Researchers have shown that spectroscopic methods based on near-infrared spectroscopy can distinguish between fat and muscle tissue in the heart. This distinction is crucial when using radiofrequency ablation to treat aserious cardiac arrhythmia, which doctors know as ventricular tachycardia. Ablation is the only treatment for this and identifies areas of the heart that are triggering abnormal signals. These can then be heated to the point that they can no longer be transferred. During the procedure, it is important yet challenging to determine exactly where to deliver energy while the doctor spares healthy tissue.
New approach to spectroscopic methods
The researchers confirm for the first time that an ablation catheter using near-infrared spectroscopy mapping can successfully distinguish different tissues in the heart. This is how medicine can help patientsBetter treatment of cardiovascular diseases. Ventricular tachycardia is the leading cause of sudden death. An estimated 300,000 deaths per year are caused by the disease. The scientists hope to transfer this technology to the clinic. In this way, the effectiveness of radiofrequency ablation therapy may increase and reduce associated complications in patients with ventricular tachycardia.
Today, most clinical mapping of the heart is based on functional measurements such as voltage. This is an optical measurement that provides information about the underlying tissue composition. However, doctors could also use these for spectroscopic methods to improve ablation success rates. The researchers used near-infrared spectroscopy, in which they shined light over a wide range of wavelengths onto the tissue and then captured the reflected light. This reflection spectrum provides information about tissue composition based on its absorption and scattering properties. The approach could not only be used to guide ablation, but also provide information that could be used to develop new computational models to improve understanding of the mechanisms involved in arrhythmias.
Ablation procedure in the heart
To use near-infrared spectroscopy during radiofrequency ablation, researchers had to develop new ablation catheters. These contained the optical fibers for emitting and detecting light. They also offer a custom tip for tracking the instrument. They also developed new signal and data processing techniques, a workflow for rendering anatomical maps, and a tracking system to enable spatial mapping of tissue. Using the new catheter, researchers tracked the instrument's position as it moved along the surface of the heart. They recorded reflection spectra at each location. The team used these to calculate an optical index for both fatty and lesional tissue.
The experiments were performed on donor hearts from deceased people with cardiovascular disease to replicate what would likely occur in the clinic. So far, researchers have achieved extremely encouraging results.your workt shows that optics can play a large and effective role in the field of cardiac electrophysiology. Researchers are currently working on a new prototype that can more fully integrate mapping. They also plan to demonstrate spectroscopic methods in large animals to test how well it works when the heart muscles move and blood circulates through the heart.
