DM3 Pt2-2 Cardiomyopathies Flashcards
What does the term ‘cardiomyopathy’ mean?
Cardiomyopathy means disease of the heart muscle, used when the cause is unknown. If the cause of heart muscle hypertrophy is known, it is termed secondary myocardial hypertrophy.
What diseases can cause secondary myocardial hypertrophy in cats?
Taurine deficiency (leading to dilated cardiomyopathy), hyperthyroidism, hypertension, and acromegaly can all cause secondary myocardial hypertrophy in cats.
How is cardiomyopathy diagnosed in cats?
Cardiomyopathy diagnosis is based on clinical signs, breed predispositions, and tests such as chest radiographs, ECG, and ultrasound (echocardiography) to assess heart size and function.
What role do genetics play in feline cardiomyopathy?
Genetic mutations are suspected to play a role in cardiomyopathy, with specific mutations identified in breeds like the Maine Coon and Ragdoll. Other breed predispositions are likely but yet unidentified.
What are common breeds with a genetic predisposition to hypertrophic cardiomyopathy (HCM)?
The Maine Coon and Ragdoll breeds have identified genetic mutations linked to hypertrophic cardiomyopathy (HCM).
How does cardiomyopathy typically present in terms of age and gender in cats?
Cardiomyopathy is more common in young and middle-aged male cats.
What is the treatment focus when a cause for cardiomyopathy is not identified?
Treatment focuses on managing heart rate, controlling high blood pressure, and addressing symptoms related to heart function.
What are the main diagnostic tools used to identify cardiomyopathy in cats?
The main diagnostic tools include radiographs of the chest, ECG for heart activity, and ultrasound (echocardiography) for definitive diagnosis of heart size and function.
What characterizes Dilated Cardiomyopathy (DCM) in cats?
DCM is characterized by enlargement of heart chambers and weakening of the heart muscle, leading to insufficient blood being pumped out of the heart.
What is the primary cause of Dilated Cardiomyopathy (DCM) in cats?
DCM is primarily caused by taurine deficiency, though it is rare today due to taurine supplementation in modern cat food.
What is Hypertrophic Cardiomyopathy (HCM) and how does it affect the heart?
HCM is the most common form of heart disease in cats, characterized by thickening of the ventricular walls, reducing the heart’s capacity to pump blood and potentially causing heart failure and thromboembolic disease.
What gene mutation is linked to Hypertrophic Cardiomyopathy (HCM) in certain cat breeds?
The MYBPC3 gene mutation (myosin binding protein C) is linked to HCM, particularly in Maine Coon and Ragdoll cats, although not all carriers develop the disease.
What are some clinical signs of heart disease in cats?
Clinical signs include a heart murmur, gallop rhythm (third heart sound), and arrhythmias. These signs should prompt further investigation with ECG and echocardiography.
What is the significance of a heart murmur in cats?
A heart murmur indicates turbulent blood flow and is a sign of potential heart disease, warranting further investigation.
How does a gallop rhythm sound and what does it indicate?
A gallop rhythm sounds like galloping horses and indicates heart disease in cats, prompting further investigation.
What treatment is recommended for cardiomyopathy in cats?
Treatment focuses on managing congestive heart failure as there is little evidence that treating before heart failure delays disease progression.
What breeds are most commonly associated with Hypertrophic Cardiomyopathy (HCM)?
Maine Coon and Ragdoll cats are most commonly associated with HCM due to the MYBPC3 gene mutation, but other factors may contribute to disease development.
What is the prognosis for cats with Hypertrophic Cardiomyopathy (HCM)?
HCM can lead to heart failure, thromboembolic disease, and sudden death in some cases, with no clear treatment to prevent progression before heart failure occurs.
What are the main signs of congestive heart failure in cats?
Breathlessness, lethargy, and loss of appetite are the most common signs, often developing quickly due to pulmonary oedema or pleural effusion.
Why is coughing not a common sign of heart failure in cats?
Unlike dogs, cats rarely cough with heart failure. Instead, the primary signs are related to fluid accumulation in the lungs, causing breathlessness and lethargy.
What causes pulmonary oedema and pleural effusion in heart failure?
Increased blood pressure from heart failure leads to fluid leakage into lung tissue (pulmonary oedema) or around the lungs (pleural effusion), impairing lung function.
What is thromboembolic disease, and why is it common in cats with heart failure?
Thromboembolic disease occurs when a blood clot (thrombus) forms in the heart, often in the left atrium, and travels to block small arteries, commonly affecting the hind legs and causing sudden pain and loss of limb function.
What are the signs of a thromboembolic event in cats?
Cats with a thromboembolic event may show sudden loss of use of both hind legs, cold limbs, and pain. This condition is often mistaken for a road traffic accident.
What is the prognosis for cats with thromboembolic disease?
The outlook is often poor due to underlying heart disease and the risk of further clots. Analgesia and appropriate discussion with owners are vital, as it is a painful condition.
What are the treatment goals for congestive heart failure in cats?
Treatment focuses on reducing fluid accumulation with diuretics, supporting heart function with drugs like ACE inhibitors and beta-blockers, and reducing the risk of thromboembolism with aspirin, clopidogrel, or heparin.
Which diuretic is commonly used to treat pulmonary oedema or pleural effusion in cats?
Furosemide is commonly used as a diuretic, though it can cause side effects like dehydration and low potassium, so monitoring is important.
What medications help reduce the risk of thromboembolism in cats with heart disease?
Aspirin, clopidogrel, and heparin may be used to reduce the risk of thromboembolism by inhibiting platelet function and decreasing blood clotting.
What medications are used to support heart function in cats with heart failure?
Common medications include ACE inhibitors, calcium channel blockers (e.g., amlodipine), and beta-blockers, depending on the cause of the heart disease.
