Prevalence of anatomic variants in coronary arteries of Japanese Black cattle.

Coronary artery anomalies that can cause sudden cardiac death have been described in some mammals. However, few studies have investigated coronary anomalies and coronary artery branching patterns in cattle. Therefore, understanding of bovine coronary arteries is incomplete. The aim of this study was to clarify anatomic variants in coronary arteries of Japanese Black cattle. The gross anatomy of the coronary arteries was examined in the hearts of 100 cattle. A total of 14 of 100 hearts exhibited confirmed coronary anomalies in the left main trunk. These 14 hearts were classified into 5 types potentially associated with cardiac ischemia. Regarding the coronary branches, the subsinuosal interventricular branch originated from the left circumflex branch (LCX) in 98 hearts and from the right coronary artery in 2 hearts. The origin of the sinoatrial nodal branch was classified into 3 types. In 99 hearts, the atrioventricular nodal branch originated from the LCX at the heart crux. This study characterized the prevalence of coronary anomalies, branching patterns of coronary arteries, and coronary artery anatomic variants in Japanese Black cattle.

Right coronary artery to left ventricle coronary cameral fistula in a cat.

A six-month-old female intact domestic shorthair cat was presented for evaluation of a loud heart murmur. Transthoracic echocardiography revealed dilation of the left ventricle secondary to an abnormal vessel shunting blood into the left ventricular outflow tract at a high velocity during diastole. Multidetector computed tomography angiography revealed a coronary cameral fistula that originated at the right coronary artery, encircled the heart, and then terminated into the left ventricular outflow tract. This case report documents the first known case of a coronary cameral fistula in a cat. Multimodal imaging was an essential aspect to diagnosing the congenital lesion in this case.

Advanced imaging findings in a cat with left ventricular apical aneurysm.

An eight-year-old, male neutered, domestic shorthair cat presented with severe anemia. Two-dimensional echocardiography identified severe left ventricular apical dilation with wall thinning and akinesia. The basal portion of the left ventricle showed equivocal hypertrophy and subjective hyperkinesis. Speckle tracking echocardiography showed marked abnormalities in all deformation planes (longitudinal, circumferential, radial strain) and twist. Three-dimensional Bull's eye plot reconstruction was also performed. Post-mortem evaluation showed a pale and paper-thin left ventricular apex and histopathology confirmed full-thickness cardiomyocytes loss with fibrous replacement. Left ventricular acquired apical aneurysms are the result of chronic damage of the myocardium and are associated with many disease conditions in people, including coronary artery disease and cardiomyopathy. The exact pathophysiological mechanism could not be determined with certainty in the cat of the present report, but advanced echocardiographic evaluation added some fine details into the characterization of this infrequently reported abnormality.

Novel coronary artery anomaly in a French bulldog with pulmonary stenosis.

A 9-month-old French Bulldog with pulmonary stenosis (PS) underwent transthoracic echocardiography (TTE) and electrocardiogram-gated coronary computed tomography angiography (ECG-CCTA) for presurgical planning of pulmonary balloon valvuloplasty (PBV). Transthoracic echocardiography revealed severe PS and identified two distinct coronary ostia (left and right). Electrocardiogram-gated coronary computed tomography angiography showed a circumpulmonary course of the interventricular paraconal coronary artery, which abnormally originated from the right coronary artery. Based on this case report, the echocardiographic identification of two coronary ostia does not rule out a coronary artery anomaly with circumpulmonary course (as previously hypothesized), and coronary computed tomography angiography may be recommended for presurgical planning of PBV in French Bulldogs.

Effects of protocatechuic acid on ameliorating lipid profiles and cardio-protection against coronary artery disease in high fat and fructose diet fed in rats.

