Standard Limb Leads Review

Starting and ending points of Lead I

• The left arm as negative and the right arm as positive

• The right arm as negative and the left arm as positive

• The left leg as positive and the right arm as negative

• The right leg as negative and the left leg as positive

ECG leads considered limb leads

• The standard limb leads (I, II, III) and the augmented leads (aVR, aVL, aVF)

• Only the standard limb leads (I, II, III)

• Only the augmented leads (aVR, aVL, aVF)

• The precordial leads (V1, V2, V3, V4, V5, V6)

Einthoven’s Triangle limbs

• Right arm, left arm, left leg

• Right arm, right leg, left leg

• Left arm, left leg, right foot

• Right arm, left arm, right foot

Starting and ending points that create Lead aVL

• Wilson’s Central Terminal to the left arm

• Wilson’s Central Terminal to the right arm

• Wilson’s Central Terminal to the left leg

• Wilson’s Central Terminal to the right leg

Positive deflection on the ECG occurs when electrical activity moves toward the positive electrode.

• This indicates that the heart's electrical impulses are directed towards the electrode, resulting in a positive reading.

• This indicates that the heart's electrical impulses are directed away from the electrode, resulting in a negative reading.

• This indicates that there is no electrical activity in the heart, resulting in a flat line on the ECG.

• This indicates that the heart is in a state of arrhythmia, resulting in irregular readings.

Limb not used in the electrical basis of the limb leads

• Right leg used as a ground or reference point

• Left arm used for signal acquisition

• Left leg used for signal acquisition

• Right arm used for signal acquisition

The ECG machine detects electrical activity moving toward the positive electrode.

• It will mark a positive deflection on the ECG paper.

• It will mark a negative deflection on the ECG paper.

• It will show no deflection on the ECG paper.

• It will cause the ECG paper to tear.

Starting and ending points of Lead III

• The left arm as positive and the left leg as negative.

• The right arm as negative and the left leg as positive.

• The left arm as negative and the left leg as positive.

• The right arm as positive and the right leg as negative.

Non-polar reference point at the heart used for unipolar leads

• Wilson’s Central Terminal

• Einthoven’s Triangle

• Lead II

• Augmented Vector Right

Starting and ending points that create Lead aVF

• Wilson’s Central Terminal to the left leg

• Wilson’s Central Terminal to the right arm

• Wilson’s Central Terminal to the right leg

• Wilson’s Central Terminal to the left arm