Happy Silly Cat

Feline Heart Health: Understanding Atrial Fibrillation and Flutter in Cats

Atrial Fibrillation and Atrial Flutter in Cats: Understanding the


Causes, and

Treatment Options

An animal’s heart is one of the most crucial parts of its body, allowing it to live, breathe, and move as it pleases. Cats, like humans, can suffer from a range of heart diseases, among which is atrial fibrillation (AF) and atrial flutter (AFL).

Both conditions are a form of arrhythmia that affects the normal heart rhythm in cats. In this article, we will explore what AF and AFL are, their symptoms, causes, diagnosis, and treatment options.

Heart Chambers and Valves

Before getting into the specifics of AF and AFL, it is essential to understand the anatomy of a cat’s heart. A cat’s heart is made up of four chambers – two atria and two ventricles – and four valves.

The atria are the upper chambers of the heart that collect blood from the veins and pump it into the ventricles. The ventricles, on the other hand, are the lower chambers of the heart that pump blood out of the heart and into the arteries.

The valves of the heart regulate blood flow by opening and closing, ensuring that blood moves in the right direction. The four valves in a cat’s heart are the mitral valve, tricuspid valve, aortic valve, and pulmonary valve.

Atrial Fibrillation vs Atrial Flutter

Now that we have a basic understanding of the heart’s chambers and valves let us look at AF and AFL. Atrial fibrillation is an abnormal heart rhythm characterized by the rapid, irregular beating of the atria.

The irregular beats can cause the heart to pump blood inefficiently, leading to a range of symptoms in cats, including exercise intolerance, lethargy, and coughing. Atrial flutter, on the other hand, is a heart rhythm problem that often occurs in cats with underlying heart disease such as cardiomyopathy.

AFL causes the heart to beat too fast or too slow due to an interruption of electrical signals, which can cause blood clots to form in the atria, increasing the risk of stroke and heart failure. Diagnoses for AF and AFL usually involve an electrocardiogram (ECG), a test that measures the heart’s electrical activity.


The common symptoms of AF and AFL include a galloping heart, coughing, weakness, dyspnea, tachypnea, lethargy, and syncope. Cats with AF may also experience ventricular arrhythmias, in which the ventricles beat out of sync with the atria.

Additionally, cats with AFL may be prone to fainting episodes due to inefficient blood flow or blood clots.


The underlying causes of AF and AFL can vary, and they include chronic diseases such as hypertension, hyperthyroidism, or chronic kidney disease. Enlarged hearts or cardiomyopathy, congenital heart defects, and neoplasia or cancer can also cause AF and AFL.

In some cases, taking medication such as digoxin can also lead to AF and AFL. Additionally, cats with congestive heart failure (CHF) are at an increased risk of developing AF or AFL.


To diagnose AF and AFL, a veterinarian will typically gather the animal’s medical history and perform a physical examination. Blood tests, a biochemical profile, and a urinalysis may also be ordered to evaluate the cat’s overall health.

Additionally, an echocardiography test or color Doppler may be ordered to image the heart for structural damage or abnormalities. If necessary, X-ray imaging may also be used.


The treatment options for AF and AFL vary depending on the cat’s specific case, severity of the condition, and underlying causes.

Treatment may involve medication to stabilize the heart rhythm, such as beta-blockers, calcium channel blockers, or antiarrhythmics.

Additionally, electrical shock therapy, known as cardioversion, may be used in more severe cases to reset the heart’s rhythm. Furthermore, treatment may include addressing underlying diseases such as hyperthyroidism, hypertension, and congestive heart failure (CHF).

In some cases, surgical procedures such as pacemaker implantation or angioplasty may be necessary. Finally, home care may play a crucial role in reducing symptoms and managing the condition.

Owners may be advised to limit their cats’ physical activity, reduce their stress levels, and provide them with a low sodium diet.

Types of Atrial Fibrillation in Cats

Finally, it is important to note that there are different types of AF in cats. Primary atrial fibrillation is characterized by no underlying cardiac disease, and the cause is unknown.

Secondary atrial fibrillation is typically seen in cats with severe underlying cardiac disease, such as cardiomyopathy or CHF. Paroxysmal atrial fibrillation occurs as periodic, recurrent episodes, and is of short duration.

Persistent atrial fibrillation lasts more than 48 hours and requires treatment, while permanent atrial fibrillation is ongoing and unable to be treated.


AF and AFL can significantly impact a cat’s quality of life, but with an early diagnosis and proper treatment, cats can often live a long and healthy life. While the causes and treatment options may vary, it is essential to be aware of the possible symptoms and seek veterinary care at the first sign of any irregularities or changes in your cat’s behavior.

Understanding the different types of AF and AFL can also help provide insight into the cause and severity of the condition. By working with a veterinarian and providing ongoing home care, owners can help improve their cat’s chances of maintaining a healthy heart rhythm and overall wellness.

