[Changes in the left ventricular function with growing doses of dobutamine in healthy individuals]

The study aimed to assess ventricular function in response to increasing doses of dobutamine in healthy young volunteers. Isotopic ventriculography was performed at baseline, low dose (10 microg/Kg/min) and high dose (40 microg/Kg/min) of dobutamine. Global and segmentary ejection fraction, ejection fraction in the first third of systole, peak filling rate and peak filling rate time were analysed. A progressive increase in the global ejection fraction in relation to the increasing doses was observed. The segmentary ejection fraction and ejection fraction in the first third of systole also increased with the low dose, but no significant differences were found between both doses. Concerning the diastolic function, the peak filling rate increased significantly with both doses, with no differences between them. We conclude that dobutamine at these doses leads to an increase in all systolic parameters and in the peak filling rate without changing the peak filling rate time in healthy subjects.