Analysis of right ventricle function with strain imaging before and after pulmonary valve replacement

Abstract

Background: Pulmonary valve insufficiency may develop after surgical treatment of tetralogy of Fallot (ToF). Severe pulmonary valve insufficiency may result in right ventricular dysfunction. We aimed to compare cardiac magnetic resonance (CMR), with echocardiography.

Methods: Patients who developed severe pulmonary valve insufficiency after total correction for ToF, were included in the study. CMR was used to measure end-diastolic, end-systolic volumes and ejection fraction of the right ventricle before and 6 months after replacement, and echocar-diographic strain imaging was obtained before, and 1, 3, and 6 months after replacement.

Results: There were significant differences between pre- and post-replacement QRS durations, and right ventricle end-diastolic and end-systolic volumes measured with CMR (p < 0.05). However, right ventricular ejection fraction (RVEF) did not change. Therefore, CMR determined that right ventricle size and volume increased, and right ventricular function deteriorated before replacement. After replacement, no significant improvement was seen in RVEF. Lower-than-normal right ventricle strain and strain rate before replacement indicated that healthy and dysfunctional myocardium could be differentiated by this method. Pre-replacement strain and strain rate of asymptomatic and symptomatic patients were similar. Strain and strain rate values increased 6 months after replacement (p < 0.05).

Conclusions: We suppose that increased experience with strain imaging, and further studies on a larger patient group with a longer follow-up period would show that this method is quite advantageous, and it will take its place in the literature as a non-invasive technique that may be used instead of magnetic resonance.

Keywords: cardiac surgery; echocardiography; magnetic resonance; right ventricular dysfunction; strain.