Kardiologi

Question 0

SAIM – kap 1 – Nævn objektive tegn på hjerte sygdom?

Answer 0

1) Cardiac murmurs
2) Rytme forstyrrelser
3) Jugular pulsationer
4) Hjerte forstørrelse

Question 1

Slides - Beskriv blodets vej gennem hjertet?

Answer 1

Vena cava, højre atrium, tricuspidalklap, højre ventrikel, pulmonær semilunærklap, lunge, pulmonal-vene, mitralklap, venstre ventrikel, aorta semilunærklap, aorta, kroppen og celler

Question 2

SAIM – kap 1 – Nævn kliniske tegn som kan resultere fra hjertesygdom?

Answer 2

1) Syncope
2) Meget svag eller stærk arteriel puls
3) Hoste
4) Respirationsbsvær
5) Motionsintolerance
6) Abdominal distention
7) Cyanosis
Sygdomme der ikke inkluderer hjertet, kan også fremkalde disse tegn.

Question 3

SAIM – kap 1 – Hvordan vil man undersøge nærmere, når kliniske tegn tyder på en cardiovaskulær sygdom?

Answer 3

Thoracic radiography
Electrocardiography (ECG)
Echocardiography

Question 4

SAIM – kap 1 – Hvornår sker hjertesvigt?

Answer 4

Når hjertet ikke kan opfylde kroppens cirkulatoriske behov tilstrækkeligt, eller kun kan gøre det med en høj venetryk.

Question 5

SAIM – kap 1 – Hvad er skyld i stasen ved højrehjertesvigt, og hvad giver stasen ved venstre hjertesvigt?

Answer 5

Højre = Stasen stammer fra systemisk venøs hypertension og de resulterende stigninger i systemisk kapillær tryk.
Venstre= Stasen giver pulmonær venøs hypertension og ødem..

Question 6

SAIM – kap 1 – Hvorfor fås motionsintolerance ved hjerte sygdom eller svigt?

Answer 6

1) Utilstrækkeligt cardiac output. Impaired skeletmuksle perfusion under motion relateret til vaskulær og metaboliske ændringer som sker over tid.
2) Øget pulmonær vaskulær tryk og ødem.
3) Akut fald i cardiac output forårsaget af arytmier.

Question 7

SAIM – kap 1 – Hvad karakteriserer det kliniske tegn syncope?

Answer 7

Forbigående bevidstløshed associeret med af postural tonus (kollaps) pga utilstrækkelig øxygen eller glukose levering til hjernen.

Syncope kan forveksles med seizure episodes.

Bagben svaghed eller pludselig kollaps.
Lateral recumbency
Stive forben og opisthotonos
Micturition
Vokalisering er alm.
Tonic/clonisk motion, facial fits og defækation er IKKE tegn på syncope!!!!

Question 8

SAIM – kap 1 – Hvordan skelner man mllem syncope anfald, episodisk svaghed og rigtige anfald?

Answer 8

En detaljeret beskrivelse af dyrets adfærd eller aktivitet før kollapset, under kollapset og efter kollapset, samt kende til hvilken medicin den har fået.

Question 9

SAIM – kap 1 – Hvordan tester man for at finde årsagen til forbigående svaghed eller syncope?

Answer 9

ECG (under afslapning, motion og/eller efter motion eller vagal manøvre)
Complete blood count (CBC)
Serum biochemical analysis (incl elektrolytter og glycose)
Neurologisk eksamination
Thoracic radiographs
Hjerteorms test
Echocardiography

Question 10

SAIM – kap 1 – Hvilke cardiovaskulære årsager giver synope?

Answer 10

Typiske=
Forskellige arytmier
Ventrikulær outflow obstruktioner
Cyanotiske congenital hjerte defekter
Acquired sygdomme der fører til dårlig cardiac output (fx dilateret cardiomyopati og alvorlig mitral insufficiens)

Atypiske =
Aktivering af vasodepressor reflekser
Store doser af cardiovaskulære lægemidler (fx vasodilators og diuretika)

Question 12

SAIM - kap 1 - Hvilke dyr får hoste synkope (cough-drop), og hvad indebærer det?

Answer 12

Det forekommer hos nogle hunde med markant venstre arteriel forstørrelse og bronchial kompression, og også hos hunde med primær respiratorisk sygdom.

Akut fald i hjerte fyldning og output under hostet.

Perifer vasodilatation efter hostet.

Øget cerebrospinal væske tryk med intracranial vene kompression.

Question 13

SAIM - kap 1 - Hvad resulterer kongestiv hjerteinsufficiens(CHF) i ?

Answer 13

1) Hoste
2) Tachypnø
3) Dyspnø

Question 14

SAIM - kap 1 - Hoste, tachypnø og dyspnø kan associeres med hvilke sygdomme?

Answer 14

1) Kongestiv hjerteinsufficiens
2) Pulmonær vaskulær sygdom (hund og kat)
3) Pneumonitis pga hjerteorm (hund og kat)
4) Pleural og pericardiel effusioner er nogengange forbundet med hoste.

Hoste forårsaget af hjerte pumonær ødem hos hunde er blød og fugtig, men lyder noglegange som gagging. Modsat er hoste et usædvanlig tegn på pulmonær ødem hos katte.

Tachypnø der udvikler sig til dyspnø forekommer hos både hund og kat.

Question 15

SAIM - kap 1 - Hvilke sygdomme associeres med hoste?

Answer 15

1) Pleural og pericardiel effusioner er nogengange forbundet med hoste.

2) Hoste forårsaget af hjerte pumonær ødem hos hunde er blød og fugtig, men lyder noglegange som gagging. Modsat er hoste et usædvanlig tegn på pulmonær ødem hos katte.
3) Hovedstamme bronchie kompression forårsaget af en alvorlig venstre arteriel forstørrelse kan stimulere hoste (ofte tør eller hacking) hos hunde med kronsik mitral indufficiens, selv uden pulmonær ødem eller kongestion.
4) Hjertebasis tumor
5) Forstørrede hilar lymfeknuder
6) Andre masser der kolliderer med luftvejene kan mekanisk stimulere hoste.

Question 16

SAIM - kap 1 - Hvad ses typisk når respiratoriske tegn er forårsaget af en hjertesygdom?

Answer 16

1) Genereliseret cardiomegali
2) Venstre atrie forstørrelse
3) Pulmonær vene kongestion
4) Lunge infiltrater som løsnes med diuretisk terapi
5) Positiv hjerteorms test

Question 17

SAIM - kap 1 - Hvad bruger man til at skelne hjerte fra ikke-hjerte grunde til respiratoriske tegn?

Answer 17

Fysisk eksamination

Thorax røntgenbilleder

Echocardiogram (hvis muligt)

Elektrocaridiografi (nogengange)

Question 18

SAIM - kap 1 - Beskriv fremgangsmåden for en hjerteundersøgelse?

Answer 18

Question 19

SAIM - kap 1 - Hvad betyder hyperpnø og hvad resulterer det fra?

Answer 19

Det betyder forøget dybde af respirationen.

Resulterer fra:

Hypoxæmi

Hyperkapni

Acidose

Question 20

SAIM - kap 1 - Hvilke symptomer ses ved pulmonær ødem (og også andre pulmonære infiltrater)?

Answer 20

Øget lungestivhed

Hurtig og overfladisk vejrtrækning (tachypnø) = forsøger at minimere arbejdet med at trække vejret.

Øget hvile respirationsfrekvens er en tidlig indikator på pulmonær ødem når der ikke er primær lungesygdom.

Question 21

SAIM - kap 1 - Hvad er forlænget, besværet inspiration er normalt associeret med ?

Answer 21

Øvre luftvejssygdomme (obstruktion)

Question 22

SAIM - kap 1 - Hvad er forlænget ekspiration asssocieret med?

Answer 22

Nedre luftvejs obstruktion eller pulmonær infiltrativ sygdom incl ødem.

Question 23

SAIM - kap 1 - Hvordan reagerer dyr med alvorlig kompromitteret ventilation?

Answer 23

De kan nægt at lægge sig ned. De står eller sidder med albuerne abducted for at tillade maximal ribbens udvidelse.

De vil ikke ligge i lateral(sideleje) eller dorsal recumbency (orthopnø).

De trækker vejret med åben mund (katte).

Katte vil savle (også hunde) pga de sjældent synker og pupillerne kan være dilaterede pga den forhøjet sympatisk tonus.

Question 24

SAIM - kap 1 - Hvad kan giv forhøjet respirationsfrekvens?

Answer 24

Dyspnø

Fornøjelse (exitement)

Feber

Frygt

Smerte

Question 25

SAIM - kap 1 - Hvordan evaluerer man perifer perfusion?

Answer 25

Tjekker slimhindefarver (Mund + vagina/prepuce) og kapillær genopfyldningstid (CRT) (farve skal komme inden for 2 sek).

Hvis de orale slimhinder er pigmenterede, kan okulær konjunktiva evalueres.

Question 26

SAIM - kap 1 - Hvis slimhindefarven vender tilbage efter senere end 2 sek, hvad er det tegn på?

Answer 26

Dehydrering og andre grunde til nedsat cardiac output pga høj perifer sympatisk tonus og vasokonstriktion.

Question 27

SAIM - kap 1 - Hvad er blege slimhinder tegn på?

Answer 27

Anæmi eller perifer vasokonstriktion.

CRT er normal hos anæmiske dyr dog ikke/undtagen når hypoperfusion er tilstede.

Question 28

SAIM - kap 1 - Hvordan undersøger man polycytæmiske katte og hunde for bevis på differential cyanose?

Answer 28

Farven af de caudale slimhinder skal sammenlignes med farven på de orale membraner.

Question 29

SAIM - kap 1 - Hvis petekkier i slimhinderne opdages hos hunde og katte kan det skyldes?

Answer 29

Blodplade forstyrrelser/trombocytforstyrrelser.

Question 30

SAIM - kap 1 - Hvor detekteres ikterus (gulsot) først?

Answer 30

Orale og okulære slimhinder.

Hvis det opdages skal man undersøge nærmere for hæmolyse eller hepatobiliær sygdom.

Question 31

SAIM - kap 1 - Hvornår ses persisterende jugular vene distention?

Answer 31

Hos patienter med:

1) højresidet CHF (pga højreside hjertefyldnings tryk)
2) ekstern kompression af cranial vena cava
3) jugular vene eller craial vene trombose.

Question 32

SAIM - kap 1 - 1) Hvor højt må jugulare pulsationer gå op af halsen når det er normalt?

2) Hvad er grunden till de normale pulsationer?

Answer 32

1) En tredjedel op af halsen fra brystindløbet.
2) Jugular pulsbølger er relateret til atriekontraktion og fyldning.

Question 34

SAIM - kap 1 - Hvornår ses synlige pulsationer (må være over en tredjedel på halsen)?

Answer 34

Hos dyr med:

1) trikuspidal insufficiens (efter den første hjertelys, under ventrikel kontraktion).
2) Tilfælde der forårsager en stiv og hypertrofisk højre ventrikel (lige før første hjertelyd, under atriekontraktion)
3) Arytmier som får atriet til at kontrahere mod lukkede AV klapper (so-called cannon “a” waves).

Question 35

SAIM - kap 1 - Nævn grunde til unormale slimhinde farver?

Answer 35

Question 36

SAIM - kap 1 - Hvad kan skabe en positiv hepatojugular reflux selv uden jugular distension eller pulsationer i hvile.

Answer 36

1) Nedsat højre ventrikel fyldning
2) Reduceret pulmonær blodflow
3) Trikuspidal regurgitation (opstød)

Question 37

SAIM - kap 1 - Hvad mærker man efter ved vurdering af perifere arterielle trykbølger og pulsfrekvensen?

Answer 37

Styrken og regelmæssigheden.

Subjektiv vurdering af pulsstyrken er baseret på forskellen mellem den systoliske og diastoliske arterielle tryk (puls trykket). Når forskellen er stor, føles pulsen stærk.

