Pulmonary artery wedge pressure during treadmill exercise in warmblood horses with atrial fibrillation.

This study evaluates the impact of atrial fibrillation (AF) on the heart rate and pulmonary artery wedge pressure (PWP) of warmblood horses during treadmill exercise. The findings reveal that exercise impacts heart rate and PWP more significantly in horses with AF, possibly explaining exercise intolerance in some of these horses.

Objective and Methodology

• The objective of the research was to understand the effect of atrial fibrillation (AF) on the haemodynamic changes in warmblood horses during treadmill exercise.
• This was done by comparing the changes in heart rate and Pulmonary Artery Wedge Pressure (PWP) in 10 healthy warmblood horses and in six warmblood horses with AF, both at rest and during standardized treadmill exercise.

Findings

• The heart rate increase during treadmill exercise was significantly higher in horses with AF compared to healthy horses.
• Similarly, the PWP in horses with AF showed a noteworthy increase at treadmill velocities of 5m/s and faster, compared to the pressure in healthy horses.
• The differences in PWP between healthy horses and those with AF increased with treadmill strain, indicating that physical exertion has a greater impact on the hearts of horses with AF.

Implications

• The research provides evidence that there is an effect on the haemodynamics in horses with AF during intense exercise.
• This discovery could help explain why some horses with AF show exercise intolerance, giving potential insights for vets and horse trainers to understand the limits of horses with this heart condition.