Impact of Doppler-Derived Left Ventricular Diastolic Performance
Background: Doppler-derived left ventricular (LV) diastolic indexes have been shown to correlate with exercise capacity in patients with heart diseases as well as healthy individuals. However, it is uncertain whether they predict exercise capacity independent of noncardiac factors.
Methods: To clarify the impact of the LV diastolic index on exercise capacity, 160 healthy individuals were investigated. All underwent Bruce protocol treadmill stress testing and 2-dimensional and Doppler echocardiography. Estimated metabolic equivalent was calculated from exercise time (metabolic equivalent = 1.11 + 0.016 ¥ exercise time). Diastolic performance was assessed by Doppler transmitral flow velocity pattern. Pulmonary function tests and complete blood cell count were also performed.
Results: LV diastolic indexes correlated well with metabolic equivalent (peak transmitral filling velocity (A): r = -0.51, P < .0001; ratio of early and late transmitral filling velocities (E/A): r = 0.58, P < .0001). However, there was no significant correlation between LV systolic indexes and metabolic equivalent. Independent predictors for a higher metabolic equivalent by multivariate analysis were higher E/A (P < .0001), higher vital capacity (P = .001), smaller body mass index (P = .0003), younger age (P = .0050), and higher hemoglobin concentration (P = .0026).
Conclusion: Doppler-derived LV diastolic index may help in predicting exercise capacity in normal individuals independent of other cardiac and extracardiac factors.
Previous studies have suggested that measurements of left ventricular systolic indexes do not predict maximal exercise time in normal individuals or in patients with impaired left ventricular function. Some authors have shown that echocardiographic Doppler indexes of left ventricular diastolic function are associated with exercise capacity in normal individuals. However, these previous reports have observed relatively small numbers of individuals and have not included other data that might affect exercise capacity, such as body mass index, pulmonary function, and hematologic data. Because of these limitations in previous reports, it is not clear whether left ventricular diastolic function is the strongest predictor of exercise capacity independent of other noncardiac factors. Therefore this study was undertaken to evaluate whether Doppler-derived left ventricular diastolic index is the independent predictor of exercise capacity in normal individuals.
Background: Doppler-derived left ventricular (LV) diastolic indexes have been shown to correlate with exercise capacity in patients with heart diseases as well as healthy individuals. However, it is uncertain whether they predict exercise capacity independent of noncardiac factors.
Methods: To clarify the impact of the LV diastolic index on exercise capacity, 160 healthy individuals were investigated. All underwent Bruce protocol treadmill stress testing and 2-dimensional and Doppler echocardiography. Estimated metabolic equivalent was calculated from exercise time (metabolic equivalent = 1.11 + 0.016 ¥ exercise time). Diastolic performance was assessed by Doppler transmitral flow velocity pattern. Pulmonary function tests and complete blood cell count were also performed.
Results: LV diastolic indexes correlated well with metabolic equivalent (peak transmitral filling velocity (A): r = -0.51, P < .0001; ratio of early and late transmitral filling velocities (E/A): r = 0.58, P < .0001). However, there was no significant correlation between LV systolic indexes and metabolic equivalent. Independent predictors for a higher metabolic equivalent by multivariate analysis were higher E/A (P < .0001), higher vital capacity (P = .001), smaller body mass index (P = .0003), younger age (P = .0050), and higher hemoglobin concentration (P = .0026).
Conclusion: Doppler-derived LV diastolic index may help in predicting exercise capacity in normal individuals independent of other cardiac and extracardiac factors.
Previous studies have suggested that measurements of left ventricular systolic indexes do not predict maximal exercise time in normal individuals or in patients with impaired left ventricular function. Some authors have shown that echocardiographic Doppler indexes of left ventricular diastolic function are associated with exercise capacity in normal individuals. However, these previous reports have observed relatively small numbers of individuals and have not included other data that might affect exercise capacity, such as body mass index, pulmonary function, and hematologic data. Because of these limitations in previous reports, it is not clear whether left ventricular diastolic function is the strongest predictor of exercise capacity independent of other noncardiac factors. Therefore this study was undertaken to evaluate whether Doppler-derived left ventricular diastolic index is the independent predictor of exercise capacity in normal individuals.