Left and right ventricular adaptation assessed by Doppler tissue echocardiography in athletes

Changes induced by intensive training in the morphology and kinetics of both ventricles in athletes (soccer players) were assessed by 2-dimensional echocardiography and Doppler tissue echocardiography (DTE). DTE has yet to find widespread application in sports medicine, and the right ventricle (RV) is often neglected in the examination of athletes. DTE-determined velocities were measured along the short and long axis in the left ventricle (LV) and over the long axis in the RV. Wall displacements (systolic shortenings and diastolic elongations) were computed at each site as time-velocity integrals. Normalized velocities and excursions were calculated with reference to the long and short diastolic dimensions.

A total of 20 athletes and 15 age- and sex-matched control subjects were enrolled in the study. All participants underwent history screening, physical examination, electrocardiogram, and blood analysis.

The athletes had significantly greater RV long-axis dimension and LV short-axis dimension than control subjects. LV ejection fraction was similar in the 2 groups. In athletes, peak systolic velocities were significantly increased along the LV short axis and the RV long axis. Early diastolic velocities were significantly increased for the LV short axis and nonsignificantly increased at all other sites. The ratio of these peak velocities to the proper diastolic dimension (fractional or normalized velocities) did not significantly differ between the groups. Time-velocity integrals (ie, wall tissue displacements) were increased in all directions examined in both ventricles, both in systole and early diastole. However, normalized or percent shortenings and elongations were similar in athletes and control subjects.

These data suggest that an increase in RV and LV cavity size is associated with higher DTE-reported velocities in athletes. These higher velocities correspond to greater excursions of the muscle segments involved. Normalized velocities and excursions, however, indicate an unchanged fractional shortening, so that contractility has to be considered unaffected in these athletes. We suggest that DTE is instructive in unveiling functional adaptations of the heart in athletes, but questions of data interpretation have to be settled. For example, one should be cautious in comparing absolute velocities between chambers of different size. Nonnormalized velocities may be an objectionable index in the presence of cardiac enlargement.