CORONARY-ARTERIES IN PHYSIOLOGICAL HYPERTROPHY - ECHOCARDIOGRAPHIC EVIDENCE OF INCREASED PROXIMAL SIZE IN ELITE ATHLETES

One hundred and twenty-five healthy, male top-level athletes were evaluated by echocardiography (Echo) and assigned to six groups according to the size of the left ventricular mass (L. V. Mass) , calculated according to Devereux R. B. et al.: ≤200, 201-250, 251-300, 301-350, 351-400, or > 400 g. Echo evaluation of coronary artery (c.a.) proximal size was performed following the method described by Kalavathy et al. (J Am Coll cardiol 1986, 8, 1119-1124). Two of us separately conducted the measurement of the c. a. diameter at 1 cm from the respective aortic ostium on M-Mode tracings and 2-D end-diastolic frames. The interobserver variability was lower for the M-Mode (4.2%) than 2D (9.3%) measurements: the correlation between A and B observers equals r = 0.867 for the right c. a., and r = 0.859 for the left main c.a. In a subset of 38 athletes, maximum oxygen uptake was tested during maximal exercise test (VO2max). For both the right and the left main c. a. the mean diameter (mm) increased in relation to increasing L.V. Mass: 5.6 ± .5 and 6 ± .5, respectively, for L. V. Mass ≤ 200 g; 6.1 ± .5 and 6.6 ±4.9 for L. V. Mass = 201-250 g; 6.4 ± .6 and 6.8 ± .6 for L. V. Mass = 251-300 g; 6.7 ± .7 and 7 ± .6 for L. V. Mass = 301-350 g; 7.2 ± .6 and 7.3 ± .8 for L. V. Mass = 351-400 g and finally 7.7 ± .9 and 7.9 ± .8 for L. V. Mass > 400 g. A significant correlation (r = 0.495; p < .01) between right + left main c.a. diameter (↑ 3) and left vetricular mass, and even higher (r = 0.686; p < .001) between c. a. diameters and left ventricular wall thickness, was found. A feeble linear correlation (r = .371, p<0.2) was found between VO2(max) (1/min) and c.a. size. This study therefore indicates that training-induced myocardial hypertrophy involves a proportionate increase of c. a. dimension.