In this post, our Pleasant Hill vets will discuss ECGs for dogs and cats, when your vet will order one as well as how to understand your pet's results so you can make the best decisions regarding their health care.
What is an ECG?
ECG, or electrocardiogram, is an abbreviation for an electrocardiogram. This is a test for monitoring the heart. Small sensors are attached to the skin and monitor electrical activity to provide an image of what the heart is doing. This is a non-invasive method of observing the heart in both pets and humans.
Your best bet is to ask your vet directly if you are curious as to how much an ECG will cost for your dog or cat. They can provide you with a more accurate estimate.
What does an ECG tell your veterinarian about your pet?
A feline or canine ECG tells your vet several things about your pet's heart. It gives the rate and the rhythm of the heartbeat along with an understanding of the electrical impulses that are going through each section of the heart.
A typical ECG will consist of a pattern where it will be a small bump that rises called the P wave, then A large spike upward called the QRS complex, and then another small bump called the T wave.
The P wave represents the atria contracting. The QRS complex is where the ventricles depolarize (The large contraction of the heart that is the typical heartbeat). And The T wave in the ventricles is repolarizing.
The most important information your veterinarian will be looking for is that the wave shape is correct, as well as the distance between the various parts of the wave. The information provided by the PR interval and the QRS complex interval is frequently the source of concern. These indicate how quickly the heart is taking in and pumping blood.
The next major information is to look at the peaks of the QRS complex (the big spike) and measure the distance between them. If they are a constant distance between the spikes you have a regular heartbeat if they vary in distance you have an irregular heartbeat.
Last but not least you can read how many QRS complexes there are and calculate how many there are over a time interval and you will have the heart rate.
The rate and rhythm of cats and dogs can vary please consult your veterinarian about what are the expected values for your pet.
Are ECGs safe?
Yes, ECG tests are safe. ECG is a non-invasive diagnostic test that passively monitors the heart.
When would a vet use an ECG?
Some examples of when a vet may order an ECG test are:
Abnormal Cardiovascular Physical Exam
Cardiac murmurs, gallop sounds, and arrhythmias are a few examples of obvious physical exam abnormalities that necessitate an echocardiogram. In dogs and cats, this is frequently an indication of diastolic dysfunction, and an echocardiogram is always recommended. Arrhythmias can be caused by either intracardiac or extracardiac disease. An echocardiogram can help rule out the possibility of primary cardiomyopathy and/or infiltrative cardiac disease as the cause of the arrhythmia. The echocardiogram also helps determine which anti-arrhythmic therapy is best for each patient.
Many dogs and cat breeds are genetically predisposed to heart disease. Auscultation by a board-certified cardiologist is sometimes recommended to rule out the presence of a murmur. If a murmur is detected, an echocardiogram is recommended for a complete evaluation. However, in some breeds, an echocardiogram is always recommended to screen for heart disease.
Thoracic Radiographic Changes
Cardiomegaly can be caused by cardiac enlargement, pericardial fat accumulation, and/or patient variability on radiographs. The most specific tool for determining the size of each cardiac chamber, an echocardiogram, is extremely useful in determining the cause of radiographic cardiomegaly. The echocardiogram is highly specific and sensitive for congestive heart failure and pulmonary hypertension.
Cats are especially challenging to treat as cardiology patients because they can have severe cardiomyopathy despite the absence of physical exam abnormalities, radiographic changes, and/or clinical signs. In many cases, an echocardiogram is the only diagnostic test for heart disease in cats that is both specific and sensitive. Due to the higher prevalence of heart disease in purebred cats, echocardiographic evaluation is frequently high yield in these patients. If the patient has suspected heart disease, an echocardiogram is recommended to confirm the presence of heart disease and determine the patient's therapeutic needs.
Before placing a dog or cat under anesthesia, it can be helpful to obtain a complete understanding of the patient’s cardiovascular status.
What does a normal dog or cat ECG look like?
If you're curious as to what a normal cat or dog ECG looks like, there a plenty of images you can search for on Google to give you an idea.
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.