Assessment of Right Ventricular Inefficiency Using Energy Transfer Ratio in Repaired Tetralogy of Fallot

Pulmonary insufficiency (PI) induces pulmonary regurgitation and often leads to right ventricular (RV) enlargement and RV pressure overloading in repaired Tetralogy of Fallot (rTOF) patients. The appropriate timing of surgical treatments to renormalize RV function remains uncertain due to lack of suitable clinical diagnostic parameters. An energy transfer ratio (e_MPA) between the net energy (E_net) transferred at main pulmonary artery (MPA) from RV and stroke work (SW) by RV was calculated using RV volume and pressure data for subjects in two study groups: the rTOF patient group (n = 7) and the control group (n = 7). Statistical analysis was performed to determine the difference of e_MPA between the two groups. The mean e_MPA for rTOF patients (0.64) was significantly lower (60.2%, p<0.05) than that of controls (1.61).