Ukrainian Journal of Veterinary Sciences

Electrocardiography is the main tool for diagnostics and classification of arrhythmias. In order to get a proper diagnosis for arrythmia it is essential to have a clear electrocardiogram (ECG) record and advanced results analysis skills. Due to anatomical and physiological features the ECG in horses provides little to no information about size of the heart structures and specific origin of the ectopic beat. As of today, it mostly provides information concerning heart rhythm and rate. Under normal conditions current follows a fixed pattern through the heart through sinus node and atrial myocardium, atrioventricular node, the Hiss and Purkinje system to the ventricular myocardium. This results in de- and repolarization of the myocytes, which occurs on the basal ECG as deviations in the form of P and T waves and the QRS complex. Modern devices for ECG registration are equipped with accumulator, memory card and telemetry function, which provides an opportunity for vet cardiologists to conduct ECG registration at rest, during exercise, and over long period of time. This is crucial for diagnostics of arrhythmias, collapse, poor performance, and especially during critical care and treatment by preparations affecting cardiovascular system. The electrode placement may differ according to the type of investigation, but it is important to place them along the mean electrical axis of the heart, which provides the appropriate deviations on the ECG. 

electrocardiography in horses, cardiology, ECG electrode placement