Volumetric and functional assessment of the left atrium in young competitive athletes without left ventricular hypertrophy: the MAGYAR-Sport Study.

BACKGROUND: Left atrial (LA) remodeling may be regarded as a physiologic adaptation to exercise conditioning. Three-dimensional speckle tracking echocardiography (3DSTE) is a new promising tool for volumetric and functional characterization of the LA. The present study was undertaken to assess adaptive changes in LA volumes and functional properties respecting cardiac cycle in young competitive athletes without left ventricular hypertrophy (LVH) by detailed 3DSTE assessment.

METHODS: The study group consisted of 20 young elite basketball and handball players (mean age: 28.1±10.1 years, 8 men) without LVH, their results were compared to 23 age- and gender-matched non-sportive healthy controls (mean age: 31.7±8.5 years, 11 men. All subjects had undergone standard transthoracic two-dimensional Doppler echocardiographic study with 3DSTE.

RESULTS: Increased systolic maximum (66.5±13.6 mL vs. 38.5±8.6 mL, P<0.0001) and diastolic minimum (36.7±8.1 mL vs. 17.5±5.8 mL, P<0.0001) and preatrial contraction (46.2±10.1 mL vs. 26.2±7.8 mL, P<0.0001) LA volumes could be demonstrated in athletes. Total (29.7±9.0 mL vs. 20.7±5.0 mL, P=0.0002) and passive LA stroke volumes (19.8±8.7 mL vs. 12.4±4.6 mL, P=0.0009) were increased, while total (44.2±9.1 mL vs. 54.2±9.4 mL, P=0.001) and active LA emptying fractions (20.6±11.8% vs. 31.9±8.7%, P=0.0008) proved to be decreased in athletes as compared to controls. Active LA stroke volume (9.9±5.8 mL vs. 8.3±3.3 mL, P=0.29) and passive LA emptying fraction (29.1±10.6 mL vs. 32.6±11.2 mL, P=0.31) did not differ between the groups. Only circumferential global (21.1±7.7% vs. 27.6±9.9%, P=0.02) and mean segmental (26.1±7.1% vs. 35.7±12.0%, P=0.003) peak LA strains proved to be significantly reduced in athletes as compared to controls.

CONCLUSIONS: 3DSTE-derived increased cyclic LA volumes and specific alterations in LA functional properties could be demonstrated in young competing athletes which is most likely a physiologic consequence of a global cardiac adaptation to intensive and chronic training.