= X X ! 2! STARLING S LAW OF FLUID EXCHANGE Or what keeps blood in ya vessels!

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1 VETS4010 Sem1 FinalExamNtes 15% PartA:FinaCampbellCardilgy PartB:AnnThmpsn upperrespiratrytractmedicineand lwerrespiratrytractmedicine,urinarypupd PartC:JacquieRandMendcrinlgy PartD:GregSimmnsMLwerurinarytract PartE:TaniaBanks Upperurinarytractsurgery,Respiratry tractsurgery PartF:Behaviur,behaviurmdificatinandtherapeutics 1

2 PartA:FinaCampbellCardilgy Cardilgy FinaCampbell Samematerialaslastyear Lecture1 Primaryheartdisease Mechanicaldiseasemycardialdisease,valveabnrmalityrshuntcngestiveheartfailurebackwardfailure) Electricaldiseaselwutputfailurefrwardfailure) Cngestiveheartfailure Defn:fluidretainedinrespnsetheartdiseasetypicallymechanicaldisease)whichisidentifiednphysical examinatinrwhichprducescsx Net fluid mvement acrss a membrane STARLING S LAW OF FLUID EXCHANGE Or what keeps bld in ya vessels Cngestiveheartfailure DiseasefLeftsidefheartnetlssffluidfrm vesselsreturningttheleftheartfrmlungsleft sidedcngestivehfandfluidinthelungs Pulmnaryedemaindgs Pleuraleffusinincats CSx:tachypnea,dyspnea,cughingRareincats),cyansisnlyifsevere) DiseaseftherightsideftheheartnetlssfrmvesselsreturningtrightheartfrmbdyRSCHF Ascites Pleuraleffusin Subcutaneusedemarare) Jugularveindistensin Hepatmegalyandhepaticveindistensin CHFtreatmentprinciples 1) ReducebldhydrstaticpressureincapillarybedswhicharedrivingNETmvementffluidutfthevascular space a. Diureticsfrusemide,hydrchlrthiazine,spirnlactne) 2) BluntneurhrmnalactivatintlimitincreasedbldvlumeRAASinitiallyabeneficialthing,butthis cmpensatrymechanismcanbecmeverzealusandcntributetprblemduetincreasedfluid pulmnaryedema) a. AngitensinCnvertingEnzymeInhibitrsACEinhibitrs) 3) Manuallyremvefluidinpleuraifcausingtachypnea/dyspneaandremveascitesifcausing discmfrt/inappetence LwutputfailurerarerthanCHFasbdy smainprirityistmaintainfrwardbldflw) Definitin:InsufficientfrwardbldflwtmeettheO2requirementsfthebdy.Happensnlyifccurs transientlyandabruptlyandcmpensatrymechanismscantcmpensate. 1)EpisdicLwOutputrSYNCOPEfaintingisafrmfthis)transientandprfundreductinincerebral perfusincerebralarterialpressure<25mmhg)whichresultsintransientlssfcnsciusness.mstftenduet severalsecndsfveryrapidrveryslwheartrate. 2)SustainedLwOutput sustainedimpairmentincardiacutputduetsevereheartmuscleweaknesse.g.dcm) rseverebradycardiae.g.thirddegreeavblck)prducessustainedsignsfexerciseintlerance,weaknessand terminalcllapse LwutputfailureTreatmentPrinciples Electricalcausesflwutput: Permeability f the membrane Surface area f the membrane = X X [BHP+IFOP -IFHP-BOP] Outward Inward Ntfrexam Starlingslaw=essentiallywhatkeepsbldinthe vessels Anchringcapacityfalbumininbldiswhatkeeps bldinthevessels+hydrstaticpressureinvessel tryingtfrcebldut.samefrcespresentin extravascularspace Slighttransudatinffluid=takenawayby lymphatics Semipermeablemembrane CHFfailurefveinstryingtdumpbldbackt heart)areimpairedintheircapacitytds hydrstaticpressureinveinsrisesbackstreamt capillarybedsincreasedhpincreasednet transudatinffluidutfcapillariesperivascular spacethatlymphaticscanntdealwith Amplifiedbythefactthatthehearttriest cmpensateraagsisactivatedfrcesyut accumulatemrefluidbld) Increaseslwheartratesby1)psitivechrntrpes2)pacemakerimplantatin Decreaserapidheartratesby1)antiarrythmicmedicatin 2