Question 38

SAIM - kap 1 - 1) Hvad kaldes unormal stærk puls?

2) Hvad kaldes unormal svag puls?

Answer 38

1) Unormal stærk puls kaldes hyperkinetisk.
2) Hypokinetisk. (Tryk forskellen er lille)

Question 39

SAIM - kap 1 - Hvad kan grunden være til mangel på eller svagere puls på den ene side af femur? (man palperer altid begge femorale pulse)

Answer 39

Tromboembolisme

Question 40

SAIM - kap 1 - Hos hvilke dyr er femoral puls svær at palpere?

Answer 40

Katte

Question 41

SAIM - kap 1 - Hvad er grunden til svag puls, stærk puls og meget stærk puls?

Answer 41

Question 42

SAIM - kap 1 - Hvordan vurderer man om der er puls mangel/underskud?

Answer 42

Femoral arterie puls frekvens skal evalueres samtidig med den direkte hjertefrekvens, som måles ved brystvægs palpation eller auskultation. Færre femorale pulse end hjertebank beviser en pulsmangel.

Question 43

SAIM - kap 1 - Hvilke sygdomme kan give puls mangel/underskud?

Answer 43

Forskellige hjerte arytmier pga de får hjertet til at banke før tilstrækkelig ventrikelfyldning er sket.

Question 44

SAIM - kap 1 - Hvor mærkes den stærkeste impuls ved precordiumet?

Answer 44

Under systole over området af venstre apex (lokaliseret ca ved femte intercostalrum nær den costocondrale junction).

Cardiomegali eller en pladsopfyldende masse inden i brystt kan skifte impulset til en unormal lokalisation.

Question 45

SAIM - kap 1 - Hvad kan give nedsat intensitet af det precordiale impuls?

Answer 45

Fedme

Svage hjertekontraktioner

Pericardial effusion (A pericardial effusion is an abnormal amount of fluid between the heart and the pericardium, which is the sac surrounding the heart. )

Intrathorax masser

Pleural effusion

Pneumothorax

Question 46

SAIM - kap 1 - Hvad kan give en stærkere højre precordial impuls?

Answer 46

Normalt er venstre impuls stærkest, men når højre impuls er stærkest skyldes det højre ventrikel hypertrofi eller forskydning af hjertet ind i den højre hemithorax af en masse læsion, lunge atelektase eller bryst deformitet.

Question 47

SAIM - kap 1 - Hvad er et precordieal thrill?

Answer 47

Meget høje hjerte mislyde (murmurs) giver palperbare vibrationer på brystvæggen og dette kaldes precodial thrill. Det føles som en summende følelse på hånden. Det er oftest lokaliseret til området for maximal intensitet af mislyden.

Question 48

SAIM - kap 1 - Hvad kan give unormal væske akkumulering inden i kropshuler eller i subcutis af afhængige områder?

Answer 48

Højresidet CHF.

Question 49

SAIM - kap 1 - Hvordan opdager man effusioner eller subcutane ødemer?

Answer 49

Palpation eller ballottement af abdomen

Palpation af afhængige områder

Perkussion af brystet på det stående dyr.

Question 50

SAIM - kap 1 - Hvad ledsages væskeakkumulering sekundært til højresidig hjertesvigt ofte af?

Answer 50

Unormal jugular vene distension og eller pulsationer, undtagen hvis dyrets cirkulerende blodvolumen er mindsket ved diuretikabrug eller andet.

Hepatomegali og/eller splenomegali kan også ses hos katte og hunde med højresidig hjertesvigt.

Question 51

SAIM - kap 1 - Hvad klassificeres hjertelyde som?

Answer 51

De klassificeres som forbigående lyde (dem af kort varighed) og hjertemislyde (længere lyde der sker under normal stille dele af hjertecyklus).

De beskrives ved frekvens, amplitude af vibrationer (intensitet), varighed og kvalitet.

Question 52

SAIM - kap 1 - Hvordan skal dyret placeres når man lytter på hjertet?

Answer 52

Stående position, så hjertet er i sin normale position.

Question 53

SAIM - kap 1 - Hvad bruges klokken til på stetoskopet?

Answer 53

Det bruges til auskultation af lavere-frekvens lyde som S3 og S4.

Question 54

SAIM - kap 1 - Hvilke hjertelyde er normale og kan høres hos hunde og katte?

Answer 54

S1 (associeret med lukning og spænding af AV klapper og associerede strukturer ved starten af systole).

S2 (associeret med lukning af aorta og pulmonale klapper efter ejection/udslyngning).

De diastoliske lyde (S3 og S4) kan IKKE høres hos normale hunde og katte.

Question 55

SAIM - kap 1 - Hvornår sker systole og diastole?

Answer 55

Systole: Mellem S1 og S2.

Diastole: Efter S2 og indtil næste S1.

Question 56

SAIM - kap 1 - Hvornår sker den precordiale impuls?

Answer 56

Lige efter S1 (systole).

Question 57

SAIM - kap 1 - Hvornår sker den arterielle puls?

Answer 57

Mellem S1 og S2.

Question 58

SAIM - kap 1 - Hvad kan en høj S1 (første hjertelyd) skyldes?

Answer 58

Hunde og katte med en tynd brystvæg, høj sympatisk tonus, tachycardi, systemisk arteriel hypertension eller forkortet PR intervaller.

Question 59

SAIM - kap 1 - Hvad kan en dæmpet Sq skyldes?

Answer 59

Fedme, pericardial effucion, diafragma hernia, dilateret cardiomyopati, hypovolæmi/dårlig vntrikkel fyldning eller pleural effusion.

Question 60

SAIM - kap 1 - Hvad øger intensiteten af S2?

Answer 60

Det øges af pulmonær hypertension fx ved hjerteorms sygdom, en congenital shunt med Eisenmnger’s fysiologi eller cor pulmonale.

Question 61

SAIM - kap 1 - Hvordan kan hjerte arymiter påvirke hjertelyde?

Answer 61

De giver variation i intensiteten eller endda mangel på hjertelyde.

Question 62

SAIM - kap 1 - Hvorfor kan NORMAL fysiologisk opsplitning af S2 høres hos nogle hunde?

Answer 62

Pga variation i slagvolumen under respirationscyklus. Under inspiration forårsager øget venøs return til højre ventrikel forsinket lukning af den pulmonære klap, mens reduceret fyldning af den venstre ventrikel accelererer aorta lukning.

Question 63

SAIM - kap 1 - Hvorfor kan PATOLOGISK fysiologisk opsplitning af S2 høres hos nogle hunde?

Answer 63

Det kan resultere forsinket centrikel aktivering eller forlænget højre ventrikel ejektion sekundær til ventrikel premature beats, højre bundle branch block , en ventrikel eller atrie septum defekt eller pulmonær hypertension.

Question 64

SAIM - kap 1 - Hvad betyder en galloprytme?

Answer 64

Når S3 eller S4 lyd kan høres lyder hjertet som en galloperende hest. Tilstedeværelsen eller mangel på en lydhør S3 eller S4 har dog INTET at gøre med hjertets rytme (Start at hjerteaktivering og intracaridac konduktionsprocessen).

S3 og S4 høres bedst med klokken da de er af lavere frekvens end S1 og S2.

Question 65

SAIM - kap 1 - Hvad betyder en summations gallop?

Answer 65

Når både S3 og S4 hjertelyde er tilstede kan de være superimposed (overlejret), hvilket kaldes en summations gallop.

Question 66

SAIM - kap 1 - beskriv hjertecyklus diagrammet?

Answer 66

C a r d i a c cycle diagram depicting relationships among great vessel, ventricular a n d atrial pressures, ventricular volume, heart sounds, and electrical activation. AP, Aortic pressure; ECG, electrocardiogram; IC, isovolumic contraction; IR, isovolumic relaxation; LVP, left ventricular pressure; LAP, left atrial pressure; LVV, left ventricular volume.

Fig. 1-10 correlates the hemodynamic
events of the cardiac cycle with the E C G and timing of the heart sounds. It is important to understand these events and identify the timing of systole (between S1 and S2) and diastole (after S2 until the next S1) in the animal. The precordial impulse occurs just after S1 (systole), and the arterial pulse between S1 and S2.

Question 67

SAIM - kap 1 - Forklar om S3?

Answer 67

S3 kendes også som S3 gallop eller ventrikulær gallop. Den er associeret med en lav-frekvens vibration ved slutningen af den hurtige ventrikulære fyldningsfase.

A n audible S3 in the dog or
cat usually indicates ventricular dilation with myocardial
failure. The extra sound can be fairly loud or very subtle andis heard best over the cardiac apex. It may be the only aus¬cultable abnormality in an animal with dilated cardiomyopathy.An S3 gallop may also be audible in dogs with advanced valvular heart disease and congestive failure.

Question 68

SAIM - kap 1 - Hvad kan man høre i et dyr med dilateret cardiomyopati?

Answer 68

S3 hjertelyden kan være det eneste auskultative abnormalitet man kan høre.

Question 69

SAIM - kap 1 - Hos hvilke dyr kan man høre en S3 hjertelyd?

Answer 69

Man kan (may) høre det ved dilateret cardiomyopati, og hos hunde med avanceret valvulær hjertesygdom og kongestiv svigt (congestive failure).

Question 70

SAIM - kap 1 - Forklar om S4 hjertelyden?

Answer 70

The S4 gallop, also called an atrial or presystolic gallop, is associated with low-frequency vibrations induced by blood flow into the ventricles during atrial contraction (just after the P wave of the ECG). A n audible S4 in the dog or cat is usually associated with increased ventricular stiffness and hypertrophy, as with hypertrophic cardiomyopathy or hyperthyroidism in cats. A transient S4 gallop of unknown significance is sometimes heard in stressed or anemic cats.

Question 71

SAIM - kap 1 - Hvis en kat eller hund har en lydhør S4, hvad kan dyret så fejle?

Answer 71

Øget ventrikelulær stivhed og hypertrofi, som ved hypertrofisk cardiomyopati eller hyperthyroidisme hos katte.

Question 72

SAIM - kap 1 - Hvornår hører man systoliske klik?

Answer 72

Systolic clicks are mid-to-late systolic sounds that are usually heard best over the mitral valve area. These sounds have been associated with degenerative valvular disease (endocardiosis), mitral valve prolapse, and congenital mitral dysplasia; a concurrent mitral insufficiency murmur may be present.
.

Question 73

SAIM - kap 1 - Hvornår hører man mitral klik?

Answer 73

In dogs with degenerative valvular disease, a mitral click may be the first abnormal sound noted, with a murmur developing over time.

Question 74

SAIM - kap 1 - Hvad hører man ved auskulatation af et dyr med valvulær pulmonær stenose?

Answer 74

A n early systolic, high-pitched ejection sound at the
left base may occur in animals with valvular pulmonic stenosis or other diseases that cause dilation of a great artery. The sound is thought to arise from either the sudden checking of a fused pulmonic valve or the rapid filling of a dilated vessel during ejection.

Question 75

SAIM - kap 1 - Hvordan beskrives hjertemislyde?

Answer 75

Cardiac murmurs are described by their timing within the
cardiac cycle (systolic or diastolic, or portions thereof),
intensity, PMI on the precordium, radiation over the chest
wall, quality, and pitch.

Murmur intensity is arbitrarily graded on a I to VI
scale (Table 1-1). The PMI is usually indicated by the hemi¬ thorax (right or left) and intercostal space or valve area where it is located, or by the terms apex or base. Because murmurs can radiate extensively, the entire thorax, thoracic inlet, and carotid artery areas should be auscultated. The pitch and quality of a murmur relate to its frequency and subjective assessment. “Noisy” or “harsh” murmurs contain mixed frequencies. “Musical” murmurs are of essentially one frequency with its overtones.

Question 76

SAIM - kap 1 - Hvornår forekommer systoliske hjertemislyde?

Answer 76

Systolic murmurs can occur in early
(protosystolic), middle (mesosystolic), or late (telesystolic)
systole or throughout systole (holosystolic).

