Use of 2-D Speckle Tracking Based Strain for Surveillance of Chemotherapeutic Induced Cardiotoxicity in a Pediatric Population

Abstract

Background: Cardiac toxicity is an important side effect of anthracycline therapy. Ventricular dysfunction induced by chemotherapy is often not detected by standard non invasive imaging. Myocardial deformation analysis is more sensitive than conventional methods to detect myocardial dysfunction. 2-D based strain, known also as Automated Function Imaging (AFI), using speckle tracking, provides global and segmental myocardial deformation analysis. The aim of our study was to assess the feasibility and analyze the potential use of 2-D based strain as an early indicator of myocardial damage during chemotherapy. Methods: Consecutive echoes for ventricular function evaluation post chemotherapy regardless of tumor type were studied from 1–09 to 12–09. Ejection fraction was measured using Simpson's method. Average global longitudinal peak systolic strain (%GLPSS) and presence of regional wall motion abnormalities (RWM) were quantified using AFI. An EF ≥ 55% and GLPSS ≥−18 ± 2% were classified as having normal LV function. GLPSS between ≥−12/≤−16% were considered mildly reduced values. Results: 317 patients (mean age 9.8 yrs, 140 F) with consecutive echoes following chemo were identified. AFI could not be performed in 73/317 patients secondary to poor images (44/73) and chest bandages (29/73). AFI was performed in the remaining 244 patients. 8% (19/244) of patients showed preserved EF (> 55%) but had mildly reduced GLPSS (≥−12/≤−16%). All patients in the mildly reduced group had RWM abnormalities. This was primarily in the infero-basal (13/14) and latero medial (4/14) segments. 41/244 of patients had EF <55% with abnormal GLPSS. Conclusions: 1) AFI is clinically feasible and effective in assessing LV function in pediatric patients receiving anthracycline therapy, 2) 8% of echoes with normal LVEF had abnormal GLPSS, 3) Adding strain to routine evaluation could help to detect a small subset of patients with early evidence of myocardial damage, 4) Inferior and lateral basal segments appear to be most affected.