Question

If SV decreases, What must the heart do to maintain CO?

1) Increase HR
2) Decrease HR
3) Increase SV
4) Decrease SV

Answer 1

When stroke volume (SV) decreases, the heart must increase heart rate (HR) to maintain cardiac output (CO).

Step-by-step explanation:

When stroke volume (SV) decreases, the heart must increase heart rate (HR) to maintain cardiac output (CO). This is because CO is calculated by multiplying SV by HR, so if SV decreases, HR needs to increase to compensate and maintain the same level of blood being pumped by the heart. For example, if someone's SV decreases, their heart will beat faster (increase HR) to pump more blood per minute and maintain an adequate flow.