Path 1 - Cardio 3

drraythe's version from 2016-03-03 17:15

Myocardial Dilatation & Hypertrophy

Question Answer
When does hypertrophy happen?Intrinsic response to heart failure
What are the 2 types of hypertrophy?(1) Eccentric - (The wall thickness normally ↑ in proportion to the ↑ in chamber radius)
(2) Concentric - (the chamber radius may not change; the wall thickness greatly ↑)
Why does eccentric hypertrophy occur? Examples?↑ blood volume like hypervolemia, valvular insufficiency, septal defects, polycythemia
Explain how eccentric hypertrophy occurs (cellularly) & how it looksChamber dilation occurs as new sarcomeres are added in-series to existing sarcomeres
Why does concentric hypertrophy occur? Examples?↑ blood pressure like valvular stenosis, vascular dz, pulmonary dz, hyperthyroidism in cats, hypertension in cats & dogs
Hypertrophy that hyperthyroidism in cats czs?Concentric (wall thickening)
Explain how concentric hypertrophy occurs (cellularly) & how it looks as a resultWall thickness greatly ↑ as new sarcomeres are added in-parallel to existing sarcomeres
What are some underlying features of cardiac hypertrophy?↑ in cardiomyocyte size
Enhanced protein synthesis
↑ organization of the sarcomere
What's the pathogenesis of cardiac hypertrophy in a healthy myocardium?Stretching of fibers from ↑ work load → fiber hypertrophy if healthy
3 stages of hypertrophy?Initiation
Stable hyperfxn
Deterioration of fxn
What limitations does hypertrophy impose on the heart? (4)(1) Blood supply
(2) Mechanical effect of ↑ muscle mass on fxn of adjacent areas
(3) Loss of compliance of myocardium
(4) Lack of adequate energy production (bc of ↑ myofibril:mitochondria ratio)
Gross appearance of eccentric hypertrophy?Large chamber w/ thinned or normal thickness walls
Rounded shape to heart
Double apex
Gross appearance of concentric hypertrophy?Small chamber w/ thick walls
How does hypertrophy look histologically?Fibers are thick & have large nuclei
Specific dz example of hypertrophy in cattle?"Brisket Dz ", "high altitude Dz" (result of pulmonary arterial hypertension induced by pulmonary hypoxia occurring at high altitude)
Specific dz example of hypertrophy in dogs?Dirofilariasis (HTWMs)
Specific dz example of hypertrophy in cats?Hyperthyroidism
Explain how "brisket dz"/"high altitude dz" in cattle czs hypertrophy (& other problems)Hypoxic conditions >7000ft result in pulmonary hypertension → Rt heart failure w/ subcutaneous edema of the brisket → RV hypertrophy → chronic passive congestion of the liver ("nutmeg liver“)
Explain how dirofilariasis in dogs czs hypertrophyHWs cz pulmonary vascular lesions (arteritis) → produces pulmonary hypertension → RV hypertrophy → Rt heart failure
How does hyperthyroidism in cats czd hypertrophyFxnal thyroidal adenomatous hyperplasia or fxnal adenomas. Hormones cz prominent myocardial hypertrophy (LV)

