Left Atrial Systolic Force in Children: Reference Values for Normal Children and Changes in Cardiovascular Disease With Left Ventricular Volume Overload or Pressure Overload

Abstract

Recent studies in adults have indicated that left atrial (LA) systolic force (LASF) provides useful information about LA pump function and can be used to predict cardiovascular events. However, normal values of LASF in children are not available, and little is known about atrial function in pediatric patients with heart disease. The objectives of the present study were to provide reference values for LASF in children and to determine LA pump performance in pediatric patients with heart disease using LASF. LASF was measured using combined two-dimensional imaging and Doppler echocardiography in 185 healthy children and 71 pediatric patients with ventricular septal defects (VSDs; as a representative heart disease with chronic left ventricular [LV] volume overload; n=48) or coarctation of the aorta (COA; as a representative heart disease with chronic LV pressure overload; n=23). LASF in children significantly increased with advancing age (P<.005). The major determinants of this change were body surface area, stroke volume, and heart rate, with a linear model fit (r2) of 0.72. In patients with VSD and those with COA, LASF was significantly elevated in proportion to the degree of LV volume or pressure load, suggesting adaptive mechanisms of LA pump function to facilitate LV filling in chronically overloaded hearts. LASF was normalized after anatomic correction of VSDs but remained elevated even after the relief of COA, indicating persistent overwork of the left atrium. The present study provides reference data for the evaluation of atrial function in pediatric patients with cardiac disease. In addition, altered LASF in patients with VSDs with even small left-to-right shunts and in those with COA even after anatomic correction may have pathologic implications that could lead to a novel therapeutic target.