potentials are sharp in shape and have a high amplitude.
Far-field potentials represent electrical activity observed from a distance: it is characterized by “blured” shape and lower amplitudes
Final classification whether observed potential is near- or far-field may require observation during manipulation of the catheter or by observing capture of the structure with stimulation.
In practice far-field and near-field potentials may help in catheter manipulation and placement (eg. within coronary sinus) or to assess lines of block.