14/02/2026
⚠️ The Concertina Effect — When the Artery Lies to the Eye
In the cath lab, not every narrowing is pathology.
Sometimes, the vessel is simply reacting to our intervention.
The concertina effect occurs when a tortuous coronary artery is straightened by a stiff guidewire or device. This mechanical straightening shortens the vessel and creates transient folds in the arterial wall, producing the illusion of multiple stenoses on angiography.
To the inexperienced eye, it looks dramatic — new lesions, sudden narrowing, apparent dissection-like segments.
But in reality, the artery is not diseased. It is displaced.
🔹 Why this matters clinically
Misinterpreting concertina effect can lead to: • Unnecessary stent implantation
• Increased contrast load
• Longer procedure time
• Higher complication risk
• Permanent metal for a temporary illusion
🔹 How to recognize it
✔ Appears after stiff wire/device advancement
✔ Seen mainly in tortuous vessels (especially RCA)
✔ Flow usually remains preserved
✔ Lesions disappear after wire withdrawal
🔹 The teaching point
Interventional cardiology is not only about seeing —
it is about understanding what we see.
The angiogram shows anatomy.
Experience reveals truth.
Before placing a stent, always ask:
Is this disease… or is this physics?
Because sometimes the best intervention in the cath lab
is simply pulling the wire back.
