Comparing Exercise Echocardiography of Children in Upright and Recumbent Postures

Abstract

0461 Exercise echocardiography in children is difficult due to movement artifacts. Cardiac physiologic measures may change with different postures. Because the recumbent cycle ergometer offers support to the upper torso, in contrast to the traditional upright cycle ergometer and treadmill, we hypothesized a reduction in movement artifacts during exercise in children. PURPOSE: To determine if exercise echocardiogram of children in a recumbent position is superior to an upright position with no difference in physiologic measurements. METHODS: Twenty healthy children, 8 to 10 years of age (10 males), completed two exercise tests on an upright and a recumbent cycle ergometer at a random order. The work rate was adjusted to maintain heart rate at 70% predicted peak heart rate (140–150 bpm). Echocardiograms were performed at rest and during exercise. Echocardiographic measurements were made offline and study quality was graded by a blinded reader. Echocardiographic measurements, acquisition time, work rate and child's preference were compared. RESULTS: There was no difference between upright and recumbent postures at rest or during exercise in the following echocardiographic measures: left ventricle end-systolic and end-diastolic dimensions, ejection fraction, stroke volume, cardiac output, mitral inflow E and A waves and left atrial dimension. The work rate required to maintain heart rate was similar between upright and recumbent ridings (38.5 ± 9.9 and 38.9 ± 12.1 watts, p = 0.90). More children (65%) preferred the recumbent cycle than the upright cycle (35%), but the difference was not significant (p = 0.14). Acquisition time was significantly shorter for recumbent studies (129 ± 26 sec) than upright studies (151 ± 30 sec, p = 0.02). The quality of resting echocardiograms was similar between the recumbent and upright studies (p = 0.16), however, the quality of exercise echocardiograms in recumbent studies was significantly better than upright studies (p = 0.03). CONCLUSIONS: Exercise echocardiograms in a recumbent position require less acquisition time and produce better study quality than an upright position. For pediatric patients, exercise echocardiography in a recumbent position is superior to an upright position with no difference in cardiac physiologic measures.