Left ventricular remodeling in elite and sub-elite road cyclists

Area of Science:

• Cardiology
• Sports Medicine
• Physiology

Background:

• Left ventricular (LV) structural adaptation in endurance athletes is well-documented.
• Previous studies on functional and mechanical adaptations have yielded contradictory results.
• Discrepancies may stem from a lack of clearly defined athletic performance levels in prior research.

Purpose of the Study:

• To characterize the structural, functional, and mechanical adaptations of the left ventricle in cyclists.
• To differentiate these adaptations based on clearly defined elite (EC) and sub-elite (SEC) performance levels.
• To compare these characteristics against a non-athlete (NA) control group.

Main Methods:

• Comparative study involving male elite cyclists (EC, n=69), sub-elite cyclists (SEC, n=30), and non-athletes (NA, n=46).
• Utilized conventional and speckle tracking 2D echocardiography for comprehensive cardiac assessment.
• Analyzed parameters including hypertrophy patterns, ejection fraction (EF), global circumferential strain (GCε), and diastolic filling velocities (E and E').

Main Results:

• Dilated eccentric hypertrophy was prevalent in EC (34.7%) but rare in SEC (3.3%).
• EC exhibited higher chamber concentricity than SEC (P < .001).
• Lower ejection fraction (EF) was observed in EC compared to NA (P < .05), with reduced EF more common in EC (11.6%).
• Global circumferential strain (GCε) was significantly greater in both EC and SEC compared to NA (P < .05 and P < .001).
• EC showed lower early diastolic filling (E) and septal/lateral E' velocities compared to SEC (P < .001 and P < .05).

Conclusions:

• The magnitude of LV structural adaptation is significantly greater in elite cyclists compared to sub-elite cyclists.
• Elevated global circumferential strain (GCε) in athletes likely serves as a compensatory mechanism to maintain stroke volume despite increased LV chamber volume.
• Reduced early diastolic filling (E and E') velocities in elite cyclists may indicate a substantial functional reserve.