29
3 Left Atrium
LA has an oval shape and is located in the back position of the other chambers in the
mediastinum. The adaptation of athlete’s heart also involves the LA, that presents
larger dimension in the athletes, because LA pressure and volume increase during
exercise [ 33 ]. In athletes, LA adaptation is not isolated but always associated with
LV cavity enlargement. During ventricular diastole, the LV pressure is transmitted
back to the LA. During diastole LV filling pressure increase and it is necessary that
also LA pressure rises to obtain a complete LV filling. This mechanism determines
LA enlargement and stretch on atrial cardiomyocites. The imaging technique used
to study LA dilatation and function is the standard transthoracic-echocardiography
with color Doppler and the novel techniques such as Doppler Tissue Imaging (DTI),
STE and 3-dimensional echocardiography. The novel DTI and STE allow to evalu-
ate the atrial myocardium remodeling before the eventual occurrence of dilation
Fig. 2.1 Determinant factor of RA area. (a) type of training. (b) Gender [ 32 ]
Table 2.2 Mean absolute and for body surface area (BSA) of the right atrium (RA) [ 32 ]
RA area (cm^2 ) RA area Index (cm^2 /m^2 )
Number
of
subjects Mean ± SD Q-95Q-95
(L-CI/U-CI) Mean ± SD Q-95Q-95
(L-CI/
U-CI)
Men
Non-athletes 137 12.5 ± 2.0 15.7 15.1–16.5 6.7 ± 1.0 8.4 8.1–8.8
Strength 155 12.7 ± 1.6 15.3 14.8–15.9 6.9 ± 0.8 8.3 8.0–8.6
Endurance 255 15.4 ± 2.1 18.9 18.4 ± 19.5 8.3 ± 1.1 10.1 9.8–
10.4
Women
Non-athletes 93 11.9 ± 1.9 15.1 14.3–16.0 6.5 ± 1.0 8.2 7.7–8.6
Strength 100 12.8 ± 1.5 15.3 14.7–16.0 7.0–0.8 8.3 8.0–8.6
Endurance 140 15.3 ± 2.1 18.7 18.0–19.5 8.2 ± 1.1 10.0 9.6–
10.42 Acute and Chronic Response to Exercise in Athletes: The “Supernormal Heart”