Doppler Echocardiographic Reference Values in Healthy

Introduction Doppler echocardiography provides a means to non-invasively evaluate the anatomy and function of the heart, and is playing an increasingly important role in the evaluation and management of patients or animals with all forms of cardiac disease [13]. It has now become a routine for the diagnosis and evaluation of heart disease in veterinary medicine [4]. This is especially true in large animals in which most of the non-invasive cardiac diagnostic tools are of limited value because of the size and the specific anatomy and physiology of the heart in those species [5]. The diagnostic value of echocardiography must first be based on a global evaluation of the heart and on comparison between the visible structures which, in conjunction with the cardiologist experience, gives a preliminary general impression of the heart function [4,6]. Moreover, Doppler echocardiography allows an accurate quantitative assessment of cardiac morphology and function based on morphological echocardiographic, blood flow velocities and systolic time intervals measurements [2,3,6-10]. However, in any species, for echocardiography to allow such an accurate measure of cardiac dimensions and indices of cardiac function, it is important to dispose of reference values determined by using standardized measurement guidelines in this species [7-10]. Moreover, in most species, echocardiographic data have been shown to be affected by several physiological factors such as breed [10], body size [4,7-10] and shape [4], growth [7,8], aging [4], training [2,6,12,13] and heart rate [2,3,8,14,15]. Contrary to published reference values in most species including horses, there are very limited reported echocardiographic data in donkeys [16], which obviously limits the diagnostic and prognostic value of Doppler echocardiography in these animals. The purpose of this study was to determine, using a standardised guided technique developed in horses, normal values of echocardiographic dimension and functional indices and quantitative reference values of Doppler flow profiles in the healthy donkey, and to relate cardiac dimensions and indices to body size in this species.