Objectives: This study sought to investigate the development of left ventricular remodeling during active cycling.
Methods: A group of 17-year-old (+/- 0.2 years) highly trained competitive cyclists (group I, n = 66) and a group of 29-year old (+/- 2.6 years) professional cyclists (group II, n = 35) underwent two-dimensional (2D) echocardiography. Data from groups I and II were compared with values of normal untrained subjects based on the literature.
Results: Left atrial dimensions were significantly increased in group II as compared to group I (44 +/- 5 vs. 36 +/- 4 mm, p < 0.005). Left ventricular end diastolic diameter was significantly increased in group II as compared to group I (61 +/- 5 vs. 54 +/- 6 mm, p < 0.005). Left ventricular mass was also significantly increased in group II as compared to group I (321 +/- 77 vs. 246 +/- 59 g, p < 0.005). Wall stress showed a significant inverse relation: 104 +/- 42 mmHg in group I vs. 83 +/- 14 mmHg in group II (p < 0.005). The early filling phase of the left ventricular inflow was significantly larger in both athlete groups in relation to the normal value. The E-wave in the athletes compared to the E-wave in normal subjects was 0.87 +/- 0.17 vs. 0.71 +/- 0.14 m/s in group I, p < 0.005, 0.82 +/- 0.17 vs. 0.71 +/- 0.14 m/s in group II, p < 0.05. Late filling phase and the ratio of the diastolic filling pattern did not show significant differences between the two groups.
Conclusions: Left atrial and left ventricular remodeling starts early in the athlete's career. Athletes of 17 years of age already show significant left atrial and left ventricular dilatation compared to data of untrained subjects described in literature. The process of dilatation continues during the athlete's career. Also left ventricular mass is increased at a young age which continues for several years. More than 60% of the athletes in both groups demonstrated an intermediate form of left ventricular hypertrophy. Diastolic function of the left ventricle remains normal during a long period of athletic career performance.