Acquired Cardiovascular Disease
Acquired cardiovascular disease is much more common than congenital disease. Usually it affects the valves, but the myocardium, the pericardium or the pervasculature may also become diseased.
Optimal management of horses with cardiac disease requires the clinician to make a specific diagnosis, to assess the severity of the condition and to identify any underlying cardiac or systemic disease. Only after these factors have been addressed should treatment be considered. This may be corrective or palliative, depending on the disease process and the individual case. The most important considerations are usually the prognosis and advice about the future athletic use of the animal.
The majority of horses with cardiac disease do not benefit from any form of treatment. This is because most animals have signs which are limited to exercise intolerance, and in the case of valvular disease this is unlikely to improve with any treatment. However, selected individuals with arrhythmias, pericardial disease, bacterial endocarditis and congestive heart failure (CHF) may require specific treatment. Basic rules for the management of horses with cardiac disease are summarised in Table 6.1.
6.1 Valvular heart disease
6.2 Mitral valve disease
6.3 Tricuspid valve disease
6.4 Ruptured chordae tendineae
6.5 Aortic valve disease
6.7 Myocardial disease
6.8 Pericardial disease
6.9 Treatment of congestive heart failure in horses
6.10 Peripheral cardiovascular disease and conditions affecting the great vessels.