Which statement best explains what happens to cardiac output when the heart rate gets extremely high?

Question

1. Cardiac output is not generally affected by rapid heart rates.
2. Cardiac output lowers when the rapid rate doesn't allow enough time for complete filling of the heart chambers.
3. Cardiac output will continue to increase as long as the heart rate continues to increase.
4. Cardiac output will increase until the heart rate reaches 150 bpm, at which time it will no longer be affected.

Answer 1

2
Rationale 1: Cardiac output is affected by rapid heart rate.
Rationale 2: Cardiac output lowers when the rapid rate doesn't allow enough time for complete filling of the heart chambers.
Rationale 3: Cardiac output does not increase indefinitely with heart rate.
Rationale 4: The point at which cardiac output no longer increases depends on other factors.
Global Rationale: Cardiac output lowers when the rapid rate doesn't allow enough time for complete filling of the heart chambers. The point at which cardiac output no longer increases depends on other factors. Cardiac output does not increase indefinitely with heart rate.