A coronary heart disease leads to increase in obesity and metabolic dysfunction. Protocatechuic acid (PCA), due to its antioxidant, anti-inflammatory, neuro protective activities was found efficient as cardio-protective in coronary heart disease. Our study investigated hypolipidemic and cardioprotective effects of protocatechuic acid in the coronary artery disease induced by high fat and fructose diet (HFD) rat models. A diet rich in fat and fructose was fed to male Wistar rats prior to the start of experimental procedures. Serum lipid levels and hepatic triglycerides (TG) and total cholesterol (TC) levels were examined and analyzed. Both in vitro an in vivo pancreatic lipase activity was determined as well. Histopathological examination was performed and their results were noted. Noteworthy reduction of serum lipid levels and hepatic TG and TC levels was seen in groups treated with simvastatin (SIM; 20 mg/kg) and PCA (50 and 100 mg/kg) in comparison to HFD groups. Pancreatic lipase activity was reduced in the SIM group and the group treated with doses of PCA (50 and 100 mg/kg). A marked increase in gain in body weight per week (P<0.05) was achieved in HFD group. Coronary risk index (CRI) and Atherogenic index of plasma (AIP) showed decreased index values after treatments with SIM and PCA (50 and 100 mg/kg), respectively. Our findings confirmed the efficacious cardio-protective and hypolipidaemic activities of protocatechuic acid in coronary artery disease induced in rats with fat and fructose rich diet.

Cardiac Pathology and Genomics of Sudden Death in Racehorses From New York and Maryland Racetracks.

Postmortem evaluation of racehorses has focused primarily on musculoskeletal injuries; however, horses also die suddenly on the track (sudden death [SD]). Although cardiac conditions are frequently suspected as a cause of death, SD racehorses are often autopsy negative; however, previous studies have been limited due to inconsistent or insufficient cardiac sampling and lack of controls. SD in New York (NY) and Maryland (MD) racehorses was evaluated in an observational case vs control study comparing clinical information, postmortem evaluation including cardiac dissection, and cardiac conduction system histopathology. In the study period, there were 40 cases of SD. In NY, SD occurred in 12% (37/316) of submissions, and 36 (11%) cases of SD were exercise associated (EASD); 3 EASD cases occurred in MD. In NY/MD EASD cases with histologic examination of the heart, 11 of 36 (31%) had significant lesions, including mesenteric artery rupture (1), axial trauma (2), systemic inflammation (2), pulmonary hemorrhage (1), and cardiac disease (5). Mild myocardial fibrosis, mild inflammation, coronary arteriosclerosis, and variation in cardiac nodal connective tissue were present in both SD cases and controls and thus were not considered to be causes of SD. While not excluding a genetic basis for SD, analysis of the genotypes (GGP Equine 70 K Array) of cases and controls did not reveal significant differences in allele frequencies at any locus. Most SD racehorses were autopsy negative; further research using standardized protocols and controls is needed to understand the underlying causes of SD, which is crucial to protecting the viability of racing.

Treating cardiovascular complications of radiotherapy: a role for new pharmacotherapies.

INTRODUCTION: Available data indicate that survivors of breast cancer and Hodgkin lymphoma who received mediastinal radiotherapy are at increased risk of developing radiation-induced cardiovascular diseases (RICVD) one or two decades after treatment. Although the risk with modern radiation treatment is likely to be lower in these patient groups, cardiotoxicity is still observed in a subset of patients. In addition, radiation-associated cardiovascular complications can, in the future, extend to other groups of cancer patients who are treated for tumors that are localized near the heart. AREAS COVERED: The authors briefly describe the most commonly observed types of RICVD. They then present an overview of preclinical animal and cellular models that have been used to investigate the mechanisms underlying RICVD pathophysiology. The beneficial effects of available drugs, and potential targets for new molecules are also reported. EXPERT OPINION: There is a need to develop cardio-oncological programs and pharmacotherapies specifically targeting RICVD. Beyond statins, ACE inhibitors, anti-inflammatory and antioxidant agents, preclinical studies indicate that TGFß receptor I inhibitors, Sestrin2 inducers, recombinant neuregulin-1 and miR-21 inhibitors might represent novel promising strategies. In order to properly determine the optimal therapeutic index for these molecules, in vivo models combining cancer and RICVD should be envisioned.

