Holter study is a non-stop electrocardiographic monitoring lasting 24 hours that gives complete information about the frequency and the heart beat rhythm of dogs and cats. It is useful if the conventional electrocardiographic exam does not identify alterations.
Holter ECG monitoring (figure 1) continuously records electrical cardiac activity through some electrodes placed on the chest and connected to a little recorder (figure 2) located on the back of the animal. The whole system is maintained with a special vest that does not cause any discomfort to the animal and that allows to move freely and comfortably (figure 3). This diagnostic method is therefore completely harmless to the patient.
The Holter study can be useful in the following situations:
- To confirm the presence of intermittent arrhythmias (paroxysmal tachyarrhythmias or bradyarrhythmias) not identifiable with the conventional electrocardiographic exam
- To early identify cardiomyopathies
- To associate rhythm alterations with clinical signs such as syncope
- To verify the efficacy of the antiarrhytmic therapy or the pacemaker
- To control cardiac frequency in cases of ataxia cordis
During the execution of the Holter study, the patient has to live normally in order to evaluate the real cardiac activity; the owner will have to note in a "diary" the main activities of his dog or cat, possible clinical signs and drug administration.