Cardiovascular Pathology Pt 2 PDF

Cardiovascular Pathology SLIDESMANIA.COM Path 2, Fall 2024 SLIDESMANIA.COM  Post-Mortem Exam Normal in most animals: 4 chambers (2 atria, 2 ventricles) Reptiles: 3 chambers (2 atria, 1 ventricle)...

Cardiovascular Pathology SLIDESMANIA.COM Path 2, Fall 2024 SLIDESMANIA.COM  Post-Mortem Exam Normal in most animals: 4 chambers (2 atria, 2 ventricles) Reptiles: 3 chambers (2 atria, 1 ventricle) Fish: 2 chambers Heart layers: epicardium, myocardium, endocardium 4 valves: Right atrioventricular (tricuspid), pulmonary, left atrioventricular (mitral), and aortic These valves should be thin and shiny. You should be able to see your fingers through them When doing a post-mortem examine the cardiac silhouette, the color, and the walls Cardiac silhouette- is it heart shaped? If not, is that because of the pericardium or the heart SLIDESMANIA.COM itself? Is the heart a normal size and weight? Walls- thickness of the valves, endocardium, and great vessels Make sure you also assess pericardial fluid, the coronary fat, and the coronary vessels Rigor mortis in the heart causes contraction of the walls. The contraction may cause the L ventricle SLIDESMANIA.COM to be empty. Its also normal to see blood clots in the atria and the R ventricle  Post-Mortem Exam IC injections of barbiturates (euthasol): ❖ Barbiturates can precipitate out and create crystalline deposits on or in the heart paleness ❖ May also cause pallor of the myocardium at the injection site ❖ Can cause acute hemopericardium- this is true of any IC injection Bigheardium Pos.EE te onormu uchamnes Epicardium.muacardium.ends SLIDESMANIA.COM in t Barbitalcan c auseminimization Bbodcloti.ee hemonoradiun panorormuccardium SLIDESMANIA.COM  The Pericardium SLIDESMANIA.COM Hydropericardium, hemopericardium, serous atrophy, and pericarditis SLIDESMANIA.COM  The Pericardium A serosal membrane made up of 2 layers that cover the heart and the portion of the great vessels that are most proximal to the heart The parietal pericardium is the outside layer The visceral pericardium= the epicardium, the layer attached to the heart Hemopericardium: Blood in the pericardial sac Ex: hemangiosarcoma in one of the atria that has ruptured Hydropericardium: Transudate in the pericardial sac SLIDESMANIA.COM Ex: mulberry heart disease in pigs Pericardium outerl ayerofthehearti nto2 low serve theoutre Pariene cover SLIDESMANIA.COM c EE te En Fluid sien niinsiss seenin i Hydrocarch Transat mglkp.int  The Pericardium Pericardial hemorrhage: commonly found in animals that were hypoxic, septic, toxemic, electrocuted, had DIC or another coagulopathy, or experienced prolonged agony Petechial, ecchymotic, or paintbrush hemorrhages Serous atrophy of fat: occurs when the animal is an in extreme negative energy balance. The epicardial fat store is mobilized (along with other fat stores like bone marrow, omentum) and grossly looks like jello on the crown of the heart SLIDESMANIA.COM Lymphatics on the epicardial surface may look more prominent P.im iii icE ii Piem E SLIDESMANIA.COM seems near.ee at setih.itoEne lymphaticson msn.in epicam  Pericarditis asize ribimm Peretti.ie You’ll see an enlarged cardiac silhouette and rib imprints on the pericardium It’s characterized according to what kind of exudate is present ❖ Fibrinous- most common Commonly seen in black leg caused by C. chauvoei and traumatic reticulopericarditis/hardware disease Fibrin and purulent exudate in the pericardial sac- called “bread and butter” heart Pericardial sac is going to be thickened SLIDESMANIA.COM ❖ Suppurative/purulent ❖ Fibrinohemorrhagic ❖ Granulomatous inffmitf.int pericardium usccommn gipri SLIDESMANIA.COM iI i E.EE m a E.EE  Constrictive Pericarditis and Cardiac Tamponade ConstructiePericarditis Happens when there is some type of pericardial disease causing an accumulation of fibrin or blood in the pericardial space The stuff in the pericardium stretches it out (distension) When distension is chronic the pericardium becomes fibrous and stiff, decreasing iIiiIi ii EE.it neat man resa isitunavato FullyThe and will heart manycontracts sawa