What is an ECG?
ECG, or electrocardiogram, is an abbreviation for 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.
What Does an ECG Tell Your Veterinarian About Your Pet?
An 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 there will be a small bump that rises up that is 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 vet 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 are frequently of concern. These indicate how quickly the heart absorbs and pumps 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 the 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 breed of pet.
What are normal cat and dog ECGs?
The normal rhythm for a canine ECG should be 60 to 170 beats per minute. The normal rhythm of cats should be 140 to 220 beats per minute.
Are ECG 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 just a few of the obvious physical exam abnormalities that call for an echocardiogram. This is frequently an indication of diastolic dysfunction in dogs and cats, and an echocardiogram is always recommended. Intracardiac or extracardiac disease can cause arrhythmias. An echocardiogram can help rule out primary cardiomyopathy and/or infiltrative cardiac disease, which could be the cause of the arrhythmia. The echocardiogram also aids in the selection of antiarrhythmic therapy for the individual patient.
Many dog and cat breeds have a genetic predisposition to heart disease. In some cases, a board-certified cardiologist may recommend auscultation 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 on radiographs can be due to cardiac enlargement, pericardial fat accumulation, and/or patient variability. An echocardiogram is the most specific tool for determining the size of each cardiac chamber and is extremely helpful in determining the cause of radiographic cardiomegaly. For congestive heart failure and pulmonary hypertension, the echocardiogram is highly specific and sensitive.
Cats are particularly difficult cardiology patients to treat 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 that is both specific and sensitive for heart disease in cats. Because purebred cats have a higher incidence of heart disease, echocardiographic evaluation is frequently high yield in these patients. If this test reveals that 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.
How much is an ECG for a dog or cat?
It's always best to contact your vet directly if you're curious about the cost. They should be able to provide you with an accurate estimate.
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.