3 Mechanicalcausesflwutputmuscleistweak):1)psitiveintrpesincreasedcntractilefrce)r2) increasebldvlumewithfluidstincreasesv Cardivascularphysicalexaminatin NrmalMMclur dgshavemreredcellsandcatswillbemrepalenrmally 1)CentralcyansisSpO2<70%)impairedO2uptakevialungslungdisease,pulmnaryedema, hypventilatin);bldbypassinglungsrighttleftcardiacshunt). 2)PeripheralcyansisSpO2100%)excessO2extractinbytissuesduetdecreasedbldflwe.g. thrmbemblismfhindlimbs CRT nrmalis>3sec.capcityfcapillarybedtbereperfusedwithbldncewehaveemptiedthatcapillarybed t/fpartlydeterminedbycardiacutputbutitisalsverynnspecificandprlysensitiveindicatrfheartdisease ascanhaveprperfusintthisreginfrtherreasns.dgmaybedrwningwithpulmnaryedemaandstill havenrmalcrt Cardiacauscultatinveryimprtant) STEPS: 1)placepalmsverleftandrightaxillaandidentifyanythrillvibratincreatedbyabnrmalturbulentbld) reallysubstantialmurmurturbulence) 2)usepalmst feel theapexbeatandthennarrwitdwnt2fingers 3)placestethscpeverapexbeatandlistenthiswillbeatthemitralvalveandatICS5butyuwntneedt cuntttheics) 4)cuntHR 5)evaluaterhythm:regular,regularlyirregular,irregularlyirregular 6)murmurpresent?Ifyes.. 7)mvestethscpecranidrsallymvefrmtheMuptthePandtheAregin)andidentifyhwmurmur intensitychanges:ifmurmurgetssfter,murmurisapical&atapexftheheart).&ifmurmurgetsluder,murmuris basila&atbaseftheheart).murmurissimplyturbulentbldflw.innrmalheart,laminaflwissilent. Nrmal Cardiac Auscultatin Heart Rate: bpm Slwer fr large dgs Faster fr small dgs & puppies Rhythm Regular Regularly irregular in time with respiratin faster during inspiratin) N murmur Synchrnus pulses **Femralpulses Nrmal:strngandsynchrnuswithheartbeat Systlicpumpingut)arterialpressure=120mmHg Diastlicfilling)arterialpressure=80mmHg Pulsepressure=systlicidiastlic=40mmHg Weakpulses:DuetdecreasedPPusuallyprducedbydecreasedsystlicBPsecndarytdecreasedCOe.g. haemrrhagicshckrheartdisease.ntalltdwithheartdisease Bundingpulses:duetincreasedPPprducedbydecreaseddiastlicBPE.g.PDA)rincreasedsystlicBPe.g. sympatheticstimulatin Pulsedeficits heartsundwithutapulse.occurswhenheartcntractsprematurelybefrecmpleteheartfilling. Respiratin Nrmal:neffrtandrate<30bpm TachypneaRR>30bpm)mabeduet:leftsidedCHFpulmnaryedemarpleuraleffusin),rarelyRSCGF pleuraleffusin),anxiety/excitement,respiratrydiseaseupperairwayrlwerairway),neurmusculardisease, metablicdiseasesprducingacidsis Dyspnea *Inspiratrydyspnea pleuraleffusincatswithleftrrightsidedheartfailure,rarelydgswithrightsidedheartfailure) cats canntinspirenrmallysyuseethisreallyprlngedinspiratryphase decreasedpleuralspacemass,fluid,abdminalrgans) bstructinftheurtextrathracic) Expiratryandinspiratrydyspnea Pulmnaryedemadgsrcatswithleftsidedheartfailure Pulmnaryparenchymadisease Jugularveindistensin Returningtrightheartfrmthehead 3

4 " Tx:preclinically,nne. Ifhaspulmnaryedema: Chrnicdiuretics,ACEinhibitrs,pimbendan+/iantihypertensives Acutediuretics,xygen,pimbendan+/iantihypertensives Pulmnaryhypertensin:sildenafil,xygen Supraventriculartachycardia:antiarrythmics Valverepair/replacement:pineeringsurgeryntavailableinAustralia Dilatedcardimypathydilatinfmitralannulus) " Heartmuscleisntpumpingprperly.Thedilatinisthecmpensatryrespnse " Signalment:middleldagedlargegiantbreeddgs.Rareincats. " Aetilgy: inheritedgeneticdefectinmycytestructuralprteine.g.titinindbermans.ifinanni geneticallyeffecteddg,thencnsiderthercausese.g. Taurinedeficiencydefectintaurinehmestasis,deficientdietscats),lambandricediets