Incidence of atrial fibrillation with mitral regurgitation in a Mix-breed athletic horse
Subject Areas :
Veterinary Clinical Pathology
Hossein Khalesi
1
,
mehdi sakha
2
,
abbas veshkini
3
,
Ali rezakhani
4
1 - Department of Clinical Sciences, Science and Research branch, Islamic Azad University, Tehran, Iran.
2 - Department of Clinical Sciences, Science and Research branch, Islamic Azad University, Tehran, Iran.
3 - Department of Clinical Sciences, Science and Research branch, Islamic Azad University, Tehran, Iran.
4 - Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.
Received: 2021-10-18
Accepted : 2022-02-07
Published : 2022-01-21
Keywords:
Arrhythmia,
Atrial fibrillation,
Mix-breed athletic horse,
Mitral valve insufficiency,
Abstract :
Atrial fibrillation is one of the most important cardiac arrhythmias in athletic horses, which can be caused by cardiac valve insufficiency. This study reports the incidence of atrial fibrillation with mitral regurgitation in a Mix-breed athletic horse that showed cardiac murmur, poor performance and exercise intolerance. In a 5-year-old Mix-breed mare clinical examination, electrocardiography, hematological and biochemical serum tests, and echocardiography were performed to identify the causes of cardiac murmur and poor performance. In auscultation, an irregular-irregularity heart rhythm and the 4/6-degree holosystolic murmur with a maximum intensity point in the mitral valve region with trill, were heard. Then, the atrial fibrillation was recorded in base-apex lead electrocardiography. Increased levels of fibrinogen and white blood cells were detected in the hematological tests. Echocardiography showed flail leaflet of mitral valve, left ventricular dilatation, and moderate mitral regurgitation. The fractional shortening (FS) values were decreased that indicating a decrease in myocardial function. In mitral regurgitation, left atrium enlargement is part of the pathophysiological changes to compensate for the cardiac overload, but it will also be a sign of future heart disorders such as atrial fibrillation and even sudden death. Eventually, atrial enlargement with mitral regurgitation, atrial fibrillation and decreased fraction shortening can lead to poor performance and even a negative effect on horse's life expectancy.
References:
Fraipont, A., Van Erck, E., Ramery, E., Richard, E., Denoix, J.M., Lekeux, P. et al. (2011). Subclinical diseases underlying poor performance in endurance horses: Diagnostic methods and predictive tests. Veterinary Record, 169(6): 154-154.
Huesler, I.M., Mitchell, K.J. and Schwarzwald, C.C. (2016). Echocardiographic assessment of left atrial size and function in warmblood horses: Reference intervals, allometric scaling, and agreement of different echocardiographic variables. Journal of Veterinary Internal Medicine, 30(4): 1241-1252.
Martin, B.B., Davidson, E.J., Durando, M.M. and Birks, E.K. (2004). Clinical exercise testing: overview of causes of poor performance. In: Equine Sports Medicine and Surgery. Kenneth, W.H., Andris, J.K., Raymond, J.G. and Warwick, B. editor. 1st ed., Oxford: W.B. Saunders. pp: 32-41.
Pouyan, M., Ozmaie, S., Sakha, M. and Asghari, A. (2018). Cardiac side effects and electrocardiographic changes of the combination of pethidine with xylazine in horses. Journal of Veterinary Pharmacology and Therapeutics, 41(1): 158-162.
Reef, V.B., Bonagura, J., Buhl, R., Mcgurrin, M.K.J., Schwarzwald, C.C., Van Loon, G. and Young, L.E. (2014). Recommendations for management of equine athletes with cardiovascular abnormalities. Journal of Veterinary Internal Medicine, 28(3): 749-761.
Reef, Virginia B. (2019). Assessment of the cardiovascular system in horses during prepurchase and insurance examinations. Veterinary Clinics of North America: Equine Practice, 35(1): 191-204.
Schwarzwald, C.C. (2018). Disorders of the cardiovascular system. In: Equine Internal Medicine. Stephen, M.R., Warwick, M.B. and Debra, C.S. editor. 4th ed., Elsevier: W.B. Saunders. pp: 387-541.
