Cardiac parameters in growth hormone (GH) deficiency and the effects of GH replacement treatment (GHRT) are still controversial. We investigated 19 adult patients (mean age: 45 +/- 10 years, 7 male), with GH deficiency before and after 12 months of GHRT. Twenty age- and sex-matched healthy individuals (mean age: 44 +/- 12 years, 9 male) were taken as a control group. All participants underwent echocardiography both before and after GHRT. The patients before GHRT and control subjects had similar left ventricular sizes and ejection fraction whereas patients before GHRT had impaired diastolic indices of left ventricle. Peak systolic annular velocity, which identifies myocardial longitudinal systolic function, was lower in patients before GHRT than in the control subjects (0.08 +/- 0.01 vs 0.10 +/- 0.02, P < .05) and improved after GHRT (0.09 +/- 0.03, P < .05). Adult-onset GH deficiency is associated with normal left ventricular sizes and preserved ejection fraction whereas longitudinal systolic function obtained by Doppler tissue imaging is deteriorated, which improves with 12 months of GHRT.