Spontaneously occurring intramural coronary arteriosclerosis in regularly slaughtered veal calves and beef cattle: a screening study about prevalence and histopathological features.

OBJECTIVES: Intramural coronary arteriosclerosis has been reported in several species, but no systematic studies are currently available in bovine. The present study aimed to describe the arteriosclerotic changes in regularly slaughtered veal calves and beef cattle. ANIMALS: Twenty-five veal calves (6-9 months old) and 17 beef cattle (10-24 months old) housed in intensive livestock farming and regularly slaughtered were included in the present study. METHODS: Selected heart samples were submitted for histopathological and ultrastructural examination and the following parameters were evaluated: intimal hyperplasia, degenerative changes of the tunica media, medial hypertrophy/hyperplasia, myocardial fibrosis, and myocarditis. Pathological intramural coronary arteries with and without lumen narrowing were manually counted in every sample. RESULTS: Intramural coronary arteriosclerosis was observed in all the calves and cattle, with similar prevalence of fibromuscular/muscular intimal hyperplasia (92% vs 88%), degenerative changes of the tunica media (76% vs 71%), and medial hypertrophy/hyperplasia (44% vs 59%). The posterior papillary muscle of the left ventricle was the myocardial localization significantly more affected in both calves (p = 0.0007) and cattle (p = 0.0339). Anitschkow cells were detected in the coronary walls of both calves (60%) and cattle (76%). CONCLUSIONS: This is the first study that systematically describes spontaneously occurring intramural coronary arteriosclerosis in bovine species. Anitschkow cells, whose ultrastructural characteristics and localization suggest their potential origin from the smooth muscle cells of the tunica media of the arteriosclerotic coronary vessels, were also identified.

Impact of Obesity on Cardiopulmonary Disease.

Although there are known detrimental effects of obesity on the heart and lungs, few data exist showing obesity as risk factor for cardiopulmonary disorders in dogs and cats. It is probable that increased abdominal fat is detrimental as it is in humans, and there is evidence of negative effects of increased intrathoracic fat. As well as physical effects of fat, increased inflammatory mediators and neurohormonal effects of obesity likely contribute to cardiopulmonary disorders. Weight loss in overweight individuals improves cardiac parameters and exercise tolerance. Obesity in patients with obstructive airway disorders is recognized to increase disease severity.

Coronary changes in the Atlantic salmon Salmo salar L: characterization and impact of dietary fatty acid compositions.

Consumption of fatty acids from fishes is widely regarded as beneficial for preventing cardiovascular disorders. Nevertheless, salmonids themselves are victims of vascular diseases. As the pathogenesis and nature of these changes are elusive, they are here addressed using novel morphological and transcriptional approaches. Coronary arteries of wild Atlantic salmon Salmo salar L., (n = 12) were investigated using histological and immunohistochemical techniques, and RT-qPCR was employed to investigate expression of stretch-induced genes. In an experimental trial, fish were fed diets with different fatty acids composition, and histological features of the coronary arteries (n = 36) were investigated. In addition, the heart fatty acid profile (n = 60) was analysed. There were no differences in morphological or immunological features between wild fish and groups of experimental fish. Arteriosclerotic lesions consisted of smooth muscle cells in dissimilar differential stages embedded in considerable amounts of extracellular matrix in a similar fashion to what is seen in early stages of human atherosclerosis. No fat accumulations were observed, and very few inflammatory cells were present. In affected arteries, there was an induction of stretch-related genes, pointing to a stress-related response. We suggest that salmon may have a natural resistance to developing atherosclerosis, which corresponds well with their high investment in lipid metabolism.

