Endocardiosis
As endocardiosis diseases are on the forecourt flaps in which the functioning of the heart valve is affected by nodular changes of the leaflets referred to the heart of animals. Other names are myxomatous degeneration of the atrioventricular valves , "chronic valve fibrosis" or "chronic degenerative atrioventricular valve disease".
Epidemiology
Endocardiosis occurs mainly in dogs and is one of the most common disorders of this organ, accounting for 40 percent of all diagnosed heart diseases. It is a degenerative disease that can be related to a genetic predisposition in dogs of some breeds . It often only manifests itself in middle or older age and mainly affects representatives of small and medium-sized races.
In small breeds, around every third animal over the age of ten shows damage to an atrial valve. Animals of the Cavalier King Charles Spaniel breed are particularly sick ; here more than half of the animals by the age of 4 already show signs of dysfunction. Other breeds that are commonly affected include poodles , miniature schnauzers , cocker spaniels , fox terriers , Boston terriers , dachshunds, and chihuahuas . Although no gender differences are discernible in the proportion of all sick animals, male individuals often show more severe courses with rapid progression and thus faster development of congestion symptoms . As another animal species, horses seem to be more frequently affected by the disease.
Disease emergence
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By far the most common disease (60 percent) affects the mitral valve . In 30 percent of cases, the tricuspid valve is also affected. Isolated damage to the tricuspid valve (10 percent) and the aortic valve or pulmonary valve are far less common . The cause of the development of endocardiosis has not yet been clarified. The most widespread assumption is currently that a genetically influenced degeneration of collagenous connective tissue structures favors the development of valve fibrosis. This assumption is supported by the fact that dog breeds with a tendency to develop valve endocardiosis also have other characteristics of insufficient connective tissue stability (e.g. herniated disc , tracheal collapse , cruciate ligament tear ). In addition to the possibility of faulty collagen formation ( mutation-related defects in the collagen types I and III occurring in the heart), increased enzymatic destruction of connective tissue is assumed to be a possible cause. In addition, stress , high blood pressure , hypoxia , bacterial and viral infections and a large number of endocrine disorders seem to promote the development of degeneration.
Classification
There are three stages in the development of endocardiosis. Type I changes are small areas of increased density or small nodules on the edge of the valve. In type II, the nodules are slightly larger, more numerous, and begin to unite. Type III is characterized by plaque- like deposits, large, nodular changes in the valve margins and thickening of the valve holding apparatus . In addition to the edge of the valve, its base is often affected, calcified areas and punctiform hemorrhages in the tissue can be seen. In type IV changes, the valve leaflets are contracted and twisted, and the free valve edges appear rolled up. The threads of the valve holding apparatus are often elongated and thus lead to valve prolapse or are even torn.
Investigation options
In the early stages, endocardiosis often go undetected, as they do not cause any symptoms that are visible to the owner.
Auscultation often reveals abnormal heart murmurs as a result of the lack of closure of the affected valves. A reliable diagnosis can be made using sonography .
Treatment options
Restorative therapy is not common in veterinary medicine because the use of artificial heart valves is not established. The treatment is therefore primarily aimed at reducing the disturbances in cardiac function caused by endocardiosis and avoiding chronic remodeling processes in the heart. Above all, active substances such as ACE inhibitors , pimobendan and diuretics are used to lower the preload and afterload . According to recent studies, aldosterone antagonists such as spironolactone can stop the fibrotization processes in the heart and blood vessels and contribute to a significantly increased life expectancy.
Endocardiosis in human medicine
The term endocardiosis is not used in human medicine . However, the mitral valve prolapse syndrome , which is common in humans, has a large number of features in common with endocardiosis in animals, so that the terms are sometimes viewed as synonyms . The mitral valve prolapse syndrome occurs more frequently in people with asthenic physique and hereditary diseases of the connective tissue such as Marfan syndrome , Ehlers-Danlos syndrome , osteogenesis imperfecta and polyarteritis nodosa and pathologically shows what is known as myxomatous degeneration of the valve leaflets . Women are affected about twice as often as men; the frequency varies between 2.4 and 15% depending on the severity of the diagnostic criteria.
Individual evidence
- ^ LSU School of Veterinary Medicine: AV Valve Endocardiosis
- ↑ Vetstreet: Mitral Valve Disease (Endocardiosis) in Dogs
- ↑ Vetstreet: Mitral Valve Disease (Endocardiosis) in Dogs
- ↑ A Michl: Clinical and further cardiological examinations in warm-blooded horses with heart valve insufficiencies. Vet.-med.Diss., Hannover 2001, 20–21, elib.tiho-hannover.de (PDF file; 1.62 MB)
- ↑ JW Buchanan: Chronic valvular disease (endocardiosis) in dogs . In: Adv Vet Sci Comp Med. , 1977, 21, pp. 75-106, PMID 146409
- ↑ Jörg Korrell: Aldosterone and aldosterone antagonists and their significance in chronic heart failure. In: Kleintiermedizin , 11, 2008, pp. 1–3.
- ↑ T Hagel et al .: http://www.gkf-bonn.de/download/vb_hagel14.pdf ( Memento from September 29, 2007 in the Internet Archive ) Population genetic and echocardiographic investigation into the occurrence of the insufficient mitral valve apparatus in Cavalier-King-Charles -Spaniel . Ges. For the promotion of cynological research e. V., 2002, (PDF; July 29, 2007; 450 kB).
- ^ RO Bonow, E Braunwald: Mitral Valve Prolapse Syndrome . In: DP Zipes et al. (Ed.): Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . 7th edition. WB Saunders Company, Philadelphia 2004, ISBN 1-4160-0014-3 .