Cardiomyopathies/Neoplastic Dz

Question Answer
How do you usually dx a cardiomyopathy?Dx by exclusion
What is a cardiomyopathy?Progressive myocardial failure of undetermined cz
What is happening at a cellular level in a cardiomyopathy?Alterations in myocyte sarcomeric proteins
What are the types of cardiomyopathies that CATS get?(1) Dilated (congestive)
(2) Hypertrophic
(3) Restrictive
CATS → DILATED (congestive) cardiomyopathy looks like? WHY?Chambers are dilated, this is bc of a Taurine def.
CATS → HYPERTROPHIC cardiomyopathy looks like? WHY?LV is thickened, appears to be heritable (Persian, Maine coon)
CATS → RESTRICTIVE cardiomyopathy looks like? WHY?Excessive moderator bands or LV endocardial fibrosis
What are lesions of all 3 types (dilated, hypertrophic, restrictive) of cardiomyopathies in cats? (5)Pulmonary congestion & edema
Hepatic congestion
Thromboemboli in aorta, atria, or kidney
Which breeds of dogs are prone to Idiopathic cardiomyopathies & WHICH TYPE?LARGE breed dogs; Dilated/congestive type
How does dilated (congestive) myopathy present in the dog?Dilated ventricles
Multifocal subendocardial necrosis
Extracardiac lesions of congestive failure
2 kinds of cardiomyopathies in dogs?Dilated/congestive type (most common) & (Arrhythmogenic RV cardiomyopathy)
When can cardiomyopathies can be 2⁰?Hereditary
Nutritional deficiency
Endocrine disorders
Physical injury & shock
Neoplastic infiltration
Systemic hypertension
What is the heart base tumor? Usually arise from? WHO’s usually affected? Consequence?CHEMODECTOMAS! Usually arise from the aortic body & is important in dogs. Can produce an obstruction at the base of the heart
Malignant lymphoma → Which parts of the heart most effected? In WHOM? Consequence?Might involve the pericardium & myocardium. Most frequent in CATTLE. May cz cardiac failure
Hemangiosarcoma → WHO? WHERE? What should you know about the 1⁰ tumor?Usually in DOGS in the RA. (+/-) 1⁰ tumor in the SPLEEN
Most common cardiac dzs in the dog? (6)Valvular endocardiosis
Congenital heart dz
Dilated cardiomyopathy
Hemorrhagic pericardial effusion
Cardiac neoplasia
Most common cardiac dzs in the cat? (4)Hypertrophic cardiomyopathy
Dilated cardiomyopathy
Hyperthyroidism-associated hypertrophy
Congenital heart dz
Most common cardiac dzs in the rumi? (6)White Muscle Dz (Selenium-Vit E def)
Cardiotoxicity (Ionophores, Gossypol, Cassia occidentalis, Karwinskia humboldtiana)
Brisket Dz (High Altitude Dz)
Malignant Lymphoma
Most common cardiac dzs in the swine? (3)Mulberry heart dz (Selenium-Vit E def)
Most common cardiac dzs in the horse? (9)Congenital CV Dz (VSD)
Fibrinous pericarditis
Toxic cardiomyopathy (ionophores, white snakeroot)
Endocardial fibrosis & calcification
Valvular endocardiosis
Aortic rupture
Verminous endarteritis
Aorto-iliac thrombosis

Blood vessels - Arteries, Veins, Lymphatics Intro / Ruptures/Aneurysms / Hypertrophy & Hyperplasia / Atherosclerosis / Arteriosclerosis / Medial Calcification

