Ruptured chordae tendineae in the dog.

Journal of the American Veterinary Medical Association (Impact Factor: 1.67). 09/1969; 155(3):535-46.
Source: PubMed
  • [Show abstract] [Hide abstract]
    ABSTRACT: The paper describes clinical observations in three horses with ruptured mitral valve chordae. Horses with ruptured mitral valve chordae may have a history of sudden onset of acute distress with predominantly respiratory symptoms. On auscultation there will be a widespread pansystolic murmur with an extension of the area of cardiac auscultation. The third heart sound may be very pronounced and unduly prolonged, associated with high volume flow during early ventricular filling in diastole. However, these sounds are not specific for chordal rupture--they are typical of severe mitral regurgitation. The electrocardiogram may show predominantly backward spatial vectors during ventricular depolarisation. The condition gives rise to left ventricular volume overload and pulmonary hypertension would be expected in horses showing signs of cardiovascular disturbance or those recently affected. Care is necessary during post mortem examination to avoid cutting through the mitral valve before a proper assessment has been made of the chordal insertions.
    Equine Veterinary Journal 04/1984; 16(2):125-35. DOI:10.1111/j.2042-3306.1984.tb01880.x · 2.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mitral valve competence requires complex interplay between structures that comprise the mitral apparatus - the mitral annulus, mitral valve leaflets, chordae tendineae, papillary muscles, and left atrial and left ventricular myocardium. Myxomatous mitral valve degeneration is prevalent in the canine, and most adult dogs develop some degree of mitral valve disease as they age, highlighting the apparent vulnerability of canine heart valves to injury. Myxomatous valvular remodeling is associated with characteristic histopathologic features. Changes include expansion of extracellular matrix with glycosaminoglycans and proteoglycans; valvular interstitial cell alteration; and attenuation or loss of the collagen-laden fibrosa layer. These lead to malformation of the mitral apparatus, biomechanical dysfunction, and mitral incompetence. Mitral regurgitation is the most common manifestation of myxomatous valve disease and in advanced stages, associated volume overload promotes progressive valvular regurgitation, left atrial and left ventricular remodeling, atrial tears, chordal rupture, and congestive heart failure. Future studies are necessary to identify clinical-pathologic correlates that track disease severity and progression, detect valve dysfunction, and facilitate risk stratification. It remains unresolved whether, or to what extent, the pathobiology of myxomatous mitral valve degeneration is the same between breeds of dogs, between canines and humans, and how these features are related to aging and genetics.
    Journal of veterinary cardiology: the official journal of the European Society of Veterinary Cardiology 02/2012; 14(1):103-26. DOI:10.1016/j.jvc.2012.02.001
  • [Show abstract] [Hide abstract]
    ABSTRACT: Echocardiography was used to identify a flail left atrioventricular valve cusp caused by ruptured chordae tendineae in each of 4 dogs; two-dimensional echocardiography was superior to M-mode echocardiography in identifying the flail cusps. The following findings on two-dimensional imaging were characteristic: the tip of the flail cusp extended beyond the line of left atrioventricular valve cusp closure and pointed toward the left atrium in systole; the tip was thrust into the left ventricle, and then toward the left ventricular outflow tract in diastole, forming a convex surface to the cusp, which faced toward the left ventricle. The flail motion of the left atrioventricular valve cusp was best observed in the right parasternal long axis or left apical four-chamber views, in a plane parallel to the long axis of the left ventricle and left atrium. Rupture of chordae tendineae leading to flail cusp was attributed to chronic valve degeneration (endocardiosis) in all 4 dogs. Echocardiographic or clinical diagnoses were confirmed by postmortem gross and microscopic studies in all dogs.
    Journal of Veterinary Internal Medicine 09/1995; 9(5):341-6. DOI:10.1111/j.1939-1676.1995.tb01095.x · 2.22 Impact Factor