Assessment of Ventricular Function Using Myocardial Performance Index in Patients with Atrial Septal Defect

ABSTRACT

PURPOSE: This study was designed to define normal values for a nongeometric MPI in children and evaluate the utility of m%cardial performance index(MPI) in congenital heart disease with distorted ventricular geometry. METHODS: The study population consisted of 44 normal patients and 28 patients with atrial septal defect(ASD) with dilated right ventricle and paradoxical septal motion. Right ventricular(RV) and left ventricular(LV) isovolumic contraction time, isovolumic relaxation time, ejection time, ejection fraction and pre-ejection period/ejection time(PEP/ET) were measured using conventional echo- Doppler methods. The MPI measures the ratio of total time spent in isovolumic activity(isovolumic contraction time and isovolumic relaxation time) to ejection time. RESULTS: In normal children, the RV MPI was 0.33+/-0.09 and the LV MPI was 0.36+/-0.04. In the ASD group, LV function seemed grossly normal but LV EF was significantly lower than normal children(57+/-3% vs 67+/-4%, P<0.05), but both LV and RV MPI had no statistically significant difference. After correction of ASD, RV MPI was increased and LV EF(57+/-3% vs 64+/-3%, P<0.05) as wll as the RV PEP/ET(0.27+/-0.05 vs 0.38+/-0.06, P<0.05) were significantly greater than the normal or the preoperation group. CONCLUSION: Components of the MPI are easily measured with conventional Doppler technique using standard echocardiographic examination. These results suggest that the MPI is useful as a means of quantitative assessment of ventricular performance in patients with complex ventricular geometry, particularly RV.