Ischaemic myocardial fibrosis and aortic strongylosis in the horse.
Abstract: The hearts and aortas of 2076 unselected horses of all ages were examined immediately after slaughter. Focal zones of fibrosis, observed in the myocardium of 14.3 per cent of hearts examined, were found in both atria and ventricles and were unrelated to age. Microscopically the majority of lesions involved myocardial fibre lysis and replacement fibrosis, although acute infarction was present in some cases. Intramyocardial arterioles in or adjacent to the lesions exhibited occlusive arteriosclerotic changes whereas those elsewhere remained patent. The evidence strongly suggests that the myocardial lesions were ischaemic in origin and related to the distribution of intramyocardial arteriosclerosis. Nodular fibrous plaques and mural thrombi associated with migrating larvae of Strongylus vulgaris were observed in the thoracic aorta of 9.4 per cent of horses. These intimal lesions were often present in the aortic bulb and proximal 10 cm of the thoracic aorta indicating that larval migration in this zone is common. Statistical analysis revealed a highly significant association between the occurrence of proximal aortic S vulgaris lesions and the presence of focal ischaemic lesions in the myocardium. The association was not the result of direct larval damage but appeared to be caused by microembolisation from parasitic lesions in the proximal aorta, producing obstructive arteriosclerotic lesions in myocardial arterioles.
Publication Date: 1981-01-01 PubMed ID: 7238478DOI: 10.1111/j.2042-3306.1981.tb03446.xGoogle Scholar: Lookup
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- Comparative Study
- Journal Article
Summary
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The study investigated the presence and nature of fibrosis in the hearts and aortas of horses, establishing a significant association between ischaemic myocardial lesions and aortic strongylosis, a condition caused by larval migration of the worm Strongylus vulgaris.
Methodology and Findings
- The researchers analyzed the hearts and aortas of 2076 horses of various ages immediately post-mortem. This comprehensive sample allowed for a representative understanding of cardiovascular conditions in horses.
- We identified the presence of fibrosis zones (areas of excess fibrous connective tissue) in 14.3% of the hearts studied, in both the atria and ventricles, uncorrelated to age. The predominance of lesions revealed the presence of myocardial fibre lysis and replacement fibrosis, the body’s way of repairing damaged heart tissues. In some situations, acute infarction was visible.
- Arterioles (small arteries) in the immediate vicinity of the lesions exhibited occlusive arteriosclerotic changes, i.e., artery narrowing due to plaque accumulation. This observation was not applicable to arterioles in other parts of the heart. These findings suggest that the lesions were likely caused by ischaemia (insufficient blood supply), related to the distribution of intramyocardial arteriosclerosis (plaque build-up within the heart’s small arteries).
Connection with Aortic Strongylosis
- In 9.4% of the horses, they noticed nodular fibrous plaques and mural thrombi linked with migrating larvae of Strongylus vulgaris, a horse worm, in the thoracic aorta. These lesions were primarily located in the aortic bulb and the initial 10 cm of the thoracic aorta, indicating a common larval migration zone.
- Statistical analysis not only linked the occurrence of proximal aortic S vulgaris lesions and myocardial ischaemic lesions but also unearthed their highly significant association. This connection does not arise from direct larval damage but seemingly as a result of microembolisation – tiny, embolus-induced blood obstructions – emanating from parasitic lesions. These obstructions, in turn, cause arteriosclerotic blockages in the heart’s arterioles.
Cite This Article
APA
Cranley JJ, McCullagh KG.
(1981).
Ischaemic myocardial fibrosis and aortic strongylosis in the horse.
Equine Vet J, 13(1), 35-42.
https://doi.org/10.1111/j.2042-3306.1981.tb03446.x Publication
Researcher Affiliations
MeSH Terms
- Animals
- Aorta, Thoracic / pathology
- Aortic Diseases / pathology
- Aortic Diseases / veterinary
- Cardiomyopathies / pathology
- Cardiomyopathies / veterinary
- Horse Diseases / pathology
- Horses
- Myocardial Infarction / pathology
- Myocardial Infarction / veterinary
- Myocardium / pathology
- Strongyle Infections, Equine / pathology
Citations
This article has been cited 2 times.- Goto Asakawa M, Mehmood W, Ali M, Oikawa MA. Idiopathic multifocal myocardial atrophy with fibrosis and fatty infiltration involving Purkinje fibres in a 13-year-old Arabian broodmare: Histopathological features. Vet Med Sci 2021 Jan;7(1):3-8.
- Van Vleet JF, Ferrans VJ. Myocardial diseases of animals. Am J Pathol 1986 Jul;124(1):98-178.
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