Question 77

SAIM - kap 1 - Hvornår forekommer diastoliske hjertemislyde?

Answer 77

Diastolic murmurs generally occur in early diastole (protodiastolic) or throughout diastole (holodiastolic). Murmurs at the very end of diastole are termed presystolic.

Question 78

SAIM - kap 1 - hvornår forekommer kontinuerlige hjertemislyde?

Answer 78

Continuous murmurs begin in systole and extend through S2 into all or part of diastole.

Question 79

SAIM - kap 1 - Beskriv de forskellige hjertemislyde?

Answer 79

1) A holosystolic (plateau-shaped)
murmur begins at the time of S1 and is of fairly uniform
intensity throughout systole. Loud holosystolic murmurs
may mask the S1 and S2 sounds. AV valve insufficiency and interventricular septal defects commonly cause this type of murmur because turbulent blood flour occurs throughout ventricular systole.

2) A crescendo-decrescendo or diamondshaped murmur starts softly, builds intensity in midsystole, and then diminishes; S1 and S2 can usually be heard clearly before and after the murmur. This type is also called an ejection murmur because it occurs during blood ejection, usually because of ventricular outflow obstruction.
3) A decrescendo murmur tapers from its initial intensity over time; it may occur in systole or diastole.
4) Continuous (machinery) murmurs occur throughout systole and diastole.

Question 80

SAIM - kap 1 - hvilke systoliske hjertemislyde findes der?

Answer 80

Systolic murmurs can be decrescendo,
holosystolic (plateau-shaped), or ejection (crescendo-
decrescendo) in configuration.

Question 81

SAIM - kap 1 - Forklar om funktionelle hjertemislyde?

Hvor høres de?

Hvordan lyder de?

Hvad kan de skyldes?

Answer 81

Functional murmurs usually are heard best over the left
heartbase. They are usually soft to moderate in intensity and of decrescendo (or crescendo-decrescendo) configuration. Functional murmurs may have no apparent cardiovascular cause (e.g., “innocent” puppy murmurs) or can result from an altered physiologic state (physiologic murmurs). Innocent puppy murmurs generally disappear by the time the animal is approximately 6 months of age. Physiologic murmurs have been associated with anemia, fever, high sympathetic tone, hyperthyroidism, marked bradycardia, peripheral arteriovenous fistulae, hypoproteinemia, and athletic hearts. Aortic dilation (e.g., with hypertension) and dynamic right ventricular outflow obstruction are other conditions associated with systolic murmurs in cats.

Question 82

SAIM - kap 1 - forklar om billedet?

Answer 82

FIG 1-12
The usual point of maximal intensity (PMI) and configuration for murmurs typical of various
congenital and acquired causes are depicted on left (A) and right (B) chest walls. AS, aortic (valvular) stenosis; MVI, mitral valve insufficiency; PDA, patent ductus arteriosus; PS, pulmonic stenosis; SAS, subaortic stenosis; TVI, tricuspid valve insufficiency; VSD, ventricular septal defect. (From Bonagura JD, Berkwitt L: Cardiovascular and pulmonary disorders. In Fenner W , editor: Quick reference to veterinary medicine, ed 2, Philadelphia, 1991, JB Lippincott.)

Question 83

SAIM - kap 1 - Forklar om mitral insufficiens hjertemislyde?

Answer 83

The murmur of mitral insufficiency is heard best at the
left apex, in the area of the mitral valve. It radiates well dorsally and often to the left base and right chest wall. Mitral insufficiency characteristically causes a plateau-shaped murmur (holosystolic timing), but in its early stages the murmur may be protosystolic, tapering to a decrescendo configuration. Occasionally this murmur has a musical or “whoop-like” quality. With degenerative mitral valve disease, murmur intensity is related to disease severity.

Question 84

SAIM - kap 1 - Forklar om systoliske ejektions hjertemislyd?

Hvor høres de?

Hvad skyldes de?

Hvilke findes der?

Answer 84

Systolic ejection murmurs are most often heard at the left
base and are caused by ventricular outflow obstruction,
usually from a fixed narrowing (e.g., subaortic or pulmonic valve stenosis) or dynamic muscular obstruction. Ejection murmurs become louder as cardiac output or contractile strength increases.

Der findes subaorta stenose hjertemislyd, blød nonpatologisk systolisk ejections hjertemislyd og pulmonal stenose hjertemislyd.

Question 85

SAIM - kap 1 - Forklar om subaorta stenose hjertemislyd?

Answer 85

Det er en systolisk ejektions hjertemislyd.

The subaortic stenosis murmur is heard
well at the low left base and also at the right base because the murmur radiates up the aortic arch, which curves toward the right. This murmur also radiates up the carotid arteries and occasionally can be heard on the calvarium.

Question 86

SAIM - kap 1 - Forklar om bløde nonpatologiske systoliske ejections hjertemislyde?

Answer 86

Det er en systolisk ejection hjertemislyd.

Soft (grade I-II/VI), nonpathologic systolic ejection (physiologic) murmurs are common in sight hounds and certain other large breeds; these can be related to a large stroke volume (relative aortic stenosis), as well as breed-related left ventricular outflow tract characteristics.

Question 87

SAIM - Forklar om pulmonal stenose hjertemislyde?

Answer 87

Det er systoliske ejection hjertemislyde.

The murmur of pulmonic stenosis is best heard high at the left base. Relative pulmonic stenosis occurs with greatly increased flow through a structurally normal valve (e.g., with a large left-to-right shunting atrial or ventricular septal defect).

Question 88

SAIM - kap 1 - Hvilke hjertemislyde hører man på højre side af hjertet?

Answer 88

Most murmurs heard on the right chest wall are holosystolic, plateau-shaped murmurs, except for the subaortic stenosis murmur (above).

The tricuspid insufficiency murmur is loudest at the right apex over the tricuspid valve. Its pitch or quality may be noticeably different from a concurrent mitral insufficiency murmur, and it often is accompanied by jugular pulsations.

Ventricular septal defects also cause holosystolic
murmurs. The PMI is usually at the right sternal
border, reflecting the direction of the intracardiac shunt. A
large ventricular septal defect may also cause the murmur of relative pulmonic stenosis.

Question 89

SAIM - kap 1 - Er diastoliske hjertemislyde almindelige hos hunde og katte?

Hvad skyldes de?

Answer 89

Nej.

Aortic insufficiency from bacterial endocarditis
is the most common cause, although congenital malformation or degenerative aortic valve disease occasionally occurs.

These diastolic murmurs begin at the time of S2 and are
heard best at the left base. They are decrescendo in configuration and extend a variable time into diastole, depending on the pressure difference between the associated great vessel and ventricle. Some aortic insufficiency murmurs have a musical quality.

Question 91

SAIM - Forklar om kontinuerlige hjertemislyde?

Hvordan forløber de?

Hvad skyldes de?

Hvor er mislyden højest?

Hvad kan de forveksles med ?

Answer 91

Continuous murmurs. As implied by the name, continuous (machinery) murmurs occur throughout the
cardiac cycle.

They indicate that a substantial pressure
gradient exists continuously between two connecting areas (vessels). The murmur is not interrupted at the time of S2; instead, its intensity is often greater at that time. The murmur becomes softer toward the end of diastole, and at slow heart rates it can become inaudible.

Patent ductus arteriosus (PDA) is by far the most common cause of a continuous murmur.

The PDA murmur is loudest high at the left base above the pulmonic valve area; it tends to radiate cranially, ventrally, and to the right. The systolic component is usually louder and heard well all over the chest. The diastolic component is more localized to the left base in many cases. The diastolic component (and the correct diagnosis) may be missed i f only the cardiac apical area is auscultated.

Continuous murmurs can be confused with concurrent
systolic ejection and diastolic decrescendo murmurs.

Question 92

SAIM - kap 1 - Hvad kan kontinuerlige hjertemislyde forveksles med ?

Answer 92

**Samtidige systoliske ejektioner og diastoliske decrescendo hjertemislyde.. **

But
with these so-called “to-and-fro” murmurs (frem og tilbagegående), the ejection (systolic) component tapers (tilspidses) in late systole and the S2 can be heard as a distinct sound. The most common cause of toand- fro murmurs is the combination of subaortic stenosis with aortic insufficiency. Rarely, stenosis and insufficiency of the pulmonic valve cause this type of murmur.

Likewise,
both holosystolic and diastolic decrescendo murmurs occur occasionally (e.g., with a ventricular septal defect and aortic insufficiency from loss of aortic root support). This also is not considered a true “continuous” murmur.

Question 93

SAIM - kap 2 - Hvad tjekker man med hjerte-radiografi?

Answer 93

Thoracic radiographs are important for assessing overall
heart size and shape, pulmonary vessels, and lung parenchyma, as well as surrounding structures. Both lateral and dorsoventral (DV) or ventrodorsal (VD) views should be obtained.

Question 94

SAIM - kap 2 - Hvordan ser hjertet ud ved et VD (ventrodorsal) view på røntgen fremfor et DV view?

Answer 94

For example, the heart tends to look more elongated on the VD view in comparison with that on the DV view.

In general, better definition of the hilar area and caudal pulmonary arteries is obtained using the D V view.

Question 95

SAIM - kap 2 - Hvordan og hvornår er det bedst at foretag røntgen af hjertet?

Answer 95

High kilovoltage peak (kVp)
and low milliampere (mA) radiographic technique is recommended for better resolution among soft tissue structures. Exposure is ideally made at the time of peak inspiration. On expiration, the lungs appear denser, the heart is relatively larger, the diaphragm may overlap the caudal heart border, and pulmonary vessels are poorly delineated

Use of exposure times short enough to minimize respiratory motion and proper, straight (not obliquely tilted) patient positioning are mportant for accurate interpretation of cardiac shape and size and pulmonary parenchyma.

Question 96

SAIM - kap 2 - Hvad tjekker man først ved røntgenbilleder?

Answer 96

The radiographs should be examined systematically,
beginning with assessment of the technique, patient positioning, presence of artifacts, and phase of respiration during exposure.

Question 97

SAIM - kap 2 - Hvilken betydning har hundes brystformation for røntenbilleder af hjertet?

Answer 97

Chest conformation should be considered when
evaluating cardiac size and shape in dogs because normal cardiac appearance may vary from breed to breed. The cardiac shadow in dogs with round or barrel-shaped chests has greater sternal contact on lateral view and an oval shape on D V or V D view. In contrast, the heart has an upright, elongated appearance on lateral view and a small, almost circular shape on D V or V D view in narrow- and deepchested dogs.

Question 98

SAIM - kap 2 - Hvad skal man huske når man foretager røntgen af hvalpes hjerter?

Answer 98

The cardiac shadow in puppies normally appears slightly
large relative to thoracic size compared with that of adult
dogs.

Question 99

SAIM - kap 2 - Hvad bruger man vertebral heart score til (VHS)?

Answer 99

The vertebral heart score (VHS) can be used as a means
of quantifying the presence and degree of cardiomegaly in dogs and cats, because there is good correlation between body length and heart size regardless of chest conformation.

A VHS between 8.5 to 10.5 vertebrae is considered
normal for most breeds.

Question 100

SAIM - kap 2 - Hvad er forskellen ml. røntgen af hunde og kattehjerter set lateralt fra?

Answer 100

The cardiac silhouette on lateral view in cats is aligned
more parallel to the sternum than in dogs; this parallel positioning may be accentuated in old cats.

Question 101

SAIM - kap 2 - Hvad skal man tænke på når man røntgenfotograferer kattehjerter?

Størrelse?

Answer 101

Radiographic positioning
can influence the relative size, shape, and position of
the heart because the feline thorax is so flexible.

On lateral view the normal cat heart is less than or equal to two intercostal spaces (ICS) in width and less than 70% of the height of the thorax.

On DV view the heart is normally no more
than one half the width of the thorax. Measurement of VHS is useful in cats also. From lateral radiographs in cats, mean VHS in normal cats is 7.5 vertebrae (range 6.7 to 8.1 v).

