Peer-reviewed veterinary case report
Heart conduction damage in dogs with mitral valve disease and AV block
By Kaneshige, T et al.·Published in Journal of comparative pathology·2007·Tokyo University of Agriculture and Technology, Japan·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: A histological study of the cardiac conduction system in canine cases of mitral valve endocardiosis with complete atrioventricular block.
- Species:
- dog
Plain-English summary
A group of dogs with mitral valve endocardiosis, a heart condition, experienced complete atrioventricular (AV) block, which means their heart's electrical signals were disrupted. In these cases, the heart's conduction system showed significant damage, with a reduction in important conduction fibers and signs of degeneration. This damage was likely worsened by the stress from the heart's abnormal movement and long-term pressure from the leaking valve. Unfortunately, these conduction issues can lead to serious heart problems in dogs with this condition.
People also search for: dog heart block symptoms · mitral valve endocardiosis treatment · dog heart disease signs
Abstract
The cardiac conduction system was examined histologically in four canine cases of endocardiosis of the mitral valve (MV) with complete atrioventricular (AV) block. In all cases, moderate to severe reduction of the conduction fibres due to fibrous or fibro-fatty replacement was observed in the penetrating and branching portions of the AV bundle. In addition, degenerative and fibrotic lesions were commonly seen at the upper portions of the left and right bundle branches. These changes in the AV conduction system were associated with marked degeneration and fibrosis of the base of the central fibrous body and the upper part of the ventricular septum. The degenerative and sclerotic changes of the AV junctional region, affecting the AV bundle and bundle branches, were qualitatively similar to those in age-matched control dogs, but were more severe. It is possible that the pathological process occurred as a result of ageing and may have been exaggerated or accelerated by the abnormal mechanical forces created by excessive motion of the prolapsed MV and the long-term haemodynamic stresses of mitral regurgitation, resulting in interruption of the AV conduction system to produce complete AV block. Conduction abnormalities represent a possible complication in some canine cases of MV endocardiosis.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/17362978/