Hiperplasia em túnicas de artérias coronárias de beijupirás criados em sistema offshore / Hyperplasia in tunics of coronary arteries in beijupirá farmed in offshore system

As lesões coronarianas já foram relatadas em espécies de peixes anádromos, com características semelhantes às observadas em aterosclerose humana, mas não em peixes cultivados sem interferência de padrões reprodutivos. Objetivou-se descrever lesões coronarianas em beijupirá (Rachycentron canadum) criado em sistema offshore, em 54 exemplares coletados ao longo do cultivo de oito meses. Amostras de tecido cardíaco de alevinos e juvenis foram submetidas à análise histopatológica e à microscopia eletrônica de transmissão (MET), para visualização de lesões coronarianas, sendo as lâminas histológicas coradas pela técnica de hematoxilina-eosina, ácido periódico de Schiff, alcian blue e reticulina de Gomori. Exames realizados pela fotomicroscopia de luz evidenciaram lesões arteriais caracterizadas por hiperplasia das túnicas íntima e média de artérias coronárias em, respectivamente, 29,63% e 79,63% dos animais, com redução do lúmen arterial. Na MET, foram observadas alterações na estrutura das coronárias com espessamento do endotélio e membrana basal, proliferação de fibroblastos e fibras colágenas, com acúmulo de material lipídico subendotelial, resíduos celulares aderidos à membrana basal e vesículas pinocitóticas com presença de lisossomos isolados. Constatou-se que os peixes da espécie Rachycentron canadum criados em cativeiro desenvolvem lesão arterial do tipo crônica degenerativa inflamatória.

The coronary lesions have been reported in species of anadromous fish with similar characteristics as those observed in human atherosclerosis, but not in farmed fish without interference of reproductive patterns. This study aimed to describe coronary lesions in beijupirá (Rachycentron canadum) farmed in an offshore system, in 54 specimens collected along an eight month cultivation period. Samples of heart tissue of fry and juveniles were subjected to histopathological analysis and transmission electron microscopy (TEM) for visualization of coronary lesions, the histology slides were stained using hematoxylin-eosin, periodic acid Schiffh, alcian blue, and reticulin of Gomori. Examinations performed by light microscopy showed arterial lesions characterized by hyperplasia of the intima and media tunics, respectively in 29.63% and 79.63 % of the animals, with reduced lumen. In TEM changes in the structure of the coronary endothelium and thickening of the basement membrane, proliferation of fibroblasts and collagen fibers, with subendothelial accumulation of lipid material, cellular debris adhering to the basement membrane and presence of pinocytotics vesicles and isolated lysosomes were observed. It has been found that the Rachycentron canadum fish species farmed in captivity develop arterial lesion of the chronic inflammatory degenerative type.

Cardiac troponin-I concentration, myocardial arteriosclerosis, and fibrosis in dogs with congestive heart failure because of myxomatous mitral valve disease.

BACKGROUND: Few previous studies have investigated the association between biomarkers and cardiac disease findings in dogs with naturally occurring myxomatous mitral valve disease (MMVD). AIM: To investigate if histopathological changes at necropsy could be reflected by in vivo circulating concentrations of cTnI and aldosterone, and renin activity, in dogs with naturally occurring congestive heart failure because of MMVD. ANIMALS: Fifty privately owned dogs with MMVD and heart failure. METHODS: Longitudinal Study. Dogs were prospectively recruited and examined by clinical and echocardiographical examination twice yearly until time of death. Blood was stored for batched analysis of concentrations of cTnI and aldosterone, and renin activity. All dogs underwent a standardized necropsy protocol. RESULTS: cTnI were associated with echocardiographic left ventricular end-diastolic dimension (P < .0001) and proximal isovolumetric surface area radius (P < .004). Furthermore, in vivo cTnI concentrations reflected postmortem findings of global myocardial fibrosis (P < .001), fibrosis in the papillary muscles (P < .001), and degree of arterial luminal narrowing (P < .001) Aldosterone or renin activity did not reflect any of the cardiac disease variables investigated. CONCLUSION AND CLINICAL IMPORTANCE: Cardiac fibrosis and arteriosclerosis in dogs with MMVD are reflected by circulating cTnI concentration, but not by aldosterone concentration or renin activity. Cardiac troponin I could be a valuable biomarker for myocardial fibrosis in dogs with chronic cardiac diseases.

