PREVALENCE AND UPPER LIMIT OF CARDIAC-HYPERTROPHY IN PROFESSIONAL CYCLISTS

The term athlete's heart refers to an increased left ventricular mass. Few studies have assessed the prevalence and normal upper limit of ca rdiac hypertrophy in highly trained cyclists and this was the aim of t his study. A group of 40 professional road cyclists [mean age 26 (SD 3 ) years] who had participated in European competitions for 3-10 years, were evaluated at the beginning of the 1992-93 season. Evaluation inc luded a clinical history and physical examination, one and two-dimensi onal echocardiography, 12-lead resting electrocardiogram and a graded exercise test. Determination of the left ventricular mass index (LVMI) was performed using Devereux's formula with correction for the body s urface area. Systolic and diastolic blood pressure were measured at re st and at peak exercise. Of the group 23 cyclists (58%) presented a LV MI greater than 130 g . m(-2), 21 cyclists presented a diastolic ventr icular thickness equal to or greater than 13 mm, with a superior limit of 19 mm; 3 cyclists presented asymmetrical septum hypertrophy; and t he relationship between posterior wall and left ventricular diastolic radius was equal to or greater than 0.45 in 14 cases (35%). Electrocar diographic abnormalities of ST-T segment were seen in only 1 subject. No correlation was found between the degree of ventricular hypertrophy and arterial blood pressure. We concluded that these professional cyc lists showed a high prevalence of cardiac hypertrophy (58%). The distr ibution of this hypertrophy was concentric in 20/33 and asymmetric in 3/23 of the subjects with left ventricular hypertrophy. The electrocar diograms were normal in 98% of the subjects.