Overview of Equine Cardiac Disease.

Equine heart diseases can be categorized with morphologic, etiologic, and physiologic diagnoses and classified anatomically as diseases of the pericardium, myocardium, valves (endocardium), and great vessels. An appreciation of normal and pathologic physiology is a key to understanding diagnosis and therapy of heart disease. Pathophysiologic diagnoses include arrhythmias, congestive heart failure, and pulmonary hypertension. Heart rhythm disturbances can occur in isolation or with structural disease. Heart failure stems from arterial filling owing to insufficient cardiac output. Pulmonary hypertension is associated with strenuous exercise, left heart failure, bronchopulmonary diseases, and pulmonary arteriopathies. The etiopathogenesis of these disorders are incompletely understood.