Lead

lead (Pb) (led) a chemical element, at. no. 82. Absorption or ingestion causes poisoning, which affects the brain, nervous and digestive systems, and blood.

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lead (led) any of the conductors connected to the electrocardiograph, each comprising two or more electrodes that are attached at specific body sites and used to examine electrical activity by monitoring changes in the electrical potential between them.

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lead I  the standard bipolar limb lead attached to the right and left arms.

lead II  the standard bipolar limb lead attached to the right arm and left leg.

lead III  the standard bipolar limb lead attached to the left arm and left leg.

augmented unipolar limb lead  a modified unipolar limb lead; the three standard leads are: aVF (left leg), aVL (left arm), and aVR (right arm).

aVF lead  an augmented unipolar limb lead in which the positive electrode is on the left leg.

aVL lead  an augmented unipolar limb lead in which the positive electrode is on the left arm.

aVR lead  an augmented unipolar limb lead in which the positive electrode is on the right arm.

bipolar lead  an array involving two electrodes placed at different body sites.

limb lead  an array in which any registering electrodes are attached to limbs.

pacemaker lead , pacing lead the connection between the heart and the power source of an artificial cardiac pacemaker.

precordial leads  leads in which the exploring electrode is placed on the chest and the other is connected to one or more limbs; usually used to denote one of the V leads.

standard leads  the 12 leads used in a standard electrocardiogram, comprising the standard bipolar limb leads I–III, the augmented unipolar limb leads, and the standard precordial leads.

unipolar lead  an array of two electrodes, only one of which transmits potential variation.

V leads  the series of six standard unipolar leads in which the exploring electrode is attached to the chest, designated V1 to V6.

Positioning of V leads.

XYZ leads  leads used in one system of spatial vectorcardiography.

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lead ¹ (ld)

n.

1. Any of the conductors designed to detect changes in electrical potential when situated in or on the body and connected to an instrument that registers and records these changes, such as an electrocardiograph.

2. A record made from the current supplied by one of these conductors.

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lead ² (ld)

n. Symbol Pb

A soft ductile dense metallic element. Atomic number 82.

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Lead

Name given the electrode when it is attached to the skin.

Mentioned in: Electrocardiography

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lead,

n a toxic metal that can be found in lead-based paints, leaded solder joints, and some fuel substances. Exposure has been linked to poor functioning of central nervous system as well as learning and behavioral difficulties.

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lead (Pb),

n a common soft, blue-gray, metallic element. Its atomic number is 82, and its atomic weight is 207. In its metallic form, it is used as a protective shielding against radiographs. (In dentistry, lead acts as a protective shield against the radiographic beam and is found in the lead apron and walls of the surrounding operatory.) It is poisonous, a characteristic that has led to a reduction in the use of lead compound as pigments for paints and inks.

lead apron,

n See apron, lead.

lead glass,

n See glass, lead.

lead poisoning,

n See plumbism.