1986 Volume 19 Issue 19 Pages 84-90
Electrocardiographical changes were studied in growing beagles with the following results.
1. The variable measured values of ECG were synchronized with adult values after 9 months of age.
2. The QRS eletricai axis was markedly shifted to the right (-152°) at 2 days of age. It shifted back counterclockwise at 3 months of age to be in the normal range of the adult dog. During this process, the QRS electrical axis shifted temporarily further to the left from the normal range.
3. A number of individuals showed negative waves at 1 month and 2 weeks of age probably due to the influence of the vagal nerve.
4. Respiratory arrhythmias appeared at 1 month and 2 weeks of age.
5. Electrical alternans appeared in dogs during growth.