leadstodam its pliability diss orh ereto Faline resoduring Because the pericardium now isn’t distensible, that fluid starts pushing on the dato firm in Bissepeace heart which prevents it from being able to relax fully during diastole→ the heart prolongs diastole to try to increase cardiac output so the HR starts getting slower SLIDESMANIA.COM Each pump of the heart puts more fluid into the pericardial space, worsening the pressure on the heart which in turn makes the heart slow more and more until eventually their heart cannot relax at all anymore or gets too slow and they die 1 a SLIDESMANIA.COM  The Endocardium 0 Valvular degeneration, endocardial fibrosis, edocardial mineralization, SLIDESMANIA.COM valvular cysts, and endocarditis imam E SLIDESMANIA.COM  Valvular Endocardiosis Notit's AKA degenerative valve disease, valvular fibrosis, myxomatous/mucoid valvular degeneration ❖ Age related degeneration of the collagen in the valve ❖ Common in dogs, especially male small-medium breeds Cavalier King Charles have a breed predisposition ❖ Most common cause of CHF in old dogs ii.itiiiE canbe incidence i ❖ It usually affects the mitral valve but can also affect the tricuspid neverprecesneutron Tricanistvalues vaanresuroita.in ❖ It doesn’t always cause problems, a lot of times its an incidental finding Characterized by nodular thickening of the valve which (when severe) prevents the valve from being able to close all the way→ valvular regurgitation SLIDESMANIA.COM a SLIDESMANIA.COM  Endocardial Fibrosis mail.EE Etiiin aaiman It can be localized or diffuse vaiuueenesmecdegnvoma s.thige.be gg e i aim eiincei Localized: also called jet lesions ❖ Abnormal blood turbulence in the atria or ventricles causes tiny mechanical injuries to the endocardium ValuhrEndocardit ❖ Most commonly seen in the atria above a valve with degenerative valve disease ❖ Grossly, the endocardium looks thick and rough in that spot. There’s NO clinical relevance Diffuse: SLIDESMANIA.COM ❖ Secondary to prolonged cardiac dilation ❖ Grossly, the endocardium will look diffusely thickened, rough, and stiff The stiffness will hinder its ability to distend and fill during diastole→ CHF SLIDESMANIA.COM  Endocardial Mineralization ❖ Calcium or other minerals getting deposited in the endocardium and arteries ❖ The endocardium is hard and the surface is rough. You’ll see gritty white plaques. ❖ Metastatic: hypervitaminosis D or hypercalcemia: PVitdo.ca D Eating toxic plants, rodenticide poisoning, cachectic diseases like Johne’s or TB, renal failure, or as part of a paraneoplastic syndrome ❖ Dystrophic: the endocardium is injured and the injured tissue calcifies EEEItaae EE SLIDESMANIA.COM iiE Metastaticavitdicaduto.is East Dystrophic p.gg Engage SLIDESMANIA.COM  Valvular Cysts An incidental finding that’s common in calves, don’t mistake it for a parasitic cyst They can rupture and disappear with no clinical signs Valvularcysts Valvular hematocysts: filled with blood in DDIParasite Incidental calves Valvular lymphocysts: filled with clear fluid HemavlymphoMemo B lose filled lymphoClearfilled Atrial Thrombosis The turbidity of the blood in failing ventricles causes clots to form t.is i Seen in dogs and cats with cardiomyopathies, Syrian hamsters, and some mice SiriHam SLIDESMANIA.COM Endocardial Hemorrhage Petechiae or ecchymoses iii.ittI tii Seen with septicemia, bluetongue virus, infectious canine hepatitis, SLIDESMANIA.COM toxemia, and sometimes just as a result of death in adult cows  Endocarditis ❖ Usually caused by bacteria, the heart is almost never the primary site of Efftia Turbinacoague infection WentFalimdueto ❖ Endocarditis can cause endothelial cell injury, blood turbulence, and dyston valvular Location valueman hypercoaguability→ the animal dies from heart failure due to valve dysfunction aron reach Uncommon ulcer ❖ Named according to location or the gross appearance of the lesions day ten Location: valvular or mural Appearance: vegetative/verrucous or ulcerative ❖ Uncommon in dogs and cats SLIDESMANIA.COM SLIDESMANIA.COM  VegolateValvularEndocarditis Venacavathrombos Vegetative Valvular Endocarditis