Effects of different training protocols on left ventricular myocardial function in competitive athletes: a Doppler tissue imaging study.
BACKGROUND
The aim of the study was to analyze the differences in myocardial function in case of left ventricular (LV) hypertrophy induced by either endurance or strength training in top-level athletes.


METHODS
Standard Doppler echo and pulsed Doppler tissue imaging (DTI) of the interventricular septum and of the LV inferior wall were performed in 26 competitive endurance athletes (long-distance swimmers) (group A) and in 20 strength-trained athletes (short-distance swimmers) (group B). By means of DTI, the following parameters of myocardial function were assessed: the systolic peak velocities (Sm), the pre-contraction time, the contraction time, the early (Em) and late (Am) diastolic velocities, the Em/Am ratio and the relaxation time.


RESULTS
The two groups were comparable for age and sex, but at rest group B showed a higher heart rate, systolic blood pressure and body surface area. The LV mass index and fractional shortening did not significantly differ between the two groups. However, group B showed an increased sum of the wall thicknesses (septum + posterior wall) (p < 0.001) and of the relative wall thickness, while the LV stroke volume and LV end-diastolic diameter (p < 0.001) were greater in group A. All transmitral Doppler indexes were higher in group A, with an increased E/A ratio. DTI analysis showed, in group A, a higher Em and Em/Am ratio as well as a longer relaxation time both at the septal and at the inferior wall levels, with comparable Sm, pre-contraction and contraction times. Distinct multiple linear regression models revealed an independent positive association between the inferior peak Em velocity and the LV end-diastolic diameter (p < 0.001) in group A, and an independent direct correlation of the inferior peak Sm velocity with the sum of the wall thicknesses (p < 0.001) and with the end-systolic stress in group B.


CONCLUSIONS
The early diastolic myocardial function is positively influenced by the preload increase in group A, while an increased afterload and LV wall thickness in group B mainly seem to induce an enhancement of the regional myocardial systolic function.
D'Andrea
Antonello
A
Department of Cardiothoracic and Respiratory Sciences, Second University of Naples, Italy. adandrea@synapsis.it
Caso
Pio
P
Severino
Sergio
S
Galderisi
Maurizio
M
Sarubbi
Berardo
B
Limongelli
Giuseppe
G
Cice
Gennaro
G
D'Andrea
Luigi
L
Scherillo
Marino
M
Mininni
Nicola
N
Calabrò
Raffaele
R
D000222:Adaptation, Physiological; D000328:Adult; D018618:Echocardiography, Doppler, Color / Q000379:methods; D018619:Echocardiography, Doppler, Pulsed / Q000379:methods; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D013550:Swimming / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*