What is the measurement provided by the PR interval on an ECG?
a. the time needed for the impulse to spread through the ventricles and pass through the SA node
b. the time needed for the impulse to spread through the atria and pass through the SA node
c. the time needed for the impulse to spread through the ventricles and pass through the AV junction
d. the time needed for the impulse to spread through the atria and pass through the AV junction
Answer: D