HCM/RCM Flashcards
T/F: maine coon, ragdoll, american shorthair, sphynx, british shorthair, persian, birman, himalayan, siberian, and turkish van are all breeds that are predisposed to HCM and RCM
FALSE, HCM only
what is the most common breed to be diagnosed with HCM?
DSH
what is the most common presenting complaint in symptomatic cats with HCM?
dyspnea
a cat comes in with back leg paralysis and cyanotic paws. what is on the top of your differential list?
aortic thromboembolism (ATE) “saddle thrombus”
in HCM cats due to stagnant blood in atria from mitral regurgitation (SAM) in dilated atria (elevated filling pressures)
what are two important co-morbidities in cats with HCM?
hyperthyroidism and renal dz
T/F: HCM w/o SAM and/or DLVOTO does not cause turbulent blood flow (no murmur)
TRUE
what are the main physiologic differentials for heart murmurs in cats?
DRVOTO, anemia (decreased viscosity), hyperthyroidism (increased HR and contractility), fever (increased SNS tone)
you have a 7 year old asymptomatic cat with an arrhythmia (or heart murmur or gallop) come in to the clinic. the owners are hella rich and willing to do whatever’s needed. what are the main tests you would perform?
MDB, BP and TT4 +/- thoracic rads, NT-proBNP
*ECG in arrhythmia case
a 8 year old asymptomatic ragdoll comes in whose owners are major hypochondriacs. dr. google told them there cats is going to die of sudden death because all ragdolls have HCM. they only have $100 to their name. what tests can you suggest?
NT-proBNP +/- genetic test
a symptomatic patient is unstable and has respiratory distress. what is the first test you should do?
thoracic FAST (check for pleural effusion)
an unstable cat with respiratory distress does not have severe pleural effusion (confirmed with thoracic FAST). what is your next plan of action?
furosemide, O2, other CHF tx
what are the differential diagnoses for LV concentric hypertrophy?
aortic stenosis, systemic hypertension, hyperthyroidism, acromegaly, infiltrative dz
what are the most common arrhythmias in cats with HCM?
VPCs, VT, APCs, SVT/A fib
what is the most common cardiac biomarker used in feline cardiology?
N-terminal proBNP
point-of-care SNAP (IDEXX) test “cardiopet” available!!
though there are no definitive treatments for HCM in cats, what are some drugs that have potential benefits?
channel blockers (diltiazem), ACE inhibitors, aldosterone antagonists, beta blockers (atenolol), anti-platelet drugs (clopidogrel)
what is left atrial enlargement a risk factor for?
CHF, ATE, sudden death
recommend one or more drugs when present
why do some cardiologists prescribe beta blocker therapy in cats with mod to severe HOCM?
reduce dynamic LVOTO (i.e. atenolol > - inotrope and decrease HR)
what drug therapy would you suggest for an HCM cat with refractory CHF?
spironolactone, higher doses furosemide or HCTZ, pimobendan
what is a major cause of pain in cats during recovery in cats with severe ATE?
reperfusion injury. reperfusion produces a large amount of free radicals which cause systemic toxemia and inflammation
what is the criteria for treatment of arrhythmias in cats with HCM?
ventricular or supraventricular tachycardia, frequent singles, coupletss, and/or triplets, R-on-T
when should you reevaluate a patient diagnosed with HF?
w/in 1 week of starting a medication or increasing the dose
T/F: prognosis is good for 80% of asymptomatic cats with HCM
TRUE
T/F: sudden death can be the first sign of a cat with HCM
TRUE, may be asymptomatic and never develop murmur or other abnormal exam findings
what is the major difference between HCM and RCM?
there is NORMAL ventricular wall thickness
“intermediate” or “unclassified” cardiomyopathy
what do you see histologically in a cat with RCM?
focal or diffuse fibrosis in the endocardium and/or myocardium
what is restrictive filling?
diastolic dysfunction when the ventricle is stiff and non-compliant
occurs in RCM rather than delayed myocardial relaxation in HCM
which dz is harder to diagnose, HCM or RCM?
RCM because SAM doesn’t occur therefore no destruction disorder causing auscultable abnormalities
what sign might you see in an echo of a cat with RCM?
fibrosis is hyperechoic, atrial systole wave short because there’s no ventricular compliance (in transmitral flows)
ATE is more common in HCM or RCM?
RCM
what drug is routinely used in cats with RCM that have systolic function?
pimobendan
