Figure 4-5 Three different ECGs resulting from the same vector, due to different lead placements.
© Jones & Bartlett Learning.
DescriptionThe electrodes are sensing devices that pick up the electrical activity occurring beneath them. When a positive electrical impulse is moving away from the electrode (Figure 4-5A), the ECG machine converts it into a negative (downward) wave. When a positive wave moves toward an electrode, the ECG records a positive (upward) wave (Figure 4-5C). When the electrode is somewhere in the middle (Figure 4-5B), the ECG shows a positive deflection for the amount of energy that is coming toward it and a negative wave for the amount going away from it. This is similar to the Doppler effect. We are all familiar with this effect when an ambulance approaches us with its siren on. As it moves closer, it gets louder; as it gets farther away, the noise diminishes.
Figure 4-5 Three different ECGs resulting from the same vector, due to different lead placements.
© Jones & Bartlett Learning.
Description