Abstract
Objectives : Dobutamine stress echocardiography has been proposed as a useful method to identify myocardial viability. However, increasing the dose of dobutamine leads to the increase of the left ventricular (LV) work, and its sensitivity for detecting myocardial viability is subsequently reduced. Olprinone is one of the phosphodiesterase III inhibitors that has both actions of positive inotropy and afterload reduction. To improve the sensitivity of stress echocardiography, we evaluated the effects of olprinone combined with dobutamine for assessment of myocardial viability, compared with dobutamine alone.
Materials and methods : In 33 patients (ischemic heart disease : n=29; healthy : n=4), regional wall motion of the LV was examined with 2-dimensional echocardiography at the baseline, during the loading of low-dose dobutamine (2, 5, 10μg/kg/min=γ) and a combination of 2γ olprinone with 10γ dobutamine. Wall motion of the LV in 30 segments was evaluated visually by using a 4-grade scoring system (normokinesis-4, hypokinesis-3, severe hypokinesis-2, akinesis-1). LV work was calculated from end-systolic pressure and stroke volume.
Results : Average wall motion score (WMS) per person in 22 asynergic patients significantly increased when given the combination of dobutamine and olprinone, compared to 10γ dobutamine alone (2.09±0.16 vs 1.9±0.15, p=0.003).Average WMS per segment in 232 asynergic segments also significantly increased at each stage of the dobutamine loading and combination with olprinone (p<0.0001). WMS per segment in the severe hypokinesis segments (2.64±0.11 to 2.81±0.1, p=0.003) and the akinesis segments (1.32±0.05 to 1.53±0.07, p<0.0001) was especially significantly increased by combination with olprinone. LV work was significantly increased from baseline to the stage of 10γ dobutamine (0.6±0.04J to O.78±0.04J, P<0.01). However, the combination with olprinone significantly reduced LV work, compared with the stage of 10γ dobutamine (0.57±0.06J, P<0.01). Conclusion : Olprinone combined with dobutamine for stress echocardiography improved the sensitivity for detecting myocardial viability by its additional effects of positive inotropic action and afterload reduction. This combination may be a more useful method for clinical examination than dobutamine alone.
