If both the SA node and the AV node fail, what would be the expected outcome of impulse rate within the heart?
A) The rate would be 30 -40 beats per minute due to the concentration of pacemaker cells in the Purkinje fibers.
B) The sympathetic nervous system takes over and maintains normal heart rate.
C) The individual would be in heart failure or have a myocardial infarction due to the lack of a beating heart.
D) The vagus nerve takes over and maintains a normal heart rate.
E) The heart is autorhythmic therefore it continually beats even after death because death is defined as a lack of brain waves.

Question

Quizplus · Accepted Answer

If both the SA node and the AV node fail, the heart's intrinsic pacemaker activity shifts to the Purkinje fibers, which can generate impulses at a rate of 30-40 beats per minute, ensuring that the heart continues to pump blood, albeit at a slower rate than normal.

If Both the SA Node and the AV Node Fail