The usefulness of Doppler myocardial imaging in the study of the athlete's heart and in the differential diagnosis between physiological and pathological ventricular hypertrophy.

Athlete's heart is a cardiac adaptation to long-term, intensive training, which includes changes as increased ventricular cavity diameters, wall thickness and mass, produced with a degree consistent with sports activities and exercise programs. The Doppler myocardial imaging (DMI) permits characterization of the velocities of each ventricular myocardial segment by placing the sample volume at the center of the cardiac muscle. Even if the standard two-dimensional (2D) echocardiography represents an irreplaceable method in the evaluation of cardiac adaptations to physical exercise, the data currently available suggests the usefulness of DMI in the assessment of the myocardial systolic and diastolic functions of the athlete's heart. In particular, an athlete's left ventricular hypertrophy is characterized by a "supernormal" DMI pattern, with increased myocardial early-diastolic velocity. Therefore, DMI analysis in the trained subject has demonstrated interesting prospective for: (1) the differential diagnosis from pathological, both, left and right ventricular hypertrophy; (2) the prediction of cardiac performance during physical effort; (3) the evaluation of the biventricular interaction; (4) the analysis of the myocardial adaptations to various training protocols; and (5) the early identification of specific genotypes associated with cardiomyopathies. On this ground, a combined use of standard 2D echo and DMI may be taken into account for a valid noninvasive and easy-repeatable evaluation of both physiological and pathological ventricular hypertrophies.