Senta, T., Smetzer, D.L. and Smith, C.R. (1970). Effects of exercise on certain electrocardiographic parameters and cardiac arrhythmias in the horse. A radiotelemetric study. The Cornell Veterinarian, 60(4): 552-569.
Slack, J., Boston, R.C., Soma, L.R., and Reef, V.B. (2015). Occurrence of cardiac arrhythmias in Standardbred racehorses. Equine Veterinary Journal, 47(4): 398-404.
Zucca, E., Ferrucci, F., di Fabio, V., Croci, C. and Ferro, E. (2003). The use of electrocardiographic recording with Holter monitoring during treadmill exercise to evaluate cardiac arrhythmias in racehorses. Veterinary Research Communications, 27(1): 811-814.
Zucca, E., Ferrucci, F., Stancari, G., Saporiti, T. and Ferro, E. (2010). The prevalence of cardiac murmurs among standardbred racehorses presented with poor performance. Journal of Veterinary Medical Science, 72(6): 781-785.
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Fraipont, A., Van Erck, E., Ramery, E., Richard, E., Denoix, J.M., Lekeux, P. et al. (2011). Subclinical diseases underlying poor performance in endurance horses: Diagnostic methods and predictive tests. Veterinary Record, 169(6): 154-154.
Huesler, I.M., Mitchell, K.J. and Schwarzwald, C.C. (2016). Echocardiographic assessment of left atrial size and function in warmblood horses: Reference intervals, allometric scaling, and agreement of different echocardiographic variables. Journal of Veterinary Internal Medicine, 30(4): 1241-1252.
Martin, B.B., Davidson, E.J., Durando, M.M. and Birks, E.K. (2004). Clinical exercise testing: overview of causes of poor performance. In: Equine Sports Medicine and Surgery. Kenneth, W.H., Andris, J.K., Raymond, J.G. and Warwick, B. editor. 1st ed., Oxford: W.B. Saunders. pp: 32-41.
Pouyan, M., Ozmaie, S., Sakha, M. and Asghari, A. (2018). Cardiac side effects and electrocardiographic changes of the combination of pethidine with xylazine in horses. Journal of Veterinary Pharmacology and Therapeutics, 41(1): 158-162.
Reef, V.B., Bonagura, J., Buhl, R., Mcgurrin, M.K.J., Schwarzwald, C.C., Van Loon, G. and Young, L.E. (2014). Recommendations for management of equine athletes with cardiovascular abnormalities. Journal of Veterinary Internal Medicine, 28(3): 749-761.
Reef, Virginia B. (2019). Assessment of the cardiovascular system in horses during prepurchase and insurance examinations. Veterinary Clinics of North America: Equine Practice, 35(1): 191-204.
Schwarzwald, C.C. (2018). Disorders of the cardiovascular system. In: Equine Internal Medicine. Stephen, M.R., Warwick, M.B. and Debra, C.S. editor. 4th ed., Elsevier: W.B. Saunders. pp: 387-541.
Senta, T., Smetzer, D.L. and Smith, C.R. (1970). Effects of exercise on certain electrocardiographic parameters and cardiac arrhythmias in the horse. A radiotelemetric study. The Cornell Veterinarian, 60(4): 552-569.
Slack, J., Boston, R.C., Soma, L.R., and Reef, V.B. (2015). Occurrence of cardiac arrhythmias in Standardbred racehorses. Equine Veterinary Journal, 47(4): 398-404.
Zucca, E., Ferrucci, F., di Fabio, V., Croci, C. and Ferro, E. (2003). The use of electrocardiographic recording with Holter monitoring during treadmill exercise to evaluate cardiac arrhythmias in racehorses. Veterinary Research Communications, 27(1): 811-814.
Zucca, E., Ferrucci, F., Stancari, G., Saporiti, T. and Ferro, E. (2010). The prevalence of cardiac murmurs among standardbred racehorses presented with poor performance. Journal of Veterinary Medical Science, 72(6): 781-785.
