{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T16:06:32Z","timestamp":1779465992130,"version":"3.53.1"},"reference-count":14,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T00:00:00Z","timestamp":1779408000000},"content-version":"vor","delay-in-days":21,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,5,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Paroxysmal atrial fibrillation (pAF) occurs sporadically in horses and has been implicated in poor performance. Diagnosis in large numbers of horses has previously relied on post-exercise ECGs.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Hypothesis\/Objectives<\/jats:title>\n                    <jats:p>Describe pAF-like bursts detected during exercise and determine their effect on speed, stride, and racing performance.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Retrospective case control study, evaluating records of exercising ECG consultations referred to a specialist practice to identify horses with pAF-like bursts. Controls were selected from the same population as racehorses with normal exercising ECGs.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Eleven cases with pAF-like bursts and 10 controls with normal exercising ECGs were identified, among 100 ECG consultations. The pAF-like bursts occurred in all horses during peak exercise (60-68\u00a0km\/h; heart rate, 206-217 beats per minute), with normal ECGs during warm-up and recovery. The duration of pAF-like bursts ranged from 10 to 90\u00a0s, returning to normal rhythm in all horses before the end of peak exercise. During the pAF-like bursts, 5 horses decelerated, 3 accelerated, and in 3 horses speed was unaffected. Immediately after the pAF-like bursts, 5 horses slowed down, 4 horses did not change their speed and 2 horses accelerated. Root mean square of successive differences (RMSSD) and standard deviation of normal-to-normal intervals (SDNN) during peak exercise were high in all horses. During recovery, RMSSD was normal and SDNN was high in both the pAF-like burst and control horses. Racing performance after the pAF-like burst was available for 8 horses and 7 did not race successfully.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion and clinical importance<\/jats:title>\n                    <jats:p>Paroxysmal atrial fibrillation-like bursts occurred during high-intensity exercise in racehorses and may be missed on post-exercise ECGs. These findings emphasize the value of peak-effort ECGs for detecting transient arrhythmias.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/jvimsj\/aalag095","type":"journal-article","created":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T15:36:50Z","timestamp":1779464210000},"source":"Crossref","is-referenced-by-count":0,"title":["Paroxysmal atrial fibrillation-like bursts in racehorses: do they affect speed and performance? A case control study"],"prefix":"10.1093","volume":"40","author":[{"given":"Fe","family":"ter Woort","sequence":"first","affiliation":[{"name":"Equine Sports Medicine Practice , Waterloo ,","place":["Belgium"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guillaume","family":"Dubois","sequence":"additional","affiliation":[{"name":"Arioneo, LIM France , Bordeaux ,","place":["France"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stephen","family":"O\u2019Connor","sequence":"additional","affiliation":[{"name":"Hong Kong Jockey Club, Department of Veterinary Clinical Services, Sha Tin Equine Hospital , New Territories ,","place":["Hong Kong"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emmanuelle","family":"van Erck-Westergren","sequence":"additional","affiliation":[{"name":"Equine Sports Medicine Practice , Waterloo 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