Question 102

SAIM - kap 2 - Hvad skal man tænke på når man røntgenfotograferer kattekillinger?

Answer 102

In kittens, as in puppies,
the relative size of the heart compared with that of the thorax is larger than in adults because of smaller lung volume.

Question 103

SAIM - kap 2 - Hvad kan give en unormal lille hjerteskygge på røntgen?

Answer 103

An abnormally small heart shadow results from reduced
 venous return (e.g., from shock or hypovolemia). The apex appears more pointed and may be elevated from the sternum.

Question 104

SAIM - kap 2 - Hvad kan en forstørrelse af hjerteskyggen på røntgenbilleder skyldes?

Answer 104

Generalized enlargement of the heart shadow on plain thoracic radiographs may indicate true cardiomegaly or pericardial distention.

With cardiac enlargement, the contours of different chambers are usually still evident, although massive right ventricular (RV) and atrial (RA) dilation can cause a round cardiac silhouette.

Fluid, fat, or viscera within the pericardium tends to obliterate these contours and create a globoid heart shadow.

Question 105

SAIM - kap 2 - Hvlke hjertekamre forstørres ved mitral insufficens?

Answer 105

Mitral insufficiency leads to left ventricular (D7) and left atrial (LA) enlargement;

Question 106

SAIM - kap 2 - Hvilke hjertekamre forstørres ved pulmonær stenose?

Answer 106

Pulmonic stenosis causes RV enlargement, a
main pulmonary artery bulge, and often RA dilation.

Question 107

SAIM - kap 2 - Hvordan ser en forstørret venstre atrium ud på røntgen?

Answer 107

The LA is the most dorsocaudal chamber of the heart. A n enlarged LA bulges dorsally and caudally on
lateral view. There is elevation of the left and possibly right mainstem bronchi; compression of the left mainstem bronchus occurs in patients with severe LA enlargement.

On DV or VD view, the mainstem bronchi are
pushed laterally and curve slightly around a markedly
enlarged LA (sometimes referred to as the “bowed-legged cowboy sign”). A bulge in the 2- to 3-o’clock position of the cardiac silhouette is common in cats and dogs with concurrent left auricular enlargement.

Question 108

SAIM - kap 2 - Hvad påvirker venstre atriums størrelse?

Answer 108

L A size is influenced by the pressure or volume
load imposed, as well as the length of time the overload has been present.

Question 109

SAIM - kap 2 - Hvordan ser venstre ventrikel forstørrelse ud på røntgen?

Answer 109

LV enlargement is manifested on lateral view by a taller
cardiac silhouette with elevation of the carina and caudal
vena cava. The caudal heart border becomes convex, but
cardiac apical sternal contact is maintained. On D V / VD
view, rounding and enlargement occur in the 2- to 5-o’clock position.

Some cats with hypertrophic cardiomyopathy maintain the apical point; concurrent atrial enlargement creates the classic “valentine-shaped” heart.

Question 110

SAIm - kap 2 - Hvad giver generaliseret forstørrelse af hjerteskyggen på røntgen?

Answer 110

Generalized Enlargement of the Cardiac Shadow:

Dilated cardiomyopathy
Mitral and tricuspid insufficiency
Pericardial effusion
Peritoneopericardial diaphragmatic hernia
Tricuspid dysplasia
Ventricular or atrial septal defect
Patent ductus arteriosus

Question 111

SAIM - kap 2 - Hvad giver forstørret venstre atrie på røntgen?

Answer 111

Left Atrial Enlargement:

Early mitral insufficiency
Hypertrophic cardiomyopathy
Early dilated cardiomyopathy (especially Doberman Pinschers)
(Sub)aortic stenosis

Question 112

SAIm - kap 2 - Hvad giver både forstørret venstre atrie og ventrikel på røntgen?

Answer 112

Left Atrial and Ventricular Enlargement:

Dilated cardiomyopathy
Hypertrophic cardiomyopathy
Mitral insufficiency
Aortic insufficiency
Ventricular septal defect
Patent ductus arteriosus
(Sub)aortic stenosis
Systemic hypertension
Hyperthyroidism

Question 113

SAIM - kap 2 - Hvad giver både højre atrie og ventrikelforstørrelse?

Answer 113

Right Atrial and Ventricular Enlargement:

Advanced heartworm disease
Chronic, severe pulmonary disease
Tricuspid insufficiency
Pulmonic stenosis
Tetralogy of Fallot
Atrial septal defect
Pulmonary hypertension (with or without reversed shunting
congenital defect)
Mass lesion within the right heart

Question 114

SAIM - kap 2 - Hvad ses ved højre atrium forstørrelse på røntgen?

Answer 114

RA enlargement causes a bulge of the cranial heart border and widening of the cardiac silhouette on lateral view. Tracheal elevation may occur over the cranial portion of the heart shadow.

Bulging of the cardiac shadow on DV/VD view occurs in the 9- to 11-o’clock position. The RA is largely superimposed (overlejret) over the RV; although differentiation from RV enlargement is difficult, concurrent enlargement of both chambers is common.

Question 115

SAIM - kap 2 - Hvad ses ved højre ventrikel forstørrelse på røntgen?

Answer 115

Right Ventricle
RV enlargement (dilation or hypertrophy) usually causes
increased convexity of the cranioventral heart border and
elevation of the trachea over the cranial heart border on
lateral view.

With severe RV enlargement and relatively
normal left heart size, the apex is elevated from the sternum. The carina and caudal vena cava are also elevated. The degree of sternal contact of the heart shadow is not, by itself, a reliable sign of RV enlargement because of breed variation in chest conformation.

On D V / V D view, the heart tends to take on a reverse-D configuration, especially without concurrent left-sided enlargement. The apex may be shifted leftward, and the right heart border bulges to the right.

Question 116

SAIM - kap 2 - Hvad får aorta og main pulmonær arterien til at dilatere?

Answer 116

Kronisk arteriel hypertension eller øget turbulens (post-stenotisk dilatation).

Subaortisk stenise giver dilatation af ascending aorta. Widening and increased opacity of the dorsocranial heart shadow may be observed.

Patent ductus arteriosus causes a localized
dilation in the descending aorta just caudal to the arch,
which is where the ductus exits; this “ductus bump” is seen on D V or V D view. A prominent aortic arch is more common in cats than dogs.

Question 117

SAIM - kap 2 - Hvad får main pulmonary trunk til at dilatere?

Answer 117

Severe dilation of the main pulmonary trunk (usually
associated with pulmonic stenosis or pulmonary hypertension) can be seen as a bulge superimposed over the trachea on lateral radiograph.

O n D V view in the dog, main pulmonary trunk enlargement causes a bulge in the 1- to 2-o’clock position. In the cat the main pulmonary trunk is slightly more medial and is usually obscured within the mediastinum.

Question 118

SAIM - Hvordan påvirkes vena cava caudalis (CaCV) ved forstørrelse af ventriklerne i hjertet?

Hvad skyldes det?

Answer 118

The CaVC-cardiac junction
is pushed dorsally with enlargement of either ventricle. Persistent widening of the CaVC could indicate right ventricular failure, cardiac tamponade, pericardial constriction, or other obstruction to right heart inflow.

Question 119

SAIM - kap 2 - .Hvad kan en tynd vena cava caudalis skyldes?

Answer 119

A thin CaVC can indicate hypovolemia, poor venous
return, or pulmonary overinflation.

Question 120

SAIM - hvilke 4 pulmonære vaskulære mønstre er normalt beskrevet?

Answer 120

1) Overcirkulation
2) Undercirkulation
3) Prominent pulmonære arterier
4) Prominente pumonære vener

Question 121

SAIM - kap 2 - Hvad skyldes overcirkulation som er en af de 4 pulmonære vaskulære mønstre?

Answer 121

An overcirculation pattern occurs when the lungs are
hyperperfused, as in left-to-right shunts, overhydration, and other hyperdynamic states. Pulmonary arteries and veins are both prominent; the increased perfusion also generally increases lung opacity.

Question 122

SAIM - kap 2 - Hvad skyldes undercirkulation som er en af de 4 pulmonære vaskulære mønstre?

Answer 122

Pulmonary undercirculation is characterized
by thin pulmonary arteries and veins, along with
increased pulmonary lucency. Severe dehydration, hypovolemia, obstruction to right ventricular inflow, right-sided congestive heart failure, and tetralogy of Fallot can cause this pattern. Some animals with pulmonic stenosis appear to have pulmonary undercirculation. Overinflation of the lungs or overexposure of radiographs also minimizes the appearance of pulmonary vessels.

Question 123

SAIM - kap 2 - Hvad skyldesprominente pulmonære arterier som er en af de 4 pulmonære vaskulære mønstre?

Answer 123

Pulmonary arteries larger than their accompanying veins
indicate pulmonary arterial hypertension. The pulmonary
arteries become dilated, tortuous, and blunted, and visualization of the terminal portions is lost. Heartworm disease often causes this pulmonary vascular pattern, as well as patchy to diffuse interstitial pulmonary infiltrates.

Question 124

SAIM - kap 2 - Hvad skyldes prominente pulmonære vener som er en af de 4 pulmonære vaskulære mønstre?

Answer 124

Prominent pulmonary veins are a sign of pulmonary
venous congestion, usually from left-sided congestive heart failure. On lateral view, the cranial lobar veins are larger and denser than their accompanying arteries and may sag ven¬ trally. Dilated, tortuous pulmonary veins may be seen entering the dorsocaudal aspect of the enlarged LA i n dogs and cats with chronic pulmonary venous hypertension. But pulmonary venous dilation is not always visualized i n patients with left-sided heart failure. In cats with acute cardiogenic pulmonary edema, enlargement of both pulmonary veins and arteries can be seen.

Question 125

SAIM - kap 2 - Hvad kan øge pulmonær skyggen (dvs gøre skyggen mere mørk) på røntgen?

Answer 125

Pulmonary interstitial fluid accumulation (pulmonær ødem) increases pulmonary opacity.

The air-filled bronchi appear as lucent, branching lines surrounded by fluid density (air bronchograms).

Question 126

SAIM - kap 2 - Hvor lokaliseres cardiogen pulmonær ødem hos hunde?

Answer 126

Cardiogenic pulmonar edema in dogs is classically located in dorsal and perihilar areas and is often bilaterally symmetric. Nevertheless, some dogs develop an asymmetric or concurrent ventral distribution of cardiogenic edema.

Question 127

SAIM - kap 2 - Hvor lokaliseres cardiogen pulmonær ødem hos katte?

Answer 127

The distribution of cardiogenic
edema in cats is usually uneven and patchy. The infiltrates are either distributed throughout the lung fields or concentrated in the middle zones.

Question 128

SAIM - kap 2 - Hvad påvirker de interstitielle infiltraters alvorlighed?

Answer 128

Both the radiographic technique
and the phase of respiration influence the apparent severity of interstitial infiltrates.

Question 129

SAIM - kap 2 - hvad repræsenterer EKG grafisk?

Answer 129

The electrocardiogram (ECG) graphically represents the
 electrical depolarization and repolarization of cardiac muscle.

Question 130

SAIM - kap 2 - Hvad kan et EKG fortælle om hjertet?

Answer 130

The E C G provides information on heart rate, rhythm, and
intracardiac conduction; it may also suggest the presence of specific chamber enlargement, myocardial disease, ischemia, pericardial disease, certain electrolyte imbalances, and some drug toxicities.

Question 131

SAIM - kap 2 - Hvad kan et EKG alene IKKE fortælle om hjertet?

Answer 131

But the ECG alone cannot be used to make a
diagnosis of congestive heart failure, assess the strength (or even presence) of cardiac contractions, or predict whether the animal will survive an anesthetic or surgical procedure.

Question 132

SAIM - kap 2 - Forklar om EKG’ets QRS kompleks?

