The heart is responsible for moving blood throughout the body. Blood is essential to carry nutrients to and waste products from all the cells of the body. The heart is broken down into four chambers, each with openings protected by "doors" called valves. The heart forces blood from one chamber to another. This entire process results in heart sounds. A cat normally has two beats that can be heard-lub dub. However, when they have a heart murmur, one of those beats is replaced by a "whoosh" sound -- either a lub "whoosh" or a "whoosh" dub. Rarely, they can have both beats replaced - "whoosh whoosh." The whoosh sound is similar to the sound produced by a river rapids. Basically, a heart murmur is a turbulent sound heard while listening to the heart.

There are many things that can cause heart murmurs. Causes can stem from problems within the heart (cardiac) or from problems outside the heart (not directly involving the heart).

Non-cardiac

• Low red blood cell numbers (anemia)
• High blood pressure
• Fever
• Certain medications
• Hyperthyroidism

Cardiac

• Cardiomyopathy (changes in the heart musculature)
• Valvular defects (defect with the heart valves)
• Innocent murmurs (murmurs heard in young, growing animals. These disappear by 6 months of age.)
• Congenital defects (birth defects associated with the heart such as valvular defects, a deformed heart, "hole" in the heart)

Blood tests will help screen for thyroid disease as well as anemia. Blood pressure readings can help evaluate for high blood pressure. A chest x-ray allows your veterinarian to get a general pictures of the chest to help evaluate for both abnormal heart shape and sizes as well as to evaluate for any lung disease that can be stemming from heart disease. An echocardiogram (sonogram of the heart) can help evaluate the inside of the heart-allowing an accurate evaluation of the heart chamber size, muscle thickness, as well as valve function. This will allow us to screen for actual heart disease. An electrocardiogram can also be helpful in diagnosing the cause of the murmur when a murmur is originating from the heart, especially if an abnormal heart rhythm is heard.

There always is risk with any anesthesia. Having a heart murmur can increase this risk. We advise having the heart evaluated to make sure it is functioning normally before any anesthetic procedure is done. Typically, an xray and echocardiogram is performed.  Occasionally, an EKG is also needed, especially if an arrhythmia is also noted. In addition, we will use the safest anesthesia we can to try to support the heart during an anesthetic procedure, along with intravenous fluids and any other appropriate medication.

Treatment depends on the underlying cause of the heart murmur. Cats with high blood pressure will most likely be placed on blood pressure reducing medications. Treatment for cats with anemia is geared towards the cause of the anemia. Medications for this can vary from vitamins, antibiotics, anti-inflammatories, and/or erythropoietin (a hormone that stimulates the body to make red blood cells). Treatment for cats with murmurs due to hyperthyroidism is geared towards curing or controlling the over abundance of thyroid hormones being produced by the abnormal thyroid gland. No treatment is needed for cats with innocent growing murmurs as these murmurs go away upon reaching adulthood. Cats with valvular disease or cardiomyopathy may need to be on medications to allow the heart to pump more effectively. Sometimes cats with these problems develop heart failure. Cats in heart failure are considered much more fragile and need much more monitoring. They will need more frequent check-ups along with bloodwork, x-rays, and electrocardiogram monitoring to screen for any progression or complications which may require a change in their current therapy. Although there is no cure for heart failure, should it develop, we do have medications to keep your cat comfortable for as long as possible. Often cats in heart failure are on a variety of medications such as a "water pill" (Lasix) to help prevent fluid accumulation in the body, medications to allow the heart to pump effectively (Diltiazam or Enalapril), prescription low salt diets, potassium supplements, and blood vessel dilators.

Not all cats with cardiac murmurs will develop heart failure. Your veterinarian will monitor your cat’s heart disease by listening for any changes in the sound of the heart or lungs. You can help at home by monitoring for any coughing, open-mouth breathing, fainting, exercise intolerance, or any other breathing difficulties.

Kentwood Cat Clinic
Cat Clinic North

Dr. Tammy P Sadek, Diplomate ABVP Feline
Dr. Maria Berger
Dr. Kathleen Cannady
Dr. Joe Simon