Path 1 - Cardio Review

drraythe's version from 2016-03-04 17:58

Cardio Pathology Intro

Question Answer
What is SequelaeA condition that is the consequence of a previous dz or injury
**Thickness of the walls proportional toPressure in the chamber, left:right ratio = 3:1
**Sig. change in weight or shape of the heartDilation & Hypertrophy
Exception of wall thickness?Apex
The normal heart has a 3 to 5 fold reserve capacity that is achieved by ↑ the heart rate & stroke volume. Long term compensation to ↑ the work load viaMyocardial hyperTROPHY (NEVER HYPERPLASIA)
Sub-lethal injuries or degen?Fatty degen
**Vacuolar degen
- Result in distinctive myocyte alterations
*Pump failureWeak contractility & emptying of chambers impaired filling
Obstruction to forward blood flowValvular stenosis
Vascular narrowing
Systemic or pulmonary hypertension
Regurgitant blood flowVolume overload of chamber behind failing valve (esp. AV Valve)
Shunted blood flows from what congenital defects?Septal defects in heart & shunts btwn blood vessels
Rupture of the heart or a major vesselCardiac tamponade, massive internal hemorrhage
Cardiac conduction disorders (arrhythmias)Failure of synchronized contraction
**Left CHF sequelaePulmonary congestion & edema BEHIND the failing chamber
Czs of Left CHF- Myocardial contractility loss associated w/ myocarditis, myocardial necrosis or cardiomyopathy
- Dysfnx of the Mitral or Aortic valves
- Severe congenital heart dz
**Right CHF sequelaeHepatic congestion (nutmeg liver) & more severe Na & H2O retention than seen w/ LtCHF. Edema is evident predominantly as ventral subcutaneous edema in horses & ruminants, ascites in dogs & ***hydrothorax in cats***
Czs of Right CHF- Pulmonary hypertension
- Cardiomyopathy
- DZ of Tricuspid & Pulmonary valves
*Valentine shapesHorse & Cow
**If the LVis filled w/ clotted blood 15-30 minutes after death is means some kind of?Myocardial dz was present pre-mortem

Embryological Defects & Congenital Anomalies

Question Answer
**Patent Ductus Arteriosus (PDA)- Dogs & Calves
- Calves delayed fnxal closure
**Atrialar Septal Defect (ASD)Patent Foramen Ovale
**Ventricular Septal Defect (VSD)Usually subarotic
**Tetralogy of Fallot (ToF)VSD
PV stenosis
Dextroposed aorta
- 2° RV hypertrophy
**Pulmonary Valve Stenosis (PS)- Pulmonic stenosis, dogs
- May be supravalvular, valvular, or subvalvular
- 2° compensatory RV hypertrophy
Aortic Valve Stenosis (AS)- ***Subaortic stenosis - Pig/Dog
- ***2° compensatory LEFT Ventricular hypertrophy
Valvular hematomasHematocysts of little clinical significance in ruminants
Persistent Right Aortic Arch (PRAA)- Dogs
- Ligamentum arteriosum forms vascular ring over esophagus (stricture → Megaesphagus)
- 5th RAA persists
Transposition of aorta & pulmonary arteriesAbnormality of Great Vessels, Rumies
Sequelae of abnormality of great vessels- Neonatal death
- Gradual cardiac decompensation
- Stunted, cyanosis, exercise intolerance, murmur, CHF
- No clinical dz
Czs of 2° compensatory RIGHT Ventricular hypertrophy? Why?- Pulmonary Valve Stenosis
- Tetralogy of Fallort (ToF)
RIGHT ventricle must work harder to make up for pressure loss
Czs of 2° compensatory LEFT Ventricular hypertrophy? Why?Aortic Valve Stenosis
LEFT ventricle must work harder to make up for pressure loss

Shit that ain't s'posed to be here!

Question Answer
**Hemopericardium definition/czCLOTTED Blood in pericardial sac
- Iatrogenic puncture
- FB (nail, wire)
- Ruptured vessel (aorta of horse) or chamber (post-infarction aneurysm, spontaneous atrial rupture in dogs)
- Rupture of neoplasm
**Hemopericardium lesion1° lesion present, CLOTTED blood in pericardial sac czing compression of the heart (tamponade)
**Hemopericardium sequelaeCardiac failure, shock from compression of atria & inability to fill the chambers
*Hydropericardium definition/czEdema
- Serous pericarditis (uremia, Na/Cl poisoning in chickens)
- Rt CHF
- Obstruction at base of heart
Hydropericardium pathogenesis- ↑ vascular permeability
- ↑ hydrostatic pressure
- Hypervolemia of CHF
Hydropericardium lesionClear yellow fluid distending pericardial sac
Hemorrhagic pericardial effusions- Most frequent in big dogs
- 1° Idiopathic or 2° to hemangiosarcoma
**Differentiate Hemorrhagic Pericardial Effusions from Hemoparicardium?Hemorrhagic Pericardial Eff. = Blood NOT clotted
What pigment may you find in the heart of an elderly animal or an Ayrshire cow/bull?Lipofuscin (age pigment) = Yellow-brown granules in cardiac mm cells