Answer 132

The E C G waveforms, P-QRS-T, are generated
as heart muscle is depolarized and then repolarized. The QRS complex, as a representation of ventricular muscle electrical activation, may not necessarily have each individual Q, R, or S wave components (or variations thereof). The configuration of the QRS complex depends on the lead being recorded as well as the pattern of intraventricular conduction.

Question 133

SAIM - kap 2 - Hvad er en ledningsakse?

Answer 133

The orientation of a lead with respect to the heart is called the lead axis.

Each lead has direction and polarity.

Question 134

SAIM - kap 2 - Hvordan fungerer ledningerne i et EKG?

Answer 134

Each lead has a positive and a negative
pole or direction. A positive deflection will be recorded in a lead i f the cardiac activation wave travels toward the positive pole (electrode) of that lead. If the wave of depolarization travels away from the positive pole, a negative deflection will be recorded in that E C G lead.

Question 135

SAIM - kap 2 - Hvordan fungerer bipolære EKG ledninger?

Answer 135

Both bipolar and unipolar
ECG leads are used clinically. A bipolar lead records electrical potential differences between two electrodes on the body surface; the lead axis is oriented between these two points.

Question 136

SAIM - kap 2 - Hvordan fungerer unipolære EKG ledninger?

Answer 136

(Augmented) unipolar leads have a recording electrode
(positive) on the body surface. The negative pole of
the unipolar leads is formed by “Wilson’s central terminal”
(V), which is an average of all other electrodes and is analogous
to zero.

Question 137

SAIM - kap 2 - Hvordan placeres en hund når den skal have foretaget en EKG?

Answer 137

Routine ECG recording is usually done with the animal
placed on a nonconducting surface in right lateral recumbency. The proximal limbs are parallel to each other and perpendicular to the torso.

However, if only heart rate and rhythm
are desired, any recording position can be used.

The animal is gently restrained in position to minimize movement artifacts.

Holding the mouth shut to discourage panting or placing a hand on the chest of a trembling animal may be helpful.

Question 138

SAIM - kap 2 - Hvordan placeres ledningerne ved et EKG?

Answer 138

Front limb
electrodes are placed at the elbows or slightly below, not
touching the chest wall or each other. Rear limb electrodes are placed at the stifles or hocks. With alligator clip or button/plate electrodes, copious E C G paste or (less ideally) alcohol is used to ensure good contact. Communication between two electrodes via a bridge of paste or alcohol or by physical contact should be avoided.

Question 139

SAIM - kap 2 - Hvad er standard kalibreringen der bruges ved EKG?

Answer 139

Standard [1 cm = 1 mV]

The calibration used during the recording must be known to accurately measure waveform amplitude.

A calibration square wave (1 m V amplitude)

The paper speed and lead(s) recorded also must be evident for interpretation.

Question 140

SAIM - Hvordan analyserer man en EKG?

Answer 140

First the paper speed, lead(s) used, and calibration
are identified. Then the heart rate, heart rhythm, and M EA are determined. Finally, individual waveforms are measured.

Individual waveforms and intervals are usually measured
using lead II. Amplitudes are recorded in millivolts and
durations in seconds.

At 50 mm/sec paper speed, each small box equals 0.02 seconds. A deflection from baseline (up or down) of 10 small boxes (1 cm) equals 1 m V at standard calibration.

For example, endurance-trained dogs can have E C G measurements that exceed the “normal” range, probably reflecting the training effects on heart size. Such changes i n nontraineddogs suggest pathologic cardiac enlargement.

Question 141

SAIM - kap 2 - Hvad karakteriserer regelmæssig sinusrytme ved EKG?

Answer 141

Regular sinus rhythm is characterized by less than 10% variation in the timing of the QRS to QRS (or R to R) intervals.

Normally the QRS complexes are narrow and upright in leads II and aVF. However, an intraventricular conduction disturbance or ventricular enlargement pattern may cause them to be wide or abnormally shaped.

Question 142

SAIM - kap 2 - Hvad karakteriserer sinusarytmi på EKG?

Answer 142

Sinus arrhythmia is characterized by cyclic slowing and
speeding of the sinus rate. This is usually associated with
respiration; the sinus rate tends to increase on inspiration
and decrease with expiration as a result of fluctuations in
vagal tone.

There may also be a cyclic change in P-wave
configuration (“wandering pacemaker”), with the P waves
becoming taller and spiked during inspiration and flatter in expiration.

Sinus arrhythmia is a common and normal
rhythm variation in dogs. It occurs in resting cats but is not often seen clinically.

Pronounced sinus arrhythmia is associated with chronic pulmonary disease in some dogs.

Question 143

SAIM - kap 2 - Hvordan definerer man et sinusstop på en EKG?

Answer 143

Sinus arrest is absence of sinus activity lasting at least
twice as long as the animal’s longest expected QRS to QRS interval. A n escape complex usually interrupts the resulting pause i f sinus activity does not resume in time. Long pauses can cause fainting or weakness. Sinus arrest cannot be differentiated with certainty from sinoatrial (SA) block by the surface ECG.

Question 144

SAIM - kap 2 - Hvad betyder ektopiske rytmer?

Answer 144

Impulses originating from outside the sinus node (ectopic
impulses) are abnormal and create an arrhythmia (dysrhythmia).

Ectopic impulses are described on the basis of their general site of origin (atrial, junctional, supraventricular, ventricular) and their timing (Fig. 2-9). Timing refers to whether the impulse occurs earlier than the next expected sinus impulse (premature) or after a longer pause (late or escape). Escape complexes represent activation of a subsidiary pacemaker and function as a rescue mechanism for the heart. Premature ectopic impulses (complexes) occur singly or in multiples; groups of three or more constitute an episode of tachycardia.

Question 145

SAIM - kap 2 - Hvad er et bigeminal mønster?

Answer 145

Det er noget ektopiske rytmer kan gøre. When one premature complex follows each normal QRS, a bigeminal pattern exists; the origin of the premature complexes determines whether the rhythm is described as atrial or ventricular bigeminy.

Question 146

SLIDES - Hvilke kompensatoriske mekanismer findes der for hjertet?

Answer 146

Arterio-venøs iltdifferens
Slagvolumen
Hjertefrekvens

Question 147

Slides - Hvilke hunde får Mitralklapdysplasi?

Answer 147

Bullterrier. > 80 % afficerede hunde

Question 148

Slides - Nævn kongenitale hjertesygdomme hos familiedyr?

:

Answer 148

Kongenitale:
Aortastenose/subaortalstenose
Persisterende ductus arteriosus
botalli
Pulmonalstenose
Ventrikelseptumdefekt
Fallots tetrade
Atrioventrikulære dysplasier
Atrieseptumdefekt
Persisterende højre aortabue

Question 149

Slides - Nævn erhvervede hjertesygdomme hos familiedyr?

Answer 149

Erhvervede:
1. Myxomatøs mitral valvulær sygdom
2. Dilateret kardiomyopati
3. Hypertrofisk kardiomyopati
4. Restriktiv kardiomyopati
5. Arytmogen højre ventrikeldysplasi
6. Myokarditis
7. Endokarditis
8. Aytmier – supra- og ventrikulære
9. Neoplasier
10. Cor pulmonale
11. Perikardiesygdomme
12. Systemisk arteriel hypertension
13. Tromboembolisme
14. Hyperthyreoidisme
15. Parasitære sygdomme f.eks.
angiostrongylose

Question 150

Slides - Hvilke hunde og katteracer har man screeningprogrammer for i DK ifht hjertelidelser?

Answer 150

Echo-group in Denmark
• Newfoundland
• Dogue de Bordeaux
• Cavalier King Charles Sp.
• Boxer
• Irish wolfhound, Great Dane,
Bullterrier
• Voluntary basis
• Cat breeds
• Maine coon, Norwegian forrest
cat, British shorthair ……
• Pawpeds.com

Question 151

SAIM - kap 2 - Hvor udspringer supraventrikulære premature/umodne komplekser fra?

Hvordan ser de ud på EKG’en?

Answer 151

Supraventricular premature complexes are impulses that
originate above the atrioventricular (AV) node, either in the atria or the AV junctional area.

If the specific origin of the ectopic complex(es) is unclear, the more general term supraventricular premature complex (or supraventricular tachycardia) is used.

Because they are conducted into and through the ventricles via the normal conduction pathway, their QRS configuration is normal (unless an intraventricular conduction disturbance is also present).

Question 152

SAIM - kap 2 - Hvad “forårsager” en P-bølge på EKG?

Answer 152

Premature complexes arising within the atria are usually preceded by an abnormal P wave (positive, negative, or biphasic configuration) called a P’ wave.

Question 153

SAIM - kap 2 - Hvad forårsager fysiologisk AV blok?

Answer 153

If an ectopic P’ wave occurs
before the AV node has completely repolarized, the impulse may not be conducted into the ventricles (an example of physiologic AV block).

Question 154

SAIM - kap 2 - Hvad giver en negativ P bølge på EKG’et?

Answer 154

Although P’ waves usually do not
precede junctional complexes, retrograde conduction into
the atria sometimes causes a negative P’ wave to follow, be superimposed on, or even precede the associated QRS complex.

Question 155

SAIM - kap 2 - Hvad kan en nonkompensatorisk pause på EKG’et skyldes?

Answer 155

Supraventricular premature complexes that also depolarize the sinus node reset the sinus rhythm and create a “noncompensatory pause” (i.e., the interval between the sinus complexes preceding and following the premature complex is less than that of three consecutive sinus complexes).

Question 156

SAIM - kap 2 - Hvad kan starte en reentrant supraventrikulær tachycardi (SVT?)? (supraventrikulærte tachycardier)

Hvordan ser EKG’et ud?

Answer 156

A premature supraventricular
or ventricular impulse can initiate reentrant supraventricular tachycardia (SVT).

During episodes of reentrant
SVT in animals with ventricular preexcitation, the PR interval usually normalizes or is prolonged, and retrograde P’ waves may be evident. The QRS complexes are of normal configuration unless a simultaneous intraventricular conduction disturbance is present.

Question 157

SAIM - kap 2 - Hvad forårsager atriel tachycardi?

Answer 157

Atrial tachycardia is caused by rapid discharge of an
abnormal atrial focus or by atrial reentry (repetitive activation caused by conduction of the electrical impulse around an abnormal circuit within the atria).

Atrial tachycardia can be paroxysmal or sustained. It is
usually a regular rhythm unless the rate is too fast for the AV node to conduct every impulse, in which case physiologic AV block and irregular ventricular activation result.

Question 158

SAIM - kap 2 - Hvad kan give en bundle branch block pattern på EKG’et?

Answer 158

(Atrie tachycardi) Sometimes the impulses traverse the AV node but are delayed within the ventricular conduction system, causing a bundle branch block pattern on the ECG.

(Supraventrikulær tachycardi) In some cases, the premature impulse is conducted slowly (prolonged P ‘Q interval) or with a bundle branch block pattern.

(Atrieflimren) Minor variation in QRS complex amplitude is common, however, and intermittent or sustained bundle branch blocks can occur.

(intraventrikulære ledningsforstyrrelser) Left bundle branch block (LBBB) is usually related to clinically relevant underlying left ventricular disease. The left anterior fascicular block (LAFB) pattern is common in cats with hypertrophic cardiomyopathy.

Question 159

SAIM - kap 2 - Hvad er atrieflagren (atrial flutter) og hvordan ser det ud på EKG’et?

Answer 159

Atrial flutter is caused by a very rapid (usually greater than 400 impulses/min) wave of electrical activation regularly cycling through the atria. The ventricular response may be irregular or regular, depending on the pattern of AV conduction. The E C G baseline consists of “sawtooth” flutter waves that represent the fast, recurrent atrial activation. Atrial flutter is not a stable rhythm; it often degenerates into atrial fibrillation or may convert back to sinus rhythm.

Question 160

SAIM - kap 2 - Hvad er atrieflimren og hvordan ser det ud på EKG’et?

