Cardio - Hypertrophic CM Flashcards
What is HOCM?
Disease of the myocardial sarcomere caused by/characteristic of:
genetic mutations in MyBPC, dietary/environmental factors, impaired LV myocardial relaxation, and concentric hypertrophy
What cat breeds are prone to HOCM?
Maine Coons and Ragdolls
HOCM is a disease of _____ dysfunction.
diastolic
What do HOCM hearts look like?
Myofiber disarray, replacement fibrosis, arteriosclerosis (small vessel disease)
What does the O in HOCM stand for?
obstructive
Where is the obstruction in HOCM?
At area where blood leaves LV as it crosses the aorta
What role does the MV play in HOCM?
It is anatomically near the obstruction location, and can swing and get in the way of the outflow tract, contributing to HOCM
What is the signalment for HOCM?
Cats (Maine Coons, Ragdolls), males (75%), middle-age (~6 yr)
What is the prevalence of HOCM in cats?
15%
What is part of the breeder screening for HOCM?
Echo and genetic testing
What is part of the veterinarian screening for HOCM?
Murmur, arrhythmia, cardiac biomarkers (NT-proBNP)
What can HOCM be a complication of?
CHF, ATE
How is HOCM definitively diagnosed?
Echo
What are signs of HOCM seen on echo?
LV hypertrophy, LV diastolic function, +/- LA enlargement
What are DDx for LV hypertrophy in cats?
4H/4 “hypers”
HCM, hypertension, hyperthyroidism, hypersomatotropism (acromegaly)
How does hypertension cause LV hypertrophy?
Ventricle is working harder to pump blood out due to increased afterload
How can hyperthyroidism cause LV hypertrophy?
Thyroid hormone can directly cause hypertrophy –> hypertension
What causes a heart murmur in HOCM?
Dynamic LVOT obstruction +/- mild mitral regurg
What is easier to diagnose, HOCM or HCM? Why?
HOCM because most HCM cats don’t have murmurs and HOCM cats do
What are DDx for murmurs in adult cats?
HOCM, hyperthyroidism/SHT, physiologic, anemia
What are the 3 complications of HOCM and which is most common?
L-CHF (most common), ATE, sudden cardiac death
What CS come with HOCM due to L-CHF?
Dyspnea, tachypnea, inappetance, ADR, hiding
What CS come with HOCM due to ATE?
acute paresis/pain, bilateral hindlimb > other
Where does fluid go in cats with L-CHF?
Pulmonary edema, pleural eff, pericardial eff
T/F: Most cats with HOCM are never diagnosed or treated
True
___% of cats who are diagnosed will progress and experience a complication.
50
What is the average survival in asymptomatic HOCM cats?
~5 years
What is the average survival of HOCM cats following an episode of CHF?
6 months - 2 years
What is the average survival of HOCM cats following an ATE?
3-6 months
What are negative prognostic indicators of HOCM?
Severe LA enlargement, severe LV hypertrophy, older age
Do HOCM cats or HCM cats have better prognosis?
HOCM because they have murmurs and so get detected earlier
What drugs are important in HOCM and why?
Clopidogrel, aspirin, heparin, tPA
(Anti-coagulants bc HOCM cats love to form clots)
What meds are used in asymptomatic (stage B) HOCM?
Atenolol, ACEi, clopidogrel
What meds are used in CHF HOCM (stage C)?
Acutely = sedation, oxygen, +/- thoracocentesis
Furosemide, ACEi, Pimobendan, Spironolactone
What meds are used in ATE?
Analgesia (opioids), clopidogrel, heparin/low mol weight heparin, tPA for thrombolysis
