Contribution of left ventricular diastolic function to exercise capacity in normal subjects

Area of Science:

• Cardiology
• Exercise Physiology
• Sports Medicine

Background:

• Exercise capacity, or maximal oxygen consumption (VO2 max), varies significantly among individuals due to factors like age and training.
• The precise determinants limiting VO2 max in healthy subjects are still debated.
• Left ventricular diastolic function is a potential, yet under-explored, contributor to individual differences in VO2 max.

Purpose of the Study:

• To investigate the hypothesis that left ventricular diastolic performance influences the heterogeneity of VO2 max in healthy sedentary individuals and endurance athletes.
• To identify correlations between echocardiographic measures of diastolic function and aerobic capacity.

Main Methods:

• Studied 57 sedentary volunteers and 9 endurance athletes.
• Assessed aerobic capacity via VO2 max during a dynamic cycle exercise test.
• Evaluated resting left ventricular systolic and diastolic function using 2D and Doppler echocardiography.
• Analyzed relationships using stepwise multiple regression.

Main Results:

• VO2 max varied widely, from 25-58 ml.kg-1.min-1 in sedentary subjects and 44-60 ml.kg-1.min-1 in athletes.
• Significant correlations found between VO2 max and age, maximal heart rate, and maximal workload.
• Key diastolic function indices, including peak early transmitral filling velocity (r=0.80) and early/late filling velocity ratio (r=0.87), strongly correlated with VO2 max.

Conclusions:

• Left ventricular diastolic function plays a significant role in determining individual differences in maximal oxygen consumption (VO2 max).
• Echocardiographic measures of diastolic function are valuable predictors of aerobic capacity.
• These findings contribute to understanding the physiological basis of exercise capacity variations.