An electrocardiogram (EKG or ECG) is a readout of the electrical activity of the heart. If your veterinarian hears a heart rhythm abnormality (called an arrhythmia) in your pet's heart beat, they will recommend an ECG. The readout allows your veterinarian to accurately determine the cause and appropriate treatment for the arrhythmia. Although the ECG procedure requires that your pet hold very still for a few minutes to obtain the electrical data, it generally does not require sedation. Several clips (called leads) are placed onto your pet's skin at various body points in order to accurately record the information your veterinarian requires.