Myocardial acceleration during isovolumic contraction as a new index of right ventricular contractile function and its relation to pulmonary regurgitation in patients after repair of tetralogy of Fallot

Abstract

Background Myocardial acceleration during isovolumic contraction (IVA) by Doppler tissue imaging has been proposed to be a new index of right ventricular contractile function that is unaffected by ventricular shape or loading conditions. Objectives We sought to assess the use of IVA to evaluate right ventricular contractile function. Methods In all, 22 pediatric patients with pulmonary regurgitation (PR) after repair of tetralogy of Fallot (TOF) (8 ± 3 years) and 27 age-matched children were examined. The degree of PR (mild, moderate, and severe) for patients with TOF was on the basis of pulsed and color Doppler findings. Using Doppler tissue imaging, the peak myocardial velocities during early diastole, late diastole, systole, and isovolumic contraction were recorded. Results Compared with healthy children, Doppler tissue imaging velocities for patients with TOF showed decreased myocardial velocities during early diastole ( P = .007), late diastole ( P < .0001), systole ( P < .0001), and isovolumic contraction ( P < .0001). Patients with TOF had a lower IVA when compared with healthy children ( P < .0001). There was a stepwise decrease in the IVA from mild to severe PR. We found a significant relationship between the IVA and the degree of PR ( r = −0.86, P < .0001). Conclusion The analysis of IVA allows the assessment of right ventricular contractile function for patients with repaired TOF and various degrees of PR.