Left ventricular response to exercise in regular runners and controls. A radionuclide evaluation

Area of Science:

• Cardiology
• Exercise Physiology
• Sports Medicine

Background:

• Regular aerobic exercise, such as running, is known to induce cardiac adaptations.
• Understanding the specific changes in left ventricular function during exercise in athletes is crucial for performance optimization.

Purpose of the Study:

• To compare left ventricular function during upright exercise in regular runners versus healthy controls.
• To identify specific hemodynamic and volumetric parameters that differ between the groups during exertion.

Main Methods:

• Radionuclide angiography was employed to assess cardiac function in nine regular runners and nine age-matched controls.
• Measurements included heart rate, blood pressure, left ventricular ejection fraction (LVEF), end-diastolic volume index (EDVI), end-systolic volume index (ESVI), and stroke volume index (SVI) at rest and during incremental exercise.

Main Results:

• No significant differences in heart rate, systolic blood pressure, or LVEF were observed between runners and controls during exercise.
• Runners demonstrated significantly higher stroke volume index (SVI) and end-diastolic volume index (EDVI) during exercise (P < 0.05).
• End-systolic volume index (ESVI) was lower in controls at 60% exercise capacity (P < 0.05).

Conclusions:

• Enhanced cardiac performance in regular runners during exercise is associated with an increased left ventricular end-diastolic volume.
• A sustained increase in diastolic volume is key for maintaining elevated stroke volume and cardiac output in athletes.
• These findings highlight the adaptive capacity of the athlete's heart to meet increased metabolic demands during physical activity.