Left ventricular dimensions and mechanics in distance runners

Area of Science:

• Cardiology
• Sports Medicine
• Physiology

Background:

• Endurance athletes often display cardiac adaptations.
• Understanding these changes is crucial for sports science and cardiology.

Purpose of the Study:

• To assess heart size and mechanics in highly trained distance runners.
• To correlate cardiac adaptations with race performance.

Main Methods:

• Two-dimensional echocardiography used to compare 62 runners (over 40 miles/week) and 84 nonrunners.
• Measurements included left ventricular volumes, mass, and wall stress.
• Cardiac shape and dimensions were analyzed from parasternal short-axis and apical views.

Main Results:

• Runners showed significantly larger left ventricular end-diastolic volume index and mass index compared to nonrunners.
• Lower end-systolic and peak-systolic wall stresses were observed in runners.
• Cardiac adaptations included basilar hypertrophy and increased cavity length, maintaining a normal overall volume/mass ratio.
• No cardiac parameter or physical characteristic predicted race times.

Conclusions:

• Highly trained runners exhibit cardiac remodeling characterized by increased size and reduced wall stress.
• These cardiac adjustments are likely adaptations to sustained pressure and volume loads.
• Cardiac size and mechanics in isolation do not determine race performance in elite endurance athletes.