ATRIAL FLUTTER · THE SIMPLE EXPLANATION

Atrial flutter, made clear.

Start with three things: the electrical loop, stroke prevention, and how ablation works.

01 · YOUR HEART RHYTHM

What is atrial flutter?

An electrical signal gets caught in a repeating loop.

Normal heart conduction showing the SA node, AV node, and pathways into the ventricles. — **First, a normal heartbeat:** The signal starts in the SA node, spreads through the atria, passes through the AV node, and travels to the ventricles. The upper chambers squeeze first; the lower chambers follow.

Typical flutter circuit repeating around the tricuspid valve in the right atrium. — **In typical flutter:** A signal keeps circling around the tricuspid valve in the right upper chamber. Each lap makes the atria beat again, much faster than normal.

The AV node lets only some signals reach the lower chambers, so your pulse may be slower than the atrial rhythm.

You may feel a racing heart, tiredness, or shortness of breath—or have no symptoms.

Atypical flutter follows a different loop in either upper chamber.

02 · STROKE PREVENTION

Why can flutter increase stroke risk?

A regular-feeling pulse does not rule out stroke risk.

A clot forms in the left atrial appendage, travels to the brain, and blocks a brain artery.

The upper chambers beat too quickly to empty well. Blood may pool in the left atrial appendage, allowing a clot to form and travel to the brain.

Your care team checks your stroke risk to decide whether you need a blood thinner.

Blood thinners reduce stroke risk. They do not stop the flutter circuit.

03 · TREATING THE RHYTHM

How does flutter ablation work?

Break the loop so the signal cannot keep circling.

An ablation catheter creates a line between the tricuspid valve and inferior vena cava, blocking the typical flutter circuit. — The catheter is inserted through a **femoral vein in the groin** and advanced up to the heart.

For typical flutter, the catheter creates a short line of electrical block between the tricuspid valve and the large vein entering the right atrium from below.

The signal can no longer complete its loop. Ablation is highly effective for this type of flutter.

AFib or a different flutter circuit can still occur. Keep follow-up visits and take prescribed blood thinners until your care team tells you otherwise.

American Heart Association: Atrial flutter · Mayo Clinic: Flutter ablation

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