Background: Two-dimensional speckle-tracking echocardiography is an emerging modality for the assessment of systolic and diastolic myocardial deformation in a broad variety of clinical scenarios. However, normal values and physiologic limits of left ventricular strain and strain rate in trained athletes are largely undefined.
Methods: Two hundred consecutive Olympic athletes (grouped into skill, power, mixed, and endurance disciplines) and 50 untrained controls were evaluated by two-dimensional speckle-tracking echocardiography. Left ventricular global systolic longitudinal strain (GLS), systolic strain rate, early diastolic strain rate (SRE) and late diastolic strain rate (SRA) were calculated.
Results: GLS was normal, although mildly lower, in athletes compared with controls (-18.1 ± 2.2% vs -19.4 ± 2.3%, P < .001), without differences related to type of sport. Systolic strain rate was also lower in athletes (-1.00 ± 0.15 vs -1.11 ± 0.15 sec(-1), P < .001), with the lowest value in endurance disciplines (-0.96 ± 0.13 sec(-1), P < .001). No difference existed for SRE (1.45 ± 0.32 vs 1.51 ± 0.35 sec(-1), P = .277), while SRA was lower in athletes (0.67 ± 0.25 vs 0.81 ± 0.20 sec(-1), P < .001). Both SRE (1.37 ± 0.30 sec(-1), P < .001) and SRA (0.62 ± 0.23 sec(-1), P < .001) showed the lowest values in endurance disciplines. The fifth and 95th percentiles calculated as reference values in athletes were as follows: for GLS, -15% and -22%; for systolic strain rate, -0.8 and -1.2 sec(-1); for SRE, 1.00 and 2.00 sec(-1); and for SRA, 0.30 and 1.20 sec(-1).
Conclusion: The present study shows that highly trained athletes have normal GLS and strain rate parameters of the left ventricle, despite mild differences compared with untrained controls. These data may be implemented as reference values for the clinical assessment of the athletes and to support the diagnosis of physiologic cardiac adaptations in borderline cases.
Keywords: Athletes; Left ventricle; Speckle tracking; Strain; Strain rate.
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