Cardiovascular System

Heart, Valve - Degeneration, Myxomatous

    Narrative
    Heart, Valve - Degeneration, Myxomatous in a female F344/N rat from a chronic study. With myxomatous degeneration, the valve leaflets are often thickened (arrows).
    Heart, Valve - Degeneration, Myxomatous in a female F344/N rat from a chronic study. With myxomatous degeneration, the valve leaflets are often thickened (arrows).
    Heart, Valve - Degeneration, Myxomatous in a female F344/N rat from a chronic study (higher magnification of Figure 1). The valve leaflet is thickened and rounded.
    Heart, Valve - Degeneration, Myxomatous in a female F344/N rat from a chronic study (higher magnification of Figure 1). The valve leaflet is thickened and rounded.
    Heart, Valve - Degeneration, Myxomatous in a female F344/N rat from a chronic study (higher magnification of Figure 1). Abundant fibromyxoid tissue is present within the subendocardium, giving the valve a pale, basophilic, mucoid appearance.
    Heart, Valve - Degeneration, Myxomatous in a female F344/N rat from a chronic study (higher magnification of Figure 1). Abundant fibromyxoid tissue is present within the subendocardium, giving the valve a pale, basophilic, mucoid appearance.
    Heart, Valve - Degeneration, Myxomatous in a male Wistar Han rat from a chronic study. The spongiosa of the valve leaflet is expanded with myxomatous material (arrow).
    Heart, Valve - Degeneration, Myxomatous in a male Wistar Han rat from a chronic study. The spongiosa of the valve leaflet is expanded with myxomatous material (arrow).
    Heart, Valve - Degeneration, Myxomatous in a male Wistar Han rat from a chronic study. The valve leaflet has marked thickening due to fibromyxoid tissue in the subendocardium.
    Heart, Valve - Degeneration, Myxomatous in a male Wistar Han rat from a chronic study. The valve leaflet has marked thickening due to fibromyxoid tissue in the subendocardium.

    Authors:

    Crystal L. Johnson, DVM, DACVP
    Veterinary Pathologist II
    Charles River Laboratories, Inc.
    Research Triangle Park, NC

    Abraham Nyska, DVM, Diplomate ECVP, Fellow IATP
    Expert in Toxicologic Pathology
    Visiting Full Professor of Pathology
    Sackler School of Medicine, Tel Aviv University Timrat Israel

    Reviewers:

    Brian Berridge, DVM, PhD, DACVP
    Director, WW Animal Research Strategy
    GlaxoSmithKline R&D
    Research Triangle Park, NC

    Mark F. Cesta, DVM, PhD, DACVP
    Staff Scientist, NTP Pathologist
    Cellular and Molecular Pathology Branch
    Division of the National Toxicology Program
    National Institute of Environmental Health Sciences
    Research Triangle Park, NC