Capillary — ECG/EKG Terminology

Definition: Smallest blood vessel. Materials pass to and from the bloodstream through the thin capillary walls.

Key Facts

• Smallest vessels where gas, nutrient, and waste exchange occurs.
• Single endothelial-cell thickness supports diffusion across tissues.
• Capillary perfusion depends on adequate cardiac output and pressure.

ECG Connection: Poor cardiac rhythm and output can reduce capillary perfusion despite preserved electrical activity.

Why It Matters: Monitor technicians should correlate rhythm with bedside perfusion indicators.