Bridge Concept

A pressure is not the same thing as flow.

Blood pressure, CVP, atrial pressure, or ventricular pressure may give important clues.

But pressure alone does not tell us whether blood is moving effectively through the circulation.

The better question is:

Is this pressure producing forward flow — or showing us where flow is getting stuck?

Why It Appears Across Lesions

This concept appears across congenital heart disease because many circulations depend on more than pressure alone.

A patient may have:

• acceptable blood pressure but poor systemic perfusion
• high CVP but poor effective filling or forward output
• elevated RV pressure but limited pulmonary blood flow
• low diastolic pressure with runoff
• preserved saturation but falling oxygen delivery

The number may look reassuring.

The circulation may not be.

Core Physiology

Flow is what delivers oxygen.

Pressure helps drive flow, but pressure can also reflect resistance, obstruction, congestion, or poor ventricular compliance.

A high pressure may mean the ventricle is generating force.