Exercise Echocardiography of Left Ventricular Diastolic Function in Healthy Subjects: Insights From the RIGHT-NET.

Area of Science:

• Cardiology
• Echocardiography
• Physiology

Background:

• Exercise transthoracic Doppler echocardiography (TTE) uses mitral Doppler E/e' ratio and tricuspid regurgitation velocity (TRV) to assess left ventricular (LV) diastolic dysfunction.
• Exercise intensity can influence these measurements, necessitating the definition of normal exercise limits.

Purpose of the Study:

• To define the normal limits of LV diastolic function indices during exercise TTE in healthy adults.
• To investigate the impact of exercise intensity on diastolic function measurements.

Main Methods:

• 192 healthy adults underwent resting and exercise TTE with a semirecumbent cycle ergometer.
• LV diastolic measurements (E/e' ratio, TRV) were acquired at rest and during midlevel exercise.
• E/e' ratio was calculated using average septal and lateral e' measurements.

Main Results:

• E/e' ratio increased modestly from 6.3 ± 1.9 at rest to 7.3 ± 2.3 during midlevel exercise (P < 0.001).
• The 95th percentile for exercise E/e' was 11.8.
• Both E/e' and TRV were found to be dependent on exercise intensity and cardiac output (CO).

Conclusions:

• LV diastolic function indices, specifically E/e' and TRV, are influenced by exercise intensity.
• Expressing E/e' and TRV as a function of CO is recommended for accurate diagnosis of LV diastolic response to exercise.
• Established normal limits for exercise TTE diastolic function are crucial for reliable interpretation.