Also called verrucous valvular endocarditis (verrucous means “warty”) Causes in dogs: Staph. aureus, Strep. spp., or Bartonella spp. Causes in cats: Bartonella spp. or Strep. Spp. NOTSTATU Causes in horses: Strep. equi, Actinobacillus equuli, E. coli, or P. aeruginosa NOTSTAPH Bar Causes in pigs: Strep. suis, E. rhusiopathie, or Staph. sureus that affects the Not Ban mitral valve To Trueperella pyogenes that sets up shop Much more common in cattle! Usually Vegetavalualem on the right AV valve as part of vena caval syndrome/metastatic pneumonia am SLIDESMANIA.COM onRight Chronic lesions can cause the valves to under granulation and mineralization Complete resolution of endocarditis is uncommon R heart vegetative valvular endocarditis: auchc venaam RH L heart vegetative valvular endocarditis: ❖ Valvular distortion will lead to L heart failure spulmthr in SLIDESMANIA.COM ❖ Thrombi will embolize everwhere BUT the lungs ❖ Valvular distortion will lead to R heart failure (common sites are kidney, spleen, myocardium, ❖ Pulmonary thrombosis and metastatic pneumonia are common consequences EEEr brain, and joints) ❖ May cause septal defects or pericarditis as a result of the endocardial inflammation  Ulcerative Valvular Endocarditis Secondary to chronic kidney disease, usually in dogs AKA uremic endocarditis- one of the non-renal lesions of uremia! The urea damages the endocardium and it becomes thick, wrinkled, and ulcerated Sometimes the ulcerated areas will mineralize too You’ll see raised white plaques of fibrous and mineralized tissue on the endocardium This is usually mural endocarditis rather than valvular SLIDESMANIA.COM UlceratieValvular End hen DoD q in somn 2nstocap Uren SLIDESMANIA.COM  The Myocardium Cardiomyopathy, myocardial degeneration, nutritional deficiencies, toxicities, and myocarditis SLIDESMANIA.COM Epi MG SLIDESMANIA.COM End  Cardiomyopathy Structural or functional abnormality of the myocardium THE MYOCARDIUM DOES. NOT. REPLACE. DAMAGED CELLS! DAMAGE IS PERMANENT AND CANNOT BE REPAIRED! Primary cardiomyopathies in animals are idiopathic- these are most common DCM, HCM, restrictive cardiomyopathy, arrhythmogenic R ventricular cardiomyopathy, or nonspecific cardiomyopathy Secondary cardiomyopathies can be caused by genetic defects, nutritional deficiencies, toxins, ischemia, inflammation, thyroid dysfunction, diabetes SLIDESMANIA.COM mellitus, neoplasia, or systemic hypertension SLIDESMANIA.COM  Dilated Cardiomyopathy Dilation will cause decreased contractability→ systolic dysfunction Most commonly affects large and giant breed dogs and is the most common form of cardiomyopathy CS depend on the side affected but can include: cough, dyspnea, depression, weight loss, syncope, murmur, arrhythmia, abdominal distension and occasionally sudden death without preceding signs Gross: cardiomegaly, dilation of any and all chambers, and thin, weak, flabby walls and papillary muscles SLIDESMANIA.COM It can be idiopathic or genetic Saint Bernards, Great Danes, Irish Wolfhounds, Doberman Pinschers, Portuguese Water Dogs + others have a genetic predisposition In general, prognosis for idiopathic and genetic cases is poor SLIDESMANIA.COM laserer mi Cardiomy  Hypertrophic Cardiomyopathy Demitcontractabing DCM Syserby Hypertrophy causes decreased distensability→ diastolic dysfunction 0 Most common form of cardiomyopathy in cats The most common cause of anesthetic death in cats Maincoons Ragdoll Males and females both get it but males tend to be affected at an earlier age o Maine Coons and Ragdolls can have inherited defects in the gene that encodes cardiac myosin binding protein which leads to HCM CS: lethargy, anorexia, dyspnea, tachypnea, murmur, abdominal distension, or jpimiy sudden death SLIDESMANIA.COM Gross: Increased heart mass but it still looks heart shaped, L ventricle is cat thiiiiiiiick (sometimes R ventricle and/or interventricular septum too), atrial maincontror mainian dilation Histo: Cardiomyocytes are arranged in a weaved pattern instead of running SLIDESMANIA.COM parallel to each other  FATE/Saddle Thrombus Feline Aortic ThromboEmbolism A serious, fatal