Improving procedures to treat abnormal heart rhythms

Abnormal heart rhythms (often called arrhythmias) are when your heart beats very slowly, very quickly or irregularly. They occur when the electric signals that coordinate the heartbeat don’t work properly.

A range of treatments exist depending on the type and severity of the arrhythmia, from medication to minimally invasive intervention and heart surgery.

One of them is cardiac ablation, which works by applying heat (radiofrequency ablation) or cold (cryoablation) to destroy the faulty electrical pathways in the heart triggering the arrhythmia. Back in the 1980s, work by BHF Professors Ronnie Campbell and John Camm contributed towards the development of radiofrequency ablation.

To carry out the procedure, doctors need be able to pinpoint where the abnormal electrical activity is within the heart in order to target it. A catheter is inserted through a blood vessel in the groin or wrist and is guided toward the heart. Sensors on the tip of the catheter send electrical impulses and record the hearts electricity. This allows the doctor to identify the area causing the abnormal heart rhythm and decide whether to apply the ablation. This manual method requires a highly trained member of staff and can be a lengthy procedure for the patient.

Improving accuracy of cardiac ablation

With BHF support, Professor Prapa Kanagaratnam and colleagues at Imperial College London developed a new method to identify the areas in the heart causing the arrhythmia. The team have used computer modelling to develop ‘Ripple Mapping’ which allows the electrical activity of the heart to be tracked through a 3D visualisation.

The 3D visualisation allows doctors to see where in the heart the electrical disturbances are coming from so they can target the ablation. A clinical trial part funded by BHF compared Ripple Mapping with conventional mapping and found that Ripple Mapping enabled a substantially higher success rate (90% versus 71%) in stopping the arrhythmia in the short term with one set of ablations. It also has the added advantage of reducing the time taken to perform the ablation compared to manual mapping.

The Ripple Mapping technology has been incorporated into a commercial mapping system and is now used in 3,000 hospitals across the world.

First published February 2023