ABSTRACT
OBJECTIVE: The fluorescence of tissue when stimulated by a laser beam is a well-known phenomenon. The resulting emission spectra depend on the biochemical and structural composition of the tissue. In this study, we examined the spectra of laser-induced fluorescence emitted by myocardial tissue. METHODS: We used an argon-ion laser to stimulate the myocardium of 20 intact sheep hearts. For each spectral emission, we calculated the intensity in specific regions in order to characterize the spectra and to reveal intercavitary and intracavitary morphologic differences. RESULTS: The statistical analysis showed significant differences in the emission spectra intensity between atria and ventricles. The intensity was higher in the atria than in the ventricles (p < 0.001). The atrial emission spectra were morphologically different from those of the ventricles. There was no difference in the intensity or morphology of emission spectra within each chamber. All measurements showed good reproducibility after a short period of time. CONCLUSIONS: Laser-induced fluorescence of myocardial tissue seems to have the characteristics necessary for tissue recognition. This might prove useful in identifying cardiomyopathies and transplant rejection, as well as for myocardial mapping, assisting electrophysiologists in discovering fibrotic arrhythmogenic foci.
