Non-Geometric Echocardiographic Indices of Ventricular Function in Patients with a Fontan Circulation

Background Complex anatomy and limited windows complicate echocardiographic assessments of ventricular function in Fontan patients. For the Pediatric Heart Network Fontan Cross-Sectional Study, data were acquired from which mean ventricular pressure change during isovolumetric contraction (dP/dtic ), Tei index, and maximal systolic annular velocity (S′) could be measured. The purpose of this study was to compare these nongeometric indices of ventricular function to cardiac magnetic resonance (CMR) measurements of ventricular ejection fraction (EF). Methods Echocardiographic and CMR studies were performed prospectively using standardized protocols; measurements were completed by core laboratories. Data from both modalities were available from 137 patients. Results A weak but statistically significant correlation was observed between mean dP/dtic and CMR-derived EF ( r = 0.20, P = .022). This correlation was strengthened when preload was taken into account ( r = 0.30, P = .001). Statistically significant correlations did not exist between CMR-derived EF and the Tei index or S′. Conclusions Among Fontan patients, the correlation between CMR-derived EF and nongeometric echocardiographic indices of ventricular function is not strong. Of the indices evaluated, however, mean dP/dtic appears to be the best.