Effect of a lactate-guided conditioning program on heart rate variability obtained using 24-Holter electrocardiography in Beagle dogs

Observational Study on Cardiac Activity in Rescue Dogs with Holter and Electrocardiogram Methodologies during a Simulated Search Activity

The aim of this study was to observe electric cardiac activity in real working conditions, with the application of Holter and the electrocardiogram in search and rescue dogs. Thirty-one handlers of search and rescue dogs voluntarily participated in this study. Nine dogs were selected to wear the Holter, and twenty-three were submitted to electrocardiographic recordings (one dog, excluded by Holter examination, was then included in the ECG group). Our results showed few cardiac rhythm alterations, such as escape beats, premature ventricular beat, and depression and elevation of the ST segment, particularly during the working phase in the Holter group and during recovery time immediately after activity in the electrocardiographic group. Detected alterations in real working conditions may provide more information than routine checks, and Holter monitoring can be more functional. However, not all dogs tolerate wearing the Holter harness, and more time is thus needed to apply the equipment. In addition, the results are not immediate, and the absence of water is essential because it would damage the equipment.

Assessment of Right Ventricular Function, Blood Lactate Levels, and Serum Peptidomics Profiles Associated With Mitral Valve Disease in Dogs

Background

Degenerative mitral valve disease is a common heart problem in dogs. The aims are to evaluate the relationships between right and left ventricular function, and blood lactate concentrations, assess prognostic contribution, and investigate whether serum peptidomics profile could reveal markers or determine the stage in dogs with valve degeneration.

Materials and Methods

Ninety-three dogs were evaluated in this study. Thirty-nine dogs' serum was collected and analyzed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The Kaplan–Meier curve was used to predict the outcomes of mitral valve disease. Follow-up was obtained by a questionnaire or telephone to determine a survival time.

Results

The BUN/creatinine ratio, vertebral heart score, and left atrium/aorta ratio were the independent predictors of cardiac mortality. Right ventricular systolic dysfunction was found in 50% of dogs with mitral valve disease. Dogs with right ventricular dysfunction had a significantly higher incidence of lower fractional shortening and larger right ventricular dimensions. The occurrence of right-sided dysfunction is proportionate to age and the degree of left ventricular dysfunction. High blood lactate concentrations were investigated in dogs with mitral valve disease stage C compared with stage B. The peptides such as mitogen-activated protein kinase, kallikrein, and tenascin-C appeared in the heart disease progression group.

Conclusion

Right-hearted function assessment, blood lactate levels, and peptidomics analysis may help early detection and prognosis of this disease in dogs. Peptidomics profiles from this study demonstrate the possibility for prognosis indicators of heart valve degeneration.

Conditioning Program Prescribed from the External Training Load Corresponding to the Lactate Threshold Improved Cardiac Function in Healthy Dogs

This research focuses on the adjustments in systolic and diastolic functions that are not fully understood in dogs submitted to athletic training. Beagle dogs carried out an endurance training program (ETP) prescribed from the external training load, corresponding to 70-80% of the lactate threshold (VLT) velocity. Eighteen dogs were randomly assigned to two groups: control (C, n = 8), active dogs that did not perform any forced exercise, and trained (T, n = 10), submitted to the ETP during eight weeks. All dogs were evaluated before and after the ETP period using two-dimensional echocardiography, M-mode, Doppler, and two-dimensional speckle tracking. A principal component analysis (PCA) of the echocardiographic variables was performed. The ETP improved the left ventricular internal dimension at the end of diastole (LVDd), the left ventricular internal dimension at the end of diastole to aorta ratio (LVDd: Ao), and the strain rate indices. PCA was able to capture the dimensionality and qualitative echocardiography changes produced by the ETP. These findings indicated that the training prescribed based on the lactate threshold improved the diastolic and systolic functions. This response may be applied to improve myocardial function, promote health, and mitigate any injuries produced during heart failure.