Automated morphometric characterization of cardiac fibers by second harmonic microscopy imaging

Cardiovascular diseases are one of the main causes of mortality in the world. For this reason it is important to develop techniques that allow for better understanding of cardiac remodelling prior to heart failure. In this line, Second Harmonic Imaging (SHI) provides a label-free microscopy approach to image cardiac fibers. In this work, we automated means for measuring average sarcomere length, intrasarcomeric A-band distance and sarcomere fiber density as such features have been repeatedly correlated with major cardiomyopathies in the literature (previously measured by manual means). We tested our approach on healthy cardiac tissue of rabbits and human samples and compared such results with manual measurements on the same images to validate our methods. We also measured morphometric differences in cardiac fibers from our animal model which undergoes an irregular heart development. We then conclude that our automated measurements enable reliable characterization of cardiac fiber tissues.