Echocardiographic assessment of the right ventricular response to exercise

Although exercise echocardiography has been widely used among adult patients, its application in the pediatric population has not been well explored. A few studies have examined the response of the pediatric left ventricle (LV) to exercise. However, although many congenital heart defects result in abnormalities of right ventricle (RV) anatomy and function, little is known about the RV's response to exercise. The purpose of this study was to assess the effect of exercise on RV dimensions and function and to compare the RV's response to that of the LV. Twenty-nine consecutive pediatric subjects (age 12.1 +/- 3.2 years) with structurally normal hearts, who were referred for exercise stress testing, were studied echocardiographically prior to and within 2 minutes following peak exercise. Adequate studies were obtained in 28 of the 29 patients. RV dimensions and area during the first 2 minutes following the termination of exercise were slightly smaller than those observed prior to exercise. However, the decline in RV area at end systole was proportionally greater than the decline in RV area at end diastole. Consequently, the RV fractional area change following exercise exceeded the preexercise value. The response of the LV to exercise was qualitatively similar to that observed for the RV. This study demonstrates that echocardiographic measurement of RV size and function immediately after exercise is feasible. Data from this study can be used as normal reference standards against which data from patients with congenital heart defects may be compared.