L69: acquired cardiac diseases

what is the most common acquired cardiac condition identified in the dog?

valvular disease

which animals do we see chemodectomas in?

brachycephalic animals

where do we see lymphomas in the heart of cattle?

base of the heart

where do we see hemangiosarcomas in the heart of dogs?

atria

what is the treatment for sick sinus syndrome?

pacemaker

what heart rate do you expect to see an animal where the heart rate is coming from the SA node?

80-120 bpm

what heart rate do you expect to see an animal where the heart rate is coming from the AV node?

60-80 bpm

what heart rate do you expect to see an animal where the heart rate is coming from the purknje fiber?

40-60 bpm

what things will you see on an ECG in an animal with sick sinus syndrome?

1. P without QRS

2. slow ventricular rate with escape beats

3. supraventricular tachycardia alternating with severe sinus bradycardia

what is sick sinus syndrome also known as?

bradycardia-tachycardia syndrome

what is sick sinus syndrome?

prolonged asystole with paroxysmal SVT

what clinical symptoms are associated with sick sinus syndrome?

1. episodic weakness

2. syncope

3. stoke-adams seizures

what breed and age are you thinking of for sick sinus syndrome?

older female mini schnauzer

what is the treatment for arrythmogenic right ventricular cardiomyopathy?

1. pending holter monitor

2. sotalol

3. recheck with holter monitor

how many VPCs will you see in a day for an animal with arrythmogenic right ventricular cardiomyopathy?

50-100

what is the prognosis for arrythmogenic right ventricular cardiomyopathy if CHF is present?

less than 6 months

what are the categories for arrythmogenic right ventricular cardiomyopathy?

1. V-tac with no clinical signs

2. sustained V-tac with syncope or weaknes

3. poor myocardial function, arrhythmias, and CHF

what breeds do we think of with arrythmogenic right ventricular cardiomyopathy?

1. BOXERS

2. german sheperds

3. english bulldogs

what happens to the heart with arrythmogenic right ventricular cardiomyopathy?

1. fibrotic myocarditis

2. atrophy

3. fatty infiltration

what can arrythmogenic right ventricular cardiomyopathy proceed to?

dilated cardiomyopathy (DCM)

what may be seen in an acute trypanosoma infection?

1. various tachyarrhytmias

2. AV conduction disturbances

3. sudden death

what may be seen in a latent trypanosoma infection?

antibodies against trypanosoma and cardiac muscle

what may be seen in a chronic trypanosoma infection?

cardiomegaly (either generalized or right sided)

what viral diseases can cause myocarditis?

1. parvovirus

2. canine distemper virus

what bacterial diseases can cause myocarditis?

1. bartonella

2. lyme

what protozoal diseases can cause myocarditis?

1. trypanosoma

2. toxoplasma

3. neospora

4. babesia

5. hepatozooan

what drug can cause toxic myocardial disease?

doxorubicin

what is bovine hereditary dilated cardiomyopathy?

a fatal autosomal recessive heart disease in cattle that leads to ventricular dilation then congestive heart failure

which breeds do we see bovine hereditary dilated cardiomyopathy in?

1. holstein-fresian

2. red holstein

3. swiss fleckvieh

what is the pathology of bovine hereditary dilated cardiomyopathy?

progressive myocardial fibrosis and loss of cardiomyocytes leading to reduced heart function

what are the clinical signs of bovine hereditary dilated cardiomyopathy?

1. exercise intolerance

2. reduced milk yield

3. subacute subcutaneous edema

4. jugular vein

how do we diagnose bovine hereditary dilated cardiomyopathy?

echocardiography

what is a common arrhythmia identified in conjunction with DCM?

atrial fibrillation

what is the prognosis of DCM?

guarded to poor

what is the prognosis for a dog with DCM?

6-12 months

what is the prognosis for a dog with DCM if they present with congestive heart failure?

less than 7 weeks

what breed do you associated dilated cardiomyopathy with?

1. dobermans

2. boxers

3. great danes

4. portuguese water spaniels

what is shown in the echocardiogram?

eccentric hypertrophy from DCM

what is the treatment of choice for dilated cardiomyopathy?

pimobendan

what is the action of pimobendan?

1. increases Ca2+ sensitivity → increase contractility

2. peripheral vasodilator → decrease afterload

A dog is diagnosed with DCM. He has been on pimobendan for treatment, but you notice that he is hypertensive. What drug can be given to address the hypertension?

ACE inhibitor

A dog is diagnosed with DCM. He has been on pimobendan for treatment, but you notice that the dog has atrial fibrillation. What drug can be given to address this?

diltizem

what is stage A dilated cardiomyopathy?

dogs at risk for developing DCM without electrical or morphological abnormalities

what is stage B1 dilated cardiomyopathy?

arrhythmias related to DCM such as atrial fibrillation or VPCs

what is stage B2 dilated cardiomyopathy?

echo evidence of DCM and possible electrical abnormalities

what is stage C dilated cardiomyopathy?

past or current clinical signs of CHF secondary to DCM

what is stage D dilated cardiomyopathy?

end stage DCM refractory to standard treatment

what is the secondary cause of DCM in dogs?

1. toxic

2. nutritional

what is the secondary cause of DCM in cats?

nutritional

what breeds may we see L-carnitine deficiency that can lead to DCM?

