Abstract
Hemodynamic and left ventricular responses were studied echocardiographically in 20
males (31.5 ± 4.5 yrs) and 20 females (30.4 ± 4.3 yrs) at rest and during 3 min of
isometric deadlift exercise at 30% of maximum voluntary contraction. Maximal tension
exerted was significantly (P < .001) lower in the female group (87.4 ± 8.1 kg) compared
with the male group (127.3 ± 15 kg). Significant (P <.001) increases in heart rate
and contractility index were noted in both groups during exercise compared to the
resting values. Mean arterial blood pressures were significantly (P < .05) higher
in the males at rest and during exercise. Ejection fraction and fractional shortening,
both at rest and during exercise, differed significantly (P < .05) between the two
groups. It was raised by exercise only in the males (from 62 ± 5% to 65 ± 5% and 32
± 4% to 35 ± 4%, respectively) but remained unchanged in the females. No significant
changes in end diastolic dimension and stroke volume were observed in either group
during exercise. End systolic dimension was significantly (P < .001) lower during
exercise in females and males (from 3.25±.23 to 3.1 ±.26 and 3.12±.33 to 3.00±.32
cm, respectively). These data indicate that hemodynamic and left ventricular function
in normal male and female subjects were augmented during submaximal isometric exercise.
However, females do so with lower after-load than males.
Key words
Isometric exercise - gender - echocardiography - left ventricular function
