Atrial fibrillation, characterized by rapid disorganized electrical activation of myocardium, is caused by and accompanied by remodeling of myocardial tissue. Fibrosis, fatty degeneration and loss of structured myocyte formation are routinely observed. At present, the only option for detailed remodeling characterization is: take a biopsy, fix, slice, stain and image it by microscopy. Fast and direct visualization in vivo is an urgent request. The technical feasibility is still in its infancy, but well on the way as we want to show in a series of images. We applied nonlinear optical microscopy (NLOM) for visualization of typical myocardial features as well as atrial fibrillation effects. Coherent anti-Stokes Raman scattering, endogenous two-photon excited fluorescence, and second harmonic generation were used to inspect unstained human atrial myocardium from patients who underwent surgical Cox-MAZE procedure with amputation of left atrial appendage. Using NLOM techniques, we collected detail-rich pictures of unstained tissue that enable comprehensive characterization of myocardial characteristics. Development of in vivo application of the NLOM technique may represent a revolutionary approach in characterizing myocardial tissue characteristics.
Credits: Petra Buttner, Roberta Galli, Daniela Husser, Andreas Bollmann