Category:Cardiomyopathy
Cardiomyopathies are diseases affecting the cardiac myocardium causing dysfunction. Primary cardiomyopathies are characterized by having an unknown cause while secondary cardiomyopathies have an identifiable cause. The primary cardiomyopathies will be the centre of our discussion.
There are four types of primary cardiomyopathies:
- Dilated Cardiomyopathies
- Hypertrophic Cardiomyopathies
- Restrictive Cardiomyopathies
- Intermediate/Unclassified Cardiomyopathies - occur when the cardiomyopathy does not match the normal diagnostic checklist for either dilated or hypertrophic cardiomyopathies. Not enough information is available on this condition at this time.
The first three are the most common idiopathic cardiomyopathies.
There are five types of secondary cardiomyopathies:
- Infectious (e.g. Parvovirus, Toxoplasmosis)
- Infiltrative (e.g. Neoplasia)
- Metabolic (e.g. Endocrine disorders)
- Nutritional (e.g. L-Carnitine deficiency, Taurine deficiency)
- Toxic (e.g. Lead, Doxorubicin, Monensin)
Dilated Cardiomyopathy
Hypertrophic cardiomyopathy
Incidence:
The cat is most commonly affected. There is some evidence of inheritance, as in man, and the disease is said to be more common in male cats. There is a wide age range of 7 months to 24 years.
Inherited in Maine Coon cats.
Clinical signs:
Grossly there is disproportionate hypertrophy of the left ventricle and often the interventricular septum. The chamber size is dramatically reduced.
Histologically there is haphazard hypertrophy of the myocardial fibres.
The reduction in left ventricular volume and the stiffened ventricular wall results in diastolic dysfunction, the stroke volume is reduced resulting in congestive heart failure and the following clinical signs:
- Tachycardia.
- Arrhythmia (abnormal myocardium)
- Dyspnoea.
The force of the left ventricular contraction reduces afterload and reduces end-systolic volume to zero in some cases. This is cavity obliteration.
- Thromboembolic disease is a frequent complication. The thromboemboli most often impact in the femoral arteries manifesting as an acute hindlimb paralysis.
Restrictive Cardiomyopathy
Other Cardiomyopathies
Feline Hyperthyroidism
A hypertrophic cardiomyopathy is seen secondary to this disease in elderly cats. Thyroid hormones induce the growth of the myocardium.
Secondary to toxic agents
Includes:
- Dilated myopathy in horses with monensin toxicity.
- Dilated myopathy in dogs with long term administration of doxorubicin.
- Dilated myopathy in cats due to taurine deficiency.
Pages in category "Cardiomyopathy"
The following 4 pages are in this category, out of 4 total.