HEART AND CIRCULATION
Electrocardiogram (ECG)
A recording of the heart’s electrical activity used to evaluate heart rhythm, rate and selected conduction problems.
THE SHORT VERSION
Testing helps answer a clinical question.
An electrocardiogram records electrical signals produced by the heart. It is primarily a rhythm test—not a complete picture of chamber size, valve structure or pumping function.
What is this test?
An electrocardiogram records electrical signals produced by the heart. It is primarily a rhythm test—not a complete picture of chamber size, valve structure or pumping function.
What information can it provide?
- Heart rate and rhythm can be assessed for abnormal electrical patterns.
- Timing between electrical events can suggest conduction changes.
- Some abnormal rhythms are intermittent and may require extended monitoring.
- Results are interpreted together with history, examination, blood pressure and other cardiac tests.
When might your veterinarian recommend it?
- Investigate fainting, collapse, irregular heartbeat, weakness or anesthesia concerns.
- Assess suspected arrhythmias or electrolyte-related rhythm changes.
- Monitor a known cardiac condition or a patient receiving certain treatments.
What can owners do before the visit?
- The test usually uses small skin electrodes and gentle positioning.
- Tell the team about fainting episodes, exercise intolerance and medications.
- Ask whether a longer monitoring period is needed for intermittent events.
What can this test not tell you by itself?
- An electrocardiogram does not directly show heart-valve structure or chamber dimensions.
- A brief recording can miss an intermittent arrhythmia.
- An abnormal rhythm requires interpretation in the context of symptoms and overall patient stability.
Do not change medication, interpret an abnormal number as a diagnosis or delay urgent treatment without direction from your veterinary team.
Useful questions for your appointment
- Is the concern a heart rhythm problem, structural disease or both?
- Would echocardiography, blood pressure or longer monitoring be helpful?
- Do fainting or collapse signs require emergency action?