Answer 160

This common arrhythmia is characterized by rapid and
chaotic electrical activation within the atria. There are no P waves on the E C G because there is no uniform atrial depolarization wave. Rather, the baseline usually shows irregular undulations (fibrillation waves).Lack of organized electrical activity **prevents meaningful atrial contraction. **The AV node, being bombarded by chaotic electrical impulses, conducts as many as possible to the ventricles. Ultimately the (ventricular) heart rate is determined by AV conduction velocity and recovery time, which are influenced by prevailing autonomic tone.

Atrial fibrillation (AF) causes an irregular heart rhythm that is often quite rapid

The QRS complexes are usually normal in configuration because intraventricular conduction pathway is usually normal.

Question 161

SAIM - kap 2 - Hvad giver atrieflimren?

Answer 161

A F tends to be a consequence of severe
atrial disease and enlargement in dogs and cats; it is usually preceded by intermittent atrial tachyarrhythmias and perhaps atrial flutter. AF sometimes occurs spontaneously in giant breed dogs without evidence of underlying heart disease (“lone” AF). The heart rate can be normal in these dogs.

Question 162

SAIM - kap 2 - Hvad er ventrikulær umodne komplekser og hvordan ser de ud på EKG’er?

Answer 162

Ventricular premature complexes (VPCs or PVCs) originate below the AV node and do not activate ventricular muscle via the normal ventricular conduction pathway. Therefore their QRS configuration differs from the animal’s sinus complexes.

Ventricular ectopic complexes are usually wider
than sinus-origin complexes because of slower intramuscular conduction. Because VPCs usually are not conducted backward through the AV node into the atria, the sinus rate continues undisturbed; thus the V P C is followed by a “compensatory pause” in the sinus rhythm.

When the configuration
of multiple VPCs or ventricular tachycardia is consistent
in an animal, the complexes are described as being uniform, unifocal, or monomorphic. When the VPCs occurring in an individual have differing configurations, they are said to be multiform or polymorphic. Increased electrical instability may accompany multiform VPCs or tachycardia.

Question 163

SAIM - kap 2 - Hvad er ventrikulær tachycardi og hvordan ser det ud på EKG’et?

Answer 163

Ventricular tachycardia consists of a series of VPCs (usually at a rate greater than 100 beats/min). The RR interval is most often regular, although some variation can occur. Noncon¬ ducted sinus P waves may be superimposed on or between the ventricular complexes, although they are unrelated to the VPCs because the AV node and/or ventricles are in the refractory period (physiologic AV dissociation).

Question 164

SAIM - kap 2 - Hvad betyder capture beat?

Answer 164

The term capture beat refers to the successful conduction of a sinus P wave into the ventricles uninterrupted by another V P C (i.e., the sinus node has “recaptured” the ventricles).

Question 165

SAIM - kap 2 - Hvad er fusionskomplekser, og hvornår sker de? EKG

Answer 165

If the normal ventricular activation sequence is interrupted by a VPC, a “fusion” complex can result. A fusion complex represents a melding of the normal QRS configuration and that of the VPC (see Fig. 2-10, E). Fusion complexes are often observed at the onset or end of a paroxysm (anfald) of ventricular tachycardia; they are preceded by a P wave and shortened PR interval.

Identification of P waves (whether conducted or not) or fusion complexes helps in differentiating ventricular tachycardia from SVT with abnormal (aberrant) intraventricular conduction.

Question 166

SAIM - kap 2 - hvad er polymorf ventrikulær tachycardi og hvordan ser det ud på EKG’et?

Answer 166

Polymorphic ventricular tachycardia is characterized by
QRS complexes that vary in size, polarity, and often rate;
sometimes the QRS configuration appears as i f it were rotating around the isoelectric baseline. Torsades de pointes is a specific form of polymorphic ventricular tachycardia associated with Q-T interval prolongation.

Question 167

SAIM - kap 2 - hvad er accelerert ventrikulær

Answer 167

Also called idioventricular tachycardia, accelerated ventricular rhythm is a ventricular-origin rhythm with a rate of about 60 to 100 beats/min in the dog (perhaps somewhat faster in the cat). Because the rate is slower than true ventricular tachycardia, it is usually a less serious rhythm disturbance.

An accelerated ventricular rhythm may appear intermittently during sinus arrhythmia, as the sinus rate decreases; the ventricular rhythm is often suppressed as the sinus rate increases. This is common in dogs recovering from motor vehicle trauma. Often this rhythm disturbance has no deleterious effects, although it could progress to ventricular tachycardia, especially in clinically unstable patients.

Question 168

SAIM - kap 2 - Hvad er ventrikelflimren og hvordan ser det ud på EKG?

Answer 168

Ventricular fibrillation is a lethal rhythm that is characterized by multiple reentrant circuits causing chaotic electrica activity in the ventricles; the E C G consists of an irregularly undulating baseline (Fig. 2-12). The ventricles cannot function as a pump because coordinated mechanical activity cannot occur in the presence of incoordinated electrical activation. Ventricular flutter, which appears as rapid sine-wave activity on the ECG, may precede fibrillation. “Course” ventricular fibrillation (VF) has larger E C G oscillations than “fine”VF.

Question 169

SAIM - kap 2 - Hvad er Escape komplekser?

Answer 169

Ventricular asystole is the absence of ventricular electrical (and mechanical) activity. Escape complexes and escape rhythms are a protective mechanism. An escape complex occurs after a pause in the dominant (usually sinus) rhythm.

Escape activity originates from automatic cells within the atria, the AV junction, or the ventricles.

It is important to differentiate escape from premature complexes. Escape activity should never be suppressed with antiarrhythmic drugs.

Question 170

SAIM - kap 2 - Forklar om ledningsforstyrrelser i hjertet?

Answer 170

Abnormal impulse conduction within the atrium can occur
at several sites.

1) Wit h sinoatrial (SA) block, impulse transmission from the SA node to the atrial muscle is prevented. Although this cannot reliably be differentiated from sinus arrest on the ECG, with SA block the interval between P waves is a multiple of the normal P to P interval. A n atrial, junctional, or ventricular escape rhythm should take over after prolonged sinus arrest or block.

Atrial standstill occurs when diseased atrial muscle prevents normal electrical and mechanical function, regardless of sinus node activity; consequently, a junctional or ventricular escape rhythm results and P waves are not seen. Because hyperkalemia interferes with normal atrial function, it can mimic atrial standstill.

Question 171

SAIM - kap 2 - Hvad kan give ledningsforstyrrelser i AV knuden?

Answer 171

Abnormalities of AV conduction can occur from:

1) excessive vagal tone

2) drugs (e.g., digoxin, xylazine, medetomidine,
verapamil, and anesthetic agents)

3) organic disease of the AV node and/or intraventricular conduction system.

Question 172

SAIM - kap 2 - Hvilke tre kategorier af AV knude ledningsforstyrrelser findes der?

Answer 172

Threecategories of AV conduction disturbances are commonly described (Fig. 2-13).

1) First-degree AV block, the mildest, occurs when conduction from the atria into the ventricles is prolonged. All impulses are conducted, but the PR interval is longer than normal.
2) Second-degree AV block is characterized by intermittent AV conduction; some P waves are not followed by a QRS complex. When many P waves are not conducted, the patient has high-grade second-degree heart block. There are two subtypes of second-degree AV block.

• Mobitz type I (Wenckebach) is characterized by progressive
  prolongation of the PR interval until a nonconducted P wave occurs; it is frequently associated with disorders within the AV node itself and/or high vagal tone.

- Mobitz type II is characterized by uniform PR intervals preceding the blocked impulse and is thought to be more often associated with disease lower in the AV conduction system (e.g., bundle of His or major bundle branches).

• A n alternative classification of second-degree AV block based on QRS configuration has been described. Patients with type A second-degree block have a normal, narrow QRS configuration; those with type B second-degree block have a wide or abnormal QRS configuration, which suggests diffuse disease lower in the ventricular conduction system. Mobitz type I AV block usually is type A, whereas Mobitz type II frequently is type B. Supraventricular or ventricular escape complexes are common during long pauses in ventricular activation.
  3) Third-degree or complete AV block is complete failure of AV conduction; no sinus (or supraventricular) impulses are conducted into the ventricles. Although a regular sinus rhythm or sinus arrhythmia is often evident, the P waves are not related to the QRS complexes, which result from a (usually) regular ventricular escape rhythm.

Question 173

SAIM - kap 2 - Hvornår sker intraventrikulære ledningsforstyrrelser?

Answer 173

Abnormal (aberrant) ventricular conduction occurs in association with slowed or blocked impulse transmission in a major bundle branch or ventricular region. The right bundle branch or the left anterior or posterior fascicles of the left bundle branch can be affected singly or in combination. A block in all three major branches results in third-degree (complete) heart block. Activation of the myocardium served by the blocked pathway occurs relatively slowly, from myocyte to myocyte; therefore the QRS complexes appear wide and abnormal.

Right bundle branch block (RBBB) is sometimes identified in otherwise normal dogs and cats, although it can occur from disease or distention of the right ventricle.

Left bundle branch block (LBBB) is usually related to clinically relevant underlying left ventricular disease.

The left anterior fascicular block (LAFB) pattern is common in cats with hypertrophic cardiomyopathy.

Question 174

SAIM - kap 2 - Hvad menes med ventrikulær præexcitation og hvorfor sker det? Hvordan ser det ud på EKG?

Answer 174

Early activation (preexcitation) of part of the ventricular
 myocardium can occur when there is an accessory conduction pathway that bypasses the normal slow-conducting AV nodal pathway. Several types of preexcitation and accessory pathways have been described. Most cause a shortened PR interval.

Wolff-Parkinson-White (WPW) preexcitation is
also characterized by early widening and slurring of the QRS by a so-called delta wave (Fig. 2-15). This pattern occurs because the accessory pathway (Kent’s bundle) lies outside the AV node (extranodal) and allows early depolarization (represented by the delta wave) of a part of the ventricle distant to where normal ventricular activation begins.

The presence of the WPW pattern on ECG in conjunction with reentrant supraventricular tachycardia that causes clinical signs characterizes the W PW syndrome.

Other accessory pathways connect the atria or dorsal areas of the AV node directly to the bundle of His. These cause a short PR interval without early QRS widening.

Question 175

SAIM - kap 2 - Hvad er det farlige ved ventrikulær præexitation?

Answer 175

Preexcitation can be intermittent or concealed (not evident on ECG). The danger with preexcitation is that a reentrant supraventricular tachycardia can occur using the accessory pathway and AV node (also called AV reciprocating tachycardia).

Usually the tachycardia impulses travel into the ventricles via the AV node (antegrade or orthodromic conduction) and then back to the atria via the accessory pathway, but sometimes the direction is reversed. Rapid AV reciprocating tachycardia can cause weakness, syncope, congestive heart failure, and death.

Question 176

SAIM - kap 2 - Hvad beskriver mean electrical axis (MEA)?

Answer 176

The mean electrical axis (MEA) describes the average direction of the ventricular depolarization process in the frontal plane. It represents the summation of the various instantaneous vectors that occur from the beginning until the end of ventricular muscle activation. Major intraventricular conduction disturbances and/or ventricular enlargement patterns can shift the average direction of ventricular activation and therefore the MEA. Only the six frontal plane leads are used to determine MEA.

Question 177

SAIM - kap 2 - Hvad skyldes ændringer i EKG kurver?

Answer 177

Changes in the ECG waveforms can suggest enlargement or abnormal conduction within a particular cardiac chamber. However, enlargement does not always produce these changes.

Question 178

SAIM - kap 2 - Hvordan ser EKG ud ved LA forstørrelse?

Answer 178

A widened P wave has been associated with LA
enlargement (p mitrale); sometimes the P wave is notched
as well as wide.

Question 179

SAIM - kap 2 - Hvordan ser EKG ud ved RA forstørrelse?

Answer 179

Tall, spiked P waves (p pulmonale) can
accompany RA enlargement.

Question 180

SAIM - kap 2 - Hvordan ser EKG ud ved atrie forstørrelse?