Intimal thickening of coronary arteries in the rabbitfish, Chimaera monstrosa L. (Chondrichthyes: Holocephali).

This study is the first to report the occurrence of intimal thickening of coronary arteries in a holocephalan, namely the rabbitfish, Chimaera monstrosa. The sample studied consisted of five hearts from rabbitfish with body weights ranging between 12 g and 1116 g. The specimens were fixed in formalin, in methanol:acetone:water (MAW), or in paraformaldehyde and were examined by brightfield and polarization light microscopy. Coronary arteries from three larger animals displayed focal intimal thickenings, which were located in the left main coronary artery trunk, at the level of the cono-ventricular junction, and in several intramyocardial ventricular arteries. The vascular changes were characterized by myointimal proliferation, breakage or absence of the inner elastic lamina, and, in one case, by increased collagen within the myointimal proliferation. Taking into account the severity of the coronary arterial changes, their location, and the body weight of the affected animals, we conclude that (1) these changes are age-related in the rabbitfish and (2) local intense mechanical tension seems to be an important factor in their formation in this species.

El conejo como modelo de experimentación. Inducción de lesión vascular: técnica e incidencias / The rabbit as an experimental model: technique for the induction of vascular lesions and incidents

Objetivo: Describir el proceso para conseguir la lesión aterogénica en el conejo, mostrar el daño vascular producido por 2 catéteres de balón de diferente calibre y el valor de la ecografía para su cuantificación. Material y métodos: Se emplearon 36 conejos. Se estudiaron los valores de triglicéridos y colesterol, y se realizó una ecografía de aorta e ilíacas. Se realizó una arteriografía y se indujo la lesión vascular denudando la arteria ilíaca izquierda con catéter de balón: grupo A, catéter-balón 2,5mm, y grupo B catéter-balón 3mm de diámetro. Tras 8 semanas con dieta hiperlipídica se realizaron nuevas mediciones bioquímicas y ecográficas. Resultados Colesterol antes de la dieta 37,96±19,3mg/dl, y tras la dieta 1.761±296,91mg/dl. Los hallazgos ecográficos mostraron un diámetro de la aorta de 4,1±0,7mm, de la arteria ilíaca derecha de 3±0,3mm, de la arteria ilíaca izquierda de 3±0,4mm. Tras el daño vascular y 8 semanas de dieta, en el grupo A la luz de la aorta era de 2,78±1,21mm, la arteria ilíaca derecha medía 2,18±0,81mm y la arteria ilíaca izquierda 1,16±0,63mm; en el grupo B la luz de la aorta fue de 3,07±1,06mm, la arteria ilíaca derecha 2,53 ± 0,9mm y la arteria ilíaca izquierda 1,39±1,1mm. Resultados: Murieron 4 conejos y de los 32 restantes hubo más morbimortalidad con el catéter de balón de 3 mm. Conclusión Tras la denudación con catéter de balón y dieta los conejos desarrollan estenosis de la arteria. El daño con catéter de 2,5 mm de diámetro disminuye las complicaciones (AU)