Question Answer
When the vessels respond to injury, there is a complex interaction btwn 2 things?Cellular & non-cellular elements of the vessel wall & cellular & non-cellular elements of the blood
2 major post-mortem changes you will see in the vessels?(1) Imbibition of blood-red staining of the intima by Hb
(2) Clotting - "currant jelly" or "chicken fat" types (May be absent if death from hypoxia)
When might clotting be absent in vessels post-mortem?May be absent if death from hypoxia
What is a congenital anomaly of the vessels?Lymphatic hypoplasia
Lymphatic hypoplasia → What does this congenital problem cz? Who is it hereditary in? What is it called in dogs?Produces Anasarca (generalized edema)
Hereditary in Ayrshire cattle
In dogs its called Hereditary Lymphedema
Where do HORSES usually rupture of a vessel? Why/What happens in a rupture?AORTA! Usually intrapericardial hemorrhage associated w/ exertion
Where do TURKEYS (esp MALES) usually get a rupture of a vessel? Which type & what is the result?Aorta! Often the dissecting type → rupture → exsanguination
Who usually ruptures the CAROTID artery & Why? What is a common CS?HORSES, 2⁰ to guttural pouch mycosis → epistaxis
Who is prone to rupture of the thoracic duct? (Lymph vessel) What condition does this cz?CAT & DOG, results in chylothorax
What czs hypertrophy of the vessels?↑ volume & pressure load
Examples of ↑ volume & pressure load of vessels czing hypertrophy? (8)(1) Uterine arteries in pregnancy
(2) Pulmonary vessels in cardiac shunts
(3) "High altitude dz"
(4) Aelurostrongylus sp (Cat nematode)
(5) Toxocara sp. (round worms)
(6) Dirofilariasis in cats
(7) Ergot & fescue toxicosis
(8) Idiopathic in cats
How do the lesions of hypertrophy of vessels appear?Thick walls, medial hyperplasia
Big cz in cattle & in dogs of vessel hyperplasia?Cattle = Brisket dz
Dog = Dirofilariasis
What is an Aneurysm, what is it a type of?Type of dilation - thin outpouching of arterial wall
3 things can cz an aneurysm?(1) Cu def
(2) Lathyrism (sweet pea toxicosis)
(3) In HORSES, strongylosis (equine intestinal threadworms)
What are Varicosities?(Varicose veins) elongation & dilation of veins
What is Arteriosclerosis?“Hardening of arteries”
What is Atherosclerosis?Atherosclerosis is a specific type of arteriosclerosis & refers to the buildup of fats, cholesterol etc on artery walls (plaques), which can restrict blood flow
2 czs of Atherosclerosis?(1) HypERcholesterolemia
(2) HypOthyroidism
Explain the pathogenesis of ATHEROsclerosis↑ Dietary cholesterol & saturated fat intake → ↑ level of serum LDL → ↑ permeability of endothelium → entry of lipids into wall to form lesions
4 characteristic lesions of ATHEROsclerosis?(1) Fatty streaks on intima (early)
(2) Later, thick rough plaques on intima & adhered thrombi
(3) Accumulation of "foam cells" in intima & media
(4) Fibrosis
What are foam cells? When do you see them?Fat-laden macrophages seen in atherosclerosis. Is an indication of plaque build-up or atherosclerosis
What are the sequelae of atherosclerosis?Thrombosis → Infarction (heart, brain, kidney) → tissue ischemia
Vit D poisoning appears in the vessels as?Medial calcification
Poisoning by plants containing 1,25(OH)2cholecalciferol czs?Medial calcification
Hyperparathyroidism czs what vessel pathology?Medial calcification
How does Mg poisoning affect the vessels?Medial calcification
How does cachexia (John’s Dz) affect the vessels?Medial calcification
Medial calcification can be czd by? (5)(1) Vit D poisoning
(2) Poisoning by plants containing 1,25(OH)2cholecalciferol
(3) Hyperparathyroidism
(4) Mg poisoning
(5) Cachexia (Johne's Dz)
Degeneration & necrosis of vessels → Medial necrosis & hemorrhage: WHERE does this occur, in WHO & what induces it?Occurs in the muscular arteries of DOGS, induced by vasoactive drugs
How can you dx Fibrinoid necrosis histologically?Hyaline degeneration but stains (-) by PAS & fibrin stain
In what dz processes does fibrinoid necrosis occur?"Mulberry Heart Dz"
Edema dz
Cerebrospinal angiopathy in swine
Organic Mercury toxicity

