Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Cardiology > Myocardial disease NB: more being added > Flashcards

Myocardial disease NB: more being added Flashcards

(70 cards)

Start Studying
1
Q

Signalment of DCM in dogs

A

Large and giant breed dogs esp Doberman, Great Dane, Irish Wolfhounds

+ exception to rule = cocker spaniels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is DCM

A

A primary myocardial disease characterised by left ventricular systolic dysfunction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the aetiology of DCM

A

Assumed familial
Mutations have been found in Dobermans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Pathology of DCM

A

There is ventricular systolic dysfunction, leads to left ventricular dilation –> get progressive left atrial dilation
In same cases get dilation and dysfunction of the right ventricle too

There is eccentric hypertrophy with thinner ventricular walls that normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the pathophysiology of DCM

A

Cellular level metabolic dysfunction and contractility defects
–> Get systolic dysfunction
–> Reduction in stroke volume and CO which activates RAAS and sympt system causing remodelling, increased myocardial O2 demand and cell death leading towards CHF

+ reduced function and ventricular dilation leads to increases in LV end diastolic pressures and therefore rise in left atrial and venous pressures

So get left sided CHF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some potential sequelae of DCM

A

Left sided congestive heart failure
Forward failure
RIght sided CHF because of arrhythmias
Arrhythmias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

at what point of DCM is the dog at risk of congestive heart failure

A

When the left atrium is enlarged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What arrhythmias can occur in DCM

A

Atrial fibrillation esp in giant breeds
Ventricular arrhythmias and sudden death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Current staging of DCM

A

Pre-clin = have DCM but not in heart failure
Clnical = in heart failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does pre-clinical DCM mean

A

Either echo or electrical changes or both
No signs of congestive heart failure

= typically a slowly proressive disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How prevalent is DCM in dobermans

A

Up to 60% have it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

History and clinical exam of pre-clin DCM

A

History = asymptomatic usually, but often family history
May show exercise intolerance, or collapse

Clin exam may be unremarkable; may head soft murmur or arrhythmia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why might we hear a soft murmur with pre-clinical DCM

A

Due to ventricular dilation causing stretching of the mitral valve and some regurgitation occuring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

History of clinical DCM

A

= of congestive heart failure
- Exercise intolerance
- Lethargy, weakness
- Collapse/syncope
Tachypnoea, dyspnoea
Cough
Abdominal distension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What clinical exam signs can we see with clinical DCM

A

Murmur
Tachycardia
Tachyarrhythmias
Pulse deficits/reduced pulse quality
Dyspnoea
PUlmonary crackles
Weakness, collapse

+ in some cases have signs of right sided CHF - abdominal distension, jugular distension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What do we look for on echo with DCM evaluation

A

LV systolic function
Assess LV and LA size
Identify any murmurs
Assess right side size and function too

Hallmarks = LV systolic dysfunction and dilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do we use the ECG holter for in DCM analysis

A

Assess ventricular arrhythmias for burden i.e number of VPCs in 24hrs, severity of arrhythmias e.g couplets/triplets etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the ECG criteria for DCM

A

> 300 VPCs Or two wtihin 12 months showing 50-300

Frequent couplets or triplets are assocaited with higher risk of sudden death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the gold standard way to diagnose pulmonary oedema

A

Thoracic radiographs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What two cardiac biomarkers can we look at

A

NT-proBNP: tells us about myocardial stretch and strain

Cardiac troponin 1: indicator of myocardial cell damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Advantages/disadvantages of NT-proBNP as DCM biomarker

A

Predicts pre-clinical DCM with echo changes well but not those with just arryhtmias

Can get false +ves in renal disease, sepsis, hypertension

Takes a while so not good for emergency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do very high values of cardiac troponin 1 suggest

A

Myocarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do we treat pre-clinical DCM

A

Pimobendan; PDE III inhibitor should be introduced now
Advise monitoring of respiratory rate for increases that indicate moving into heart failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is different about resting respiratory rate monitoring in large dogs with DCM vs small ones with mitral valve

