CARDIAC ANATOMY AND DIASTOLIC FILLING IN PROFESSIONAL ROAD CYCLISTS

In the literature two divergent types of exercise-induced cardiac hype rtrophy have been described: isotonic exercise induced eccentric hyper trophy with proportional increase in end-diastolic left ventricular di mension and wall thickness and isometric exercise induced concentric h ypertrophy with normal end-diastolic left ventricular dimension but in creased wall thickness. Using echocardiography, cardiac anatomy and di astolic filling were studied in 26 professional road cyclists. Compare d to 21 control subjects, matched according to age, sex and morphometr y the athletes had significantly larger left atrial dimension [41.3 (S D 4.8) vs 36.6 (SD 4.5) mm], left ventricular dimension [56.0 (SD 3.8) vs 53.2 (SD 4.7) mm], end-diastolic septum thickness [11.1 (SD 2.5) v s 8.4 (SD 1.9) mm], end-diastolic posterior wall thickness [11.6 (SD 2 .2) vs 8.4 (SD 1.5) mm] and left ventricular mass index [170.4 (SD 40. 6) vs 107.0 (SD 27.7) g.m-2]. We concluded that the hypertrophy in the road cyclists was of the mixed type (concentric-eccentric) with an in crease in the internal dimension of the left ventricle and an even lar ger increase in the thickness of the ventricular walls. Diastolic fill ing however was similar in the athletes and control subjects. No corre lations were found between the left ventricular mass index and diastol ic filling parameters. We concluded therefore that professional road c ycling causes mixed cardiac hypertrophy without diastolic filling abno rmalities and can therefore be considered benign.