The Role of Laser-Induced Fluorescence in Myocardial Tissue Characterization

The fluorescence of tissue when stimulatedby a laser beam is a well-known phenomenon. The resulting emissionspectra depend on the biochemical and structural composition of thetissue. In this study, we examined the spectra of laser-inducedfluorescence emitted by myocardial tissue. Weused an argon-ion laser to stimulate the myocardium of 20 intact sheephearts. For each spectral emission, we calculated the intensity inspecific regions in order to characterize the spectra and to revealintercavitary and intracavitary morphologic differences. The statistical analysis showed significantdifferences in the emission spectra intensity between atria andventricles. The intensity was higher in the atria than in theventricles (p < 0.001). The atrial emission spectra weremorphologically different from those of the ventricles. There was nodifference in the intensity or morphology of emission spectra withineach chamber. All measurements showed good reproducibility after ashort period of time. Laser-inducedfluorescence of myocardial tissue seems to have the characteristicsnecessary for tissue recognition. This might prove useful inidentifying cardiomyopathies and transplant rejection, as well as formyocardial mapping, assisting electrophysiologists in discoveringfibrotic arrhythmogenic foci.