Electroanatomical Mapping
3D Electroanatomical Mapping
3D electroanatomical mapping builds a three-dimensional model of a heart chamber and overlays its electrical activity. It helps the team understand where an abnormal rhythm starts or travels.
On this page
Understanding the technology
What Is 3D Mapping?
A mapping system tracks the position of a catheter inside the heart and records the electrical signal at each point. The software combines position and signal into a three-dimensional model that the team can rotate and examine.
The map is a tool. It does not replace the electrophysiology study or the physician’s judgement. It adds spatial information to the recordings.
Step one
Creating Chamber Geometry
The catheter is moved gently around the inside of the chamber. Each position it reaches is recorded, and the system builds a model of the chamber’s shape from these points.
In some cases, images from a CT or MRI scan can be added to the model. Whether this is done depends on the case and the equipment available.
Chamber shell, conceptual illustration
Step two
Catheter Localisation
The system calculates where the catheter tip is by using magnetic fields, electrical fields, or both, depending on the technology. The position is shown on the screen in real time.
This helps the operator move precisely and return to a chosen point. Some procedures may need less X-ray imaging with this guidance, but this depends on the case.
Catheter tracking, conceptual illustration
Step three
Electrical Data Collection
At each point the catheter touches, the system stores the local electrical signal together with its position. Many points together form the electrical map.
Position
The system records where the catheter tip is.
Signal
The local electrical signal is recorded.
Timing
The signal is compared with a reference signal.
Model
Each point is added to the three-dimensional model.
The quality of the map depends on good catheter contact and on correct annotation of the signals.
A type of map
Activation Mapping
An activation map shows when the electrical signal arrives at each point compared with a reference. The timing is usually displayed with colour on the model.
Focal source
The earliest point of activation can show where a rhythm starts.
Spread
The pattern shows how the impulse spreads through the chamber.
Circuits
In a re-entry circuit, the map shows how the impulse travels around a loop.
Limits
Maps need a stable rhythm, so not every rhythm can be mapped this way.
A type of map
Voltage Mapping
A voltage map shows the strength of the local electrical signal. Healthy muscle usually gives a stronger signal than scarred or diseased tissue.
Areas of low voltage may point to scar or diseased tissue, which can support an abnormal rhythm. How low voltage is defined varies with the settings and the clinical context, so it is interpreted by the physician together with other findings.
Using the maps
Identifying Circuits, Foci and Substrate
Mapping helps answer three questions about an arrhythmia.
Focus
Origin
A small area that fires abnormal impulses.
Circuit
Loop
A loop of tissue that sustains a rhythm.
Substrate
Tissue
Tissue that can support an abnormal rhythm, such as scarred muscle.
Clinical use
Mapping During Different Arrhythmias
How mapping is used depends on the rhythm. The examples below are general.
Maps show the pulmonary veins and the atrium, which helps guide treatment.
Maps help show the circuit when it is not the typical one.
Maps may help locate the origin or pathway.
Maps help locate sources and areas of diseased tissue.
Related studies
Relationship with EPS
The electrophysiology study is the diagnostic recording of the heart’s electrical signals. Mapping is an additional technology that can be used during that study to show the signals in space. A study can be done with or without a 3D map.
Treatment
Relationship with Catheter Ablation
When ablation is planned, the map can help the team choose where to treat and record where energy has been delivered. It is used with different energy sources.
Patient journey
Procedure Workflow
A general outline. The steps depend on the patient and the findings.
Planning
Review of the rhythm, tests and aims of the procedure.
Catheter placement
Catheters are guided to the heart through a vein.
Geometry
The chamber model is created.
Mapping
Electrical data are collected and the maps are built.
Target identification
The team decides whether treatment is needed and where.
Treatment
If ablation is done, energy is delivered and the sites are recorded.
Re-check
The electrical behaviour is checked again.
Recovery
Monitoring while the patient recovers.
Questions
Frequently Asked Questions
What is 3D electroanatomical mapping?
Is it the same as an electrophysiology study?
Is mapping needed for every ablation?
Does it use X-rays?
What does the colour on a map mean?
Can every rhythm be mapped?
Does mapping guarantee a result?
Who interprets the maps?
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