HYPERTROPHIC CARDIOMYOPATHY IN CATS
(HCM)
General Information:
Hypertrophic cardiomyopathy is an abnormal thickening
(hypertrophy) of the heart muscle in cats. It is unknown whether
the condition has a single cause or is due to a number of factors.
Suggested causes include viral infections, an allergic reaction
("self-allergy"), toxins and lack of the essential nutrient
taurine.
Thickening of the heart muscle causes both improper
filling of the heart chambers and impaired pumping action of the
heart, as well as abnormal heart rhythm. These changes result
in difficult breathing, fluid accumulation in the lungs and abdominal
cavity, blood clots and sudden death. In mild cases, lethargy
and a poor appetite may be the only signs in the early stages.
Male and female cats of any age may be affected,
but the disease is most common in middle-aged males.
Diagnostic Information:
Diagnosis of hypertrophic cardiomyopathy is based
on suggestive findings on thoracic radiographs, blood profile
and electrocardiograph.
Treatment Information:
Treatment involves increasing the efficiency of the
filling and pumping action of the heart, removing any fluid build-up
in the lungs or abdominal cavity, preventing the formation of
blood clots (emboli) and performing any emergency treatments that
are necessary at presentation.
These goals are achieved through the use of medications,
altering diet and exercise.
- Medications:
Two commonly used drugs that will decrease the heart
rate, lower chamber pressures (allow better filling of the heart
chambers), enhance the relaxation of the heart muscles (myocardium):
Diltizam and Propanalol.
*Use medications as directed by your veterinarian's
office*
- Diet:
A diet low in sodium, magnesium and potassium, and
increased in taurine is essential for your pet. In most cases, we recommend feeding
Hill's Prescription Diet h/d.
- Exercise:
Exercise should be greatly restricted, any increased
work load placed on the heart could result in a sudden death scenario.
Prognosis:
The mean survival times for all cats with HCM was
732 days. Increased survival times have been noted in patients
that are presented with heart rates less than 200 beats/minute,
and decreased in patients that are presented with heart rates
greater than 200 beats/minute.
We hope that you will find this information helpful in your quest
for better pet care. If you have any questions or comments, please call your
veterinarian's office, or feel free to
e-mail us.
David E. Hammett, DVM
and the Staff of All Creatures Veterinary Clinic, PC
