Sport category is an important determinant of cardiac adaptation: an MRI study

Background Physiological cardiac adaptation in athletes is influenced by body surface area, gender, age, training intensity and sport type. This study assesses the influence of sport category and provides a physiological reference for sport category and gender. Methods Three hundred and eighty-one subjects (mean age 25 +/- 5 years, range 18 to 39 years; 61% men) underwent cardiac MRI and ECG: 114 healthy non-athletes (<= 3 training h/week) and 267 healthy elite athletes (mean 17 +/- 6.6 training h/week). Athletes performed low-dynamic high-static (LD-HS, n=42), high-dynamic low-static (HD-LS, n=144) or high-dynamic high-static sports (HD-HS, n=81). Results Left ventricular (LV) end-diastolic volume (EDV) index (ml/m(2)) for non-athletes/LD-HS/HD-LS/HD-HS, respectively, was 101/107/122/129 in men and 90/103/106/111 in women. LV end-diastolic mass (EDM) index (g/m(2)) for non-athletes/LD-HS/HD-LS/HD-HS was, respectively, 47/49/57/69 for men and 34/38/42/51 for women. Left or right ventricular EDV ratios were alike in all groups. LV EDV/EDM ratios were similar in nonathletes/ LD-HS/HD-LS athletes, and only lower in HD-HS athletes, disproving selective ventricular wall thickening in LD-HS athletes. Multivariate linear regression demonstrated HD-LS and HD-HS sport category coefficients (p<0.01) larger than those of training hours, gender and age (LV EDV/EDM coefficients for sport category LD-HS 6/0.75, HD-LS 16/7, HD-HS 21/17). ECG abnormalities were most frequent in HD-HS athletes and in male subjects. Conclusions This study demonstrates a balanced cardiac adaptation with preserved ratios of LV/right ventricular volume (in all sport categories) and LV volume/wall mass (in LD-HS and HD-LS sports). Sport category has a strong impact on cardiac adaptation. HD-HS sports show the largest changes, whereas LD-HS sports show dimensions similar to non-athletes.