Objective: To describe the process for inducing atherogenic lesions in rabbits, to show the damage to vessels caused by two different caliber balloon catheters, and to show the usefulness of ultrasonography in the quantification of vascular damage. Material and methods: We used 36 rabbits. We studied the levels of triglycerides and cholesterol and examined the aorta and iliac arteries by ultrasonography. We performed arteriography and induced a vascular lesion by denuding the left iliac artery with a balloon catheter: group A 2.5mm diameter balloon catheter, group B 3mm diameter balloon catheter. After 8 weeks on a hyperlipidic diet, biochemical and ultrasonographic measurements were repeated. Results: Cholesterol before the diet: 37.96±19.3mg/dL and after the diet: 1761±296.91mg/dL. The baseline ultrasonographic measurements of vessel diameter were: aorta 4.1±0.7mm, right iliac artery 3±0.3mm, left iliac artery 3±0.4mm. After vascular damage and 8 weeks hyperlipidic diet, in group A the ultrasonographic measurements of vessel diameter were: aortic lumen 2.78±1.21mm, right iliac artery 2.18±0.81mm, and the left iliac artery 1.16±0.63mm; in group B, the aortic lumen measured 3.07±1.06mm, the right iliac artery 2.53±0.9mm, and the left iliac artery 1.39±1.1mm. Results: Four rabbits died; in the 32 remaining rabbits, morbidity was higher with a 3mm balloon catheter. Conclusion: After denudation with a balloon catheter and a hyperlipidic diet, the rabbits developed arterial stenosis. The damage with a 2.5mm diameter catheter reduces complications (AU)

Cardiac valvular and vascular disease in Bull Terriers.

The hearts of 27 Bull Terriers and 6 control dogs were evaluated. Heart murmurs were auscultated in 14 (52%) Bull Terriers. At necropsy, 25 Bull Terriers (93%) had myxomatous degeneration of the mitral valve or abnormalities of the left ventricular outflow tract. Small vessel arteriosclerosis in the myocardium and fibrosis of cardiac conduction tissue were common histologic findings in Bull Terriers with clinical cardiac disease. These lesions were also detected in dogs without clinical evidence of cardiac disease and only mild murmurs or structural valvular disease.

Use of isoxsuprine for treatment of clinical signs associated with presumptive atherosclerosis in a yellow-naped Amazon parrot (Amazona ochrocephala auropalliata).

A 35-year-old yellow-naped Amazon parrot (Amazona ochrocephala auropalliata) was presented for gradually increasing inappetence, ataxia, weakness, and lethargy. Radiographic and ultrasonographic findings were strongly suggestive of atherosclerosis. Isoxsuprine, a peripheral vasodilator demonstrated to be of benefit in humans with intermittent limb pain, weakness, and lameness secondary to occlusive vascular disease, was selected for treatment. The bird's clinical signs resolved during treatment but recurred after varying periods of time when the medication was stopped intermittently. Nearly 3 years after the initial examination, the parrot was doing well on isoxsuprine therapy, with normal prehension of food with its feet and no recurrence of clinical signs.

Influence of dietary lipid composition on cardiac pathology in farmed Atlantic salmon, Salmo salar L.

The present study investigated the short-term (5 months) effect of replacing dietary marine oils with vegetable oils on the development of arteriosclerotic changes in the heart of Atlantic salmon, Salmo salar. The experiment was performed as a randomized observer-blinded and controlled trial. Farmed Atlantic salmon were randomly sampled from a study population containing 900 individuals. The salmon were divided into three groups and given diets with either 100% fish oil (Diet 1), a 50/50% mixture of fish oil and rapeseed oil (Diet 2) or 100% rapeseed oil (Diet 3). Ten sexually immature salmon from each dietary group were sampled in March and August 2002. Additionally, 47 sexually mature wild salmon were randomly collected in mid-September 2001. Serial histological sections were taken from the bulbus arteriosus and ventricle wall for histopathological evaluation of the coronary arteries and myocardium. No significant differences in mean coronary changes recorded by the main variable 'mean range lesion' (MRL) were detected between the groups in March or August. MRL increased significantly between March and August with Diet 2 (P < 0.01), was nearly significant with Diet 3 (P = 0.06) and was unchanged with Diet 1. This pattern coincided with the Diet 2 group having the highest increase in heart weight. MHC class II immunoreactive cells in the coronary changes were detected in sections from one individual in each group. Heart weight was the most dominant variable in the data set and explained linearly 15.5% of the variation in MRL. Body weight, fish length and heart weight were all significantly, positively and linearly correlated to MRL. The Diet 2 group had the highest growth rate and also exhibited a significant increase in MRL. The possible influence of diet composition on weight gain and MRL needs to be further elucidated. Increase in heart weight seems to be the dominating predictor of the appearance of MRL in Atlantic salmon. However, the present results cannot exclude the possibility that differences in fatty acid composition of fish feed can influence the development of arteriosclerotic changes in Atlantic salmon.

