Abstract
Background: The electrocardiography is a useful diagnostic tool for the characterization of the cardiac rhythm in veterinary medicine. In cattle, standard electrocardiographic exam is commonly performed using the base-apex lead system and reference values for ECG parameters have been reported for different breed of cows. However, no electrocardiographic studies have been conducted in Chianina breed.
Aim: To determine the feasibility and normal values for standard base-apex electrocardiography in clinically healthy Chianina cows.
Methods: A standard base-apex electrocardiographic examination was acquired in 45 Chianina cows. All the cows were considered healthy based on history and physical examination. The following ECG parameters were evaluated: heart rate; morphology of P wave, QRS complex and T wave; amplitude and duration of P wave, QRS complex, and T wave; duration of PR and QT intervals. Correlations between ECG parameters and clinical variables were analyzed.
Results: Morphology of the electrocardiographic waves/complexes and values for all ECG parameters recorded in the 45 clinically healthy Chianina cows were reported. Correlations between heart rate and body weight, QT interval and body weight, QT interval and heart rate, P wave amplitude and heart rate, PR interval and heart rate, R wave amplitude and age were observed. Statistical difference between heart rate in pregnant and not-pregnant cows was also found.
Conclusion: Base-apex electrocardiogram is suitable for monitoring heart rhythm in clinically healthy Chianina cows and reference values for main electrocardiographic parameters have been reported for this breed. This study can be a useful contribution to the literature, updating current knowledge on the electrocardiography in cattle.

Key words: Arrhythmias; cattle; electrocardiogram; heart