Influence of age on the electrical auricular systole in swine

The electrocardiographic outline from 30 Landrace x Blanco Belga swines was analysed at ages of 1, 5, 20, 45 days, 3, 4 1/2 and 6 months in order to establish how the heart rate and the auricular electrical systole were affected by physical maturation. All parameters analysed undergo significant changes throughout the study phase. The first change could be observed between the 1st and 5th day of postnatal life which resulted in an increase of the heart rate, a decrease of the RR and PQ intervals and PQ segment, and in a decrease of the amplitude (leads I and V10) and duration (leads aVF and V10) of the P wave. From 5 days of age all the parameters analysed underwent a new change in the opposite direction that was detected in a more significant manner between 5 and 45 days of age.