indgs; drugse.g.dxyrubicin,txins infectiusagentsparvvirus,trpansma) tachycardiainduced thers. " Pathphysilgy:prgressivesystlicdysfunctinftheventricularmycardiumreducedfrward SVstimulatesRAASandSNSfrNaandH2OretentinetctmaintainfrwardSVelevatedLV diastlicandlapressureincreasedbldatendfsystleplustheextrabldvlumefrmthe RAASsystem)LVandLAeccentrichypertrphyDilatin)either1)nrmalisatinfLV diastlicandlapressure.maintenanceffrwardsvr2)mvannulusdilatesandregurgitatin ccurseccentriccapacityeceeededlvdiastlicandlapressurerisespulmnaryvenus pressureandcapillaryhydrstaticpressurerisesandpulmnaryedemaddevelps.tachycardia alsdevelpssecndarytdiseasedmycardimandyuwillseereducedfrwardsvandlwutput signs. " Clinicalutcme:1)CHFleftsided,rightsided,bthleftandright2)Syncpe/suddendeath ventriculartachycardia,ventricularfibrillatin " Dx: Echcardigraphynecessaryfrdefinitivediagnsis;necessarytscreenfrearlyDCM whichmayntbeassciatedwithaheartmurmur;bjectiveassessmentfseverity nrmal fractinalshrtening>25%,nrmalla:arati<1.6.fs%=lvd LVs)/LVdx100.Nedt measurelvdiameterinsystlevsdiastletherelativereductinindimensinbetween systleanddiastleisdescribedas Fractinalshrtening therelativereductinin ventriculardimensin,usually>25% Thracicradigraphs:tidentifypulmnaryedema.Subjectiveassessmentfseverity generalisedcardimegalyandlaenlargementprecedespulmnaryedema.ntsensitiveat identifyingearlydcm. ECG/Hltermnitr:arrhythmiasarecmmnlyassciatedwithDCMatrialfibrillatin, ventricularprematurecmplexes/ventriculartachycardia.indicatedinalldgstidentify ventricularectpywhichmaypseariskfsyncpe/suddendeath.mstsensitivescreening testfrpreclinicaldcmventricularectpy). " Tx: *pimbendandelaysnsetfthedisease Preclinical ACEImaydelaynset Pulmnaryedema diuretics,acei,pimbendan Ascites diuretics,acei,pimbendan,abdmincentesis Ventricularectpy classi,iriiiantiarrythmicse.g.ligncainermexiletinei),atenll II)rslatlII).IfatrialfibrillatinusedigxinplusclassIIatenll)rclassIV Dilitazem).CarefulwithclassIIatiarrhytmicsbetablckers)whichhaveanegative intrpiceffectandmayprecipitate/exacerbateepulmnaryedema. Cngenitalmitralvalvedysplasia " Rarecngenitalheartdefectinlargebreed,yungdgs: " Pathphysilgy:asfrmyxmatusMVDbutdysplasticvalvemayalsbestentic " Tx:medicaltreatmentfrpulmnaryedemaasfrmyxmatusMVD,palliativeballn valvuplastytattenuatestenticmv Mitralvalveendcarditis " Mitralvalveleaksduetbacteriainducedmass 6

5 " Signalment:>5yrs,males,midlargebreeddgs,rareincats,mitraland/rarticvalves.VERYsick dgs. " Pathphysilgy requires: 1)bacteremia usuallytidentified 2)valvularendthelialdamage micrtraumawithnrmalbldflwrhighvelcity bldflwwithcngenitalheartdiseasenotmyxmatusmvd 3)plateletandfibrinadhesintdamagedvalvularendtheliumasanidusfrbacterial invasin 4)bacterialadherence 5)+/iimmunesystemcmprmisee.g.cushings,immunemediateddiseasesduet impairedclearancefnrmaltransientbacteremias " Clinicalutcmes 1)cardiaceffects valvularregurgitatinandcngestiveheartfailure,arrhythmias 2)chrnicimmunestimulatinandimmunemediateddiseasese.g.IMhaemlyticanemia, IMthrmbcytpenia,glermylnephritis,plyarthritis 3)septthrmbemblismtprducereginalinfectin,inflammatinandischaemia CNS,limbs,kidneys,bwel,eye,skinetc " Diagnsis " Treatment:standardmedicalTxfrpulmnaryedemaandarrhythmiasasnecessary;lngtermIV thenral)antibiticsbasednc&s;additinaltxfrmultiirgandisease RightApicalSystlicMurmur Tricuspidvalveregurgitatinventricularseptaldefect).Duringsystle,tricuspidvalveshuldbeclsed. DDx: 1. CBC/ Chemistry/ UA - inflammatry leukgram & reflects affected rgans 2. ECG - Any arrhythmia pssible, nne pathnmnic. 