Cardiac Arrhythmias in Cats
By: PetPlace Veterinarians

Section: Veterinary Care In-depth

Diagnosis In-depth

Cardiac arrhythmias are often detected during the physical examination process. Your veterinarian will listen to your pet's heart with a stethoscope and can determine if your pet's heart rate is too slow, too fast, or is erratic. Once an arrhythmia is suspected, it is confirmed with an electrocardiogram (ECG, EKG). Your pet will be positioned on his right side and have clips or pads applied to his arms and legs. This process is painless. The machine is then turned on and a tracing is obtained of the electrical activity of the heart. The tracing is examined to determine that the heart rate or heart rhythm is normal.

Sometimes, a simple ECG is inadequate to evaluate the significance of an arrhythmia. Other methods of evaluating the heart rhythm include post-exercise ECG, hospital telemetry, ambulatory (Holter) ECG, and the use of a cardiac event monitor. These methods are particularly useful in assessing the overall frequency of an arrhythmia, the relationship of an arrhythmia to clinical signs, or the effectiveness of treatment.

In addition, other diagnostic tests are performed to determine the overall health of your pet.

Complete blood count – This is performed to evaluate the red blood cells, white blood cells and platelets. Some animals may be anemic or have an elevated white blood cell count.

Biochemical profile – This blood work is performed to determine the function of the body's organs and electrolyte levels. Some cats may have a high or low potassium level, elevated thyroid hormone levels or kidney or liver disease.

Radiographs – X-rays of the chest will help determine if congestive heart failure is present or if there is underlying heart disease.

Ultrasound – An ultrasound of the heart (echocardiogram) can help determine if underlying heart disease is present.

Treatment In-depth

Treatment will vary and depends on the type of arrhythmia and underlying disease. Some arrhythmias do not require treatment and may spontaneously revert to normal. Other arrhythmias are more serious and necessitate treatment. Some of the treatment options include:

Various medications to help control the arrhythmia, treat the underlying heart disease, or improve cardiac function. Medications that are used include digoxin, diltiazem, propranolol, enalapril, procainamide, lidocaine, and atropine.

Certain types of cardiac arrhythmias require the placement of a pacemaker to control the arrhythmia. Severe heart blocks often require a pacemaker to keep the heart rate and rhythm normal.

Cats in congestive heart failure may need to be treated with a diurectic (e.g. furosemide) and possibly nitroglycerine.

Cats with underlying disease may require additional medication. For example, hyperthyroid cats may benefit from anti-thyroid medication.