A

They go intro heart failure at much lower RRs so very important to have a base level to spot increase (Can’t jsut use over 30 rule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What imaging signs do we see as DCM progresses to clinical stage
Echo shows worse ventricular dysfunction, atria now may be dilated X rays show pulmonary oedema
26
What drugs do we use once in clinical DCM
[already should be on pimobendan] Add in diuretics until stable Then spironolactone, ACE inhibitors (e.g cardalis contains spironolactone + benazepril which is an ACE inhibitor)
27
What drugs should we use to treat atrial fibrillation in DCM
Want to get HR back until 125bpm Diltiazem Digoxin
28
What do we need to remember about digoxin
Very narrow therapeutic window
29
How to treat sustained ventricular tachycardia in DCM
Lidocaine Amiodarone Then can move to chronic oral therapy later; amiodarone, sotalol, mexiletine
30
Primary vs secondary cardiomyopathy
Primary = no apparent cause; i.e genetic - this is most cases Secondary = where systemic disease is causing damage to myocardium
31
What systemic diseases can cause secondary cardiomyopathy cat HCM phenocopies
Hypertension, hyperthyroidism, acromegaly, lymphoma, nutritional
32
What is the most common cardiomyopathy in cats
Hypertrophic cardiomyopathy Up to 15% of cats have this and most are asymptomatic with normal life expectancy
33
Basic complications of HCM in cats
~30% get complications > Congestive heart failure > Thromboembolic events > Sudden cardiac death
34
What is the aetiology of HCM
Disease of the sarcomere Familial in several breeds and some mutations identified e.g in myosin binding protein e.g Maine coon, ragdoll, DSH
35
How do we diagnose HCM
Echocardiography showing left ventricular hypertrophy (wall thickness >6mm in diastole)
36
What does a HCM phenocopy look like and what are the most common ones
Thick walls; but not necessarily hypertrophy could be oedema or infiltration
37
What are the most common causes of HCM phenotype
First one is HCM Then systemic hypertension and hyperthyroidism
38
What are the categories of causes of increased left ventricular thickness
- Myocardial hypertrophy: from aortic stenosis, hypertension, HCM, acromegaly, hyperthyroidism Pseudohypertrophy due to dehydration Accumulation of cells of fluid e.g TMT, lymphoma
39
At what blood pressures can we get significant changes to the heart
>180mmHg
40
What condition are acromegalic cardiomyopathy cats frequently presented with
Diabetes mellitus
41
If thick ventricular walls normalise after IV fluid therapy what does this tell us
It was pseudohypertrophy due to dehydration
42
What tumour can cause thickened left ventricle and HCM phenotype
Cardiac lymphoma
43
What is transient myocardial thickening
Present with thick walls and in congestive heart failure - There is reverse remodelling over time to revert to normal Good prognosis so can stop treatment evnetually unlike heart failure
44
What is the key difference between HCM and TMT
Typically young cats Reverts to normal over time Classifcally there is an antecedent stressful event a couple of weeks before the presentation in heart failure
45
What are two proposed ideas for transient myocardial thickening in cats
Acute myocarditis; causing myocardial oedema and cellular infiltration which makes walls thick causing acute dysfunction - Then inflammation resolves Broken heart syndrome = where severely stressful event causes catecholamine surge
46
Murmur frequency in HCM cats
~50 have systolic murmur Up to 70% have normal sounds
47
What is systolic anterior motion of mitral valve
Where the mitral valve is pushed towards the outflow tract in systole, against the interventricular septum which creates an obstruction to blood flow So blood accelerates to go round leaflet giving a murmur + this holds valve open so get regurgitation into atria Also more likely in HCM bcecause ventricle very thick, longer leaflets and hypercontractive ventricle
48
What is the most common cause of systolic anterior motion of mitral valve
HCM
49
What other than HCM can cause SAM
