Heart block is a condition in which the SA node is properly functioning but the atria and ventricles are contracting out of synch. Which of the following statements explains why this happens?
A) The SA node is working extra hard to make the ventricles catch up.
B) The heart valves are allowing blood to flow backward through the heart.
C) The AV node is not sending signals to the ventricles as it should.
D) The coronary arteries are not delivering blood to the heart.
Answer: C
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