Recommendations for Management of Equine Athletes with Cardiovascular Abnormalities

Abstract

Murmurs and arrhythmias are commonly detected in equine athletes. Assessing the relevance of these cardiovascular abnormalities in the performance horse can be challenging. Determining the impact of a cardiovascular disorder on performance, life expectancy, horse and rider or driver safety relative to the owner's future expectations is paramount. A comprehensive assessment of the cardiovascular abnormality detected is essential to determine its severity and achieve these aims. This consensus statement presents a general approach to the assessment of cardiovascular abnormalities, followed by a discussion of the common murmurs and arrhythmias. The description, diagnosis, evaluation, and prognosis are considered for each cardiovascular abnormality. The recommendations presented herein are based on available literature and a consensus of the panelists. While the majority of horses with cardiovascular abnormalities have a useful performance life, periodic reexaminations are indicated for those with clinically relevant cardiovascular disease. Horses with pulmonary hypertension, CHF, or complex ventricular arrhythmias should not be ridden or driven.

Assessment of cardiovascular disease in the donkey: clinical, echocardiographic and pathological observations

“…The prevalence is slightly less than that reported for older horses (Patteson and Cripps 1993, Marr 2010b), but the pathology in donkeys (Morrow and others 2011) is similar to that described for horses (Else and Holmes 1972a). None of the donkeys had other clinical signs consistent with haemodynamically significant aortic regurgitation (Reef and others 2014). …”

Appropriate threshold levels of cardiac beat-to-beat variation in semi-automatic analysis of equine ECG recordings

“…Furthermore, the clinical interpretation of analysis results is challenged by limited knowledge of the clinical significance of various arrhythmias [1]. Both supraventricular and ventricular premature beats have raised concerns in equine cardiology as potential initiators of atrial fibrillation [2] and fatal ventricular arrhythmias [3].…”

Horse: anaesthetic management for open castration of a Belgian draught horse with interventricular septum defect, aortic regurgitation and ventricular premature depolarisations

“…On the other hand, conditions such as hypocapnia, alkalaemia, spontaneous ventilation or deep anaesthesia can decrease pulmonary vascular resistance (PVR), which will increase the shunt fraction (Perkowski and Oyama 2015). Often, as in the current case, the functional size of the VSD is reduced by prolapse of the aortic valve into the defect, leading to aortic regurgitation (Leroux and others 2013, Reef and others 2014). This condition may lead to chronic left ventricular volume overload, which can result in myocardial hypoxaemia and arrhythmias.…”

“…A VSD is the most common congenital cardiac defect in horses (Reef and others 2014). Under normal circumstances, this results in left to right shunting of blood.…”