[Pulmonary wedge pressure and heart frequency measurements during standardized treadmill exercise for extension of left atrial function diagnosis in warmblood horses].

This research paper examines the effects of standardized treadmill exercise on heart rate and pulmonary wedge pressure in warmblood horses, and investigates the potentially differing effects on trained and untrained horses. The study found that neither heart rate nor pulmonary wedge pressure at rest or during exercise had a significant correlation, but a weak correlation could be found between left atrial size and the pulmonary wedge pressure.

Research Methodology

• The research was conducted on 12 healthy warmblood horses, consisting of six trained and six untrained ones.
• The pulmonary wedge pressure and heart rate of these horses were measured both at rest and during a standardized treadmill exercise.
• The treadmill test involved different intensities, including walking (1.8 m/s), trotting (4 and 5 m/s), canter (6 m/s) and gallop (8 m/s).

Results on Pulmonary Wedge Pressure

• The mean pulmonary wedge pressure at rest was established to be 14.53 +/- 2.36 mmHg.
• The researchers found that the mean pulmonary wedge pressure increased with each incremental step of the treadmill test.
• However, there was no significant difference in the pulmonary wedge pressure between trained and untrained horses, either at rest or during exercise.

Results on Heart Frequency

• A highly significant increase in mean heart frequency was observed at the beginning and end of the treadmill exercise. The increment was more pronounced in untrained horses compared to trained ones, especially at higher intensities.
• But the increase of heart frequency and pulmonary wedge pressure during exercise did not correlate, with no significant correlation factor greater than 0.5 being observed.

Correlation between Left Atrial Size and Pulmonary Wedge Pressure

• The researchers also explored the correlation between left atrial size and pulmonary wedge pressure.
• A statistically weak correlation could be observed up to a treadmill velocity of 6 and 7 m/s.