Feline Flash Notes - Feline HCM

Question 1

what cats may be predisposed to HCM?

Answer 1

any ages, males more severe than females

autosomal dominant in maine coon & ragdoll breeds

Question 2

what are the clinical signs associated with HCM?

Answer 2

CHF - tachypnea, dyspnea, open-mouth breathing, anorexia, & weight loss

aortic thromboembolism

Question 3

what are the 4 p’s of saddle thrombus?

Answer 3

pain, paralysis, pallor, & pulselessness

Question 4

what is appreciated on auscultation of a cat with HCM?

Answer 4

tachycardia, murmur, dull ventral lung sounds, crackles

Question 5

what is seen on ECG in a cat with HCM?

Answer 5

tachycardia, supraventricular or VPCs, left atrial dilation (p mitrale), left ventricular hypertrophy (left axis deviation)

Question 6

what is seen on radiographs in a cat with HCM?

Answer 6

DV view - valentine heart representing bi-atrial enlargement, left atrial bulge at 1-3 o’clock, elongated heart

lateral - elevated trachea & round heart silhouette

Question 7

what is seen on echo in a cat with HCM?

Answer 7

concentric left ventricular hypertrophy >/= 6 mm septum or left ventricular free wall (end diastolic thickness), papillary hypertrophy, & left atrial enlargement

Question 8

what other diagnostic test would you use on a maine coon or ragdoll cat that you suspect has HCM?

Answer 8

myBPC gene test

Question 9

what is the test of choice for diagnosing HCM in a cat?

Answer 9

echocardiogram

Question 10

what is the treatment of choice for chronic HCM?

Answer 10

3 D’s & rest

diet - low sodium, palatable (very important for patient to eat!!)

diuretics - to reduce pulmonary edema, furosemide!!

dilators - ace inhibitor (enalapril) & beta blockers/calcium channel blockers (atenolol or diltiazem/amlodipine)

Question 11

what are 3 possible presentations of a cat with HCM?

Answer 11

1. compensated HCM - murmur ausculted on annual exam & no overt signs
2. CHF due to HCM - tachypnea, (> 40 bpm), dyspnea, open mouth breathing, syncope, cyanosis, etc
3. aortic thromboembolism due to HCM - pelvic limb paralysis, cyanotic nail beds, crying/painful, absent femoral pulses, & contracted gastrocnemius muscles

Question 12

what are 4 differentials for secondary HCM?

Answer 12

1. systemic hypertension
2. hyperthyroidism
3. sub-aortic stenosis
4. acromegaly

Question 13

what two breeds of cat have a genetic predisposition to HCM?

Answer 13

maine coon & ragdoll breeds

Question 14

what are the 3 key treatments for feline HCM?

Answer 14

diet - low sodium, palatable

diuretics - to reduce pulmonary edema

dilator - afterload & preload reducers, beta adrenergic blockers, & calcium channel blockers

Question 15

what are the 4 signs of aortic thromboembolism in a cat?

Answer 15

4 p’s!!!

pain, paralysis, pallor, & pulselessness

Question 16

what are 4 signs seen on rads that are suggestive of HCM in a cat?

Answer 16

1. valentine heart on DV view
2. left atrial bulge at 1-3 o’clock
3. elongated heart on lateral view
4. dorsally elevated trachea on lateral view

Question 17

what 4 findings on echo are supportive of diagnosing a cat with HCM?

Answer 17

1. concentric left ventricular hypertrophy - >/= 6 mm septum +/- left ventricular free wall end diastolic thickness
2. papillary hypertrophy
3. systolic anterior motion of the mitral valve (common but not all HCM)
4. left atrial enlargement in moderate to severe disease