Chronic myocardial infarction due to arteriosclerosis of coronary arteries followed by acute thromboembolism of caudal abdominal aorta in a cat.

A 10-year-old cat with the paresis of hind limbs was initially diagnosed as a hypertrophic cardiomyopathy followed by acute thromboembolism of caudal abdominal aorta from the findings of the medical examinations. However, this case was proved to be an chronic myocardial infarction due to arteriosclerosis of coronary arteries by the pathologic diagnosis. In the left ventricular, the hypertrophy and the narrowing were slight, and a coagulative infarction was seen obviously. The intramural coronary arteriosclerosis showed thickening of the wall due to medial hyperplasia by fibrosis, and arterial stenosis. Myocardial infarction and arteriosclerosis are scarcely any reports of these lesions in cats. This case is valuable for an extremely rare case of myocardial infarction in the cat.

Introduction and comparison of two methods of assessment of coronary lesions in Atlantic salmon, Salmo salar L.

This study investigated and compared quantitative and semi-quantitative coronary lesion evaluation in Atlantic salmon, Salmo salar. A total of 121 immature farmed and 47 sexually mature wild Atlantic salmon were included. Coronary arteries from all fish were morphometrically evaluated using a semi-quantitative method. A subsample of 76 salmon was additionally evaluated using a quantitative method. Another subsample of 71 salmon was used for reliability testing of the semi-quantitative method. Ten cross-sections of coronary arteries located on the ventral surface of the bulbus arteriosus were semi-quantitatively scored with regard to myointimal coronary lesions. Quantitative measurements comprised maximal intimal thickness and area lesion (%) while semi-quantitative measurements comprised maximal intimal thickness and lesion degree (%). Scores for individual fish were expressed as the average of lesion score, denoted as mean range lesion. One person performed all evaluations blindly. Two pathologists tested repeatability of the semi-quantitative lesion score measurements blindly. Both semi-quantitative and quantitative variables increased significantly with increasing lesion score. Semi-quantitative estimation gave significantly higher maximal intimal thickness values than quantitative measurement. Semi-quantitative measurements were found to explain 63.2% of variation in quantitatively measured maximal intimal thickness. Due to lack of agreement, the two methods are not directly comparable and one method cannot replace the other. Repeatability within and between observers with regard to semi-quantitative classification was very good with Kappa values larger than 61.5%. The semi-quantitative method was a valid and reliable method for coronary lesion evaluation in Atlantic salmon.

Coronary arteriosclerosis with myocardial atrophy in a 13-year-old dog.

Myocardial ischemia, an uncommon cause of sudden death in dogs, usually results in infarction and fibrosis of the myocardium. Necropsy examination of a 13-year-old German Shepherd dog that died suddenly demonstrated multifocal myocardial thinning and loss in the left and right ventricular free wall and right atrium. Histopathologic examination confirmed the myocardial thinning to be sites of myocyte atrophy and loss, with loose reticulin-positive fibrovascular tissue and adipocytes and little fibrosis. Many intramural coronary arteries were irregularly thickened and partially occluded by segmental intimal and medial deposits of periodic acid-Schiff-positive, Congo red-negative amorphous extracellular material. This finding is consistent with hyaline arteriosclerosis. These vascular lesions likely lead to insufficient perfusion of the affected myocardium and gradual loss of myofibers without the acute necrosis and fibrosis characteristic of infarction.