Irregular Heartbeat in Cats

An irregular heartbeat could be an indication of a serious underlying condition, but may not be a cause for concern. In some cases, irregular heartbeats have no known cause and do not require any medical attention. It is impossible to know without medical analysis if the heartbeat irregularity is serious or not. Any cat with an irregular heartbeat should be seen by a medical professional and tested using an electrocardiogram or other diagnostic method.

An irregular heartbeat, also referred to as an arrhythmia, occurs when an abnormality is observed in the heart’s normal rhythm. This irregularity could include beating too fast, too slow, or pauses between heartbeats, which is often referred to as “skipping a beat”.

An irregular heartbeat may not cause any observable symptoms. In many cases, the only sign of an irregularity is the audible difference noticed when listening to the heart with a stethoscope or similar medical device. With more severe arrhythmias other symptoms may be noticed. It is possible for symptoms to come and go rather than being present all the time. 

Symptoms Include:

• Abnormal heartbeat or rhythm
• Weakness
• Lethargy
• Exercise intolerance
• Depression
• Lack of appetite
• Trouble breathing
• Panting or rapid breathing
• Pale gums or mucous membranes
• Bluish tint to gums, mucous membranes, or skin
• Excessive sleeping
• Fainting or collapse
• Sudden death

Types

Several different types of irregular heartbeat can occur in cats. The type of irregularity is generally described by how the rhythm differs from a normal heartbeat. Types that may be present in cats include:

• Bradycardia, or a beat that is too slow
• Tachycardia, or a beat that is too fast
• Premature beat
• Irregular rhythm
• Pauses in rhythm
• Heart murmur

Numerous issues can cause an irregular heartbeat. Commonly, arrhythmia is caused by heart disease. It is also possible for an irregular heartbeat to occur with no discernable cause. An irregular heartbeat can occur in any cat regardless of age, sex, or breed. Some common causes of irregular heartbeat in cats or other companion animals include:

• Heart disease
• Heart failure
• Hyperthyroidism, or excessive thyroid hormones
• Electrolyte imbalances
• Anemia or low red blood cell count
• Hypoproteinemia, or low protein levels
• Certain medications
• Nerve conditions
• Heart tumors or other types of cancer
• Trauma or injury
• Blood clots
• Congenital or birth defects
• Toxicity
• Parasite infestation
• Obesity

Diagnostic methods will focus on determining the type and severity of the arrhythmia as well as its underlying cause. Be prepared to discuss your cat’s medical history and any symptoms you have observed with your veterinarian. A full physical examination is necessary for any animal suspected of having a heart condition. Your veterinarian will look for signs of severe conditions, including fluid retention, fever, and pain. During the physical examination, your veterinarian will listen to your pet’s heart sounds to determine the type of irregularity. Anytime an irregular heartbeat is found, an electrocardiogram or ECG will be used to examine the electrical impulses in the heart. Blood analysis and x-rays or other imaging methods may also be used to determine the underlying cause of the arrhythmia. Certain causes may require additional diagnostic methods be employed, including tissue biopsy, urinalysis, or visual examination of airways or other passages with an inserted camera. 

In many cases, arrhythmia will not require medical treatment. If treatment is needed, it is generally prescribed to treat the underlying cause of the irregular heartbeat. Depending on the cause, medications or other treatment may be required. If the irregularity is severe, hospitalization may be needed to stabilize your pet. Restriction of activity is also commonly recommended, even when treatment is available on an outpatient basis. Some common treatment methods include:

Oxygen Therapy 

Providing additional oxygen support using tubes, masks, or an oxygen cage may be prescribed if your pet is having trouble breathing or their blood oxygen saturation is low. This therapy carries a very low risk but does require hospitalization or inpatient treatment. 

Intravenous (IV) Fluids 

Fluid therapy is commonly used when a cat is suffering from lethargy, weakness, or dehydration. The goal of this treatment is to restore proper hydration levels and maintain blood volume. This common treatment carries a low risk and is normally performed for a shorter period on an inpatient basis. 

Anti-inflammatory Medications 

This category of drug is used to reduce swelling throughout the body. It is often used in response to conditions that cause inflammation, which can interfere with the heart’s ability to perform. As with any medication, proper dosing for your cat’s size and health is essential to minimize the risk of side effects. 

Your pet’s prognosis will rely heavily on the underlying cause of the arrhythmia. In many cases, especially those where the cause is not life-threatening, the prognosis is excellent. Many cats, even those with congenital defects, can live a full life with an irregular heartbeat. Your veterinarian may recommend restricting your cat’s activity for a short period, or they may require a long-term change in lifestyle to compensate for poor heart performance. Proper nutrition is also important and dietary changes may be suggested, especially when obesity is the suspected cause. Be sure to follow all of your veterinarian’s recommendations, including proper dosing of any prescribed medications and returning for any requested follow-up visits.