Hypovolaemia because the empt ventricle creates conditions that can drag the vlve MV dysplasia Subaortic stenosis
50
What is the classic pulmonary oedema lung pattern in dogs with congestive heart failure and how is it different in cats
Dogs show alveolar pattern in caudo-dorsal region In cats no pattern is followed; so cannot exclude pulmonary oedema based on X ray distribution
51
What is restrictive cardiomyopathy
= the second most common cardiomyopathy in cats = due to replacement fibrosis in the ventircular walls so they are normal thickeness but fibrosed This means high pressure in ventricles, atrial dilation, restrictive LV filling pattern
52
What are the two phenotypes of restrictive cardiomyopathy
Myocardial form = where myocardium very fibrotic; normal wall thickness; very large atria Endomyocardial form = where muscle/scar tissue bridge in the middle of the left ventricle
53
What is the aetiology of restrictive cardiomyopathy
Unclear could be congenital, could be just very late stage HCM where walls become thinner due to fibrosis
54
What is presentation of restrictive cardiomyopathy like and what must we be aware of
Middle age/older cats typically Around half have systolic murmurs Gallop rhythms or arrhythmias are more specific NB: many cats have no abnormalities on auscultation
55
Characteristics of dilated cardiomyopathy in cats
Severe LV dilation and systolic dysfunction (BUT there are other phenocopies of this e.g late stage HCM, L to R shunt, tachycardia induced]
56
What has dilated cardiomyopathy classically been assocaited with in cats
Taurine deficiency
57
What are the characteristics of arrhythmogenic RV cardiomyopathy
Fibrous and fatty infiltration into the right ventricle Causes severe dilation of RV, thin RV wall Associated with malignant ventricular arrhythmias due to scar tissue blocking normal conduction
58
What does B1 vs B2 stage of feline cardiomyopathy mean
Both are subclinical But B1 = low risk of complications B2 = high risk These complications = heart failure, thromboembolic disease
59
How does a cat with thromboembolic disease from left atrium embolising into aorta often present
Suddenly paraparetic on hind limbs Cold, painful legs with no pulse, pale toe MMs
60
What does the appearance of smoke in the atrium on ultrasound mean
Blood is flowing slowly in the large atrium, allowing RBCs to aggregate and form mini thrombi This means there is a high risk for thrombus formation and thromboembolic disease
61
What should we do at stage B2 feline cardiomyopathy
Start clopidogrel blood thinner to reduce thromboembolism risk Ask owners to start taking resting respiratory rates to help detect going into heart failure
62
What do we do in stage C of feline cardiomyopathy
Congestive heart failurue treatment Oxygen Furosemide
63
What should we do if a thromboembolic event has occured (e.g HCM in cats)
Antithrombotics e.g unfractionated heparin, clopidogrel etc Pain management because this is very painful But do NOT remove thrombus or attempt to lyse it; instead stop growth and give body time to make collateral circulation
64
Risk factors for poorer prognosis in HCM
LA dilation LA thormbus Smoke on U/S
65
Survival time of asymtomatic HCM cats
Normal i.e >10 years
66
What things can cause a DCM phenotype in dogs
Hypothyroidism, hypoadrenocorticim SIRS Chronic volume overload e.g anaemia, high fluids Chronic myocarditis Taurine deficiency Grain free/legume rich diets Long term arrhythmias
67
What is arrhythmogenic right ventricular cardiomyopathy and what breeds are commonly affected
Myocardiac disease mostly affecting right ventricle with progressive loss of myocytes and replacement with fatty/fibrous tissue Can affect electrical systmon most and present with arrythmias Seen in boxers and bulldogs
68
Treatment of arrhythmogenic right ventircular cardiomyopathy
Sotalol = first line oral treatment to manage arrhythmias If there is systolic function add in pimobendan
69
What are the three forms of ARVC presentation
Asymptomatic; but see VPCs on holter Symptomatic; synvope with arryhtmias but normal systolic function DCM phenotype and arrhythmias
70

Cardiology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions