Atrial fibrillation as a risk factor for exercise-induced pulmonary haemorrhage following a standardised exercise test.
- Journal Article
Summary
This research article investigates the proposed link between Atrial Fibrillation (AF), a heart-related disorder, and exercise-induced pulmonary haemorrhage (EIPH), a lung-related disorder, in horses, using a standardized exercise test (SET). The study found signs of EIPH in horses that were induced with AF, indicating that AF might be a risk factor for EIPH.
Objective and Methods
The aim of the research was to test if AF could be associated with increased risk of EIPH in horses after they undergo a SET to fatigue. AF is a cardiovascular disorder where the heart rhythms become irregular and sometimes rapid, leading to poor blood flow. EIPH, on the other hand, is a condition that often occurs in racehorses when they exercise, and it results in bleeding into the lungs.
- The study involved a controlled two-arm experiment with ten untrained Standardbred mares of average age six years.
- Each horse performed a SET on a treadmill in sinus rhythm (ordinary heart rhythm) (SET1), and then another SET 25-44 days later after the induction of AF, labelled as SET2. AF was artificially induced in the horses through a method called tachypacing, which was done using a pacing device.
- Endoscopic examinations, consisting of both tracheal wash and bronchoalveolar lavage (BAL), were performed 48-72 hours before and 24 hours after the SETs. This also included an endoscopic grading of tracheal blood taken 2 hours after each SET.
Results and Conclusion
After the first SET (SET1), no horses showed blood in the trachea, and only two showed erythrophagocytosis (a process in which red blood cells are ingested). However, following the second SET (SET2), two horses had grade 1 blood in the trachea and showed signs of both free erythrocytes and erythrophagocytosis in the BAL.
- In the AF-induced SET2, it was observed that the overall performance on the treadmill was reduced compared to the sinus rhythm SET1, with a lower maximum velocity, a higher heart rate, and more abnormal QRS complexes (wave patterns observed in an electrocardiogram).
- Interestingly, two horses in the AF-induced SET showed signs of EIPH, visible as blood in the trachea, when compared to the SET in sinus rhythm.
Despite the observed signs of EIPH in AF-induced horses, the researchers concluded that more studies are required to conclusively link EIPH, pulmonary pressure, and AF. The findings nonetheless indicated preliminary evidence that AF might be a possible risk factor for EIPH in horses.
Cite This Article
Publication
Researcher Affiliations
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark.
Grant Funding
- Brdr. Hartmann Foundation
- Augustinus Foundation
- Kustos Foundation
- 675351 / European Union's Horizon 2020
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