Acquired Heart Diseases: HCM + RCM Flashcards
What is the most common acquired heart disease in cats?
HCM
What is false about cats with HCM?
A. Many affected cats are asymptomatic
B. Most common heart disease in cats
C. Secondary concentric hypertrophy due to underlying systemic hypertension
D. Heritable condition in maine coons, ragdolls and sphynx
C. Secondary concentric hypertrophy due to underlying systemic hypertension
primary concentric hypertrophy, no underlying cause
HCM results in _________ dysfunction due to impaired relaxation of ventricular myocytes and increased ventricular wall thickness
diastolic
What radiographic exam findings would you expect to see on a cat with CHF due to HCM?
(left sided CHF)
- Pulmonary edema
- +/- pleural effusion
- LA enlargement
Which patients are considered under Class A HCM?
Clinically normal pets with genetic risk of HCM
- Ragdolls
- Maine coon
- Sphynx
- DSH (most common)
_______ is the most common breed diagnosed with HCM
DSH
HCM is more common in _________ (male/female) cats
Male
What classifies a patient under Stage B1 HCM?
- Asymptomatic with normal or mild atrial enlargement
What classifies a patient under Stage B2 HCM?
- Asymptomatic with moderate or severe atrial enlargement
What classifies a patient under Stage C HCM?
Current or previous L sided CHF and/or ATE
______ is the most common presenting complaint in a cat with Stage C HCM
Dyspnea (due to L sided CHF)
Most common cause of cats progression from stage B2 HCM to stage C HCM?
HCM progression to CHF usually precipitated by:
- Fluid therapy
- Anesthetic procedures
- Corticosteroids
What heart sound can be heard in 30% of cats with HCM?
Gallop (bc diastolic dysfunction)
Abnormal femoral pulses in a cat with HCM suggests?
- ATE
- Arrhythmia
or - Low output HF
(femoral pulses are usually normal otherwise)
If a murmur is present in a cat with HCM, it is often a _________ heart murmur with PMI on the _____ side
Systolic, left
DDX for LV concentric hypertrophy in a cat?
- Systemic hypertension
- Hyperthyroidism
- Acromegaly
- Aortic stenosis
- Neoplasia (lymphoma)
- HCM (must rule out the above first)
_________ is the most commonly used biomarker in clinical feline cardiology
N-terminalBNP
(POC snap test to help screen for HCM + RCM in cats)
When is placement of a 24hr holter monitor considered for cats with HCM?
If an arrhythmia is present
(VPCs common in HCM cats)
Treatment protocol for a cat with Stage B2 HCM?
- Clopidogrel (for ATE prevention)
no drug for myocardial dysfunction as of now :/
Treatment protocol for a cat with Acute Stage C HCM?
- Furosemide IV/IM
- Clopidogrel (ATE prevention)
- Supplemental O2
- Thoracocentesis (drains pleural fluid due to L-CHF)
Treatment protocol for a cat with Chronic Stage C HCM?
- Furosemide PO
- Clopidogrel (ATE prevention)
- Thoracocentesis as needed
Treatment protocol for a patient presenting with ATE?
- Analgesic (Buprenophine, fentanyl)
- Antithrombotic (Heparin acutely, Clopidogrel for long term)
What do you tell an owner regarding prognosis of a cat with Stage B HCM?
Fair prognosis for asymptomatic cats in Stage B HCM
Although sudden death and/or ATE is a potential complication of HCM
What do you tell an owner regarding prognosis of a cat with CHF and ATE due to HCM?
Guarded prognosis - 77 days
What do you tell an owner regarding prognosis of a cat with Stage C HCM?
Stage C means they have CHF or ATE
- Poor prognosis, ~ 1.5 years
What are 4 physiologic causes of a heart murmur in a cat that must be ruled out before considering structural heart disease as the cause?
- Dynamic right ventricular outflow obstruction (DRVOTO)
- Anemia
- Hyperthyroidism
- Fever
What is the main difference between HCM vs RCM, in regards to the pathophysiology?
HCM: Diastolic dysfunction and increased ventricular wall thickness
RCM: Diastolic (and sometimes systolic) dysfunction and normal wall thickness
RCM is a primary myocardial disease characterized by _______ dysfunction
Diastolic (and sometimes systolic)
What is the 2nd most common cause of cardiomyopathy in cats?
RCM
What pathology is associated with RCM in cats?
- Fibrosis of the endocardium or myocardium
- Normal ventricular wall thickness
- Atrial dilation is common
What is the estimated prognosis for symptomatic cats with RCM?
Poor (9 months)
How can HCM lead to LVOTO?
Hypertrophy pulls chordae tendenae and mitral valve into the LV outflow tract, causing obstruction of blood flow into the aorta
Known as Systolic anterior motion of the mitral valve (SAM)
This causes mitral regurg too
Systolic anterior motion of the mitral valve (SAM) is common in cats with ____________
HCM
In a cat with HCM, LA enlargement might be exacerbated by ____________
Mitral regurg from systolic anterior motion of the mitral valve (SAM)
What is true about RCM in cats?
A. Diastolic dysfunction and thickened ventricular walls
B. No sex or breed predilection
C. Sudden death is not a risk factor
D. Many affected cats have no auscultable abnormalities
B. No sex or breed predilection
How can RCM be detected on echo?
A lot of bright white representing fibrous tissue
What is the treatment protocol for a cat with RCM?
(Same staging as HCM)
Asymp with mod-severe RCM: (B2) Clopidogrel, +/- ACEi (Pimobendan if systolic dysfunction)
Symptomatic = CHF or ATE
- Furosemide
- Clopidogrel
- ACEi
- Pimobendan