Answer 180

With atrial enlargement, the usually obscure atrial repolarization (T_a) wave may be evident as a baseline shift in the opposite direction of the P wave.

Question 181

SAIM - kap 2 - Hvordan ser EKG ud ved RV forstørrelse?

Answer 181

A right-axis deviation and an S wave in lead I are strong
criteria for RV enlargement (or RBBB). Other ECG changes can usually be found as well. Three or more of the criteria listed in Box 2-4 are generally present when right ventricular enlargement exists. RV enlargement (dilation or hypertrophy) is usually pronounced if it is evident on the ECG because LV activation forces are normally so dominant.

Box 2-4:

Right Ventricular Enlargement:

Right-axis deviation
S wave present in lead I
S wave in V2-3 larger than R wave or >0.8 mV
Q-S (W shape) in V10
Positive T wave in lead V10 (except Chihuahua breed)
Deep S wave in leads II, III, and aVF

Question 182

SAIM - kap 2 - Hvordan ser EKG ud ved LV forstørrelse?

Answer 182

LV dilation and eccentric hypertrophy (see Chapter 3) often increase R-wave voltage in the caudal leads (II and aVF) and widen the QRS. LV concentric hypertrophy inconsistently produces a left-axis deviation.

Box 2-4:
Left Ventricular Hypertrophy:

Left-axis deviation
R wave in lead I taller than R wave in leads II or aVF
No S wave in lead I

Question 183

SAIM - kap 2 - Hvordan ser EKG ud ved ledningsforsinkelse?

Answer 183

Conduction block in the major ventricular conduction
pathways disturbs the normal activation process and alters
QRS configuration. Electrical activation of ventricular
muscle regions served by a diseased bundle branch occurs late and progresses slowly. This widens the QRS complex and shifts the terminal QRS orientation toward the area of delayed activation.

Question 184

SAIM - kap 2 - Hvis amplituden af QRS-komplekserne bliver mindre, hvad kan det skyldes?

Answer 184

Small-voltage QRS complexes sometimes occur. Causes of reduced QRS amplitude include pleural or pericardial effusions, obesity, intrathoracic mass lesions, hypovolemia, and hypothyroidism. Small complexes are occasionally seen in dogs without identifiable abnormalities.

Question 185

SAIM - kap 2 - Hvad er ST-segmentet på et EKG?

Answer 185

The ST segment extends from the end of the QRS complex (also called the J-point) to the onset of the T wave. In dogs and cats this segment tends to slope into the following T-wave, so clear demarcation is uncommon.

Question 186

SAIM - kap 2 - Hvad kan ændringer i ST-segmentet på et EKG skyldes, og hvordan ser det ud på EKG’et?

Answer 186

Abnormal elevation or depression of the J point and ST
segment in leads I, II, or aVF may be significant and can be caused by ischemia and other types of myocardial injury.

Atrial enlargement or tachycardia can cause pseudode¬
pression of the ST segment because of prominent T_a waves.

Other secondary causes of ST segment deviation include
ventricular hypertrophy, slowed conduction, and some drugs (e.g., digoxin).

Question 187

SAIM - kap 2 - Hvad repræsenterer T-kurven på EKG’et og hvilke ændringer kan ses i denne og hvad skyldes det?

Answer 187

The T wave represents ventricular muscle repolarization;
it may be positive, negative, or biphasic in normal cats and
dogs. Changes in size, shape, or polarity from previous
recordings in a given animal are probably clinically important.

Abnormalities of the T wave can be primary (i.e., not
related to the depolarization process) or secondary (i.e.,
related to abnormalities of ventricular depolarization). Secondary ST-T changes tend to be in the opposite direction of the main QRS deflection.

Question 188

SAIM - kap 2 - Hvad repræsenterer QT-intervallet på EKG’et og hvilke ændringer kan ses i denne og hvad skyldes det?

Answer 188

The QT interval represents the total time of ventricular activation and repolarization. This interval varies inversely with average heart rate; faster rates have a shorter QT interval. Autonomic nervous tone, various drugs, and electrolyte disorders influence the duration of the QT interval (see Box 2-6). Inappropriate prolongation of the QT interval may facilitate development of serious reentrant arrhythmias when underlying nonuniformity in ventricular repolarization exists. Prediction equations for expected QT duration have been derived for normal dogs and cats.

Question 189

SAIM - kap 2 - Hvilke lægemidler kan ændre hjerterytme og/eller ledningsevne?

Answer 189

Digoxin, antiarrhythmic agents, and anesthetic drugs often
alter heart rhythm and/or conduction either by their direct
electrophysiologic effects or by affecting autonomic tone

Question 190

SAIM - kap 2 - Hvordan på virker kalium hjertet og hvordan ses hypokalæmi og hyperkalæmi på et EKG?

Answer 190

Potassium has marked and complex influences on cardiac
electrophysiology.

Hypokalemia can increase spontaneous
automaticity of cardiac cells, as well as nonuniformly slow
repolarization and conduction; these effects predispose to
both supraventricular and ventricular arrhythmias.

Hypokalemia can cause progressive ST segment depression, reduced T-wave amplitude, and QT interval prolongation. Severe hypokalemia can also increase QRS and P-wave amplitudes and durations. In addition, hypokalemia exacerbates digoxin toxicity and reduces the effectiveness of class I antiarrhythmic antiarrhythmic agents (see Chapter 4). Hypernatremia and alkalosis worsen the effects of hypokalemia on the heart.

Moderate hyperkalemia actually has an antiarrhythmic
effect by reducing automaticity and enhancing uniformity
and speed of repolarization. However, rapid or severe
increases in serum potassium concentration are arrhythmogenic primarily because they slow conduction velocity and shorten the refractory period.

The sinus node is relatively resistant to the effects of hyperkalemia and continues to function, although often at a slower rate. Despite progressive atrial muscle unresponsiveness, specialized fibers transmit sinus impulses to the ventricles, producing a “sinoventricular” rhythm. The characteristic “tented” T-wave appearance may be more apparent in some leads than in others and may be of small amplitude.

Fig. 2-18 illustrates the ECG effects of severe
hyperkalemia and the response to therapy in a dog with
Addison’s disease.

Question 191

SAIM - kap 2 - Hvilke tilstande påvirker EKG ændringerne forårsaget af hyperkalæmi?

Answer 191

Hypocalcemia, hyponatremia, and acidosis
accentuate the ECG changes caused by hyperkalemia, whereas hypercalcemia and hypernatremia tend to counteract them.

Question 192

SAIM - kap 2 - Hvilken elektrolyt forstyrrelse laver markante EKG ændringer?

Answer 192

Kalium. Det er sjældent andre elektrolytter gør det.

Question 193

SAIM – kap 2 – Hvad er forskellen ml. artifakter og arytmier på en EKG?

Answer 193

Other artifacts are sometimes confused with arrhythmias; however, artifacts do not disturb the underlying cardiac rhythm. Conversely, ectopic complexes often disrupt the underlying rhythm and are followed by a T wave. Careful examination for these characteristics usually allows differentiation between intermittent artifacts and arrhythmias.

Question 194

SAIM - kap 2 - hvordan virker Holter monitorering? (Ambulatorisk EKG)

Answer 194

Holter monitoring allows the continuous recording of
cardiac electrical activity during normal daily activities (except swimming), strenuous exercise, and sleep. This is useful for detecting and quantifying intermittent cardiac arrhythmias and therefore helps identify cardiac causes of syncope and episodic weakness. Holter monitoring is also used to assess the efficacy of antiarrhythmic drug therapy and to screen for arrhythmias associated with cardiomyopathy or other diseases.

During the recording period, the animal’s activities
are noted in a patient diary for later correlation with
simultaneous E C G events.

Question 195

SAIM - kap 2 - Er hjerte rytmen den samme for hhv. hunde og katte hele dagen igennem?

Answer 195

NEJ!

Wide variation in heart rate is seen throughout the day
in normal animals. In dogs maximum heart rates of up to
300 beats/min have been recorded with excitement or activity. Episodes of bradycardia (<50 beats/min) are common, especially during quiet periods and sleep. Sinus arrhythmia, sinus pauses (sometimes for more than 5 seconds), and occasional second-degree AV block are apparently common in dogs, especially at times when mean heart rate is lower. In normal cats heart rates also vary widely over 24 hours (e.g. from ~70 to ~290 beats/minute. Regular sinus rhythm predominates
i n normal cats, and sinus arrhythmia is evident
at slower heart rates. Ventricular premature complexes occur only sporadically i n normal dogs and cats; their prevalence likely increases only slightly with age.

Question 196

SAIM - kap 2 - Hvad bruger man event recording til ? (Ambulatorisk EKG)

Answer 196

Event recorders are used most often to determine whether episodic weakness or syncope is caused by a cardiac arrhythmia.

When an episode is observed, the owner activates the
recorder, which then stores the ECG from a predetermined
time frame (e.g., from 30 seconds before activation to 30 seconds after) for later retrieval and analysis.

Question 197

SAIM - kap 2 - Hvad påvirker cariationen i tid mellem på hinanden følgende hjerteslag.

Answer 197

Phasic fluctuations in vagal and sympathetic tone during the respiratory cycle, and also during slower periodic oscillations of arterial blood pressure, influence the variation in time between consecutive heartbeats.

Question 198

SAIM - kap 2 - Hvad betyder heart rate variability (HRV) og hvad påvirkes det af?

Answer 198

HRV refers to the fluctuation (udsvinget) of beat-to-beat time intervals around their mean value.

HRV is influenced by baroreceptor function as well as by the respiratory cycle and sympathetic/parasympathetic balance.

The degree of HRV decreases with severe myocardial dysfunction and heart failure, as well as other causes of increased sympathetic tone.

Question 199

SAIM - kap 2 - Hvad bruges signal-averages EKG (SAECG) til ?

Answer 199

Digital signal averaging of the E C G provides a means of
enhancing ECG signal resolution by discarding random
components (noise) so that small-voltage potentials that
may occur at the end of the QRS complex and into the early ST segment can be detected. These so-called ventricular late potentials can be found in patients with injured myocardium; they indicate the presence of conditions that predispose to reentrant ventricular tachyarrhythmias.

The presence of late potentials on SAECG has been identified in some Doberman Pinschers with ventricular tachycardia and significant ventricular dysfunction.

Question 200

SAIM - Hvad bruges Echocardiography (hjerteultralydgrafi)

Answer 200

Echocardiography (cardiac ultrasonography) is an important noninvasive tool for imaging the heart and surrounding structures. Anatomic relationships as well as cardiac function can be assessed by evaluating cardiac chamber size, wall thickness, wall motion, valve configuration and motion, and proximal great vessels and other parameters. Pericardial and pleural fluid are easily detected, and mass lesions within and adjacent to the heart can be identified. Echocardiographic examination can usually be performed with minimal or no chemical restraint.

Sound waves do not travel well though bone (e.g., ribs) and air (lungs); these structures may preclude good visualization of the entire heart.

Three echo modalities are used clinically: M-mode, two-dimensional (2-D, realtime), and Doppler.

Higher frequency ultrasound permits better resolution of
small structures because of the beam characteristics of longer near field and lesser far field divergence. However, higher frequencies have less penetrating ability as more energy is absorbed and scattered by the soft tissues. Conversely, a transducer that produces lower frequencies provides greater penetration depth but less well-defined images.

Strongly reflective tissues are referred to as being hyperechoic or of increased echogenicity. Poorly reflecting tissues are hypoechoic; fluid, which does not reflect sound, is anechoic or sonolucent.

Optimal visualization generally is achieved for 2-D and M-mode studies when the ultrasound beam is perpendicular to the cardiac structures and endocardial surfaces of interest.

If the suspected lesion can be visualized in more than one
imaging plane, it is more likely to be real.

Light sedation is helpful if the animal does not lie quietly.
Buprenorphine (0.0075 to 0.01 mg/kg IV) with aceproma¬
zine (0.03 mg/kg IV) usually works well for dogs. Butorphanol (0.2 mg/kg IM) with acepromazine (0.1 mg/kg IM) is adequate for many cats, although some require more intense sedation. Acepromazine (0.1 mg/kg IM) followed in 15 minutes by ketamine (2 mg/kg IV) can be used in cats, but this regimen can increase heart rate undesirably.

