Emerging Light-Sheet Fluorescence Microscopy for Cardiac Vascular Imaging in Zebrafish.

Purpose of Review: Cardiac vascular remodeling is central to cardiovascular development, injury, and regeneration, yet it remains difficult to resolve in three dimensions within the living, beating heart. This review critically evaluates emerging light-sheet fluorescence microscopy (LSFM) strategies for zebrafish cardiac vascular studies, distinguishes directly demonstrated cardiac applications from transferable methods established in other tissues, and defines quantitative endpoints needed for rigorous treatment-response assessment. Recent Findings: Cardiac-gated and four-dimensional LSFM, hybrid light-field/light-sheet imaging, multiscale acquisition, automated segmentation, and deep-learning-assisted reconstruction have enabled cardiac-cycle-resolved visualization of myocardial motion, intracardiac flow, endothelial migration, vascular remodeling, and regenerative responses. However, the evidence base is uneven: several approaches are validated directly in the zebrafish heart, whereas others remain enabling technologies whose cardiac microvascular utility is inferred from noncardiac applications. Summary: LSFM can serve as a powerful discovery platform when fluorescent reporters, motion synchronization, quantitative analysis, and biological validation are integrated prospectively. The field now requires standardized acquisition and reporting, explicit separation of measured and model-derived endpoints, validation of AI-assisted reconstructions, and coordinated confirmation in mammalian or human cardiovascular models.