Question

when heart rate exceeds 160 bpm, all of the following occurs except
● stroke volume decreases
○ venous return increases
○ preload is lower
○ end - diastolic volume decreases

Explanation:

When heart rate exceeds 160 BPM, stroke volume decreases due to reduced filling time. Pre - load (end - diastolic volume) is lower as filling time is short, and end - diastolic volume decreases. Venous return does not increase under these conditions as there is not enough time for proper filling.

Answer:

B. venous return increases