What term describes steady flow with acceleration and deceleration over the cardiac cycle?

What term describes steady flow with acceleration and deceleration over the cardiac cycle?

• A. Pulsatile
• B. Steady
• C. Turbulent
• D. Laminar

Answer: (A)

Flow that changes speed with each heartbeat is pulsatile. In the arteries, the heart’s contraction during systole accelerates blood to a peak, then as the heart relaxes during diastole the flow decelerates. This repeating acceleration and deceleration creates the characteristic pulsatile pattern seen on Doppler, with systolic peaks and diastolic flow. Steady flow would keep a constant velocity with no rhythmic variation, so it doesn’t reflect the cardiac cycle. Laminar describes a smooth, layered velocity profile across the vessel, not the time-based fluctuation. Turbulent refers to chaotic, disorganized flow with eddies, which isn’t the regular, periodic variation tied to the heartbeat. Pulsatile uniquely describes the time-varying flow driven by cardiac activity.

Flow that changes speed with each heartbeat is pulsatile. In the arteries, the heart’s contraction during systole accelerates blood to a peak, then as the heart relaxes during diastole the flow decelerates. This repeating acceleration and deceleration creates the characteristic pulsatile pattern seen on Doppler, with systolic peaks and diastolic flow.

Steady flow would keep a constant velocity with no rhythmic variation, so it doesn’t reflect the cardiac cycle. Laminar describes a smooth, layered velocity profile across the vessel, not the time-based fluctuation. Turbulent refers to chaotic, disorganized flow with eddies, which isn’t the regular, periodic variation tied to the heartbeat. Pulsatile uniquely describes the time-varying flow driven by cardiac activity.