What does an electrocardiogram measure?
A) Sound waves created by the closing of heart valves
B) The volume of blood moving through the heart chambers
C) The force of muscle contraction in the heart chambers
D) Action potentials moving through the heart muscle

Respuesta :

Answer is D.

The ECG picks up electrical activity (action potentials) in the heart.
The electrocardiogram (ECG or EKG) is a diagonostic tool that is routinely used to assess the electrical and muscular functions of the heart. The heart is a two stage electrical pump and the hearts electrical activity can be measured by electrodes placed on the skin.