Hypertrophic Cardiomyopathy (HCM) in Cats
No treatment may be recommended for very mild cases with no symptoms, but regular follow-up vet visits are vital.
Initial hospital admission and stay is often recommended for severe cases, such as congestive heart failure (fluid accumulation in lung or chest cavity), abnormal heart rhythms, blood clots, kidney failure, and/or low blood pressure or shock.
Oxygen, diuretics and/or nitroglycerine ointment may be given for initial treatment of congestive heart failure.
Tapping abnormal fluid accumulations(thoracocentesis) from the chest cavity is needed when fluid when present and interferes with breathing.
Blood clot complications need treated with additional medications (for pain and clot control). (NOTE: Clot-busting drugs (TPAs) have been effective in cats, but have very serious side effects.).
Dietary modifications in cats with obvious heart failure is sometimes recommended (such as a sodium-restricted prescription or medical diet).
Beta-blockers to slow heart rate, minimize the impact of stress and reduce obstruction of the heart’s ventricular outlet.
Diltiazem (a calcium channel antagonist) if congestive heart failure or abnormal heart muscle relaxation is evident; Dilacor or Cardizem CD (long-acting forms of diltiazem) may be recommended for the convenience of once-daily dosing.
Enalapril or benazepril (to reduce blood pressure) can be recommended for cats with heart failure to reduce activity of harmful hormones and reduce sodium retention.
Diuretics (to promote urine secretion) for fluid accumulation.
Nitrates (topically applied with a gloved hand to a relatively hairless area, such as the inside of the ear) for home use if difficulty in breathing or home medicating is a problem; old dose wiped off before new dose applied.
Aspirin or coumadin for high-risk clot-formation cases.
Follow-up Care for Cats with Hypertrophic Cardiomyopathy (HCM)
Optimal treatment for a pet with HCM requires both home and professional veterinary care with follow-up being critical. Administer prescribed medications and alert your veterinarian if you are experiencing problems treating your pet. Follow-up includes:
Precise follow-up depends on the severity of your cat’s disease, its response to therapy, your vet’s recommendations and your views. A possible schedule may include follow-up every 6 to 9 months, depending on the natural course of the disease. Recheck examinations are done more frequently initially to monitor therapy.
Chest X-rays to monitor response to therapy
Blood samples checked periodically to monitor effect of drugs on kidneys and electrolytes (potassium, for example)
Blood pressure measurements taken periodically in cats receiving diuretics or ACE inhibitors like enalapril or benazepril (which reduce blood pressure).
Echocardiogram done initially and repeated periodically (at 3 to 6 months after diagnosis and again in 9 to 12 months, for example).
Disease can change rapidly, and tests to monitor disease progression will influence decisions about therapy and prognosis.