Question 202

SAIM - kap 2 - Hvad bruges to-dimensionel (2-D) Echocardiografi til?

Answer 202

A plane of tissue (both depth and width) is displayed using
2-D echocardiography. The anatomic changes resulting from various diseases or congenital defects are evident, although actual blood flow is not usually visualized with 2-D or M - mode imaging alone.

Most standard views are obtained from either the right or left parasternal positions (directly over the heart and close to the sternum). Images are occasionally obtained from subxiphoid (subcostal) or thoracic inlet (suprasternal) positions.

Images are described by the location of the transducer
and the imaging plane used (e.g., right parasternal
short-axis view, left cranial parasternal long-axis view).

The imaging allows an overall assessment of cardiac chamber orientation, size and wall thickness.

Question 203

SAIM - kap 2 - Hvor tyk er højre ventrikels hjertevæg ifht. venstre ventrikels frie hjertevæg?

Answer 203

The RV wall is usually about one third of the thickness of the LV free wall and should be no greater than half its thickness.

Question 204

SAIM - kap 2 - Hvad bruger man M-mode til ved echocardiografi og hvad er det?

Answer 204

This modality provides a one-dimensional view (depth) into
the heart.

M-mode images represent echos from various
tissue interfaces along the axis of the beam (displayed vertically on the screen). These echos, which move during the cardiac cycle, are displayed against time (on the horizontal axis).

Accurate placement of the M-mode beam using a
moveable cursor line superimposed on an appropriate 2-D
(real-time) image is important. M-mode images usually provide cleaner resolution of cardiac borders than 2-D because of higher sampling rate.

Standard M-mode views are obtained from the right parasternal transducer position. The M-mode cursor is positioned with 2-D guidance using the right parasternal
short-axis view.

Precise positioning of the ultrasound beam within the heart (perpendicular to the structures to be measured)
and clear endocardial images are essential for accurate
M-mode measurements and calculations.

The leading edge technique is used when possible (i.e., from the edge closest to the transducer [leading edge] of one side of the dimension to the leading edge of the other). In this way, only one endocardial surface is included in the measurement.

End diastolic and systolic LV internal dimensions and
wall thickness are usually obtained using M-mode, but appropriately timed 2-D frames can also be used.

Mitral valve motion is also evaluated with M-mode.

The diameter of the aortic root and sometimes its motion
are measured with M-mode.

Og andet.

Question 205

SAIM - kap 2 - Hvornår måles diastoliske målinger ved Echocardiografi?

Answer 205

Diastolic measurements are made at the onset of the QRS
complex of a simultaneously recorded ECG.

Question 206

SAIM - kap 2 - Hvornår måles systoliske målinger af LV ved Echocardiografi?

Answer 206

Systolic measurements of the LV are made from the point of peak downward motion of the septum to the leading edge of the LV free-wall endocardium at the same instant.

Question 207

SAIM - kap 2 - Hvad bruges fractional shortening til ? Echocardiografi.

Answer 207

The fractional shortening (FS; % delta D) is commonly
used to estimate LV function. FS is the percent change in LV dimension from diastole to systole ([LVIDd - LVIDs]/LVIDd x 100).

It is important to note that this index, like others taken during cardiac ejection, has the significant limitation
of being dependent on ventricular loading conditions.

Question 208

SAIM - kap 2 - Hvad giver reduceret LV afterload? Og hvad har det af betydning for fractional shortening? Echocardiografi.

Answer 208

For example, reduced LV afterload (as occurs from
mitral insufficiency, ventricular septal defect, or peripheral
vasodilation) facilitates ejection of blood and permits greater FS, although intrinsic myocardial contractility is notincreased.

Question 209

SAIM - kap 2 - Hvad bruger man calculated end-systolic volume index (ESVI) til? Echocardiografi

Answer 209

The use of the calculated end-systolic volume index
(ESVI) has been suggested as a more accurate way to assess myocardial contractility i n the presence of mitral regurgitation.

Question 211

SAIM - kap 2 - Hvis du skal måle LA størrelsen, hvilken form for echocardiografi vil du bruge?

Answer 211

LA size assessment is best done from 2-D images.

Question 212

SAIM - kap 2 - Hvad bruges Doppler echocardiografi til?

Answer 212

Blood flow direction and velocity are imaged with Doppler
echocardiography. Several types of Doppler echocardiography are used clinically: pulsed-wave (PW), continuous-wave (CW), and color flow (CF) mapping.

Important clinical applications relate to identifying abnormal flow direction or turbulence and increased flow velocity. This allows detection and quantification of valvular insufficiency, obstructive lesions, and cardiac shunts.

The Doppler modality is based on detecting frequency
shifts between the emitted ultrasound energy and echoes
reflected from moving blood cells (the Doppler shift*).
Echoes returning from cells moving away from the transducer are of lower frequency, and those from cells moving toward the transducer are of higher frequency.

Question 213

SAIM - kap 2 - Hvordan måler man optimal blood flow profiles and calculation of maximal blood flow velocity (hastighed)?

Answer 213

Optimal blood flow profiles and calculation of maximal
blood flow velocity are possible when the ultrasound beam (Doppler echocardiografi) is aligned parallel to the flow. This is in contrast to the perpendicular beam orientation needed for optimal M-mode and 2-D imaging.

As long as the angle between the ultrasound beam and path of blood flow is less than 20 degrees, maximal flow velocity can be estimated with reasonable accuracy.

Question 214

SAIM - kap 2 - Hvad er fordelen og ulempen ved pulsed wave (PW) Doppler echocardiografi?

Answer 214

The advantage of PW Doppler is that blood flow velocity, direction, and spectral characteristics can be calculated from a specific location in the heart or blood vessel. The main disadvantage is that the maximum measurable velocity is limited.

Question 215

SAIM - kap 2 - Hvad skaber ventrikulær outflow obstruktioner?

Answer 215

Ventricular outflow obstruction causes more rapid flow acceleration, increased peak velocity, and turbulence.

Question 216

SAIM - kap 2 - Hvordan placerer man pulsed wave Doppler echocardiografi bedst for at måle blodflowet forskellige ostier?

Answer 216

The four-chamber left apical view usually provides
optimal alignment for assessing mitral inflow velocities;
the left cranial short axis view is usually best for
tricuspid inflow. Peak systolic pulmonary velocity is ≤1.4 to 1.5 m/sec in most normal dogs. The left cranial views usually provide better flow alignment. Maximal aortic/LV outflow velocities are obtained in most dogs from the subcostal (subxiphoid) position; however, in some dogs the left apical view provides higher velocity recordings.

Question 217

SAIM - kap 2 - Hvad er fordelen og ulempen ved Continuous wave Doppler echocardiografi?

Answer 217

Continuous wave (CW) Doppler employs continuous and
 simultaneous ultrasound transmission and reception along
 the line of interrogation. Theoretically, there is no maximum velocity limit with CW Doppler, so high-velocity flows can be measured (Fig. 2-33). The disadvantage of CW Doppler is that sampling of blood flow velocity and direction occurs all along the ultrasound beam, not in a specified area (socalled range ambiguity).

CW Doppler is employed if aliasing occurs with PW Doppler. (Pressure gradient estimation)

Question 218

SAIM - kap 2 - Hvad bruger man Doppler estimation af tryk gradienter til?

Answer 218

Doppler estimation of pressure gradients is used in combination with M-mode and 2-D imaging to assess the severity of congenital or acquired flow obstructions.

Pressure gradient = 4(maximum velocity)²

Question 219

SAIM - kap 2 - Hvad er color flow (CF) mapping?

Answer 219

Color flow (CF) mapping is a form of PW Doppler that
combines the M-mode or 2-D modality with blood flow
imaging. However, instead of one sample volume along
one scan line, many sample volumes are analyzed along
multiple scan lines. The mean frequency shifts obtained from multiple sample volumes are color-coded for direction (in relation to the transducer) and velocity. Most systems code blood flow toward the transducer as red and blood flow away from the transducer as blue. Zero velocity is indicated by black, meaning either no flow or flow that is perpendicular to the angle of incidence.

Differences in relative velocity of flow can be accentuated (fremhævet), and the presence of multiple velocities and directions of flow (turbulence) can be indicated by different display maps that use variations in brightness and color.

Signal aliasing is displayed as a reversal of color (e.g., red shifting to blue; Fig. 2-34). Turbulence produces multiple velocities and directions of flow in an area, resulting in a mixing of color; this display can be enhanced using a variance map, which adds shades of yellow or green to the red/blue display

Question 220

SAIM - kap 2 - Hvad bruges Doppler tissue imaging til?

Answer 220

Doppler tissue imaging (DTI) is a modality used to assess
the motion of tissue, rather than blood cells, by altering the
signal processing and filtering of returning echoes.

Question 221

SAIM - kap 2 - Hvordan fungerer transesophageal echocardiografi (TEE)?

Answer 221

Transesophageal echocardiography (TEE) uses specialized transducers mounted on a flexible, steerable endoscope tip to image cardiac structures through the esophageal wall. TEE can provide clearer images of some cardiac structures (especially those at or above the AV junction) compared with transthoracic echocardiography because chest wall and lung interference is avoided. This technique can be particularly useful for defining some congenital cardiac defects and identifying thrombi, tumors, or endocarditis lesions, as well as guiding cardiac interventional procedures (Fig. 2-37).

Question 222

SAIM - kap 2 - Hvad påvirker central venetryk og hvad bruges det til?

Answer 222

Central venous pressure (CVP) is influenced by intravascular volume, venous compliance, and cardiac function. CVP measurement helps in differentiating high right heart filling pressure (as from right heart failure or pericardial disease) from other causes of pleural or peritoneal effusion.

But it is important to note that pleural effusion itself can increase intrapleural pressure enough to impair cardiac filling; this can raise CVP even in the absence of cardiac disease. Therefore CVP should be measured after thoracocentesis in patients with moderate- to large-volume pleural effusion.

CVP is sometimes used to monitor critical patients receiving large intravenous fluid infusions. However, CVP is not an accurate reflection of left heart filling pressure and thus is not a reliable way to monitor for cardiogenic pulmonary edema.

Question 223

SAIM - kap 2 - Hvilke biomarkører bruger man til at opdage myocardie skade?

Answer 223

Cardiac troponins are more sensitive for detecting myocardial injury than cardiac-specific creatine kinase (CK-MB) and other biochemical markers of muscle damage.

Circulating concentrations of cardiac troponin I (cTnl) and cardiac troponin T (cTnT) provide a specific indicator of myocardial injury or necrosis.

After acute myocyte damage, serum cTn concentration increases within a few hours, peaks in 12 to 24 hours, and then declines over the next few weeks. Myocardial inflammation, trauma, congestive heart failure, hypertrophic cardiomyopathy, and gastric dilatation/volvulus have been associated with increased cardiac toponin concentrations. In dogs with congestive heart failure or hypertrophic cardiomyopathy, this probably relates to continued myocardial remodeling, not just acute damage from myocardial infarction.

Question 224

SAIM - kap 2 - Hvilke biomarkører bruger man til at vurdere hjertesvigt?

Answer 224

The natriuretic peptides, ANP, BNP, and their precursors,
are other potentially useful biomarkers for assessing the
presence and possibly prognosis of heart failure. Circulating natriuretic peptide concentrations increase in association with vascular volume expansion and decreased renal clearance and when their production is stimulated (e.g., with ventricular strain and hypertrophy, hypoxia, or tachycardia).

BNP as well as NT-proANP are high in most cats with hypertrophic cardiomyopathy.

Question 225

SAIM - kap 2 - Hvad bruger man et hjertekateter til?

Answer 225

Cardiac catheterization allows measurement of pressure,
cardiac output, and blood oxygen concentration from specific intracardiac locations.