Evaluation of right ventricular function in operated tetralogy of Fallot patients with tissue Doppler imaging before and after pulmonary valve replacement

Abstract

Background: This study aims to investigate the efficacy of tissue Doppler echocardiography for the diagnosis of right ventricular dysfunction and for the evaluation of the response to pulmonary valve replacement.

Methods: Between December 2008 and December 2010, a total of 15 patients (8 males, 7 females; mean age: 14.5 +/- 4.5 years; range, 7 to 22 years) with pulmonary valve insufficiency in the follow-up of total correction of tetralogy of Fallot who underwent pulmonary valve replacement were included in the study. Echocardiographic imaging was performed before and one, three, and six months after replacement. Using pulse wave Doppler, early diastolic E and late diastolic A waves were measured in the flow velocity curve of tricuspid valve. Tissue Doppler measurements were made from the basal segment of right ventricular free wall and interventricular septum. S, e, and a myocardial velocities, isometric contraction time, isovolumetric relaxation time and ejection time were measured. Myocardial performance index was calculated for each patient.

Results: In pre-pulmonary valve replacement phase, s, e, a velocities and ejection time were lower in the interventricular septum compared to the basal segment of right ventricular free wall, while isometric contraction time, isovolumetric relaxation time and myocardial performance index values were higher. In the first post-replacement month, there was a significant decrease in the s value of interventricular septum, compared to pre-pulmonary valve replacement period; isometric contraction time decreased and myocardial performance index increased in the first post-pulmonary valve replacement month in the free wall of right ventricle, while isovolumetric relaxation time decreased in the postoperative third month, and s velocity, isometric contraction time and myocardial performance index increased in the postoperative sixth month. Pre-pulmonary valve replacement tissue Doppler values at the septum showed that myocardial systolic and diastolic dysfunction developed earlier than the basal segment of right ventricular free wall. This result showed that right ventricular recovery was not complete in the sixth post-pulmonary valve replacement month.

Conclusion: Tissue Doppler can show right ventricular dysfunction before replacement, but it may be insufficient to visualize right ventricular recovery until six months after treatment.