Once the arrhythmia source has been located, ablation is performed to eliminate this source and stop the arrhythmia.
In the state-of-the-art protocol, ECGI would far more quickly find the source and type of VT, saving hours of mapping.
In the future, it is hoped that experimental techniques such as gamma knife radiosurgery and high-frequency ultrasound, under study for noninvasive ablation of cardiac tissue, might be used with ECGI, paving the way for total noninvasive treatment of VTs.
'Tool that opens the door'
ECGI can locate the source of cardiac excitation in the heart with an accuracy of about 6 millimeters. In contrast, the conventional ECG provides only global information.
As Rudy explains: "The big difference between the two is that the ECG measures the reflection of the heart's electrical activity far away from the heart on the torso surface. In the process, resolution is lost.
"ECGI gets far closer," Rudy says. "Imagine a car coming toward you at night from far away. You see only one light. But as it gets closer and closer, you start to resolve the two headlights and their location in space. It's similar here. With ECG, you're far on the body surface and get only a global view instead of the real local details on the heart surface.
"ECGI is a treasure for basic medical research. It is a tool that opens the door to study the electrical functioning of the heart and arrhythmia mechanisms in people with various (hereditary and non-hereditary) cardiac disorders.
"Clinically, it is promising as a diagnostic tool that could guide therapy of cardiac arrhythmias, and because it is noninvasive, it could also be used as a follow-up tool to evaluate progression of the disorder and the results of therapy," Rudy says.
"Someday it might help to identify patients at risk of developing VT, so that preventive measu
|Contact: Diana Lutz|
Washington University in St. Louis