Effect of dobutamine on a Doppler echocardiographic index of combined systolic and diastolic performance.

Abstract

Dobutamine stress echocardiography has become accepted in the evaluation of cardiac functional reserve. Although the Doppler-derived index of combined systolic/diastolic myocardial performance (Tei index) has been reported to be easily obtainable and useful for predicting left ventricular performance, the effect of dobutamine on the Tei index has not been determined in children. To assess the effect of dobutamine on the Tei index, 8 patients who had undergone surgery for ventricular septal defect and 7 patients who had a history of Kawasaki disease were examined. Echocardiographic recordings were obtained before and after dobutamine infusion (5 microg/kg per minute). Variables measured were transmitral flow velocities (E, A, E/A), rate-corrected mean velocity of circumferential fiber shortening (rate-corrected Vcf), and IMP. We measured isovolumic contraction time (ICT), isovolumic relaxation time (IRT), and ejection time (ET) and then calculated the Tei index using the following formula: Tei index = (ICT + IRT)/ET. Dobutamine infusion increased rate-corrected Vcf (29%, p < 0.01), peak E (7%, p < 0.05), and peak A (13%, p < 0.05). E/A ratio did not change during dobutamine infusion. ET, ICT, and IRT were found to decrease during dobutamine infusion. The magnitude of the change in the ICT (-21%, p < 0.01) was greater than those in IRT (-12%, p < 0.01) and ET (-8%, p < 0.05). The decrease in Tei index (-16%, p < 0.01) resulted in a decrease in ICT/ET (-21%, p < 0.01) and a slight decrease in IRT/ET (-12%, p < 0.05). The Tei index has potential as a sensitive indicator of the effects of inotropic stimilation on global left ventricular function.