Effects of head-up and head-down tilt on the transmitral flow velocities in relation to age: a Doppler echocardiographic study in healthy persons.

To assess whether age modifies the effects of preload on the Doppler indexes of left ventricular filling, 10 younger (mean age 31 years) and 10 older (mean age 53 years) healthy subjects underwent transmitral flow velocity measurements following acute changes of venous return produced by head-up and head-down tilts. In the horizontal supine position, almost all Doppler indexes differed significantly between the groups. As venous return increased from the head-up to the head-down position, the peak early and late transmitral velocities, their ratio, and the acceleration and deceleration of the early flow increased while the relaxation time shortened. These changes did not differ significantly between the younger and older subjects. In conclusion, both age and preload have strong effects on the Doppler transmitral velocity indexes. The preload-induced changes are not modified by age.