Heart Destruction

Question Answer
Growth disturbancesAtrophy, Hypertrophy
Sub-lethal injuries- Fatty degen
- Lipofuscins (age pigment; Yellow-brown granules)
- Vascular degen
- Fatty infiltration
- Myocytolysis
Lethal injuries- Leukocytic invasion
- Phagocytosis
- Persistence of sarcolemmal tubes of basal lamina
- Severe damage (basal lamina dmg) = fibroblasts = collagen = scarring
Gelatinous Transformation of Fat
(Serious Atrophyof Fat)
Pathogenesis: Anorexia, starvation or cachexia produce mobilization of fat depots
Lesion: Epicardial fat replaced by gray wet gelatinous tissues
Fatty InfiltrationCz: Obesity
Lesion: ↑ lipocytes w/in myocardium
**Fatty DegenCz: Anemia, Toxemia, Cu def
Lesion: Mottled, pale & flabby, Thrush-breast heart, spherical vacuoles in myocytes (Oil Red Stain)
**Myofibrillar DegenAKA: Myocytolysis
Furazolidone Tox in Birds (Flabby Heart)
**Vacuolar DegenCz: Doxorubicin cardiotoxicity, Antivirals & **Anthracyclines
Histo: Sarcoplasmic vaculation due to distention of sarcoplasmic reticulum, moyofibrillar lysis, myocyte atrophy, fibrosis
Vacuolar degen & Myocytolysis result from mitochondrial swelling & disruption
Hyaline/Zenker Necrosis cz- Ischemia
- Vit E, Se deficit (Mulberry Heart Dz=Swine)
- Toxins
- Azoturia (metabolic dz)
- Physical injury or defibrillator shock
- 2° to HeartBrain Syndrome & Excess Catacholamine Release (looks like hyperthyroid cat)
Hyaline/Zenker necrosis grossResponse to toxic insult:
- Normal cell>hyaline
- Necrosis>macrophage invasion>healing w/ fibrosis
- Pale streaks/patches subendocardial & in papillary mm
- Yellow or white dry gritty calcification
- Chronic = Pale collapsed areas of scarring
Hyaline/Zenker Necrosis sequelaeHF death or scarring recovery

Inflammation of the Heart

Question Answer
****Differentiate Valvular EndcardiOsis from EndocardItisEndcardiOsis = Nodular thickenings on valve cusps
- 2° Jet lesions on ultrasound are smooth, firm & thick mitral valve nodules in aging dogs
- ***Most common CHF in older dogs***
Itis = Inflammatory response w/ vegetative growths~
**Fibrinous pericarditis czHematogenous dissemination in strep, pausteurellosis, salmonellosis, histophilus
*Fibrinous pericarditis lesion- Yellow sheet, strands of fibrin on pericardial surface "bread & butter heart", fibrous adhesions if chronic
*Fibrinous pericarditis sequelae- Death from septicemia
- Recovery w/ adhesions or resolution of exudate
**Supperative (Purulent) pericarditis lesionHardware Dz Puncture of pericardium & infection
Distended pericardial sac w/ yellow to white pus thick fibrous pericardium, fetid odor, Foreign Body
Czs of Endocarditis- Hematogenous dissemination of bacteria (Strep)
- Erysipelas (Bacterial skin infection/rash - Trueperella pyogenes, Step. etc)
- IV Catheters
- Phycomycosis (Acute fungi infection)
- Strongylosis (Parasitic Migration)
- Uremia (Vascular endothelial damage)
- Trauma
Endocarditis path- Bacteremia & mechanical stress = valvular endothelia damage = thrombosis & endocarditis = valvular dysfnx & septicemia
Endocarditis sequelaeCardiac Failure from valve disfnx due to vegetative growths & bacteria = death, septic embolism, or recovery
Czs of Myocarditis- Viral (canine PARVO)
- Bacterial
- Protozoan
- Toxoplasmosis, Sarcocytosis, Encephalitozoonosis
- Idiopathic
- Eosinophils myocarditis
- Embolic fragments from vegetative endocarditis
Myocarditis typesAccording to type of exudate:
- Suppurative
- Necrotizing
- Hemorrhagic
- Lymphocytic
- Eosinophilic
Myocarditis outcomesResolution
Residual scar
Progressive damage w/ acute or chronic cardiac failure

