Aberrant origin of the coronary arteries from the pulmonary trunk were observed in 15 (2.0%) of 733 bovine hearts showing congenital cardiovascular anomalies. The incidence of this anomaly in cattle necropsied at Miyazaki University was 0.17%. Anomalous coronary arteries originated from the pulmonary trunk were left coronary artery (7 cases), right coronary artery (5 cases), left and right coronary arteries (1 case), single coronary artery (1 case) and paraconal interventricular branch of left coronary artery (1 case).

View full abstract

Objective—The circadian rhythms of blood pressure (BP), heart rate (HR) and heart rate variability (HRV) in aged dogs are important considerations in the prescription of cardiovascular agents, especially antihypertensives. However, currently there are limited data in the literature concerning this topic. Therefore, this study determined the circadian rhythms of BP, HR and HRV in aged dogs and compared the data to those of young dogs.
Procedure—Healthy female beagles were assigned to the “aged group” (10-11 y; n=5) or “young group” (1-3 y; n=6). The systolic BP (SBP), Diastolic BP (DBP), pulse pressure (PP) and HR were continuously recorded in non-anesthetized and unrestrained dogs over seven days using a telemetry system. The high-frequency (HF) and low-frequency/high-frequency (LF/HF) data of HR variability (HRV) were also determined.
Results—In the aged group, the circadian rhythms of SBP, DBP, HR and LF/HF were bimodal, while HF was unimodal. In the young group, the circadian rhythms of HR and LF/HF were bimodal and SBP, DBP and HF were unimodal. The amplitudes of the circadian rhythms of PP were small in both groups. A unique finding in the aged group was that the average value of SBP rose (p=0.0002) and that of DBP fell (p<0.0001), resulting in a significant increase in the value of PP (p<0.0001). There were no significant differences in the average values of HR and HF in the groups. The average values of LF/HF were significantly higher in the young group (p<0.0001).
Conclusion—The findings of this study suggest that the circadian rhythms of cardiac parameters in aged dogs are different from those of young dogs. Aged dogs' variations may be more easily affected by environmental stimulations such as feeding. Additionally, in aged dogs, PP increased significantly. The observed rise in SBP and fall in DBP in the aged dogs is similar to the changes observed in humans.

View full abstract

[in Japanese]

View full abstract