Diastolic stress echocardiography in the young: a study in nonathletic and endurance-trained healthy subjects

BACKGROUND: The response of diastolic Doppler indices to exercise is not well defined for young subjects. The aims of this study were to evaluate this in nonathletic and endurance-trained probands and to correlate echocardiographic data with maximal oxygen consumption. METHODS: In this prospective study, Doppler echocardiography was performed at rest and after exercise in 40 nonathletes (NAs) and 20 endurance-trained athletes (ETs) aged > 40 years, matched for age and gender. Diastolic function was assessed by mitral inflow and early diastolic velocities of the septal (e' septal) and lateral (e' lateral) mitral annulus. Maximal oxygen consumption quantification was performed simultaneously. RESULTS: All cardiac chambers were larger in ETs than NAs. ETs had higher e' lateral at rest (18.1 +/- 2.7 vs 16.3 +/- 3.3 cm/sec, P = .02) and higher mitral E (141 +/- 15 vs 132 +/- 15 cm/sec, P = .02) and e' lateral (23.5 +/- 2.5 vs 21.4 +/- 3.0 cm/sec, P = .01) with exercise than NAs. There was a slight increase in E/e' septal (overall, from 6.8 +/- 1.3 to 7.2 +/- 1.2; P = .02) and E/e' lateral (overall, from 5.0 +/- 0.8 to 6.2 +/- 0.9; P > .0001) with exercise. Changes in diastolic parameters with exercise were similar in ETs and NAs. Percentage of predicted maximal oxygen consumption was correlated with exertional E (r = 0.28, P = .03) and e' lateral (r = 0.32, P = .01), but the strongest predictor was indexed left ventricular end-diastolic volume (r = 0.66, P > .0001). CONCLUSIONS: During exercise, E/e' increases but remains within normal ranges in healthy young subjects, and the response to exercise does not differ between ETs and NAs. These data help define the normal diastolic stress echocardiographic response in the young. Exercise capacity shows a correlation with enhanced exertional early diastolic velocities but is more closely related to cardiac structural adaption to endurance training.