Myocardial Dilation & Hypertrophy

Question Answer
What are the underlying features of Myocardial Hypertrophy?- in Cardiomyocyte SIZE~
- Enhanced protein synthesis
- Higher organization of the sarcomere
In Eccentric hypertrophy: Chamber dilation occurs as?New Sarcomeres are added in series to existing sarcomeres to accomodate ↑ workload
Cz of Eccentric hypertrophy↑ blood volume: (too much blood!)
- Hypervolemia
- Valvular insufficiency
- Septal defects
- Polycythemia
Describe Eccentric hypertrophyLarge chamber w/ thinned/normal thickness of walls, rounded shape to heart, double apex
In Concentric hypertrophy: Chamber wall thickness occurs as?New Sarcomeres are added in Parallel to existing sarcomeres to accomodate ↑ workload
Cz of Concentric hypertrophy↑ BP
- Stenosis
- Vascular dz
- Pulmonary dz
- Hyperthyroidism cats
- Hypertension in cats & dogs
Describe Concentric hypertrophySmall chamber, thick walls, Large nuclei
****Brisket Dz****Concentric RT Hypertrophy
- Hypoxia ↑ 7000 feet = PULMONARY HYPERTENSION = RHF SC edema of brisket, NUTMEG LIVER
Difilariasis dogsConcentric Hypertrophy
- Pulmonary vascular lesions (Arteritis) pulmonary hypertension = RV hypertrophy = RHF
HypERthyroid catsConcentric Hypertrophy
Especially LEFT ventricle

Cardiomyopathies & Neoplasms

Question Answer
Most common cardiomyopathy czIdiopathic
What czs Feline Dilated (congestive) cardiomyopathyTaurine def
**Feline Hypertrophic cardiomyopathy appearanceLV THICK, Persians & Maine Coons
Czs: Saddle Thrombus
Restrictive cardiomyopathy in catsExcess moderator bands, LV endocardial fibrosis
Dogs cardiomyopathiesONLY DILATED (congestive)
- Dilated ventricles
- Multifocal subendocardial necrosis
- Extra-cardiac lesions of congestive failure
**Heart base tumorsChemodectomas
- Important in dogs
- Aortic body obstructing heart base
**Malignant LymphomaCattle, peri/myocardium = FAILURE
**HemangiosarcomaMost frequent in dogs
Close to the RA
1⁰ tumor may be in the Spleen


Question Answer
**Arteries ruptured in a horseAorta: Intrapericardial hemorrhage w/ exertion
Carotid: 2° to Guttural Pouch Mycosis, Epistaxis
**Artery rupture in turkeysAorta: Dissecting = rupture = exsang. especially males
Hypertrophy cz↑ vol &/or pressure
Hypertrophy lesionThick walls, medial hyperplasia
Arterial dilation is anAneurysm
AneurysmThin out-pouching of arterial wall subject to rupture
Czs of AneurysmCU deficit
Strongylosis in horses
**Czs of ArteriosclerosisHypercholesterolemia/HypOthyroidism
**Path of Arteriosclerosis↑ permeability of endothelium, High LDL, fats, cholesterol
**Lesion of ArteriosclerosisFat streaks on intima (early)
Later thick rough plagues on intima & adhered thrombi
Accumulation of FOAM CELLS
**Sequalae of ArteriosclerosisTHROBOSIS = INFARCT = TISSUE ISCHEMIA
**Medial CalcificationVit D poisoning
Plant poisoning
Mg poisoning
*Cachexia (Manchester Wasting dz)
Medial necrosis & HemorrhageMuscular arteris of dogs induced by VASOACTIVE DRUGS
**Thombosis/emboli predisposing factors (Virchow's Triad)Endothelial dmg
Altered blood flow
Species: Pulmonary thromboembolismDogs & Cats
Species: Aortic thromboemboli in animals w/ cardiomyopathy (saddle thrombi)Cats & Dogs
*Species: Aorto-iliac thrombosis, verminous or idiopathicHorses
*Species: Verminous Arteritis via Stongylus vulgarisHorses
Spp: fibrocartilaginous emboliDogs
Spp: Thrombosis of Caudal Vena CavaCattle
Conditions accompanied by DICHog cholera, ICH, FIP, G(-) endotoxemia
Czs of arteritisMCF, EVA, FIP
Bacteria (Salmonella/E. coli)
Erysipelas (Bacterial skin infxn)
Phycomycosis (Acute fungal infxn)
Uremia (Nitrogen)
Parasites (Strongylosis/Dirofilariasis)
Periarteritis nodosa CANINE PAIN SYNDROME
Lesion of arteritisHemorrhage
VaricositiesDilation & elongation of veins
OmphaloPHLEBITISNavel ill
Czs of OmphalophlebitisColiforms
Trueperella pyogenes
-May be suppurative polyarthritis (joint ill) septicemia, umbilical abscess, hepatic abcessation
Lymphatic hypoplasiaCongenital anomaly
Produces anasarca or general edema
Ayrshire cattle hereditary
Thoracic duct ruptureDog, Cat, produces chylothorax
LymphangiectasiaDilation of lymph vessels
LymphangitisEdema of limbs, cord like or nodular masses in subcutis (may ulcerate)