Evaluation of cardiac beta-adrenergic receptor function in children by dobutamine stress echocardiography

Objective To investigate the role of dobutamine stree echocardiography in e valuating cardiac beta-adrenergic receptor (beta-AR) function and responsiv eness in children. Methods Left ventricular ejection fraction (EF), fractional shortening (FS) , left ventricular end systolic volume index (ESVI), the ratio of systolic blood pressure and ESVI (SP/ESVI) were measured by dobutamine stress echoca rdiography (DSE) in 30 children with beta-AR hypersensitivity, 15 children with dilated cardiomyopathy and 30 normal children respectively. Results Before pharmacological stress, EF and FS were 0.72 and 0.39 respect ively in beta-AR hypersensitivity group versus 0.70 and 0.35 respectively i n control group. There was no difference of the indices between the two gro ups (P > 0.05). SP/ESVI was 0.76, higher than the value of 0.66 in control group (P < 0.05); EF, FS and SP/ESVI were 0.41, 0.15 and 0.10 respectively, which were significantly lower than those in control group. After dobutami ne stress of 5 mu g.kg(-1).min(-1) and 10 mu g.kg(-1).min(-1), EF, FS and S P/ESVI were significantly increased in patients with beta-AR hypersensitivi ty and there were no changes in children with dilated cardiomyopathy compar ed with values of baseline. Conclusion Cardiac beta-AR function and responsiveness can be evaluated by dobutamine stress echocardiography.