Rapid Heart Rate in Cats

The heart of a cat is composed of four chambers; the right and left atria make up the top two chambers of the heart, while the right and left ventricles make up the bottom portion of the heart. In order to circulate the blood to each chamber and to the body, the heart has an assortment of valves that temporarily open to allow blood to pass through. The tricuspid valve is located between the right atrium and the right ventricle. The mitral valve is located between the left atrium and the left ventricle. The pulmonary valve is located between the right ventricle and the main pulmonary artery. Finally, the aortic valve is located between the left ventricle to the main artery of the body, the aorta.

These valves separate oxygenated blood from un-oxygenated blood and complete the blood exchange through the body, but in order for the blood to move, the heart muscle needs to contract. The sinoatrial node is the electric impulse that triggers the heart to pump blood through each of the heart’s valves and chambers. The sinoatrial node or pacemaker, is what we feel as the cat’s heartbeat and can measure the number of times the electric impulse triggers the heart to pump over a minute’s time, giving us the feline’s general heart rate. The average heart rate for a feline is roughly 140-220 bpm (beats per minute), depending on the size of the cat, but complications with a feline’s sinoatrial node can make the heart beat over 240 bpm. A rapid heart rate in cats is a heart rate greater than 220 bpm and is known as tachycardia.

A cat with a rapid heart rate may have little to no present symptoms, as a rapid heart rate is a symptom in itself and not the definition of a disease. Congestive heart failure is the common cause of a rapid heart rate in cats, therefore, a feline may present disease-related symptoms, such as:

• Cyanosis (blue discoloration of the mucous membranes)
• Dyspnea (difficulty breathing) 
• Cough

Additional symptoms a cat may display with a rapid heart rate may include: 

• Heart murmur 
• Weak pulse
• Tachycardia (rapid heart rate) 
• Sudden death
• Exercise intolerance
• Overall weakness
• Syncope (fainting)

There are a number of physiological and pathologic reasons a feline could develop a rapid heart rate. A cat could experience a temporarily elevated heart rate due to fear, excitement, rage, restraint, and exercise, but a prolonged rapid heart rate could be caused by a serious health condition including: 

• Pancreatitis 
• Cancer 
• Heart tumor
• Digitalis toxicity (heart medication poisoning) 
• Myocarditis 
• Gastric dilation
• Chronic heart-valve disease
• Cardiomyopathy 
• Congenital heart defect
• Anemia (low red blood cell count)
• Shock
• Thromboembolic disease 
• Hypovolemia
• Hypothyroidism
• Metabolic disease
• Pain
• Fever
• Stress

Diagnosis of a rapid heart rate in a cat can be completed simply through listening to the heart with a stethoscope, but to pinpoint the underlying cause for a cat’s heart to pump faster than it needs to, a thorough veterinary examination will be required. The veterinarian will need to take a look at your cat’s medical records, current medications, and past medical problems, as past complications could be linked the feline’s current health problem. Blood work is likely to be done in order to detect any abnormalities within the blood itself or the function of the body’s organs. 

ECG

An ECG or electrocardiogram is a non-invasive test that uses sensory attachments to detect the electric impulses produced by the heart. An ECG can determine the feline’s electrical activity and heart rhythm. 

Auscultation

Auscultation is the listening of heart sounds through the use of a stethoscope. This examination tool can help the veterinarian detect a heart murmur and arrhythmias (irregular heart beat). 

Radiography (x-ray)

A thoracic radiograph, or x-ray of the chest, can provide valuable information to assess a feline with a rapid heart rate. The veterinarian will be able to detect an enlarged portion of the heart, indicating one of the values is not working properly as blood is pooling into one heart chamber. Tumors that have grown within the heart tissues can also be detected on an x-ray and aid the doctor in proper treatment.

The treatment of a rapid heart rate in cats depends on the overall condition causing the heart to pump faster than it needs to. If the feline is unstable, he or she will need to be hospitalized until the cat is once again stable and the proper medications can be given. There is no treatment for a rapid heart rate in cats by itself.

If the overall cause of the cat’s rapid heart rate is determined to be a metabolic condition, the prognosis is generally good. However, heart disease, cancer, and congenital problems could worsen over time, increasing the chance for sudden death. The veterinarian will likely have your feline complete routine veterinary check-ups to monitor any changes in their condition.