Heart size estimated by echocardiography correlates with maximal XXXX uptake.

@entity26 @entity1641
Maximum @entity26 uptake also appears to correlate to athletic performance in @entity1641 . In the Thoroughbred industry, there has long been an empirical theory that heart size is related to athletic performance, despite a lack of scientific evidence supporting this assertion. To investigate the relationship between peak @entity26 consumption (VO2max) and cardiac size measured by echocardiography, guided M-mode and 2-dimensional echocardiography were performed in 17 conditioned Thoroughbreds with a range of VO2max from 126 to 217 ml/min/kg STPD (mean +/- s.d. 158 +/- 28 m/min/kg). @entity1641 were age 2-10 years and weighed 430-510 kg. Echocardiography was performed using a Vingmed System V echocardiograph with a 2.25 MHz phased array ultrasound transducer. All images were obtained from the right hemithorax using a short axis view of the left ventricle (LV) at the level of the chordae tendinae. All @entity1641 were free from significant regurgitation at the aortic or mitral valves. Maximal @entity26 uptake was measured during a standardised incremental treadmill exercise test to fatigue. Maximal @entity26 uptake was correlated significantly with LVIDd (r = 0.71; P = 0.001), MWT (r = 0.72; P = 0.001), LV mass (r = 0.78; P = 0.0002) and LV short-axis area (r = 0.69; P = 0.003). When indices of heart size were indexed to bodyweight, the correlation between VO2max and indices of heart size were LVIDd (r = 0.57; P = 0.01), MWT (r = 0.44; P = 0.07), LV mass (r = 0.78; P = 0.0002) and LV short-axis area (r = 0.69; P = 0.003). The current study suggests there is a strong relationship between VO2max and measurements of left ventricular size in Thoroughbred @entity1641 when individuals with a range of VO2max are compared.
