Tier 1 — must know
Feline
Cardiology
Hypertrophic Cardiomyopathy
HCM in cats · diastolic dysfunction · aortic thromboembolism · CHF management
⏱ 3–4 min read · Topic 3 of 5
5
Practice Qs
4
Traps
High
Exam freq.
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Your status
Study mode
Exam core — read this first
HCM → primary concentric LV hypertrophy without outflow obstruction; diastolic dysfunction
Clinical signs → gallop rhythm, murmur, arrhythmia, dyspnea (CHF), sudden hind limb paralysis (ATE)
Diagnosis → echo shows concentric LVH; LA enlargement predicts ATE risk
Board logic → acute hind limb paralysis + pain + cold extremities = ATE until proven otherwise
Visual summary — Normal vs HCM
| Feature | Normal heart | HCM |
|---|---|---|
| LV wall thickness | < 5.5 mm | > 5.5 mm |
| LA size | Normal (< 16 mm) | Enlarged (LA:Ao > 1.5) |
| Systolic function | Normal | Normal to hyperdynamic |
| Outflow obstruction | Absent | Absent (concentric HCM) or dynamic (HOCM) |
| Clinical risk | None | CHF, ATE, sudden death |
Key data
Echo LV wall
> 5.5 mm
Diagnostic for HCM
LA:Ao ratio
> 1.5
ATE risk predictor
NT-proBNP
↑ Elevated
Cardiac biomarker
Blood pressure
Check to rule out HTN
Hypertensive heart disease
Practice questions
A dyspneic cat has a gallop rhythm and systolic murmur. Echo shows concentric LVH with LA enlargement. Most likely diagnosis?
A cat presents with acute hind limb paralysis, vocalizing in pain, and cold hind paw pads. What is the most likely diagnosis?
What is the most important initial therapy for a cat with aortic thromboembolism?
Which breeds have known genetic mutations associated with HCM?
Which biomarker is useful for differentiating cardiac vs respiratory causes of dyspnea in cats?