complication of HCM a The disrupted blood flow and damage to the endocardium will cause a thrombus to form in the atrium→ thrombus embolizes to the iliac bifurcation of the abdominal aorta and blocks off blood supply to the limbs CS: extreme pain, cold and paretic hind limbs, weak to absent femoral pulses Their toes may be ischemic and look blue/black ratEI.tnnffftttl.ca FYI: a cool way to diagnose this is by comparing spot BG measurements from a back limb and a SLIDESMANIA.COM front limb- the back limb BG will be drastically lower than the front limb SLIDESMANIA.COM  Restrictive Cardiomyopathy Restrick The myocardium fibroses making it stiff and inflexible→ diastolic failure E Affects the left ventricle- the endocardium fibroses and theHIM heart develops Restrictie excess moderator bands (bands that connect the ventricular septum to the cardiomyopathy papillary muscles) ph Basiallydiastole The fibrosis restricts movement of the heart and leads to L heart failure Might be preceded by endomyocarditis catsa conendocardie Cats are overrepresented but it happens in dogs too Ease Cause is unknown except in cats who have congenital endocardial fibroelastosis SLIDESMANIA.COM Gross: L ventricular hypertrophy, L atrial dilation CS are the same as in HCM but prognosis is worse SLIDESMANIA.COM  Myocardial Degeneration Caused by nutritional deficiencies, toxins, ischemia, metabolic disturbances, inherited diseases, and physical trauma misitiitis Cardiomyocytes are very metabolically active so they tolerate any kind of Verymetabollyach derangement in oxygen or energy supply very poorly soholechi The most common causes in vet med are vitamin E deficiency, ionophore toxicity, gossypol toxicity, and uremia Histo: similar to skeletal muscle. Loss of striation, uptake more stain, swelling, SLIDESMANIA.COM dissolution of sarcoplasma, and nuclear condensation Followed by cardiomyolysis- phagocytes come in and start cleaning up the necrotic junk SLIDESMANIA.COM  Myocardial Necrosis Calcification of the cardiomyocytes is a common feature of degenerative diseases of the myocardium Cardiac muscle DOES. NOT. REPAIR. so necrotic tissue gets replaced by Myscout connective tissue which is not functional as cardiac tissue→ fibrosis Neem Grossly: pale foci in the myocardium that might be calcified Ischemic myocardial necrosis is common in humans but pretty rare in animals SLIDESMANIA.COM Parrots can get it from high seed diets SLIDESMANIA.COM  Nutritional Myopathy- Vit E/Selenium Deficiency AKA White muscle disease in ruminants, mulberry heart disease in pigs Myocardial degeneration and calcification, there may also be hepatocellular necrosis and skeletal muscle degeneration ieiEiT iii ivite.seuniu Antag.me Rapidlygrowing Caused by diets that are low in vitamin E/Selenium, high in polyunsaturated fats, aninnex.abo.tn pro-oxidants, or selenium antagonists Most common in rapidly growing animals and is exacerbated by exercise/stress Can affect fetuses and lead to abortion (fetuses are rapidly growing animals) If you catch it early enough it responds well to treatment SLIDESMANIA.COM The first sign of illness might be sudden death Gross: multifocal areas of necrosis and hemorrhage Histo: fibrinoid necrosis SLIDESMANIA.COM  Toxic Myocardial Necrosis There won’t be cardiomegaly but you’ll still see pale spots where the myocardiocytes have died ❖ Ionophores Monensin is the most common cause Horses are most sensitive ❖ Chemotherapeutic drugs Cyclophosphamide and doxorubicin SLIDESMANIA.COM ❖ Doxycycline ❖ Toxic plants ❖ Cantharidin toxicity Blister beetles that get stuck in the hay when its processed SLIDESMANIA.COM  Myocarditis Usually a systemic hematogenous infection that can be bacterial, viral, or H.sominiztettys.by parasitic It can also be a direct extension of pericarditis or endocarditis Bacterial myocarditis: ❖ H. somni: acute necrotizing and suppurative myocarditis 4Somnilethality b It likes to camp out on the left ventricular papillary muscle for some reason Remember this also causes bronchopneumonia and TME! Viral myocarditis: SLIDESMANIA.COM ❖ Canine parvovirus in young puppies (