HCM

Question 1

What abnormal PE findings raise suspicion for cardiomyopathies in the cat?

Answer 1

Pleural effusion
Gallop sound
Tachypnea
Weight loss

Question 2

What is a gallop sound and what is its significance?

Answer 2

S3 or S4 heart sound
S3: vibration of ventricular walls during active ventricular filling
S4: final ventricular filling by atrial contraction in a poorly compliant ventricle

Question 3

What diagnostics may you consider in a cat in respiratory distress in which cardiac disease is suspected?

Answer 3

Thoracic POCUS +/- NT-proBNP
Thoracic radiographs, echocardiogram, bloodwork, BP

Question 4

What are the 3 common causes of left ventricular concentric hypertrophy in the cat?

Answer 4

Hyperthryoidism
Systemic hypertension
Primary HCM

Question 5

What is NT-proBNP and how do you interpret an elevated value?

Answer 5

N-terminal pro B-type naturetic peptide
Hormone secreted by cardiomyocytes that causes renal and sodium loss, as well as vasodilation
Production and excretion is increased in response to stretch of the heart
>100 is abnormal

Question 6

What are radiographic signs of LV concentric hypertrophy in cats?

Answer 6

Cardiomegaly
Pleural effusion
Dilated pulmonary veins
Diffuse unstructured interstitial pattern

Question 7

What are echocardiographic signs of LV concentric hypertrophy in cats?

Answer 7

LV concentric hypertrophy
LA enlargement
Mild pericardial effusion
Spontaneous echo contrast (“smoke”) in left auricle

Question 8

Stage A HCM

Answer 8

Predisposed
No treatment, monitor

Question 9

Stage B1 HCM

Answer 9

Subclinical - normal/mild atrial enlargement
No treatment +/- atenolol for DLVOTO

Question 10

Stage B2 HCM

Answer 10

Subclinical - moderate/severe atrial enlargement
No treatment +/- atenolol if concurrent ventricular tachyarrythmias

Question 11

Stage C HCM

Answer 11

Current/previous CHF or ATE
Acute treatment: furosemide, oxygen, sedation, +/- thoracocentesis
Chronic treatment: furosemide, clopidogrel, +/- ACEi, low-sodium diet

Question 12

Stage D HCM

Answer 12

Refractory CHF
Torsemide, +/- spironolactone, +/- pimobendan

Question 13

What are 4 possible outcomes for feline cardiomyopathies?

Answer 13

CHF
Arrhythmias
Sudden death
Aortic Thromboembolism

Question 14

How should owners monitor patients with HCM at home?

Answer 14

Resting RR should be < 30 breaths per minute
Also monitor for increased respiratory effort, syncope, inappetence, hiding, paresis/paralysis