Try your first pace mapping

• what is pace mapping
• how to perform it and interpret the results
• what are the pitfalls of this technique

Pace mapping is a valid and very useful method to confirm the correct position for ablation. It is used in procedures targeting ventricular arrhythmias (especially idiopatic PVC). This approach is based on an idea that QRS morphology caused by pacing will be identical with the clinical the moment when catheter is placed at the origin side of the PVC. Consequently, as the operator approaches the site of the PVC, the paced QRS starts to look similar to the PVC. The closer to the site, the better the pace QRS gets. When the paced QRS matches the PVC in all 12 leads, the operator is likely on the successful site for ablation. Pace mapping can be used adjunct to activation mapping. In some rare cases it can be used alone when the PVC burden is too low to use activation mapping.
In order to correctly perform pace mapping you should remember that the lower the pacing output the better the spatial resolution of the map. On the other hand, by increasing pace output you can compensate to some extend the insufficient tissue contact.
Most of the modern mapping systems provide additional features helping you track the changes in QRS morphology while performing pacing mapping.