Mending broken hearts

In experiments with dogs,

researchers successfully used a 3D map of the heart and sensor-guided catheter to perform cardiac ablation, a mainstay treatment that stops abnormally fast and potentially fatal heartbeats, or arrhythmias.

The Johns Hopkins findings were presented at the American Heart Association's Scientific Sessions 2005 on November 13 in Dallas, Texas.

The Johns Hopkins team created their own 3D models of each heart from images obtained by integrating and superimposing CT and MRI scans. Using an upgraded computer software program known as electro-anatomic mapping, the scientists are able to colour-code the heart models' structures.

The scientists safely ablated, or destroyed, tiny areas of diseased heart tissue that facilitate rhythm disturbances, guided only by these anatomically precise, reconstructed 3D map.

During the procedure, a catheter containing a magnetic sensor in its tip is inserted through a vein in the dog's leg, then guided to the heart, where it is used to burn off the small part of heart muscle that gives rise to the errant signalling responsible for the arrhythmia.