Causes of Atrial Fibrillation in Cats

Atrial fibrillation (AF) is a common heart condition that can affect cats of all ages and breeds. It is vital to recognize the underlying causes of AF, as this helps with planning and implementation of appropriate treatment options.

Here we will look at some of the common causes of AF in cats and what leads to this condition. Chronic Disease of the Heart:

Valve disease and cardiomyopathy are common chronic heart diseases that can lead to AF in cats.

Valve disease occurs when there is a defect in one or more of the heart valves that control the blood flow within the heart. This defect can cause the valves to leak and result in a backward flow of blood within the heart.

The heart then needs to work harder to pump blood, leading to an enlargement of the heart that can cause the development of AF.

Cardiomyopathy, on the other hand, is a primary disease of the heart muscle that results in the heart having difficulty in pumping blood effectively.

Cardiomyopathy can be of two types: dilated cardiomyopathy and hypertrophic cardiomyopathy. Dilated cardiomyopathy is a condition where the heart becomes weakened and enlarged due to the thinning of the heart wall.

Hypertrophic cardiomyopathy, on the other hand, is a condition where the heart muscles become thickened, causing the ventricle to restrict the blood flow and leading to AF. Enlargement of the Heart:

Heart enlargement caused by either genetic or environmental factors can also lead to the development of AF in cats.

Dilated or enlarged hearts can be caused by several factors, including high blood pressure and long-term untreated heart disease. Enlarged hearts can cause changes in the rhythm of the heart leading to AF.

Hypertrophic cardiomyopathy, which was mentioned earlier, is another condition that can cause heart enlargement and lead to AF. Congenital Heart Disease:

It is possible for cats to be born with heart defects or other abnormalities that can lead to AF.

Congenital heart defects include atrial or ventricular septal defects, which occur when there is a gap in the walls separating the heart chambers. This defect can cause the heart to become overloaded and lead to an irregular heartbeat.


Cats with certain kinds of cancer or tumors may develop AF. Tumors in the heart or chest cavity can interfere with the heart’s electrical signals, leading to AF.

Digoxin Toxicity:

Digoxin is a medication often prescribed in cats with heart conditions to improve heart function. Nevertheless, an overdose or a decreased clearance of digoxin by the body can lead to toxicity, which can be fatal.

High levels of digoxin in the body can cause abnormal electrical activity in the heart leading to AF. Congestive Heart Failure (CHF):

CHF is a condition where the heart can’t pump blood effectively, causing fluid build-up in the lungs and other parts of the body.

A cat with CHF may develop AF because the heart is struggling to function properly.

Treatment of Atrial Fibrillation in Cats

The aim of the treatment of AF in cats is to restore the normal linear heart rhythm. The treatment options for AF are best determined by the cause of the arrhythmia, the severity of the condition, and the presence of other associated heart conditions.

Treatment for Rapid Heart Rate:

The first line of treatment for AF in cats includes medication to control the rapid heart rate. These medications can include beta-blockers, calcium channel blockers, and anti-arrhythmic medications.

The medication will reduce the heart rate and help the heart pump more effectively. Normalizing Heart Rhythm:

If the medication approach fails, another option is cardioversion or electrical shock therapy.

This process will reset the heart’s rhythm by synchronizing the sinoatrial node and the atrioventricular node.

Treatment for Underlying Disease:

AF is often a symptom of an underlying disease.

Treatment of the underlying disease can help ensure the proper management of AF symptoms.

This may involve treating conditions like CHF, hypertension, hyperthyroidism, and other heart diseases, which may contribute to the development of AF. Home Care and Monitoring:

Home care and monitoring are critical in managing AF in cats.

This means providing a low-sodium diet, limiting physical activity, and reducing stress levels. Regular veterinary follow-up appointments are essential to monitor the cat’s condition and progress.

Owners can also help by keeping a diary of their cat’s behavior, including any changes they notice in their cats eating, sleep, poop, and activity.


Cats with AF require long-term management, and owners should make sure to consult their veterinarian if they notice any changes in their cat’s health or behavior. Identifying and treating the underlying cause of AF is essential to effective treatment.

Proper management of the condition can help improve the quality and length of life for cats with AF. Atrial fibrillation (AF) and atrial flutter (AFL) are common heart conditions that can affect cats of all ages and breeds.

The underlying causes of AF and AFL can vary and include chronic diseases of the heart, enlargement of the heart, congenital heart disease, neoplasia, digoxin toxicity, and congestive heart failure (CHF).

Treatment options for AF and AFL include medication, electrical shock therapy, treating underlying diseases, and home care.

Early detection is essential, and symptoms such as weakness, coughing, and exercise intolerance should be monitored and referred to a veterinarian. Owners can help by keeping a diary of their cat’s behavior, providing a low-sodium diet, limiting physical activity, and reducing stress levels.

Proper management of the condition can help improve the quality and length of life for cats with AF and AFL.

Popular Posts