3. ECHO - T identify vegetatin n valve & degree f insufficiency 4. Radigraphs - Pulmnary edema withut LA enlargement if acute 5. Bld culture x 3 - but false negative cmmn 6. Urine, bne marrw, jint aspirate cultures N single test except necrpsy) is definitive. Instead diagnsis is based n Mdified Duke Criteria where a certain cmbinatin f psitive tests are highly prbable fr diagnsis. Myxmatustricuspidvalvedegeneratin " 60%MVnly,10%TVnly,30%MVandTV " signalmentandpathphysilgyasfrmvd " Clinicalutcme:cngestiverightheartfailure " Dx:thracicradigraphsmaybenrmalunlessmderateiseveredisease,echcardigraphyis necessaryfrdefinitivedxandallwsassessmentfseverityraenlargementprecedes cngestivefailure) Dilatedcardimypathyinassciatinwithleftapicalsystlicmurmur) Cngenitaltricuspidvalvedysplasia " Cngenitalheartdefectindgs>cats,largebreedssuchasLabradrs " PathphysilgyasfrAVvalveregurgitatinexceptifstensis " Clinicalutcme:rightheartfailure " Tx:standardfrRHF,palliativeballnvalvulplastyfrstenticvalve Nttricuspidvalveendcariditisbvinesnly) *Ventricularseptaldefectrightsidedmurmurifthehleissmall.Mstcmmnincatsrecngenital heartdefects.bldalwaysflwsdwnapressuregradientstypicallyflwccursfrmlvtrvduring systletprducesystlicmurmur. " Pathphysilgy: 1)bldshuntsfrmLVtRVduringsystlebldejectedfrmRVtlungsand returnstlaandlvlvandlaeccentrichypertrphydilatin)eccentriccapacity exceededlvdiastlicandlapressureriseslefttrightshuntingandcngestive LHFwithmderatetlargeVSD 2)bldshuntsfrmLVtRVduringsystlebldejectedfrmRVtlungsand returstlaandlvpulmnaryhypertensinrvsystlicpressureexceedslv systlicpressureandbldshuntsfrmrvtlvcyansis,cmpensatry plycythemia,exerciseintlerance,dyspnearighttleftshuntingccursless frequentlyandnlywithlargevsd " Treatment:FrLtRshunts: StandardmedicalTxfrpulmnaryedemaplusantihypertensivetreduceshunt fractin) Opensurgicalcrrectinntavailablehere) 7

6 Lecture4:Heartdiseaseinthecat Cardiacauscultatinfcats Sametechniqueasfrdgsexceptthatthemstcmmnmurmursdn tlcalisettheapexrbase Insteadmurmurlcatinisftendescribedas1)sternal2)leftparasternal3)rightparasternal. Nrmal:HR14i220,regular,inncentsystlicmurmurs<gradeV/VIarecmmnbutrequireecgtdistinguishfrm murmursassciatedwithdisease;s1ands2heartsundsnly.nbdisappearancefmurmurdesntmeanitisan inncentmurmur Heartdiseaseinadultcats Mrelikelymuscleratherthanvalvedisrdersfailurermuscletcntractrdilate Mstcmmnishypertrphiccardimypathy Dilated Restricted Unclassified Arrhytmgenicrightventricularcardimypathy Sequelaetheartdisease 1) Cngestiveheartfailure a. *leftsidedheartfailure=pulmnaryedemarpleuraleffusingenerallythisiswhatccursmaybe fluidinneplaceranther b. rightsidedhr=pleuraleffusinandasites 2) Felinearticthrmbemblism 3) Suddendeath Hypetrphiccardimypathy Mstcmmnheartdiseaseincats InheriteddefectinthemysinbindingprteinCgeneandthers SpntaneusCncentrichypertrphyfleftventricle AutsmaldminantinheritanceinMaineCncats Cncentric hypertrphy f the LV Diastlic LV dysfunctin Impaired LA emptying LA pressure rises Cmpensatry LA eccentric hypertrphy LA pressure nrmalizes Felinearticthrmbemblism Pathphysilgy f Cngestive Heart Failure with HCM LA eccentric capacity exceeded Increased LA pressure Increased pulmnary venus & capillary hydrstatic pressure & pulmnary edema OR pleural effusin Feline Artic Thrmbemblism: Pathphysilgy 1. Endthelial Injury Virchw s Triad 2. Hypercagulbility 3. Bld stasis Atriskfrbldcltduetmeeting3criteria endthelialinjury,bldstasisandhypercag. LeftatriumgrwsandremdelsendcardialsurfacefLAisalteredendthelialinjury CatsbynaturefspecieshavehypercagulablecharacteristicswiththerchangesinvitaminB12,plateletcuntetc ThrmbifrmintheLAandemblisedtthe: i artictrifurcatinsuddennsetfcessatinfbldflwtthebacklegs i rightfrelimbr i ther Suddennsetf3Ps 12

