What happens to impulses that travel toward a positive electrode?

• A. They create downward deflections
• B. They create upward deflections
• C. They remain flat
• D. They cause no changes

Answer: (B)

When impulses travel toward a positive electrode, they create upward deflections on the electrocardiogram (ECG). This phenomenon occurs because the electrical activity of the heart generates depolarization waves, which are recorded by the electrodes placed on the body surface.

In essence, as the impulse moves toward a positive electrode, it causes a positive deflection on the tracing. This is based on the principle that when there is an upward flow of current toward a positive reference point, the deflected waveform on the ECG will similarly rise above the baseline. This upward movement indicates that the heart's electrical activity is occurring in a direction that is congruent with the positive electrode's polarity.

Understanding this concept is crucial for interpreting ECGs accurately, as the direction of electrical impulses in relation to the electrodes significantly influences the shape and direction of the deflections observed on the tracing.