1. cocker spaniels

2. golden retrievers

3. newfoundlands

what breeds do we see secondary DCM in?

1. dobermans

2. frenchies

3. german sheperds

4. goldens

5. wolfhounds

6. pitbulls

what ECG abnormalities are typically consequences of DCM and CHF?

1. atrial fibrillation

2. VPCs

what are the two types of primary DCM?

1. congestive (great danes)

2. electrical (dobermans and boxers)

what ECG abnormality will you see with DCM?

tall R waves

what is the second most common cardiac disease in dogs?

dilated cardiomyopathy (DCM)

what is dilated cardiomyopathy?

loss of myocardial contractility

what clinical signs may be seen with dilated cardimyopathy?

1. weakness

2. syncope

3. ± arrhythmias

4. sudden death

5. exercise intolerance

what is the treatment for endocarditis?

1. IV antibiotics for the first week

2. antibiotics for 6-8 weeks

what does infective endocarditis lead to?

valve insufficiency of the heart

what distinct signs do we associate with bacterial endocarditis?

1. newly diagnosed murmur

2. hyperkinetic or bounding pulses

what bacterias lead to swine endocarditis?

1. streptococcus suis

2. erysipelothrix rhusiopathiae

what valves are often affected from bacterial endocarditis in small animals and equine?

1. aorta

2. mitral valve

what valves are often affected from bacterial endocarditis in cows?

tricuspid

A 1 year old hunting dog comes into the clinic after having bouts of infection. Upon physical exam, you note their is a new murmur. What is the most likely diagnosis?

bacterial endocarditis

what is the utility of the ACVIM consensus statement on mitral valve disease?

to assist with the prognosis, monitoring, and therapeutic choices

what is transcatheter mitral valve repair?

clamps the mitral valve leaflets together to decrease the regurgitation fraction

what stage is mitral valve repair surgery done in?

used in stage C and considered for B2 stage

what is stage A mitral valve disease?

• at risk, no identifiable signs

• normal king charles spaniel

what is stage B mitral valve disease?

murmur with no clinical signs

what is stage B1 mitral valve disease?

no imaging abnormalities

what is stage B2 mitral valve disease?

either radiographic or echocardiographic changes (left atrium)

what stage of mitral valve disease do we start treatment with pimobendan?

B2

what is stage C mitral valve disease?

past or current clinical signs of heart failure with structural heart disease

what is stage D mitral valve disease?

end stage refractory to standard treatment

what do we educate the client to do if their dog has valvular endocardiosis?

monitor respiratory rate at rest

A dog comes in with a cough and clinical signs of valvular endocardiosis. You decide to look at the NT-proBNP which is slightly elevated, but close to the normal value. What is more likely happening in this dog rather than valvular endocardiosis?

respiratory disease

what is the most common cause for heart failure in the dog?

valvular endocardiosis

what animal besides the dog is valvular endocardiosis common in?

athletic horses

what valves are commonly affected with valvular endocardiosis?

1. mitral

2. tricuspid

what type of murmur will you hear with valvular endocardiosis?

holosystolic plateau murmur at left apex

when does CHF usually occur before in valvular endocardiosis?

usually before myocardial pump function decreases

what dogs are predisposed to degenerative valvular endocardiosis?

1. king charles spaniels

2. whippets

3. dachsunds

4. older small-mid breed dogs

what factors contribute to valvular endocardiosis?

1. valve stress

2. endothelial dysfunction

3. multifactorial

what factors contribute to myxomatous degeneration?

1. nodular thickening

2. valve deformity

3. valve weakening

A 7-year-old MN Maine Coon cat presents for a recheck of his previously diagnosed and stable HCM. His owners report that he has recently walked into a wall, appears disoriented and has been PU/PD lately. What diagnostic test is indicated emergently?

blood pressure

what is a problem with feline heart diseases?

remodeling over time can change the disease

what cardiac issue is commonly seen in older cats?

hypertrophic cardiomyopathy (HCM) → 1/3 have the HCM phenotype

what is the cause of hypertrophic cardiomyopathy in cats?

idiopathic left ventricular hypertrophy

what happens with HOCM in cats?

force of contraction pulls mitral leaflets into the outflow tract → decrease diameter of valve flow → outflow obstruction

what is the cause of restrictive cardiomyopathy?

idiopathic left ventricular endomyocardial fibrosis

what can be seen in the heart with restrictive cardiomyopathy?

1. scar bridging the septum and left ventricular free wall

2. large left atrium ± right atrium

3. diastolic dysfunction

what cats is their genetic link to hypertrophic cardiomyopathy?

1. Maine coons

2. ragdolls

when are most clinical cases of HCM in maine coon cats identified by?

4 years of age

what does HCM progressively lead to?

higher left ventricular pressures

what can be seen in large animals with HCM on echocardiogram?

smoke→ swirling pattern

what is stage A feline cardiomyopathy?

predisposed (ex: maine coon cat)

what is stage B1 feline cardiomyopathy?

sublinical, mild atrial enlargement

what is the treatment plan for a cat with stage A feline cardiomyopathy?

18 month echo if the cat is not stressed

what is stage B2 feline cardiomyopathy?

subclinical, moderate to severe atrial enlargement

what is the treatment plan for stage B2 feline cardiomyopathy?

18 month echo if cat is not stressed