7 ECG/Arrythmiasfrm3 rd year WavesfanrmalECG Measuresa+Vedeflectinwhereelectricalsignaltravelsfrm vet+veelectrdeandviceversa Pwave+ve)=atrialdeplarisatincurrentflwsfrmSANinrightatriatAVN)+ve Qwaveive)=earlyventriculardeplarisatinleftendcardialsurfacefseptumisfirsttdeplarise) vefrm LVtRV) Rwave+ve)=ventriculardeplarisatin+veasnetvectristwardstheleftbecause1)herttiltstleftf thraxand2)leftheartwallislargerthanright) Swaveive)=lateventriculardeplarisatinbasalareasfseptumandventriclesdeplarise) vetwards right) Twave+ver ve)=ventricularreplarisatin.outersurfaceftheventriclereplarisesfirst.generally+ve. IntervalsfanrmalECG *PP=timebetweenatrialbeats. *RR=heartbeats.Shuldbethesamebetweenbeats. PR=timebetweenatrialdeplarisatinandventriculardeplarisatin. QT SegmentsfanrmalECG PR=atrialdeplarisatintventriculardeplarisatin.Shuldbeabut0.5secnds0.2secinatrial,0.2in ventricular) *QRScmplex=shuldbepresentfreachPwave.Canbenegativeinhrses. QT TP SettinguptheECGmachine Verticalcalibratin=10mm/mv Hrizntalcalibratinpaperspeed)=25mm/secr50mm/sec.25isstandard.Meansthateachsmallsquareis 0.04secnsandeachlargesquareis0.2secnds. IncnsideringanECG,askthefllwingquestins 1. WhatistheHR?Ifhigh,cnsidertachycardicarrhythmiassuchasventricular&tachycardia,ventricular&fibrillatin ratrial&fibrillatin 2. IstherhythmRRinterval)regularrirregular?Ifirregular,culdbeanAtrial&premature&deplarisatin& 3. IsthereaPwavefreveryQRScmplex?Ifnt,culdbeasecnd&degree&AV&blck. 4. IsthereaQRSfreveryPwave?Ifnt,culdbe2),3),4)r5) 5. Arethewavefrmsnrmalshape?E.g.QRScmplexIfnt,culdbeathird&degree&AV&blck&rVentricular& premature&deplarisatin& 6. MeasurePRandQTintervalsandduratinfQRScmplex.IsthePRintervalcnstantinlength?Ifnt,it mayindicateanatrial&premature&deplarisatin&raventricular&premature&deplarisatin Arrhythmiasfrm3 rd year) OverviewMAnarrhythmiaisanabnrmalityfrhythmresultingfrmaprblemwiththefrmatinfanAPraprblem withprpgatinfanap.canbebrachycardicrtachycardic 1) SecnddegreeAVblck spradiccnductinfapsfrmatriatventriclest/fpwaveswithnqrsfllwing 2) ThirddegreeAVblckinatrialactinptentialsreachtheventriclest/fnrmalPwaveswithspradicQRSthat dn tassciatewithpwavesmuchslwerventriculardeplart/fhr) 3) Atrialprematuredeplarisatin atriumfiresbefrethesan.t/fpwavesburiedintwavesandshrtrrinterval whereapcccurs.canpredispsetatrialfibrillatin. 4) Ventricularprematuredeplarisatinispntaneusdeplarisatininventricles.QRScmplexwideandbizarre andtall.twaveppsiteplarity. 5) Ventriculartachycardia ventriclesbeatatrapidrateduetabnrmalventricularpacemakeravn).qrsregular butwideandbizarre.nrelatinbtwnpandqrs.canleadtventricularfibrillatin 6) Ventricularfibrillatin musclentrefractryssignalreientersexcitedmuscles.nrhyhminecgfanytype. Fatal. 7) Atrialfibrillatin atriantrefractryssignalreientersexcitedmuscles.absencefpwaves,ltsffwaves betweenqrscmplexes.qrsexistbecauseavnisactivatedbyfibrillatinwavesunlikvf)..reducesco10i20%with effectsnexercise. 1) SecnddegreeAVBlck BrachycardicB) 19