Vein — ECG/EKG Terminology

Definition: Thin-walled vessel that carries blood from body tissues and lungs back to the heart. Veins contain valves to prevent backflow of blood.

Key Facts

• Returns blood toward the heart at lower pressure than arteries.
• Many peripheral veins contain valves to limit retrograde flow.
• Venous tone contributes to preload and cardiac filling.

ECG Connection: Large preload changes from venous return shifts may alter rate and rhythm stability.

Why It Matters: Sudden rhythm changes can occur with volume depletion or rapid volume loading.