Which term represents the perfusion pressure seen by organs?

Which term represents the perfusion pressure seen by organs?

• A. Systolic pressure
• B. Mean arterial pressure
• C. Diastolic pressure
• D. Pulse pressure

Answer: (B)

Perfusion pressure seen by organs is best described by mean arterial pressure. It represents the average pressure driving blood through the organs over a full heartbeat, recognizing that the heart spends more time in diastole than systole. A handy way to estimate it is MAP ≈ diastolic pressure + (systolic − diastolic) / 3, which is the same as (Systolic + 2 × Diastolic) / 3. This average pressure is what tends to sustain continuous organ perfusion; when MAP falls to about 70 mmHg or lower, organ perfusion becomes compromised. Systolic pressure is the peak pressure during heart contraction, and diastolic pressure is the lowest pressure during relaxation. Pulse pressure is the difference between systolic and diastolic pressures and reflects arterial stiffness and stroke volume, not the steady perfusion driving force.

Perfusion pressure seen by organs is best described by mean arterial pressure. It represents the average pressure driving blood through the organs over a full heartbeat, recognizing that the heart spends more time in diastole than systole. A handy way to estimate it is MAP ≈ diastolic pressure + (systolic − diastolic) / 3, which is the same as (Systolic + 2 × Diastolic) / 3. This average pressure is what tends to sustain continuous organ perfusion; when MAP falls to about 70 mmHg or lower, organ perfusion becomes compromised.

Systolic pressure is the peak pressure during heart contraction, and diastolic pressure is the lowest pressure during relaxation. Pulse pressure is the difference between systolic and diastolic pressures and reflects arterial stiffness and stroke volume, not the steady perfusion driving force.