Current flowing away from a positive electrode on an ECG trace creates which deflection?

Current flowing away from a positive electrode on an ECG trace creates which deflection?

• A. Downward deflection
• B. Upright deflection
• C. Isoelectric line
• D. Upward deflection

Answer: (A)

Think of the ECG trace as showing the direction of the heart’s depolarization vector relative to the recording electrode. When the wave front moves toward the positive electrode, the deflection is upright (positive). When it moves away from the positive electrode, the deflection is downward (negative). So, current moving away from the positive electrode produces a downward deflection on that lead. An upright deflection would mean the wavefront is heading toward the positive electrode, and the isoelectric line appears when there’s no net movement toward or away from the electrode.

Think of the ECG trace as showing the direction of the heart’s depolarization vector relative to the recording electrode. When the wave front moves toward the positive electrode, the deflection is upright (positive). When it moves away from the positive electrode, the deflection is downward (negative). So, current moving away from the positive electrode produces a downward deflection on that lead. An upright deflection would mean the wavefront is heading toward the positive electrode, and the isoelectric line appears when there’s no net movement toward or away from the electrode.