Thrombosis/Embolism, Vasculitis/Lymphangitis

Question Answer
What is the Virchow triad?3 general predisposing conditions to thrombosis/embolism:
(1) Endothelial injury
(2) Alterations in blood flow
(3) Hypercoagulability
Who most commonly gets pulmonary thromboembolism?Dogs & cats
Aortic thromboembolic aka "saddle" emboli usually occur in who, in what condition?Cats & dogs w/ cardiomyopathy
Aorto-iliac thrombosis usually happens in who & in what 2 situations?HORSES
(1) Idiopathic
(2) Verminousstrongylosis (Strongylus vulgaris)
What czs Verminous arteritis in horses?Strongylus vulgaris
Septic embolisms can come from?Vegetative endocarditis (associated w/ presence of fibrinous clots forming on ulcerated surfaces of the valves - usually due to hematogenous bacterial infxn but could be from strongylosis, uremia & trauma)
What is FCEM? Who gets this?Fibrocartilaginous emboli - dog
Thrombosis & embolism → 4 Conditions accompanied by DIC?Hog cholera
G(-) endotoxemia
Who usually gets a thrombosis of caudal vena cava?Cattle
Thrombus vs embolism?Thrombus: An abnormal clot formed in a vessel
Embolus: A floating clot that lodges somewhere
What's good to know about an embolus?Not just a clot!
Could be hair
Fibrin (DIC)
Fibrocartilaginous (CNS)
4 portals of entry for arteries?(1) Hematogenous dissemination
(2) Local extension of suppurative & necrotizing inflammatory processes
(3) Immune-mediated arterial injury
(4) Parasitic migration
2 defense mechanisms of arteries?(1) Constant blood flow thru arteries
(2) Immunologic responses - Humoral & Innate
(same for veins & lymph vessels but w/ constant flow of lymph)
“Canine pain syndrome” can cz what?Arteritis
3 viral czs of arteritis?MCF
3 bacterial czs of arteritis?Salmonellosis
E. coli (hemolytic)
What fungus can cz arteritis?Phycomycosis
What clinical syndrome can cz arteritis?Uremia
What are 2 parasites which can cz arteritis?Strongylosis (horse)
Dirofilariasis (dog)
(Parelaphostrongylus tenuis (meningeal worm) )
What is periarteritis nodosa/ what does it cz? Aka?AKA Beagle pain syndrome
CZS: Arteritis. Small & medium-sized arteries become swollen & dmgd when immune cells attack them (IMMUNE MEDIATED arteritis)
What are the gross lesions of arteritis? Histo?GROSS: Hemorrhage, Edema, Infarction
HISTO: Endothelial necrosis, PMN infiltration of vessel wall, Thrombi
Histophilus somnus czs?TME - thrombotic meningoencephalitis
5 portals of entry for veins?(1) Hematogenous dissemination
(2) Local extension of severe inflammatory processes
(3) Intravenous injxns & indwelling catheters
(4) Parasitic migration
(5) Immune-mediated venous injury
3 main czs of phlebitis?Neonatal umbilical infxn
Faulty IV injxn of irritant material
Local extension from site of inflammation
2 main lesions in Phlebitis?Thrombosis, Embolism
Omphalophlebitis is aka? What usually czs it? What else might be going w/ this dz?Aka NAVAL ILL; A condition characterized by or resulting from inflam/infxn of the umbilical vein
Usually czd by:
Coliforms (like enterobacter or escheria)
Streptococcus sp
T. pyogenes.

Animal may have suppurative polyarthritis (“joint ill”), Septicemia, Umbilical abscess or Hepatic abscess
3 portals of entry for lymph vessels?(1) Hematogenous dissemination
(2) Local extension of severe inflammatory processes
(3) Parasitic migration
What do the lesions of Lymphangitis look like?Edema of limbs, cord-like or nodular masses in subcutis, may ulcerate
Congenital anomaly of the lymphatic system?Lymphatic hypoplasia
Lymphatic hypoplasia can be a congenital condition which leads to what problems? What's the presentation?LYMPHEDEMA
CS = Brawny, Fibrous, nonpitting edema in 1/more limbs
Who does the thoracic duct usually rupture in? What happens after?CATS & DOGS; chylothorax
What is Lymphangiectasia? Where & in who?DILATION of lacteals (lymphatic vessels) in the intestines of dogs. Lacteal dilation czd by congenital malformations in the lymphatic system or 2⁰ to acquired dzs czd by neoplastic or granulomatous intestinal or mesenteric Dz

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