In this article, our veterinary experts at Los Angeles County will talk about ECGs (electrocardiograms) for dogs and cats. You will learn when your vet may need to order an ECG for your pet and how to interpret the results. Understanding your pet's ECG results will help you make informed decisions about their healthcare.
What is an ECG?
An ECG (also called an EKG) is a heart monitoring test that uses sensors attached to the skin to track electrical activity. It's a safe and painless way to observe the heart in both animals and humans without any invasive procedures.
What Does an ECG Tell Your Veterinarian About Your Pet?
An ECG is a test that provides your vet with important information about your pet's heart. It can tell them how fast and regularly your pet's heart is beating, and how electrical signals are moving through each part of the heart. The ECG will show a wave pattern that represents different actions of the heart. The P wave shows when the atria contracts, the QRS complex shows when the ventricles contract, and the T wave shows when the ventricles relax.
The vet will be looking for specific data, such as the shape and distance between the waves. They will pay attention to the PR interval and QRS complex interval, which indicate how quickly the heart is taking in and pumping out blood. The distance between the peaks of the QRS complex is also important. If the distance is the same, the heartbeat is regular, but if it varies, the heartbeat is irregular.
The vet can determine the heart rate by counting the number of QRS complexes over a certain time interval. It's important to note that the rate and rhythm of your pet's heartbeat may vary depending on their breed. Be sure to consult your veterinarian to learn more about what values are expected for your pet.
Are ECG Safe
ECG tests are safe because they are non-invasive and passively monitor the heart as a diagnostic test.
When Would a Vet Use an ECG
Some examples of when a vet may order an ECG test are:
Abnormal Cardiovascular Physical Exam
During a physical exam, the vet may detect certain abnormalities in the animal's heart, such as cardiac murmurs, gallop sounds, or arrhythmias. These could indicate a problem with the heart's ability to relax (known as diastolic dysfunction), which is why an echocardiogram is usually recommended for dogs and cats in such cases. Arrhythmias, which are irregular heartbeats, can be caused by heart diseases or other conditions. An echocardiogram can help rule out certain underlying issues such as primary cardiomyopathy or infiltrative cardiac disease. Additionally, an echocardiogram can assist the vet in determining the best anti-arrhythmic therapy for the animal.
Certain breeds of dogs and cats are more likely to inherit heart disease. Sometimes, a cardiologist needs to listen to their heart with a stethoscope to check for any unusual sounds. A full evaluation using an echo is needed if there is a murmur. However, for some breeds, an echo is always needed to check for heart disease.
Thoracic Radiographic Changes
Cardiomegaly means that the heart looks bigger than normal in X-rays. This can be because the heart is actually bigger, there is extra fat around it, or because of differences between people. To find out why the heart looks big, doctors often use a test called an echocardiogram. This test is very good at measuring the size of the heart's different parts and can help determine if the big heart is causing problems like heart failure or high blood pressure in the lungs.
Cats can have serious heart problems even if they look fine during a physical exam or on an X-ray. So, the best way to find out if a cat has heart disease is through an echocardiogram, which is very accurate. Purebred cats are more likely to have heart disease, so it's important to do this test on them. An echocardiogram can also help determine the best treatment options if a cat is diagnosed with heart disease.
Before giving a dog or cat anesthesia, knowing their heart health is useful.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.