Relationship between PP and PQ intervals in the electrocardiogram of dogs
Hamlin, R.L.
American Journal of Veterinary Research 33(12): 2441-2445
1972
ISSN/ISBN: 0002-9645 PMID: 4641200 Document Number: 45549
The PP and PQ intervals were recorded from 16 healthy dogs anaesthetized so that respiratory sinus arrhythmia persisted. Graded doses of atropine were given. Although PP fluctuated with sinus arrhythmia, PQ fluctuated very little in 13 of the dogs. In dogs given doses of atropine, PP fluctuations were smoothed, but PQ fluctuations became exaggerated. In dogs given larger doses of atropine, both PP and PQ interval fluctuations became smooth and both intervals shortened until maximal effect of atropine on rate and rhythm occurred at a dosage of 0.06 mg/kg body weight.